analysis of abstract and concrete word processing in ......semantic processing in pwa is the...
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Analysis of abstract and concrete word processingin persons with aphasia and age-matchedneurologically healthy adults using fMRIChaleece Sandberg a & Swathi Kiran aa Speech, Language, and Hearing Sciences, Sargent College of Health andRehabilitation Sciences, Boston University, Boston, MA, USAVersion of record first published: 03 Apr 2013.
To cite this article: Chaleece Sandberg & Swathi Kiran (2013): Analysis of abstract and concrete word processingin persons with aphasia and age-matched neurologically healthy adults using fMRI, Neurocase: The Neural Basis ofCognition, DOI:10.1080/13554794.2013.770881
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Neurocase, 2013http://dx.doi.org/10.1080/13554794.2013.770881
Analysis of abstract and concrete word processingin persons with aphasia and age-matched neurologically
healthy adults using fMRI
Chaleece Sandberg and Swathi KiranSpeech, Language, and Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, BostonUniversity, Boston, MA, USA
The concreteness effect occurs in both normal and language-disordered populations. Research suggests thatabstract and concrete concepts elicit differing neural activation patterns in healthy young adults, but this is undoc-umented in persons with aphasia (PWA). Three PWA and three age-matched controls were scanned using fMRIwhile processing abstract and concrete words. Consistent with current theories of abstract and concrete wordprocessing, abstract words elicited activation in verbal areas, whereas concrete words additionally activated mul-timodal association areas. PWA show greater differences in neural activation than age-matched controls betweenabstract and concrete words, possibly due to an exaggerated concreteness effect.
Keywords: Aphasia; Concreteness effect; fMRI; Semantic processing; Localization of function.
The exploration of language processing in per-sons with aphasia (hereafter PWA) using fMRIis highly informative for clinical aphasia researchin particular and cognitive neuroscience in gen-eral. However, since acquired aphasia results fromdamage to neural tissue and is by definition adeficit in language processing, using fMRI totest theories of language processing in this pop-ulation becomes highly reliant on task perfor-mance. Incorrect responses in the scanner havebeen shown to elicit different activation patternsthan correct responses (e.g., Fridriksson, Baker, &Moser, 2009; Postman-Caucheteux et al., 2010),which can be useful for comparing posttreatmentto pretreatment activations, but are confoundingwhen localizing specific language processes in PWA.This is especially important when the goal is totease apart very fine distinctions that are easilyfound in neurologically healthy cohorts, such as
Address correspondence to Chaleece Sandberg, Speech, Language, and Hearing Sciences, Sargent College of Health andRehabilitation Sciences, Boston University, 635 Commonwealth Ave., 02215 Boston, MA, USA. (E-mail: [email protected]).
This work was supported in part by the Dudley Allen Sargent Research Fund.
the difference in activations for processing canon-ical versus noncanonical sentences (Wartenburgeret al., 2004) and for processing sentences withobject-relative clauses versus those with subject-relative clauses while varying plausibility (Caplan,Stanczak, & Waters, 2008). Such distinctions arerevealed behaviorally as differences in reactiontime in healthy participants, but as differences inboth reaction time and accuracy in PWA. Thesepsycholinguistic distinctions do not necessarilysurface as differences in activations for partici-pants with aphasia (e.g., Thompson, den Ouden,Bonakdarpour, Garibaldi, & Parrish, 2010), butthis may be due to poor performance. In otherwords, the inability to perform a task may over-shadow differences in activation. Therefore, inneuroimaging studies of language processing inPWA, it is important to carefully construct theexperimental paradigm such that the participants
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(a) exhibit a behavioral difference in the contrastsof interest and (b) are able to perform the task con-sistently with reasonable accuracy (Price, Crinion,& Friston, 2006).
One contrast that is informative in exploringsemantic processing in PWA is the comparisonbetween abstract and concrete word processing.The term “concreteness effect” is used to describethe difference in performance on lexical seman-tic processing tasks between abstract (e.g., justice)and concrete (e.g., table) words. Neurologicallyhealthy individuals exhibit faster reaction timesand more accurate responses for concrete versusabstract words during lexical decision, word recog-nition, recall, and sentence comprehension tasks(see Paivio, 1991 for a review). This effect is notonly present, but more pronounced in PWA (Barry& Gerhand, 2003; Berndt, Haendiges, Burton, &Mitchum, 2002; Kiran, Sandberg, & Abbott, 2009;Newton & Barry, 1997). Some studies report areverse effect, where abstract words are associ-ated with faster reaction times and greater accu-racy than concrete words in persons with semanticdementia (SD) or encephalitis (Bonner et al., 2009;Cipolotti & Warrington, 1995; Sirigu, Duhamel,& Poncet, 1991). However, note that Jefferies,Patterson, Jones, and Lambon Ralph (2009) foundthat the reverse concreteness effect appears to bethe exception in SD rather than the rule. Regardless,there appears to be a double dissociation which pro-vides evidence of differing neural substrates for theprocessing of abstract versus concrete words.
A handful of neuroimaging studies have exam-ined the neural correlates for abstract and concreteword processing in healthy adults, but no clear con-sensus emerged until meta-analyses of these studieswere performed (Binder, Desai, Graves, & Conant,2009; Wang, Conder, Blitzer, & Shinkareva, 2010).Binder and colleagues (2009) examined 120 func-tional neuroimaging studies in order to identifyspecific brain regions that contribute to the seman-tic aspects of word retrieval. A subset of 17 studiesin their analysis focused on the processing of “ver-bal” (abstract) and “perceptual” (concrete) con-cepts. Using the activation likelihood estimation(ALE) technique, they found stronger activationfor concrete concepts in bilateral angular gyrus,which may play a role in supramodal integration;in left mid-fusiform gyrus, which may play a rolein retrieving knowledge of visual attributes; in leftdorsomedial prefrontal cortex, which may directretrieval of semantic information; and in left poste-rior cingulate cortex, which may act as an interface
between episodic memory and semantic retrieval.Stronger activation for abstract concepts was foundin left inferior frontal gyrus, which may mediatetask efficiency in addition to phonological pro-cessing and working memory; and in left anteriorsuperior temporal sulcus, whose proximity to leftsuperior temporal gyrus suggests a verbal ratherthan perceptual role in semantic processing.
Wang and colleagues (2010) examined 19 func-tional neuroimaging studies of abstract and con-crete concept processing, only 10 of which over-lapped with the Binder et al. (2009) study. Usingthe multilevel kernel density analysis (MKDA)technique, they found similar results as Binderet al. (2009); namely, that abstract words acti-vated left hemisphere language areas includinginferior frontal, superior temporal, and middletemporal gyri, whereas concrete words activatedareas related to mental image generation includingleft precuneus, posterior cingulate, fusiform, andparahippocampal gyri. The results of these meta-analyses are in line with the dual-coding theory,which posits that abstract words are processed ina verbal network, whereas concrete words are pro-cessed in a network that bridges language and mul-timodal processing (see Paivio, 1991 for a review).
The study of abstract and concrete word process-ing in PWA to date has not utilized fMRI, but hasrelied on comparing behavior with aphasia charac-teristics (in some cases including lesion character-istics) on a case-by-case basis (Barry & Gerhand,2003; Berndt et al., 2002; Kiran et al., 2009; Newton& Barry, 1997; Tyler, Moss, & Jennings, 1995).Though informative, these types of studies cannotcapture the subtle neuroanatomical differences inabstract and concrete word processing in aphasia;they can only suggest which areas, when dam-aged, cause deficits. One important reason to studyabstract and concrete word processing not onlypsycholinguistically but also neurolinguistically inPWA is that this distinction has clinical relevance.Natural conversation requires the frequent use ofabstract words and concepts. In aphasia, abstractword use is lessened relative to concrete word use—as mentioned previously—contributing to less nat-ural, albeit functional conversation. Furthermore,a recent study by Kiran et al. (2009) showedthat training abstract words results in improve-ment of those words as well as generalizationto untrained target concrete words in the samecontext-category; however, training concrete wordsresults in improvement of only those trained words.The authors suggest that the differential processing
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 3
of abstract and concrete words contributes to thedifferences in generalization, but the neurophysio-logical support for this explanation is incomplete.
Therefore, the present study examined the pro-cessing of abstract versus concrete nouns inPWA and age-matched neurologically healthy olderadults (NHOAs) in order to shed more light on theunderlying neural mechanisms for the concretenesseffect. As mentioned previously, the concretenesseffect is not only present, but more pronounced inPWA. If indeed abstract nouns are processed in averbal-only network located in the left hemisphereand concrete nouns are processed in a networkthat is both verbal and multimodal sensory, thenone would expect damage to the left hemispherelanguage areas to affect the processing of abstractwords more than concrete words. Although thisis most often what is seen behaviorally in PWA,the neural mechanisms for this behavioral phe-nomenon have not yet been explored, let aloneconfirmed.
The advantage of using abstract and concretewords to explore semantic processing in PWA istwofold. First, abstract and concrete words bothelicit semantic processing in general, but accordingto the dual-coding theory, concrete words addi-tionally elicit perceptual processing. This additionaloperation should require activation in perceptualareas, and in fact, this is what is seen in studiesof healthy young adults. As suggested by Caplan(2009), in a model where two processes occur in par-allel, the comparison between the two can informthe localization of function when one requiresa unique operation. Therefore, abstract and con-crete words provide a tight comparison with whichto explore the subtleties of semantic processing.Second, PWA exhibit an exaggerated concretenesseffect, suggesting that lesion characteristics mayinfluence the neural correlates of abstract and con-crete word processing.
In order to shed more light on the underlyingneural mechanisms for the concreteness effect, weexamined the neural activation patterns for abstractand concrete word processing of three PWA withvarying degrees of lesion during two tasks withvarying depth of semantic processing—wordjudgment and synonym judgment—and com-pared their data with three age-matched controls.We hypothesize that (a) similar to previous work,abstract and concrete words will produce differingpatterns of activation such that abstract wordsare processed in a verbal network and concretewords additionally recruit multimodal association
areas and (b) PWA will show somewhat differentactivation patterns than their NHOA counterpartsdue to lesion characteristics. For example, PWAwith very large lesions encompassing much ofleft hemisphere language areas may reorganizelanguage function to right hemisphere languagehomologues (Sebastian & Kiran, 2011; Sebastian,Kiran, & Sandberg, 2012; Turkeltaub, Messing,Norise, & Hamilton, 2011).
METHODS
Participants
Three (one female) PWA subsequent to left middlecerebral artery cerebrovascular accident and three(two females) NHOAss participated in the exper-iment. PWA ranged in age from 55 to 59 years(mean = 57.19) and were in the chronic stage ofrecovery (23–76 months post-onset) (see Table 3 fordetails). NHOAs ranged in age from 56 to 67 years(mean = 59.7). All participants were right-handed,monolingual English speakers. Handedness wasconfirmed with the Edinburgh Inventory (Oldfield,1971). A medical history and demographic ques-tionnaire was used to rule out concomitant neuro-logical disease, head trauma, psychiatric disorders,or developmental speech, language, or learning dis-abilities. Aided or unaided visual and hearing acuitywas determined to be within normal limits. All par-ticipants obtained at least a high school educationand gave informed consent according to the HumanSubjects Protocol for Boston University.
PWA were given a battery of standardizedlanguage tests, including the Western AphasiaBattery (WAB; Kertesz, 1982) to establish the typeand severity of aphasia, the Boston Naming Test(BNT; Goodglass, Kaplan, & Weintraub, 1983)to determine confrontation naming ability, thePsycholinguistic Assessment of Language Processingin Aphasia (PALPA; Kay, Lesser, & Coltheart,1992) to determine specific deficits of access tothe semantic system, the Pyramids and Palm Trees(PAPT; Howard & Patterson, 1992) to determineoverall soundness of the semantic system, andthe Cognitive Linguistic Quick Test (CLQT; Helm-Estabrooks, 2001) to determine the relative contri-bution of cognitive deficits such as attention andmemory to language dysfunction (see Table 1 fordetails).
NHOAs completed the Mini Mental State Exam(MMSE; Folstein, Folstein, & McHugh, 1975)
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TABLE 1Diagnostic and demographic information for participants with aphasia
PWA1 PWA2 PWA3
Age 56 55 59Sex Female Male MaleEducation BA MBA MBAMonths post-stroke 38 76 23Lesion region Left MCAa Left MCA Left MCAWestern Aphasia Battery
Aphasia quotient 96.70 77.70 78.60Aphasia type Anomic Conduction Transcortical Motor
Boston Naming Test 91.67% 86.67% 66.67%Psycholinguistic Assessment of Language Processing in Aphasia
Auditory lexical decision: high imageability 100.00% 100.00% 97.50%Auditory lexical decision: low imageability 100.00% 97.50% 97.50%Visual lexical decision: high imageablity 100.00% 100.00% 100.00%Visual lexical decision: low imageablity 96.67% 100.00% 93.33%Auditory synonym judgment: high imageability 100.00% 90.00% 93.33%Auditory synonym judgment: low imageability 96.67% 90.00% 76.67%Written synonym judgment: high imageability 100.00% 96.67% 86.67%Written synonym judgment: low imageability 100.00% 83.33% 76.67%Semantic association: high imageability 80.00% DNTb 73.33%Semantic association: low imageability 80.00% DNT 86.67%
Pyramids and Palm TreesPictures 96.15% 98.08% 94.23%Written words 98.08% 96.15% 94.23%
Cognitive Linguistic Quick TestComposite severity WNLc WNL WNL
aMCA = middle cerebral artery.bDNT = did not test.cWNL = within normal limits.Note that most cases of differences in performance between high and low imageability reflect better performance for lexical items withhigh imageability, which are more concrete in nature.
and the Boston Naming Test Short Form (BNT;Goodglass et al., 1983) to rule out cognitive andsemantic deficits. Average scores for these tests were97% for the MMSE and 100% for the BNT.
Tasks and stimuli
Two tasks were used to elicit specific semanticprocessing for abstract and concrete words: wordjudgment (WJ) and synonym judgment (SJ).In both tasks, participants made a semantic judg-ment and responded with a button press using theleft hand. The left hand was used to equate the taskbetween populations, since patients with aphasiaare often hemiplegic on the right side. The twotasks were designed to elicit semantic processing attwo different levels. The WJ task is a more met-alinguistic task that requires only cursory seman-tic processing, whereas the SJ task requires accessto meaning and is therefore a deeper semantic
task. All participants were allowed to practice bothtasks until they felt comfortable performing eachtask.
In the WJ task, participants decided whether aword was abstract or concrete. The control con-dition for this task was deciding whether letterstrings were composed of vowels or consonants.The words abstract/concrete for noun stimuli andvowel/consonant for letter stimuli appeared at thebottom of each screen in order to minimize possibleconfounding effects of participants not remember-ing which button to push.
The 50 abstract and 50 concrete words usedfor the WJ task, as well as their ratings forconcreteness, imageability, and frequency wereobtained from the Medical Research Councilpsycholinguistic database (www.psy.uwa.edu.au/mrcdatabase/uwa_mrc.htm; Frances & Kucera,1983; Gilhooly & Logie, 1980; Toglia & Battig,1978). Abstract and concrete words were cho-sen so that they were as far apart on the
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concreteness and imageability spectrums as possi-ble to ensure distinct behavioral and neurophysio-logical processing between word types. Therefore,abstract words had significantly lower concreteness(F (1, 98) = 2161.20, p < .01) and imageability(F (1, 98) = 494.70, p < .01) than concrete words.Abstract and concrete words were matched on fre-quency (F (1, 84) = 2.27, p = .13). The length ofeach letter string was matched to the letter lengthof each concrete and abstract word.
In the SJ task, participants decided whether ornot paired abstract and paired concrete words weresimilar in meaning. The control condition wasto decide whether or not paired nonwords werethe same.
The 50 abstract and 50 concrete words usedin the SJ task were taken from a previous treat-ment study in our lab (Kiran et al., 2009) andfrom a subtest of the PALPA (Kay et al., 1992).Psycholinguistic information for these words wasalso obtained from the MRC database (www.psy.uwa.edu.au/mrcdatabase/uwa_mrc.htm; Frances& Kucera, 1983; Gilhooly & Logie, 1980; Toglia& Battig, 1978). Again, abstract words had sig-nificantly lower concreteness (F (1, 65) = 846.43,p < .01) and imageability (F (1, 68) = 456.34,p < .01) than concrete words, but abstract andconcrete words were matched on frequency(F (1, 54) = .27, p = .61).
The 50 nonwords used in the SJ task wereobtained from the ARC nonword database (Rastle,Harrington, & Coltheart, 2002) and were matchedin letter length with the abstract and concretewords. Additionally, nonwords with no phonolog-ical or orthographic neighbors were chosen so thatunintentional processing of real words did notoccur due to similarities between nonwords and realwords.
Experimental design
For both tasks, an event-related design wasimplemented using E-Prime software (PsychologySoftware Tools, Inc., Sharpsburg, PA, USA). Eachevent stimulus lasted 4 seconds and presentationwas randomized within tasks. During each inter-stimulus interval (ISI), which randomly lasted 2, 3,or 4 seconds, a small cross centered on the screenwas presented to maintain the subject’s visual atten-tion. The WJ task consisted of three runs, lasting atotal of 17.45 minutes. The SJ task consisted of fourruns, lasting a total of 23.27 minutes.
Data collection
Magnetic resonance images were acquired at theBoston University Center for Biomedical Imagingfrom a 3T Philips MRI scanner. High-resolutionT1 images were acquired with the following param-eters: 140 sagittal slices, 1 mm3 voxels, 240 ×240 matrix, field of view (FOV) = 240 mm, flipangle = 8, fold-over direction = anterior-posterior(AP), repetition time (TR) = 8.2 ms, and echotime (TE) = 3.8 ms. Blood-oxygen-level-dependent(BOLD) sensitive functional images were collectedusing the following parameters: 31 axial slices(3 mm thick, 0.3 interslice gap), 3 mm3 voxels,FOV = 240, flip angle = 90, fold-over direc-tion = AP, TR = 2000 ms, and TE = 35 ms. Thevisual stimuli were presented on a screen behindthe scanner, which projected to a mirror fittedto the head coil. Padding was used to minimizehead motion and corrective optical lenses were usedwhen necessary to correct visual acuity. After boreentry, the magnet was shimmed to achieve maxi-mum homogeneity.
Data analysis
SPM8 software (Wellcome Trust Centre forNeuroimaging, University College London, UK)was used to analyze the fMRI data. Preprocessingwas performed to correct slice time differences,remove movement and baseline function artifacts,align the structural and functional images to eachother, and normalize both structural and func-tional images to the MNI (Montreal NeurologicalInstitute) template. Baseline functions were filteredout with a high-pass filter of 128 s cut-off period;motion artifacts were corrected using the ArtRepairtoolbox for SPM8 (Mazaika, Hoeft, Glover, &Reiss, 2009). In addition to these basic steps, thepreprocessing of PWA data required that lesionmasks be drawn using MRIcron software (http://www.cabiatl.com/mricro/) and used during nor-malization to minimize deformities during warping(Brett, Leff, Rorden, & Ashburner, 2001). MRIcronwas also then used to calculate the lesion volumefor each patient. Additionally, patient data were notsmoothed because (a) this data is not intended to beanalyzed in a group analysis—which is the primaryreason for smoothing data—and (b) smoothingmay mask small but important activations inpatient data (see Meinzer et al., 2012, for a discus-sion regarding smoothing in patient populations).
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After preprocessing, statistical analyses were per-formed at the individual level with a general linearmodel (GLM) convolved with a canonical hemo-dynamic response function (HRF) with a temporalderivative. Only correct responses were analyzed.The contrasts of interest were abstract words > con-trol items, concrete words > control items, abstractwords > concrete words, and concrete words >
abstract words.
RESULTS
Behavioral results
Analyses were performed on both accuracyand reaction time (RT) data (see Table 2).Nonparametric Kruskal–Wallis and Mann–Whitney U-tests were used due to small samplesizes. For the Kruskal–Wallis tests, there were threelevels of the factor conditions: abstract, concrete,and control. Overall, PWA and NHOAs did notdiffer significantly in reaction time on either task(p = .51 for both), nor in accuracy on the WJ task(p = .82), but during SJ, NHOAs were more accu-rate than PWA (U = 3.86, p = .05). This indicatesthat the SJ task was more difficult for PWA thanfor NHOAs. For specific effects of condition, PWAdata were analyzed separately from NHOA data.
Participants with aphasia
Accuracy. The Kruskal–Wallis test revealed asignificant effect of condition on accuracy for
both tasks (SJ: H (2) = 32.20, p < .001; WJ: H(2) = 46.59, p < .001). Post-hoc Mann–WhitneyU-tests revealed that PWA were less accurate forabstract than concrete words (SJ: U = 8.66, p < .01;WJ: U = 23.42, p < .001). For the SJ task, PWAwere less accurate for concrete words than non-words (U = 4.76, p < .05), but in the WJ task, therewas no difference in accuracy between concretewords and letter strings (U = 2.02, p = .16). Theseresults confirm the existence of the concretenesseffect in PWA.
Reaction time. The Kruskal–Wallis test showed asignificant effect of condition on RT for both tasks(SJ: H (2) = 101.76, p < .001; WJ: H (2) = 38.76, p< .001). Post-hoc Mann–Whitney U-tests revealedthat PWA were faster for concrete than abstractwords (SJ: U = 11.64, p = .001; WJ: U = 22.66,p < .001). For the SJ task, PWA were faster fornonwords than concrete words (U = 55.28, p <
.001), but in the WJ task, there was no differencein reaction time between concrete words and let-ter strings (U = 1.96, p = .16). These results againconfirm the concreteness effect in PWA.
Neurologically healthy older adults
Accuracy. The Kruskal–Wallis test revealed a sig-nificant effect of condition on accuracy for SJ (H(2) = 17.62, p < .001), but not for WJ (H (2) = 4.00,p = .14). Post-hoc Mann–Whitney U-tests for theSJ task revealed that NHOAs were less accuratefor abstract words than concrete words (U = 6.11,
TABLE 2Means and standard deviations of accuracy and reaction times
Synonym judgment Word judgment
NHOAs a
(N = 3) PWAb (N = 3) NHOAs (N = 3) PWA (N = 3)
AbstractAccuracy 89.93% (5.84%) 80.52% (5.50%) 98.65% (2.33%) 80.67% (18.15%)Reaction time 1954.38 (426.94) 2020.27 (147.50) 1517.23 (214.33) 1727.07 (328.85)
ConcreteAccuracy 98.67% (2.31%) 95.06% (4.61%) 93.33% (3.05%) 98.67% (1.15%)Reaction time 1741.65 (447.39) 1762.45 (33.23) 1541.68 (468.49) 1377.92 (55.11)
ControlAccuracy 99.33% (1.15%) 98.89% (1.02%) 95.33% (1.16%) 100.00% (0.00%)Reaction time 1757.41 (626.19) 1330.72 (34.90) 1821.95 (410.52) 1324.60 (355.49)
aNHOAs = Neurologically healthy older adults.bPWA = Persons with aphasia.Reaction time is given in milliseconds; Standard deviations shown in parentheses.
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p = .01), but there was no difference in accuracybetween concrete words and nonwords (U = .51,p = .48). These results confirm the existence of theconcreteness effect in NHOAs for SJ but not WJ.
Reaction time. The Kruskal–Wallis test showed asignificant effect of condition on RT for both tasks(SJ: H (2) = 9.23, p = .01; WJ: H (2) = 20.50, p< .001). Post-hoc Mann–Whitney U-tests revealeddiffering patterns for each task. For SJ, NHOAsexhibited longer RTs for abstract words than con-crete words (U = 4.79, p < .05), but there was nosignificant difference in RT between concrete wordsand nonwords (U = .33, p = .57). For WJ, NHOAsexhibited longer RTs for letter strings than for bothabstract words (U = 19.28, p < .001) and concretewords (U = 11.46, p = .001), but there was nosignificant difference in RT between abstract andconcrete words (U = .08, p = .78). These results
again confirm the concreteness effect in NHOAs,depending on the task.
Neuroimaging results
Data from each participant were analyzed at theindividual level, corrected with an FDR of p <
.05. FDR was used rather than FWE because thedata were not smoothed and the FWE procedurerequires the data to be smoothed.
Participants with aphasia
Importantly, all PWA showed patterns of activa-tion that showed certain consistencies (see Figures 1and 2). First, all PWA showed activation in someportion of left IFG, regardless of task or wordtype. Second, all PWA exhibited bilateral activa-tion, again, regardless of task or word type. Third,
PWA3
Word Judgment
Synonym Judgment
PWA1
PWA2
Word Judgment
Word Judgment
L
Figure 1. Activations for persons with aphasia (PWA). Activation shown at FDR of p < .05 for tight contrasts abstract > concrete (red)and concrete > abstract (blue). [To view this figure in color, please visit the online version of this Journal.]
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PWA1
PWA2
PWA3
Word Judgment
Word Judgment
Word Judgment
Synonym Judgment
Synonym Judgment
Synonym Judgment
Figure 2. Activations for persons with aphasia (PWA). Activation shown at FDR of p < .05 for contrasts abstract > control (red)and concrete > control (green). Yellow = overlap between contrasts. [To view this figure in color, please visit the online version of thisJournal.]
all PWA showed greater activation for abstractthan concrete words. PWA’s specific neuroimagingresults are described separately below.
PWA1. The first PWA was a 56-year-old femalewith a lesion encompassing about 85 cc of the lefthemisphere including roughly 48% of left IFGtri
and 32% AG/SMG (see Table 3). During the wordjudgment task, for the abstract > concrete contrast,this participant activated left IFGorb, left IFGtri,and left MTG, as well as many additional areas,including right hemisphere homologues (see Table 4and Figure 1). The concrete > abstract contrast didnot result in any significant activation. The broader
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 9
TABLE 3Lesion information for participants with aphasia
PWA1 PWA2 PWA3
Lesion volume 85 cc 133 cc 228 cc
Percentage of spared tissueby region of interest
Left inferior frontal gyrusp. opercularis
7.63 23.79 1.15
Left inferior frontal gyrusp. orbitalis
85.50 87.43 70.08
Left inferior frontal gyrusp. triangularis
52.09 70.47 2.06
Left middle frontal gyrus 86.08 73.31 21.38Left superior frontal gyrus 100.00 99.77 85.99Left middle temporal gyrus 99.97 13.71 82.45Left angular and supramarginal
gyri67.94 69.49 11.15
contrasts of abstract > control and concrete >
control show much overlap between abstract andconcrete word processing (see Table 4 and Figure 2)which aligns with the fact that the tight contrast ofconcrete > abstract was not significant.
During the synonym judgment task, PWA1did not show significant activation for either theabstract > concrete contrast or the concrete >
abstract contrast. Again, the broader contrasts ofabstract > control and concrete > control showmuch overlap between abstract and concrete wordprocessing, but some subtle differences emerge,such as activation in left AG for the concrete >
control contrast and left STG for the abstract >
control contrast (see Table 4 and Figure 2).
PWA2. The second PWA was a 55-year-old malewith a lesion encompassing about 133 cc of theleft hemisphere including roughly 30% of IFGtri,27% of MFG, 86% of MTG, and 31% of AG/SMG(see Table 3). During the word judgment task, thisparticipant activated left MTG for the abstract> concrete contrast, as well as bilateral mid-dle cingulate cortex (MCC) and precuneus, rightMFG and MTG, and left SFG (see Table 5 andFigure 1). The concrete > abstract contrast wasnot significant. Like PWA1, the broader contrasts(abstract > control and concrete > control) revealmuch overlap between abstract and concrete wordprocessing (see Table 5 and Figure 2 for details).
During the synonym judgment task, PWA2 didnot show significant activation for either theabstract > concrete contrast or the concrete >
abstract contrast. The broader contrasts of abstract
> control and concrete > control again showedsimilar patterns of activation (see Table 5 andFigure 2 for details), but notable differencesincluded bilateral anterior cingulate cortex (ACC)and left insula for the abstract > control contrastand bilateral IFGop for the concrete > controlcontrast. Additional areas of activation for thesecontrasts are listed in Table 5.
PWA3. The third participant was a 59-year-oldmale with a lesion encompassing about 228 ccof the left hemisphere including roughly 30% ofIFGorb, 98% of IFGtri, 79% of MFG, and 89%of AG/SMG (see Table 3). During the word judg-ment task, he showed significant activation in leftIFGorb and MTG for the abstract > concretecontrast and for the concrete > abstract contrast,left dorsomedial prefrontal cortex (DMPFC), AG,precuneus, and parahippocampal gyrus were signif-icantly active. Additional areas that were active forthese contrasts are listed in Table 6 and shown inFigure 1. The broader contrasts of abstract > con-trol and concrete > control showed some similarareas of activation, but again, notable differencessurfaced, including left STG for the abstract > con-trol contrast and left fusiform gyrus for the concrete> control contrast. Additional areas of activationfor these contrasts are listed in Table 6 and shownin Figure 2.
During the synonym judgment task, PWA3showed activation in left IFGorb, IFGtri, andMTG for the abstract > concrete contrast and inleft inferior parietal cortex, PCC, and precuneusfor the concrete > abstract contrast, in line with theexisting literature. Additional areas for these con-trasts are listed in Table 6 and shown in Figure 1.Again, the broader contrasts of abstract > con-trol and concrete > control showed some activationsimilarities, but again some differences stand out,such as significant activation in left AG for the con-crete > control contrast (see Table 6 and Figure 2for details).
Neurologically healthy older adults
As in PWA, NHOAs showed certain consisten-cies in their patterns of activation (see Figure 3).First, all NHOAs showed activation in left IFG.Unlike in PWA, this activation appeared to bemediated by task and word type. Second, NHOAsshowed fewer regions of activation overall thanPWA, constrained to mainly left hemisphere lan-guage areas, but notable exceptions exist, including
Dow
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at 0
5:42
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10 SANDBERG AND KIRANTA
BL
E4
MN
Icoo
rdin
ates
and
t-va
lues
ofar
eas
ofac
tivat
ion
for
PW
A1
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Ant
erio
rle
ftW
ord
judg
men
tM
iddl
eci
ngul
ate
cort
ex3.
71−3
,−21
,42
3.38
−3,−
36,3
63.
81−3
,−36
,39
Supe
rior
med
ialg
yrus
4.66
−3,3
9,45
6.19
−12,
63,1
85.
17−6
,45,
42Su
peri
orfr
onta
lgyr
us5.
24−2
4,45
,45
6.29
−24,
21,5
44.
87−1
8,27
,42
Mid
dle
fron
talg
yrus
5.29
−48,
30,3
39.
95−4
2,6,
576.
18−4
2,6,
57In
feri
orfr
onta
lgyr
usp.
orbi
talis
5.21
−45,
30,−
33.
38−4
5,21
,−9
5.77
−45,
33,−
15In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
4.87
−51,
27,3
11.0
8−4
5,30
,15
7.94
−42,
21,2
1M
iddl
eor
bita
lgyr
us3.
97−3
9,51
,-9
4.01
−45,
48,−
6In
sula
lobe
3.42
−36,
−15,
214.
89−3
0,24
,−3
3.59
−27,
24,0
Put
amen
3.38
−30,
6,0
Pal
lidum
3−9
,6,−
6Su
pple
men
tary
mot
orar
ea3.
960,
21,5
45.
90,
21,5
4P
rece
ntra
lgyr
us3.
61−3
6,−1
5,57
4.57
−39,
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0A
nter
ior
righ
tM
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eci
ngul
ate
cort
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353,
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edia
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4Su
peri
orfr
onta
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7830
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onta
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733
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27In
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orfr
onta
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usp.
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talis
3.69
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rior
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feri
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cula
ris
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lalo
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olan
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m3.
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date
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tary
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7936
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Pos
teri
orle
ftPo
stce
ntra
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15−3
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pora
lpol
e4.
81−3
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3.42
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15Su
peri
orte
mpo
ralg
yrus
3.41
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ete
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yrus
5.36
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Infe
rior
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pora
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iform
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s3.
35−4
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peri
orpa
riet
allo
bule
4.11
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Infe
rior
pari
etal
lobu
le5.
46−5
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−48,
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06−5
4,− 3
0,48
(Con
tinu
ed)
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 11TA
BL
E4
Co
nti
nu
ed.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Supr
amar
gina
lgyr
us4.
88−6
0,−5
1,30
7.76
−60,
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334.
31−5
7,−4
8,30
Ang
ular
gyru
s5.
4−4
8,−5
4,30
8.57
−57,
−57,
244.
61−5
4,−6
3,30
Post
erio
rci
ngul
ate
cort
ex3.
07−3
,−51
,24
Supe
rior
occi
pita
lgyr
us3.
4−1
5,−9
3,24
3.57
−15,
−93,
24M
iddl
eoc
cipi
talg
yrus
3.47
−21,
−93,
15In
feri
oroc
cipi
talg
yrus
4.02
−48,
−66,
−12
Cal
cari
negy
rus
4.46
−12,
−93,
−35.
69−9
,−93
,3P
recu
neus
3.9
−12,
−66,
363.
88−9
,−54
,27
Cun
eus
3.64
−9,−
93,2
4L
ingu
algy
rus
3.95
−21,
−66,
34.
863,
−81,
0C
ereb
ellu
m3.
8−1
2,−7
8,−1
53.
92−9
,−84
,−24
Pos
teri
orri
ght
Post
cent
ralg
yrus
3.05
24,−
30,6
3Su
peri
orte
mpo
ralg
yrus
4.5
63, −
48,1
84.
3266
,−48
,21
Hes
chls
gyru
s4.
9351
,−9,
63.
454
,−6,
6M
iddl
ete
mpo
ralg
yrus
4.79
54,−
42,−
36.
3551
,−39
,0H
ippo
cam
pus
3.64
39,−
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15Su
pram
argi
nalg
yrus
3.18
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cipi
talg
yrus
3.81
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13.
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Mid
dle
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pita
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us3.
9448
,−78
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cipi
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4.04
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4.27
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0,−9
Ant
erio
rle
ftS
ynon
ymju
dgm
ent
Ant
erio
rci
ngul
ate
cort
ex3.
440,
30,2
7M
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eci
ngul
ate
cort
exSu
peri
orm
edia
lgyr
us4.
69−1
2,63
,21
Supe
rior
fron
talg
yrus
3.45
−12,
18,5
13.
88−1
2,33
,54
Mid
dle
fron
talg
yrus
6.27
−42,
6,57
4.08
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8In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.96
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54−4
2,36
,−12
Infe
rior
fron
talg
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p.tr
iang
ular
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53−4
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5,39
,6In
feri
orfr
onta
lgyr
usp.
oper
cula
ris
3.56
−54,
15,1
2M
iddl
eor
bita
lgyr
us4.
15−3
6,54
,−3
Insu
lalo
be5
−30,
21,−
33.
92−3
0,21
,−3
Put
amen
3.51
−15,
6,6
(Con
tinu
ed)
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
12 SANDBERG AND KIRAN
TAB
LE
4C
on
tin
ued
.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Supp
lem
enta
rym
otor
area
4.36
−3,1
5,48
Pre
cent
ralg
yrus
5.23
−39,
6,45
4.33
−57,
0,36
Ant
erio
rri
ght
Mid
dle
cing
ulat
eco
rtex
3.41
12,1
2,45
Supe
rior
med
ialg
yrus
3.84
9,60
,27
Supe
rior
fron
talg
yrus
5.35
33,5
4,12
Mid
dle
fron
talg
yrus
4.99
45,4
2,24
Infe
rior
fron
talg
yrus
p.tr
iang
ular
is4.
857
,24,
154.
1157
,24,
15In
sula
lobe
6.86
45,1
8,−3
4.19
45,1
8,−3
Rol
andi
cop
ercu
lum
4.24
45,−
3,12
Put
amen
3.81
30,−
9,12
Cau
date
nucl
eus
3.59
12,6
,6P
rece
ntra
lgyr
us3.
7233
,0,5
13.
633
,−15
,66
Pos
teri
orle
ftPo
stce
ntra
lgyr
us6.
17−4
8,−3
9,57
Tem
pora
lpol
e3.
88−4
8,21
,−12
Supe
rior
tem
pora
lgyr
us3.
53−4
8,−1
8,0
Mid
dle
tem
pora
lgyr
us7.
65−6
0,−4
8,3
7.16
−57,
−45,
0In
feri
orte
mpo
ralg
yrus
4.53
−48,
−39,
−21
4.39
−48,
−39,
−18
Fus
iform
gyru
s4.
43−3
3,−9
,−27
4.53
−42,
−51,
−12
Infe
rior
pari
etal
lobu
le5.
3−3
0,−6
6,42
4.41
−30,
−66,
45Su
pram
argi
nalg
yrus
4.37
−48,
−45,
30A
ngul
argy
rus
4.52
−57,
−57,
24Po
ster
ior
cing
ulat
eco
rtex
3.59
−3,−
33,3
3Su
peri
oroc
cipi
talg
yrus
3.94
−24,
−69,
33M
iddl
eoc
cipi
talg
yrus
3.51
−27,
−75,
394.
05−2
4,−7
2,30
Infe
rior
occi
pita
lgyr
us3.
96−4
8,−6
0,−1
8P
arah
ippo
cam
palg
yrus
3.28
−24,
−27,
−18
Pos
teri
orri
ght
Pal
lidum
3.62
21,−
3,6
Infe
rior
pari
etal
lobu
le4.
157
,−36
,51
Not
e:A
llac
tiva
tion
sign
ifica
ntat
FD
Rp
≤.0
5.
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nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 13TA
BL
E5
MN
Icoo
rdin
ates
and
t-va
lues
ofar
eas
ofac
tivat
ion
for
PW
A2
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Ant
erio
rle
ftW
ord
judg
men
tA
nter
ior
cing
ulat
eco
rtex
3.34
−9,3
9,21
Mid
dle
cing
ulat
eco
rtex
4.29
0,−1
2,39
4.06
−3,−
45,3
6Su
peri
orm
edia
lgyr
us6.
19−3
,51,
305.
57−3
,54,
30Su
peri
orfr
onta
lgyr
us4.
86−9
,57,
366.
12−1
2,57
,27
4.81
−12,
57,2
7M
iddl
efr
onta
lgyr
us4.
96−2
7,36
,48
5.16
−27,
24,4
5In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.36
−42,
27−1
84.
57−4
5,45
−6In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
9.21
−57,
24,1
58.
89−5
7,21
,15
Infe
rior
fron
talg
yrus
p.op
ercu
lari
s3.
4−3
9,3,
24R
olan
dic
oper
culu
m5.
75−6
0,3,
6Su
pple
men
tary
mot
orar
ea5.
250,
21,5
75.
060,
21,5
7P
rece
ntra
lgyr
us6.
81−4
2,9,
486.
39−3
3,9,
30A
nter
ior
righ
tA
nter
ior
cing
ulat
eco
rtex
4.52
6,48
,18
Mid
dle
cing
ulat
eco
rtex
43,
−27,
30Su
peri
orm
edia
lgyr
us4.
219,
42,5
14.
363,
33,4
5Su
peri
orfr
onta
lgyr
us3.
7915
,6,7
5M
iddl
efr
onta
lgyr
us4.
2324
,51,
33In
feri
orfr
onta
lgyr
usp.
orbi
talis
3.74
48,2
7−1
5In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
6.57
48,4
2,0
3.52
45,4
2,0
Infe
rior
fron
talg
yrus
p.op
ercu
lari
s4.
3651
,18,
124.
5939
,18,
30In
sula
lobe
5.92
36,2
7−6
3.99
39,2
4−6
Pos
teri
orle
ftPo
stce
ntra
lgyr
us4.
31−5
4,−6
,45
3.55
−54,
−3,4
2T
empo
ralp
ole
4.68
−54,
6−1
2Su
peri
orte
mpo
ralg
yrus
4.28
−63,
−42,
15M
iddl
ete
mpo
ralg
yrus
4.09
−51,
−63,
214.
21−5
4,−4
2−9
5.04
−54,
−42
−9In
feri
orte
mpo
ralg
yrus
3.42
−48,
−48
−94.
01−5
1,−5
1−9
Supe
rior
pari
etal
lobu
le3.
82−3
3,−6
6,57
4.14
−33,
−66,
57In
feri
orpa
riet
allo
bule
3.65
−36,
−78,
424.
46−3
3,−7
2,51
Ang
ular
gyru
s3.
53−4
5,−6
3,51
3.61
−45,
−63,
51Po
ster
ior
cing
ulat
eco
rtex
3.76
0,−4
8,30
5.6
−3,−
45,3
3Su
peri
oroc
cipi
talg
yrus
3.29
−18,
−93,
24M
iddl
eoc
cipi
talg
yrus
4.4
−39,
−78,
366.
6−3
9,−7
8,36
Cal
cari
negy
rus
3.36
−3,−
69,1
85.
06−3
,−69
,18
Pre
cune
us5.
27−3
,−57
,30
4.53
−9,−
60,1
5
(Con
tinu
ed)
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
14 SANDBERG AND KIRANTA
BL
E5
Co
nti
nu
ed.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Pos
teri
orri
ght
Mid
dle
tem
pora
lgyr
us4.
0763
,−51
,0F
usifo
rmgy
rus
3.32
45,−
36−2
1Po
ster
ior
cing
ulat
eco
rtex
3.84
9,−3
9,24
Supe
rior
occi
pita
lgyr
us4.
1127
,−90
,24
3.37
27,−
90,2
4M
iddl
eoc
cipi
talg
yrus
4.48
30,−
90,1
5C
alca
rine
gyru
s3.
6312
,−99
,3P
recu
neus
4.3
9,−5
7,39
Ant
erio
rle
ftS
ynon
ymju
dgm
ent
Ant
erio
rci
ngul
ate
cort
ex3.
75−6
,27,
30M
iddl
eci
ngul
ate
cort
ex3.
110,
−6,3
63.
28−1
2,−6
,48
Supe
rior
med
ialg
yrus
2.94
0,69
,96.
6−3
,48,
42Su
peri
orfr
onta
lgyr
us4.
05−2
4,21
,54
4.25
−12,
72,6
Mid
dle
fron
talg
yrus
6.07
−27,
9,57
6.1
−24,
21,4
8In
feri
orfr
onta
lgyr
usp.
orbi
talis
6.06
−42,
27−1
84.
32−3
9,30
−15
Infe
rior
fron
talg
yrus
p.tr
iang
ular
is10
.75
−57,
18,1
210
.3−5
7,24
,15
Infe
rior
fron
talg
yrus
p.op
ercu
lari
s3.
13−3
9,6,
21M
iddl
eor
bita
lgyr
us3.
33−2
7,33
−18
Insu
lalo
be4.
43−3
6,6,
6R
olan
dic
oper
culu
m3.
18−4
8,3,
93.
84−6
0,0,
9P
utam
en3.
02−3
0,−9
,6Su
pple
men
tary
mot
orar
ea3.
18−3
,−3,
755.
260,
9,66
Pre
cent
ralg
yrus
9.12
−42,
9,48
7.9
−42,
9,48
Ant
erio
rri
ght
Ant
erio
rci
ngul
ate
cort
ex3.
923,
33,2
4M
iddl
eci
ngul
ate
cort
ex2.
793,
−33,
304.
159,
−39,
33Su
peri
orm
edia
lgyr
us3.
766,
60,3
3.96
6,57
,30
Supe
rior
fron
talg
yrus
3.07
18,6
6,21
Mid
dle
fron
talg
yrus
4.09
39,3
9,6
4.62
36,4
5,3
Infe
rior
fron
talg
yrus
p.or
bita
lis6.
3145
,21
−12
5.25
42,3
6−1
2In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
6.38
48,4
2,0
5.48
45,4
5,0
Infe
rior
fron
talg
yrus
p.op
ercu
lari
s3
60,1
8,36
Insu
lalo
be7.
7836
,27
−64.
3236
,24
−3P
utam
en3.
1930
,−9,
6C
auda
tenu
cleu
s3.
059,
9,9
3.45
15,−
6,18
Supp
lem
enta
rym
otor
area
3.89
6,−1
5,78
Pre
cent
ralg
yrus
4.09
54,6
,45
Par
acen
tral
lobu
le3.
429,
−30,
63
(Con
tinu
ed)
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 15TA
BL
E5
Co
nti
nu
ed.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Pos
teri
orle
ftPo
stce
ntra
lgyr
us3.
25−2
1,−3
6,75
3.96
−54,
−6,4
5T
empo
ralp
ole
3.62
−51,
9−1
53
−54,
9−6
Supe
rior
tem
pora
lgyr
us5.
1−6
6,−3
9,15
4.48
−60,
0,0
Mid
dle
tem
pora
lgyr
us7.
5−6
3,−4
2−9
7.29
−60,
−42
−12
Infe
rior
tem
pora
lgyr
us4.
38−5
1,−5
7−1
84.
45−5
1,−4
8−9
Supe
rior
pari
etal
lobu
le2.
77−2
1,−5
7,66
4.88
−21,
−81,
48In
feri
orpa
riet
allo
bule
7.59
−42,
−60,
515.
74−3
6,−7
2,48
Supr
amar
gina
lgyr
us3.
79−6
3,−2
4,27
Ang
ular
gyru
s2.
8−4
5,−7
2,30
6.84
−39,
−63,
48Po
ster
ior
cing
ulat
eco
rtex
6.13
−3,−
45,3
38.
74−3
,−45
,33
Supe
rior
occi
pita
lgyr
us3.
8−2
1,−6
9,33
Mid
dle
occi
pita
lgyr
us7.
66−3
9,−7
8,36
8.32
−33,
−81,
36In
feri
oroc
cipi
talg
yrus
3.39
−24,
−87
−9C
alca
rine
gyru
s4.
76−6
,−63
,15
5.96
−3,−
66,1
8P
recu
neus
4.57
−3,−
54,1
25.
41−6
,−69
,36
Cun
eus
4.43
0,−7
2,30
3.42
3,−8
4,24
Par
ahip
poca
mpa
lgyr
us2.
8−2
1,−2
1−2
7L
ingu
algy
rus
6.36
−6,−
84−9
3.06
−12,
−84
−6C
ereb
ellu
m5.
61−3
,−63
−63.
11−3
,−63
−6P
oste
rior
righ
tPo
stce
ntra
lgyr
us3.
815
,−51
,72
Supe
rior
tem
pora
lgyr
us6.
3851
,−36
,6M
iddl
ete
mpo
ralg
yrus
3.24
57,−
66,0
3.41
63,−
27−3
Infe
rior
tem
pora
lgyr
us2.
8551
,−72
−6F
usifo
rmgy
rus
5.35
27,−
63−1
53.
1630
,−72
−15
Tha
lam
us3.
529,
−21,
12Su
peri
orpa
riet
allo
bule
4.62
24,−
75,5
1In
feri
orpa
riet
allo
bule
3.51
42,−
33,4
83.
1145
,−54
,48
Supr
amar
gina
lgyr
us3.
3651
,−30
,42
Ang
ular
gyru
s3.
2545
,−63
,30
4.99
45,−
66,3
0Su
peri
oroc
cipi
talg
yrus
4.47
33,−
72,4
24.
4333
,−75
,42
Mid
dle
occi
pita
lgyr
us5.
6142
,−81
,34.
5127
,−93
,3In
feri
oroc
cipi
talg
yrus
3.94
48,−
75−1
24.
1330
,−87
−6C
alca
rine
gyru
s4.
7912
,−63
,12
3.41
27,−
69,3
Pre
cune
us2.
969,
−66,
663.
1912
,−66
,36
Cun
eus
5.3
21,−
87,3
93.
519,
−93,
15L
ingu
algy
rus
6.01
15,−
96−9
4.52
15,−
99−9
Pos
teri
orce
ntra
lC
ereb
ella
rve
rmis
3.87
3,−4
8,0
3.7
−3,−
51,6
Not
e:A
llac
tiva
tion
sign
ifica
ntat
FD
Rp
≤.0
5.
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
16 SANDBERG AND KIRANTA
BL
E6
MN
Icoo
rdin
ates
and
t-va
lue
ofar
eas
ofac
tivat
ion
for
PW
A3
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Ant
erio
rle
ftW
ord
judg
men
tA
nter
ior
cing
ulat
eco
rtex
4.87
−3,4
5,18
3.56
−12,
48,3
3.24
−3,4
5,18
Mid
dle
cing
ulat
eco
rtex
3.61
−3,−
12,3
94.
27−6
,−36
,45
Supe
rior
med
ialg
yrus
6.48
−6,3
0,57
11.0
8−6
,33,
453.
72−1
2,48
,12
5.51
−3,2
7,57
Supe
rior
fron
talg
yrus
4.01
−15,
33,5
16.
96−1
5,33
,51
4.05
−24,
45,4
24.
26−1
5,33
,54
Mid
dle
fron
talg
yrus
4.22
−42,
12,4
57.
17−2
7,21
,51
4.49
−30,
36,4
84.
15−2
7,21
,54
Infe
rior
fron
talg
yrus
p.or
bita
lis6.
25−5
1,33
−311
.82
−39,
39−3
7.31
−39,
42−3
Infe
rior
fron
talg
yrus
p.tr
iang
ular
is5.
17−5
1,33
,0In
sula
lobe
5.05
−27,
21−3
10.5
8−3
0,21
−36.
98−3
0,21
−3Su
pple
men
tary
mot
orar
ea2.
89−6
,−12
,75
4.67
−6,−
9,75
Pre
cent
ralg
yrus
6.02
−33,
3,36
6.27
−33,
3,36
Ant
erio
rri
ght
Ant
erio
rci
ngul
ate
cort
ex5.
4712
,30,
246.
3412
,30,
243.
689,
42,0
Mid
dle
cing
ulat
eco
rtex
5.96
9,18
,45
3.64
6,−1
2,33
5.46
6,−5
1,33
Supe
rior
med
ialg
yrus
4.67
6,45
,45
4.18
12,5
4,30
4.17
9,66
,12
3.47
12,5
4,30
Supe
rior
fron
talg
yrus
3.45
21,6
6,3
4.07
21,6
6,3
4.71
21,4
5,36
4.07
24,6
3,6
Mid
dle
fron
talg
yrus
6.3
36,4
5,21
8.29
51,1
8,48
5.25
33,3
3,39
5.79
45,5
1,0
Infe
rior
fron
talg
yrus
p.or
bita
lis5.
7533
,30
−610
.84
48,4
5−3
4.69
42,4
2−6
Infe
rior
fron
talg
yrus
p.tr
iang
ular
is6.
7548
,18,
189.
8348
,18,
184.
6751
,42,
0In
sula
lobe
4.16
33,1
8,3
2.94
33,2
4,−1
83.
5139
,−15
,−3
Rol
andi
cop
ercu
lum
3.5
48,−
27,1
8P
utam
en3.
2915
,9,−
6C
auda
tenu
cleu
s3.
99,
15,6
6.14
9,6,
64.
059,
12,0
Supp
lem
enta
rym
otor
area
4.05
6,18
,66
6.29
3,21
,57
Pre
cent
ralg
yrus
3.81
27,−
21,7
5P
arac
entr
allo
bule
3.41
6,−2
7,75
Pos
teri
orle
ftSu
peri
orte
mpo
ralg
yrus
3−6
3,−3
3,12
Mid
dle
tem
pora
lgyr
us8.
63−6
0,−3
9,−3
13.0
5−6
3,−3
9,−3
4.6
−51,
−69,
185.
99−6
0,−4
8,0
Infe
rior
tem
pora
lgyr
us5.
29−5
7,−5
1,−9
Fus
iform
gyru
s3.
65−2
7,−6
9,−1
2Su
peri
orpa
riet
allo
bule
3.85
−18,
−48,
72In
feri
orpa
riet
allo
bule
4.11
−36,
−78,
45A
ngul
argy
rus
3.52
−45,
−60,
424.
31−5
7,−5
7,30
Post
erio
rci
ngul
ate
cort
ex3.
9−6
,−51
,21
4.41
−9,−
48,2
7Su
peri
oroc
cipi
talg
yrus
3.02
−3,−
84,4
53.
49− 1
8,−7
8,27
Mid
dle
occi
pita
lgyr
us3.
92−4
5,−7
5,36
3.16
−24,
−99,
95.
13−3
6,−7
5,24
5.17
−42,
−78,
30
(Con
tinu
ed)
Dow
nloa
ded
by [
Bos
ton
Uni
vers
ity]
at 0
5:42
03
Apr
il 20
13
ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 17TA
BL
E6
Co
nti
nu
ed.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Infe
rior
occi
pita
lgyr
us3.
63−2
7,−7
8,−9
4.7
−54,
−69,
−3C
alca
rine
gyru
s4.
08−3
,−90
,15
Pre
cune
us3.
78−3
,−54
,45
6.85
0,−6
9,45
4.1
3,−6
9,36
5.19
0,−6
3,51
Par
ahip
poca
mpa
lgyr
us4.
21−2
1,−2
4,−2
14.
49−1
8,−2
7,−1
8L
ingu
algy
rus
3.45
−24,
−48,
−63.
34−1
5,−5
1,0
Cer
ebel
lum
4.7
−12,
−36,
−18
3.38
−3,−
48,−
153.
92−3
,−48
,−15
Pos
teri
orri
ght
Post
cent
ralg
yrus
4.26
54,−
15,3
0Su
peri
orte
mpo
ralg
yrus
3.16
45,−
12,−
94.
7960
,0,−
94.
2666
,−15
,−6
Mid
dle
tem
pora
lgyr
us5.
8466
,−45
,08.
4966
,−45
,05.
666
,−51
,94.
7754
,−66
,21
Infe
rior
tem
pora
lgyr
us3.
6945
,−54
,−9
3.92
60,−
21,−
183.
448
,−66
,−3
3.92
60,−
45,−
12H
ippo
cam
pus
3.83
18,−
24,−
123.
2333
,−33
,−3
Tha
lam
us3.
23,
−21,
3Su
peri
orpa
riet
allo
bule
3.45
15,−
57,5
7In
feri
orpa
riet
allo
bule
5.09
54,−
48,4
88.
3954
,−51
,48
3.97
48,−
33,4
85.
8657
,−51
,42
Supr
amar
gina
lgyr
us4.
2254
,−42
,39
7.26
60,−
45,3
66.
4666
,−21
,21
5.71
63,−
45,3
9A
ngul
argy
rus
3.8
54,−
60,2
46.
8639
,−57
,42
4.18
48,−
63,3
3Su
peri
oroc
cipi
talg
yrus
3.56
21,−
66,4
5M
iddl
eoc
cipi
talg
yrus
4.35
24,−
96,6
Infe
rior
occi
pita
lgyr
us4.
5236
,−93
,−3
Cal
cari
negy
rus
4.62
6,−9
0,0
3.41
6,−8
7,0
4.07
30,−
63,6
Pre
cune
us5.
4915
,−66
,39
7.74
15,−
66,3
95.
7312
,−54
,42
Cun
eus
3.41
18,−
99,9
3.24
12,−
102,
93.
723,
−78,
39L
ingu
algy
rus
4.91
15,−
66,−
94.
3818
,−42
,−12
Post
erio
rce
ntra
lC
ereb
ella
rve
rmis
4.15
0,− 4
2,−1
83.
660,
−48,
−6A
nter
ior
left
Syn
onym
judg
men
tA
nter
ior
cing
ulat
eco
rtex
3.76
−3,1
2,27
4.83
−3,4
5,18
Mid
dle
cing
ulat
eco
rtex
4.54
−3,−
9,36
3.68
0,−1
2,36
Supe
rior
med
ialg
yrus
4.16
−6,3
3,54
12.9
8−3
,30,
5710
.82
−3,3
0,57
Supe
rior
fron
talg
yrus
6.34
−12,
57,2
73.
85−1
2,51
,30
Mid
dle
fron
talg
yrus
4.38
−27,
45,1
53.
79−3
3,57
,6In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.21
−39,
24,−
312
.84
−42,
42,−
64.
28−3
6,33
,−9
9.63
−39,
39,−
3In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
3.81
−33,
30,0
13.2
8−4
5,33
,09.
94−4
5,33
,0In
sula
lobe
4.84
−27,
18,−
610
.69
−27,
21,−
33.
33−3
6,0,
−6P
utam
en2.
93−3
0,−1
2,3
Pal
lidum
4.87
−9,3
,0
(Con
tinu
ed)
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18 SANDBERG AND KIRAN
TAB
LE
6C
on
tin
ued
.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Supp
lem
enta
rym
otor
area
5.07
−3,1
2,60
8.02
−3,1
5,63
Pre
cent
ralg
yrus
4.65
−51,
−3,3
09.
46−3
3,3,
365.
66−4
5,6,
36A
nter
ior
righ
tA
nter
ior
cing
ulat
eco
rtex
4.22
6,42
,12
4.68
12,3
0,24
Mid
dle
cing
ulat
eco
rtex
3.34
6,−2
1,33
Supe
rior
med
ialg
yrus
4.86
15,5
4,30
5.3
6,48
,45
Supe
rior
fron
talg
yrus
5.21
24,1
5,42
3.63
24,6
6,6
Mid
dle
fron
talg
yrus
4.57
30,6
,54
10.4
233
,6,5
47.
1633
,9,5
7In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.33
42,3
0,−9
4.74
27,3
3,−1
85.
7945
,48,
−3In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
4.74
51,2
4,21
10.1
948
,18,
187.
4548
,18,
18In
feri
orfr
onta
lgyr
usp.
oper
cula
ris
5.59
57,2
1,12
3.23
63,2
1,27
3.18
39,1
5,33
Insu
lalo
be4.
2745
,3,0
3.88
48,1
2,−9
3.43
36,2
1,−3
Rol
andi
cop
ercu
lum
4.15
57,−
3,9
Put
amen
3.17
21,1
8,−6
Cau
date
nucl
eus
5.1
12,1
5,12
5.82
9,6,
6Su
pple
men
tary
mot
orar
ea3.
956,
15,5
72.
729,
−15,
75P
rece
ntra
lgyr
us4.
2557
,3,4
87.
1657
,3,4
84.
0460
,6,3
33.
9660
,9,3
0P
oste
rior
left
Post
cent
ralg
yrus
4.29
−60,
3,18
3.18
−54,
−18,
21Su
peri
orte
mpo
ralg
yrus
4.27
−66,
−21,
93.
92−5
1,−3
3,21
Mid
dle
tem
pora
lgyr
us4.
96−5
4,−6
3,9
12.4
8−6
0,−4
8,−3
11.5
8−6
3,−4
8,−3
Infe
rior
tem
pora
lgyr
us4.
09−5
1,−5
4,−1
53.
2−4
5,−3
6,−2
1F
usifo
rmgy
rus
2.93
−36,
−66,
−12
2.98
−36,
−24,
−21
Infe
rior
pari
etal
lobu
le8.
42−3
3,−7
8,45
9.72
−36,
−78,
42In
feri
orpa
riet
alco
rtex
5.43
−54,
−72,
18A
ngul
argy
rus
10.8
9−5
1,−6
6,24
Post
erio
rci
ngul
ate
cort
ex6.
04−3
,−39
,30
4.11
−9,−
51,3
07.
91−3
,−39
,30
Supe
rior
occi
pita
lgyr
us4.
79−9
,−99
,12
Mid
dle
occi
pita
lgyr
us3.
26−2
7,−6
9,27
5.07
−39,
−75,
21In
feri
oroc
cipi
talg
yrus
2.7
−45,
−75,
−9C
alca
rine
gyru
s4.
17−9
,−63
,15
3.87
−12,
−60,
15P
recu
neus
7.05
−3,−
69,4
24.
3−6
,−57
,15
7.46
−3,−
72,4
2L
ingu
algy
rus
2.86
−12,
−39,
0
(Con
tinu
ed)
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 19
TAB
LE
6C
on
tin
ued
.
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
MN
Ix,
y,z
Reg
ion
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
t-V
alue
coor
dina
tes
Pos
teri
orri
ght
Post
cent
ralg
yrus
2.73
27,−
27,6
0Su
peri
orte
mpo
ralg
yrus
4.46
54,−
36,6
Hes
chls
gyru
s4.
5154
,−12
,93.
5551
,−15
,6M
iddl
ete
mpo
ralg
yrus
6.01
72,−
30,−
34.
8251
,−69
,05.
2945
,−57
,15
Infe
rior
tem
pora
lgyr
us3.
4948
,−54
,−12
4.43
66,−
42,−
9F
usifo
rmgy
rus
4.66
39,−
60,−
123.
5536
,−42
,−15
Tha
lam
us3.
049,
−6,6
Supe
rior
pari
etal
lobu
le3.
0630
,−78
,51
Infe
rior
pari
etal
lobu
le9.
2554
,−48
,45
6.12
54,−
51,4
2Su
pram
argi
nalg
yrus
3.86
57,−
45,4
22.
9357
,−27
,39
5.53
57,−
45,3
3A
ngul
argy
rus
10.7
739
,−57
,39
7.67
39,−
57,3
9M
iddl
eoc
cipi
talg
yrus
3.01
33,−
93,9
Infe
rior
occi
pita
lgyr
us4.
4627
,−96
,−3
3.22
42,−
84,−
3C
alca
rine
gyru
s3.
5918
,−10
2,0
3.04
3,−6
0,18
Pre
cune
us4.
873,
−54,
484.
133,
−54,
45C
uneu
s3.
2621
,−99
,94.
4312
,−75
,21
Lin
gual
gyru
s3.
4827
,−87
,−6
3.02
12,−
45,0
Not
e:A
llac
tiva
tion
sign
ifica
ntat
FD
Rp
≤.0
5.
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20 SANDBERG AND KIRAN
NHOA1
NHOA2
NHOA3
Word Judgment
Word Judgment
Word Judgment
Synonym Judgment
Synonym Judgment
Synonym Judgment
Figure 3. Activations for neurologically healthy older adults (NHOAs). Activation shown at FDR p < .05 for contrasts abstract >
control (red) and concrete > control (green). Yellow = overlap between contrasts. [To view this figure in color, please visit the onlineversion of this Journal.]
bilateral activations which appear to be mediatedby task and word type. Third, all NHOAs showedgreater activation for abstract than concrete words,which effect also appeared to be mediated by task.Each NHOA’s specific neuroimaging results aredescribed separately below.
NHOA1. The first participant was a 67-year-old female. During the word judgment task, this
participant did not show activation for the tightcontrasts of abstract > concrete and concrete >
abstract. The broader contrasts of abstract > con-trol and concrete > control showed much overlap,but differences included activation in left superiormedial gyrus for the abstract > control contrastand activation in left fusiform gyrus, PCC, andprecuneus for the concrete > control contrast (seeTable 7 and Figure 3 for details).
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 21
During the synonym judgment task, the abstract> concrete contrast showed activation in left IFG(p. orbitalis and opercularis) and MTG, as wellas additional areas listed in Table 7, but the con-crete > abstract contrast did not reveal any signif-icant areas of activation. The broader contrasts ofabstract > control and concrete > control showedoverlap, but notable differences included activa-tion in right IFGorb and left STG for the abstract> control contrast and activation in left ITG forthe concrete > control contrast (see Table 7 fordetails).
NHOA2. The second participant was a 56-year-old male. During the word judgment task, thisparticipant did not show activation for the tightcontrasts of abstract > concrete and concrete >
abstract. The broader contrasts of abstract > con-trol and concrete > control showed similar activa-tion patterns, but the abstract > control contrastadditionally activated left superior medial gyrus,SFG, AG, and PCC (see Table 8 and Figure 3 fordetails).
Like the word judgment task, the synonym judg-ment task showed no significant activation for thetight contrasts of abstract > concrete and concrete> abstract. Additionally, there was no significantactivation for the broad contrast of concrete >
control. However, the abstract > control contrastshowed activation in left IFG (p. orbitalis and tri-angularis) and MTG (see Table 8 and Figure 3 fordetails).
NHOA3. The third participant was a 56-year-oldfemale. During the word judgment task, this par-ticipant showed activation in left superior parietallobule for the tight contrast of abstract > concrete,but did not show activation for the tight contrastof concrete > abstract. The broader contrast ofabstract > control approached significance in leftIFG and MTG, and the concrete > control contrastshowed activation in left MTG (see Table 9 andFigure 3 for details).
During the synonym judgment task, the abstract> concrete contrast showed activation in areasincluding left IFGtri, STG, and MTG, but the con-crete > abstract contrast did not reveal any signif-icant areas of activation (see Table 9). The broadercontrast of abstract > control showed much moreactivation than the concrete > control contrast,with the only overlap occurring in left MTG (seeTable 9 and Figure 3 for details).
DISCUSSION
We examined the neural activation patterns forabstract and concrete word processing of threePWA with varying degrees of lesion during twotasks with varying depth of semantic processingand compared their data with three age-matchedcontrols in order to shed more light on the con-creteness effect seen in both neurologically intactadults and PWA. As mentioned in the introduc-tion, the abstract-concrete distinction provides aunique opportunity for studying semantic pro-cessing in PWA because abstract and concretewords have been shown to elicit differing pat-terns of activation in neurologically intact adults(e.g., Binder et al., 2009; Wang et al., 2010)and can be differentially impaired due to braindamage.
Both NHOAs and PWA showed differing pat-terns of activation for abstract and concrete wordprocessing, confirming our first hypothesis. Thedirect contrast of abstract > concrete was signifi-cant in two of the three NHOAs and in all threePWA, and the direct contrast of concrete > abstractwas significant in one PWA, but none of theNHOAs. It is interesting to note that the NHOAsdid not show as robust differences between abstractand concrete word processing as PWA. This lackof robustness and agreement among NHOAs is notaltogether surprising, since there were only threeparticipants. The studies leading up to the Binderet al. (2009) and Wang et al. (2010) meta-analyseswere not in agreement until all their data werepooled together. That being said, it is somewhatsurprising that the PWA show such robust neuralactivation differences. It is possible that the exag-gerated concreteness effect seen in patients behav-iorally translates to more robust differences in neu-ral activation between abstract and concrete wordprocessing.
When the direct contrasts of abstract > concreteand concrete > abstract were significant, areas thatwere shown to be active were in line with previouswork and with the dual-coding theory, as can beseen in Table 10 and Figure 1. Interestingly, addi-tional areas of activation for these contrasts werealso noted for both NHOAs and PWA, but to amuch greater extent for the PWA (see Tables 4–9).These additional areas that were not also observedin the Binder et al. (2009) and Wang et al. (2010)meta-analyses may have been recruited due toincreased effort.
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22 SANDBERG AND KIRAN
TAB
LE
7M
NIc
oord
inat
esof
activ
atio
nan
dt-
valu
efo
rN
HO
A1
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
Reg
ion
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
Wor
dju
dgm
ent
Ant
erio
rle
ftSu
peri
orm
edia
lgyr
us5.
23−9
,45,
45Su
peri
orfr
onta
lgyr
us5.
78−1
2,45
,36
7.02
−12,
60,2
4In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
4.85
−51,
21,0
5.93
−54,
21,0
Pos
teri
orle
ftM
iddl
ete
mpo
ralg
yrus
5.06
−51,
−60,
156.
92−5
1,−6
6,21
Infe
rior
tem
pora
lgyr
us4.
21∗
−51,
−12,
−27
5.1
−54,
−3,−
36F
usifo
rmgy
rus
4.92
−33,
−39,
−21
Ang
ular
gyru
s5.
55−5
1,−6
9,24
6.21
−45,
−72,
27Po
ster
ior
cing
ulat
eco
rtex
5.34
−3,−
51,2
4P
recu
neus
4.93
−6,−
57,1
5S
ynon
ymju
dgm
ent
Ant
erio
rle
ftSu
peri
orm
edia
lgyr
us5.
973,
33,3
38.
470,
30,3
35.
050,
27,3
6Su
peri
orfr
onta
lgyr
us5.
35−2
1,27
,39
9.42
−21,
27,3
96.
75−1
5,48
,30
Mid
dle
fron
talg
yrus
4.91
−27,
18,4
56.
95−3
0,18
,48
5.48
−21,
30,3
9In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.85
−48,
42,−
99.
4−4
5,42
,−12
6.32
−54,
24,−
3In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
5.65
−54,
33,0
Infe
rior
fron
talg
yrus
p.op
ercu
lari
s4.
9−4
5,6,
27In
sula
lobe
4.39
−33,
21,−
9Su
pple
men
tary
mot
orar
ea4.
710,
12,4
5A
nter
ior
righ
tM
iddl
eci
ngul
ate
cort
ex4.
473,
21,3
9In
feri
orfr
onta
lgyr
usp.
orbi
talis
4.3∗
30,2
4,−1
24.
7933
,18,
−21
Pos
teri
orle
ftSu
peri
orte
mpo
ralg
yrus
6.67
−51,
−42,
18M
iddl
ete
mpo
ralg
yrus
4.69
−51,
−45,
−66.
63−5
4,−4
2,−6
4.73
−66,
−36,
−6In
feri
orte
mpo
ralg
yrus
7.61
−60,
−9,−
30A
ngul
argy
rus
4.82
−42,
−57,
459.
41−4
5,−6
9,36
9.57
−45,
−69,
33P
oste
rior
righ
tC
ereb
ellu
m6.
4415
,−78
,−39
4.59
12,−
78,−
39
Act
ivat
ion
sign
ifica
ntat
FD
Rp
<.0
5.A
ster
isks
indi
cate
acti
vati
ons
that
wer
esi
gnifi
cant
atp
<.1
0.
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 23
TAB
LE
8M
NIc
oord
inat
esof
activ
atio
nan
dt-
valu
efo
rN
HO
A2
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
evs
.con
trol
Reg
ion
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
t-V
alue
MN
Ix,
y,z
coor
dina
tes
Wor
dju
dgm
ent
Ant
erio
rle
ftSu
peri
orm
edia
lgyr
us7.
27−1
2,60
,30
Supe
rior
fron
talg
yrus
8.49
−15,
54,4
2M
iddl
efr
onta
lgyr
us7.
22−3
3,33
,51
5.09
−27,
27,5
7In
feri
orfr
onta
lgyr
usp.
orbi
talis
7.18
−36,
30,−
124.
55−3
6,33
,−9
Infe
rior
fron
talg
yrus
p.tr
iang
ular
is6.
5−4
8,27
,94.
59−4
5,30
,9P
oste
rior
left
Mid
dle
tem
pora
lgyr
us7.
4−5
1,−6
6,18
5.76
−51,
−66,
15A
ngul
argy
rus
5.98
−42,
−72,
45Po
ster
ior
cing
ulat
eco
rtex
4.59
−3,−
45,3
0M
iddl
eoc
cipi
talg
yrus
7.1
−42,
−72,
277.
19−3
9,−7
2,27
Syn
onym
judg
men
tA
nter
ior
left
Mid
dle
fron
talg
yrus
4.35
−36,
12,6
3In
feri
orfr
onta
lgyr
usp.
orbi
talis
5.88
−48,
33,−
3In
feri
orfr
onta
lgyr
usp.
tria
ngul
aris
5.26
−36,
33,1
5Su
pple
men
tary
mot
orar
ea5.
33−6
,24,
66P
oste
rior
left
Mid
dle
tem
pora
lgyr
us4.
78−5
1,−6
6,15
Not
e:A
llac
tiva
tion
sign
ifica
ntat
FD
Rp
≤.0
5.
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24 SANDBERG AND KIRAN
TAB
LE
9M
NIc
oord
inat
esof
activ
atio
nan
dt-
valu
efo
rN
HO
A3
Abs
trac
tvs
.con
cret
eA
bstr
act
vs.c
ontr
olC
oncr
ete
vs.a
bstr
act
Con
cret
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ABSTRACT AND CONCRETE WORD PROCESSING IN APHASIA 25
TABLE 10Comparison of activations between persons with aphasia, neurologically healthy older adults, and existing literature
Binder et al.(2009)
Wang et al.(2010) Persons with aphasia Neurologically Healthy Older Adults
Area Various tasks Word judgment Synonym judgment Word judgment Synonym judgment
Abstract > concreteLIFGtri X X X XLIFGorb X X X X X XLSTG X (STS) X XLMTG X X X X X X X
Concrete > abstractL DMPFC X XL fusiform X XLAG X X
(IPC)RAG X XLPCC X X X XL precuneus X X XL para-hippocampal
X
Only areas matching with previous meta-analyses shown. For current study, each X represents activation for one participant. See textfor abbreviations of anatomical areas.
Furthermore, there appears to be an effect oftask. For PWA, there are more areas active forboth abstract > concrete and concrete > abstractcontrasts in the WJ task than in the SJ task. ForNHOAs, this trend is reversed. The WJ task mayrequire deeper semantic processing from the PWAthan the NHOAs, resulting in greater differencesbetween abstract and concrete word processing forPWA in this task. The SJ task, which is meant torequire deeper semantic processing than the WJtask, may be the depth of semantic processing nec-essary to show the maximum differences in abstractand concrete word processing for NHOAs, but forPWA, the increased difficulty for this task mayovershadow inherent differences between abstractand concrete word processing. These speculationsare tentative and would need to be confirmed withmore subjects.
It is also informative to qualitatively comparethe activation patterns of abstract and concretewords when each has had the control conditionremoved. PWA activated areas consistent with theirage-matched counterparts as well as areas consis-tent with previous work. Specifically, regardless oftask, all three PWA activated left IFG, STG, andMTG for abstract word processing (see Figure 2and Tables 4–6), which is consistent with boththe existing literature and all three NHOAs (seeFigure 3 and Tables 7–9). For concrete word pro-cessing, again regardless of task, all three PWA
activated left AG, PCC, and portions of DMPFC(see Figure 2 and Tables 4–6), in line with the exist-ing literature and at least one NHOA (see Figure 3and Table 7). Thus, the qualitative comparison ofabstract > control and concrete > control contrastsfor both the WJ task and the SJ task confirms theresults of the abstract > concrete and concrete >
abstract contrasts and suggests that with more data,these tentative results are likely to become morerobust.
Importantly, NHOAs and PWA show surpris-ingly similar patterns of activation for abstract andconcrete words in this experiment. Most notably,both NHOAs and PWA activated left IFG (p. tri-angularis and orbitalis) and MTG for both abstractand concrete words. In fact, all three PWA activatedall three of these areas, which is quite remarkableconsidering the fact that PWA2 is missing roughly85% of left MTG and PWA3 is missing roughly 95%of IFGtri. This result reinforces the importance ofleft IFG and MTG for semantic processing in gen-eral (Lau, Phillips, & Poeppel, 2008; Vigneau et al.,2006).
The differences that surface appear to be influ-enced by cognitive demand, task, and lesion charac-teristics; therefore, our second hypothesis that dif-ferences between NHOAs and PWA would be dueto lesion characteristics is supported and extendedto task and cognitive demand. PWA in general,show increased activity in comparison to NHOAs.
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26 SANDBERG AND KIRAN
This is in the face of similar task performance;in fact, for the WJ task, there was no statisticallysignificant difference in behavioral performancebetween the two groups. In order to maintain thislevel of performance, PWA almost certainly requiremore cognitive effort due to their language deficitcaused by damage to the left perisylvian region.This increased effort may be reflected in increasedglobal activity.
Additionally, all three PWA showed perilesionalactivation. PWA1 showed activation in left IFGtriand AG, even though both areas were lesioned.PWA2’s lesion was much larger than PWA1’s, buthe too showed activation in lesioned areas includ-ing left IFG, MFG, MTG, and AG areas forabstract and/or concrete words, depending on thetask. When PWA2 did not show activation in leftMTG and AG for abstract words as NHOAs did,the amount of damage in these areas could be toblame. Although PWA3’s lesion was the largest, healso activated lesioned areas, including left IFGtri,MFG, and AG/SMG for abstract and/or con-crete words, depending on the task. When theseareas were active in NHOAs, but not PWA3, theright hemisphere homologue was often active (seeResults for details).
These individual patterns of activation can beinterpreted in the light of the amount of spared tis-sue in each region of interest and with respect tothe existing literature examining the neural corre-lates of language recovery after stroke. For all threePWA, the activation in spared tissue surroundingthe lesion in areas such as left IFG and MTG,suggest restoration of function (e.g., Fridriksson,Richardson, Fillmore, & Cai, 2012; Meinzer et al.,2008; Saur et al., 2006; Turkeltaub et al., 2011).Additionally, right hemisphere homologues wererecruited for all three PWA, which may be indica-tive of a reorganization of language function or mayrepresent supplementary—possibly nonessential—processing. For PWA3, who had the largest lesionand the most right hemisphere activation, RH acti-vation may reflect compensation, but for the otherPWAs, whose lesions were not as extensive and whohad less right hemisphere activation than PWA3,this may simply reflect increased effort. Becauseof the small sample size, it is impossible to con-duct meaningful statistics to determine the relation-ship between lesion characteristics and activationpatterns; therefore, substantial conclusions regard-ing the relative contributions of perilesional andcontralesional activations cannot be made at thistime.
CONCLUSIONS
The results of this study are in line with previ-ous neuroimaging studies of abstract and concreteword processing showing that abstract words areprocessed in a mainly verbal network, whereas con-crete words are processed in a mainly perceptualnetwork (e.g., Binder et al., 2009; Wang et al.,2010). We found this to be true in PWA andtheir neurologically healthy age-matched counter-parts. PWA and NHOAs exhibit remarkably similaractivation patterns, although notable differencesdo exist. These differences are most likely due tolesion characteristics and help to inform the processof language recovery after stroke. Notably, PWAactivated both spared tissue and right hemispherehomologues. Although this work is tentative dueto the small sample size, these activations appearto be reorganization of function rather than mal-adaptive compensation, due to the relatively highperformance of these participants.
Some limitations of this study are the small sam-ple sizes and the similarity in aphasic profiles of thepatients. Future work will incorporate more par-ticipants with greater variation in aphasia severity,with correlations between behavior and activationbeing conducted. Additionally, we plan to explorechanges in abstract and concrete word processingas a function of a theoretically based treatmentfocused on abstract word training. As mentioned inthe introduction, PWA show an exaggerated con-creteness effect which has been successfully manip-ulated in treatment to boost its therapeutic effects(Kiran et al., 2009). Knowing where abstract andconcrete words are normally processed and howthat processing may shift due to aging and left-hemisphere stroke will aid in discovering why theconcreteness effect is exaggerated in PWA and whytraining abstract words seems to be more benefi-cial than training concrete words. This study is astep forward in a continued effort to understand themechanisms underlying word retrieval deficits inaphasia in order to adopt more effective treatmentmethods.
Manuscript received 10 May 2012Revised manuscript received 16 October 2012
First published online 3 April 2013
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