functional neuroanatomy [email protected] attention language knowledge imagery memory...
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Functional neuroanatomy
• Attention• Language• Knowledge• Imagery• Memory
– States ‘of mind’ (and body)– Adaptation/plasticity– Language; visual processing; mental imagery
• How our brains integrate types of information to develop concepts; how previous experience affects processing of new information
What are we doing with our brains at this moment?
(The student’s brain)
• Feeling your chair
• Squirming (moving)
• Watching
• Listening
• Remembering
• Paying attention
• Sleeping
• Feeling anxious
• Feeling hungry
• What happens when you ask a question?
• Learning
5 types of cortical tissue
Localization of function in the nervous system: Functional networks
5 major brain systems subserving
cognition and behaviorLeft perisylvian language networkParieto-frontal network for spatial attentionOccipitotemporal network for object/face recognitionMedial temporal/limbic network for learning & memoryPrefrontal network for attention & comportment
Knowledge: The convergence of language, perception, and memory
Language & naming
Visual systems & category-specific processing
Imagery/sensory memory
Knowledge: The convergence of language, perception, and memory
Language & naming
Visual systems & category-specific processing
Imagery/sensory memory
Lesion studies of the language network:The major nodes
Broca’s (production) Wernicke’s (comprehension)
Lesion studies of the language network:Disconnection syndromes
Alexia without agraphia
Geschwind N & Kaplan E, Neurology, 1962
Functional neuroimaging of the language network
One to many, many to oneCJ Price, J Anat 2002
Language function: Using neuroimaging to test hypotheses
CJ Price, J Anat 2002
What’s in a name?A means to access specific types of
knowledge
What’s in a name?A means to access specific types of
knowledge
Elephant
Linguistic access to specific types of knowledge
Damasio H, Nature 1996
Knowledge: The convergence of language, perception, and memory
Language & naming
Visual systems & category-specific processing
Imagery/sensory memory
Visual processing: Two pathwaysDorsal (Occipito-parietal): Object & object feature recognition
Disorders:
visual object agnosia
prosopagnosia
achromatopsia
Ventral (Occipito-temporal): Visual recognition of spatial location
Disorders: optic ataxia, ocular apraxia, simultanagnosia (Balint’s); constructional apraxia, akinotopsia
Visual processing streams: Confirmation of hypotheses using neuroimaging
Ungerleider LG, PNAS 1998
Visual processing: Attention influences which stream is used
Ungerleider LG, PNAS 1998
Visual object recognition: Lesion studies
Agnosias may be specific to certain categories of information
Visual object recognition: Distinct but overlapping functional areas
Haxby JV, Science 2001
Visual object recognition: Faces & places
Kanwisher N, Science, 2006
Visual object recognition: Faces
Tsao
Knowledge: The convergence of language, perception, and memory
Language & naming
Visual systems & category-specific processing
Imagery/sensory memory
Visual perception & imagery
Ganis G, Cog Brain Res 2004
Auditory imagery
Kosslyn SM, Nat Rev Nsci 2001
Motor imagery
Kosslyn SM, Nat Rev Nsci 2001
Naming vs. recognition: Networks for conceptual knowledge
Name this animal and tell me what you know about it
Naming vs. recognition: Networks for conceptual knowledge
Name this person and tell me what you know about him
Naming vs. recognition: Networks for conceptual knowledge
Damasio H, Cognition 2004
Object-specific naming deficits Object-specific recognition deficits
Encoding & recall of category-specific information
Encoding of category-specific information activates relevant areas of cortex
Polyn SM et al., Science, 2005
Faces: Fusiform gyrus Places: Parahippocampal gyrus
Encoding & recall of category-specific information
Reactivation of category-specific areas occurs prior to verbal recall Polyn SM et al., Science, 2005
Plasticity in heteromodal cortical regions: The basis for learning
Recovery of language function after stroke: Mapping plasticity in the human brain
Fernandez B, Stroke 2004
1 year after stroke
1 month after stroke
Plasticity: Many levels of scale in both time & space
Attention, arousal, awareness
•Focused attention & visuospatial attention
•Arousal
•Coma
•Persistent vegetative state
•Sleep
•Conscious awareness
Attention
Attention: Trinodal cortical network
Mesulam MM, Phil Trans R Soc London, 1999
Hypothesized from patients & animals with lesions
Attention: Trinodal cortical network
Gitelman DR et al., Ann Neurol 1996;39:174-9Gitelman DR et al., Brain 1999;122:1093-1106
Confirmed with functional neuroimaging (fMRI & PET)
Attention
Mesulam MM, Phil Trans R Soc London, 1999
State vs channel functions
StatesSleep/arousalNeeds (e.g., hunger)Mood
Channels
The limbic system directs heteromodal cortex toward relevant information
LaBar KS, Behavioral Neuroscience 2001
Neurotransmitter systems
Neurotransmitter systems
Genetic variations in neurotransmitter substrates
Enzymes, receptors, etc (e.g., Weinberger DR)
Pharmacologic fMRI
e.g., dopaminergic modulation of attention
PET imaging of receptors & enzymes
Sleep/Anatomy
ARAS & thalamus
Sleep/EEG
Sleep/EEG
Conscious awareness:Default mode
Raichle M, et al.,
Conscious awareness:Persistent vegetative state
Owen A, et al., Science, 2006
What are we doing with our brains at this moment?
(The student’s brain)
• Feeling your chair
• Squirming (moving)
• Watching
• Listening
• Remembering
• Paying attention
• Sleeping
• Feeling anxious
• Feeling hungry
• What happens when you ask a question?
• Learning