€¦ · web viewthe human brain controls many functions of the body including physiologic,...

Lisa Otto: Lobes of the Brain

Lobes of the brain

Lisa Otto

University of North Texas

LTEC 5300.020

Dr. Lin

August 7, 2017


Introduction

The human brain controls many functions of the body including physiologic, perceptual,

sensorial, cognitive, and motor functions. Brain injury, cerebrovascular disease, inflammation of

the brain, tumors, and abnormal brain development cause brain damage. The location of the

brain damage such as frontal, temporal, parietal, or occipital lobe of the brain results in varying

deficits. Behavior such as alcohol consumption and sleep deprivation also affect brain function

and cause deficits. This paper explores the structure and functions of the brain including the

lobes of the brain, as well as cognitive and motor deficits caused by brain damage and behavior.

Brain Overview

The brain encompasses three major components including the cerebrum, brainstem, and

cerebellum. First, the cerebrum consists of right and left cerebral hemispheres. The right and left

hemispheres of the brain are further divided into the four lobes of the brain termed frontal,

temporal, parietal, and occipital (Lewis, 2014). The brainstem is composed of the midbrain pons,

and medulla. In addition, the reticular formation is located in the brainstem extending from the

medulla to the thalamus and hypothalamus (Lewis, 2014). The reticular formation is a group of

neurons and axons that relay sensory information influencing spinal motor neurons, vasomotor,

and respiratory activity thus regulating arousal and sleep-wake transitions. The medulla contains

important centers that regulate the respiratory system, vasomotor activity, and cardiac functions.

Sneezing, coughing, hiccupping, vomiting, sucking, and swallowing are also controlled by the

brainstem (Lewis, 2014). The cerebellum is located under the occipital lobe of the cerebrum. The

cerebellum influences motor activity and performs three functions 1) coordinates voluntary

movements, 2) stabilizes the trunk, and 3) maintains equilibrium (Lewis 2014).


Lewis, 2014, p. 1409 Brain MRI, Bokde, Teipel, Schwarz, et al., 2005, p. 137

Frontal LobeThe frontal lobe is located in the anterior or front part of the brain, which is superior to

the lateral sulcus and in front of the central sulcus and contains the Broca’s area (Augustine,

2017; Lewis, 2014). The frontal lobe is characterized by numerous significant functional areas

such as the primary motor cortex (Augustine, 2017). The frontal lobe controls higher cognitive

function and memory retention, as well as voluntary motor movement including eye movement.


The role of the frontal lobe has expanded to encompass complex functions including attention,

memory, executive cognition, social behavior, and consciousness (Cantani et al., 2012). Lastly,

the frontal lobe receives information in the form of signals from the senses and coordinates the

senses (Goldstein, 2015).

Sleep Deprivation

The prefrontal cortex is located in the anterior portion of the frontal brain lobe. New

research points out the sensitivity of the prefrontal cortex to the lack of sleep. Consequently,

sleep deprivation impairs the ability of the frontal lobe to function during waking hours thus

impairing executive functions of the brain. Examples of executive functions affected are self-

observation planning, prioritization and decision-making abilities. The affected executive

functions correlate with attention, working memory, temporal memory, and behavior inhibition

(Muzur, Pace-Schott, & Hobson, 2002). According to Vartanian, Bouak, Caldwell, and Cheung

et. al (2014), a single night of sleep deprivation affects working memory, cognition fluency, and

executive functions, which could result in impaired divergent thinking. The resulting effects of

sleep deprivation are comparable to “a reversible functional lesion in the prefrontal cortex” (Lim

& Dinges, 2010, p.376).

In university settings today, students often choose to eliminate sleep to participate in

desired activities or complete school related tasks. Sleep deprivation negatively impacts working

memory which is important in reasoning, language, reading ability, and learning. There is an

indirect correlation between students obtaining regular sleep wake routines and higher grade

point averages (Curcio, Ferrara, & Gennaro, 2006). “Both REM (rapid eye movement) and

NREM (non-rapid eye movement) sleep seem necessary for learning and memory: thus for an


efficient consolidation of both (declarative) knowledge and (procedural) skills, the worst risk is

sleep loss or fragmentation” (Curcio, Ferrara, & Gennaro, 2006, p. 332).

In society today, many people providing emergency services, working in hospitals,

serving in the military, and working in industrial control rooms stay up throughout the night and

into the next day with minimal sleep (Harrison & Horne, 1999). In addition, advanced

professional students such as medical interns work long shifts including staying awake all night

and all day for 1-3 days. The jobs and professional student roles require flexible, innovative

(divergent) thinking, and the possession of the ability to receive new information and revise

plans (Harrison & Horne, 1999). According to Harrison & Horne (1999), “the PFC [prefrontal

cortex] is particularly associated with dealing with divergent type thinking, innovation, novelty

and the unexpected” (p.142). This center of the brain is affected by sleep deprivation. According

to Harrison and Horne (1999), “people working for extended periods of time, who are required to

make decisions necessitating innovation, flexibility, and the ability to update plans in light of

new information, and presented under rapidly changing situations should avoid sleep loss beyond

32-36 h [hours]” (p. 142).

Alcohol

Drinking alcohol affects all age groups in society including adolescence, teenagers,

adults, and the elderly. Alcohol consumption is rising thus necessitating the need to discover the

short-term and long-term effects of dependency on brain function. People with long-term alcohol

dependency undergoing imaging of the brain demonstrate decreased prefrontal cortical grey and

white matter resulting in a smaller prefrontal cortex (Virag et.al., 2015). The prefrontal region is

the most pronounced area of the brain affected by alcohol dependency (Goldstein et al., 2004;

Virag et.al., 2015). According to Virag et.al (2015), alcohol dependency is associated with


weaker executive functions and conversely intact implicit learning. Nonetheless, when the

alcohol dependency is long-term the brain experiences irreversible and degraded implicit

learning processes (Virag et.al, 2015). The literature supports the continued residual effects of

alcohol dependency on brain function after 3 weeks of abstinence and after one year of

abstinence from alcohol (Virag et.al, 2015).

Some youth begin drinking as early as 12 years old (Zeigler et al., 2005). According to

Zeigler et al. (2005), “The prevalence of alcohol use increases with age, from 2.6% at 12 years of

age to 67% of persons aged 21 years” (p.24). Approximately 10 million youth in the United

States report consuming alcohol in the past 30 days and 6% (2.1 million) of the youth were

heavy drinkers (Zeigler et al., 2005). According to Zeigler et al. (2005), excessive consumption

of alcohol routinely or through periods of binge drinking can result in brain damage and

cognitive deficits. The adolescence period of maturation encompasses significant

neuromaturation including active development of the hippocampus and prefrontal cortex.

“Through this process the prefrontal area becomes more efficient as it matures into adulthood

and enhances the ability of the adult brain (relative to the adolescent brain) to execute such task

as planning, integrating information, abstract thinking, problem solving, judgement, and

reasoning” (Zeigler et al., 2005,p.25). Excessive alcohol consumption in adolescence may affect

prefrontal area development and the corresponding functions.

Focus on Broca’s area

The Broca’s area is responsible for expressive speech. (Lewis, 2014, p. 1408). “The loss

of articulate speech due to a brain lesion in Broca’s area is commonly termed Broca’s aphasia,

motor aphasia, or expressive aphasia” (Augustine, 2014, p. 358). Aphasia is defined as the loss

of ability to use language to convey ideas excluding vocal cord paralysis or other diseases of the


muscles involved in speech. A person with Broca’s aphasia experiences the ability to

comprehend language; however, the patient cannot speak (Augustine, 2014).

Frontal Lobe Damage

Frontal lobe damage results in numerous deficits. See summary table below.

Lobe Damage DeficitsFrontal Motor

Cognitive function

Memory

Executive functions

o Planning

o Integrating information

o Abstract thinking

o Problem solving

o Judgement

o Reasoning

Broca’s Area Aphasia

o Loss of articulate speech

o Difficulty with sounds and letters

o Difficulty expressing self

Table adapted from Augustine, 2017; Cantani et al., 2012; Harrison and Horne (1999); and Lewis, 2014

TemporalThe temporal lobes are located on the sides of the brain under the ears and contain the

Wernicke’s area. The temporal lobes receive input from multiple sensory systems including

somatosensory, visual, olfactory, and auditory. In addition, the temporal lobe is involved in

language and auditory processing, as well as social attention (Wong & Gallate, 2012). The

temporal lobe performs multiple functions including 1) auditory processing and discrimination,

2) visual processing and discrimination, 3) learning, 4) memory, 5) social cognition, 6) social


behaviors, 7) sexual behaviors, 8) language processing, 9) facial recognition 10) smell

perception, 11) taste perception, 12) semantic memory, 13) knowledge, and 14) processing of

unique stimuli (Wong & Gallate, 2012). The right temporal lobe is thought to determine

emotional responses such as empathy and social behavior. In contrast, the left temporal lobe

seems to be more involved in cognitive processes (Wong & Gallate, 2012).

Wernicke’s area

The Wernicke’s area is responsible for receptive speech (Lewis, 2014). Wernicke’s

aphasia manifests as a comprehension disorder rather than an expressive disorder. Wernicke’s

aphasia is termed sensory aphasia, central aphasia, receptive aphasia, and auditory aphasia

involving deficits in word and sentence comprehension (Augustine, 2014). A person

experiencing Wernicke’s aphasia generally maintains fluent speech but cannot understand or

comprehend language, spoken or written (Augustine, 2014).

Temporal Lobe Damage

Temporal lobe damage results in numerous deficits. See summary table below.

Lobe Damage DeficitsTemporal Right Social and Emotional Behaviors

o Social awkwardness

o Loss of empathy

o Lack of inhibition

o Bizarre affect

o Demonstration of repetitive behaviors

Prosopagnosia (cannot recognize the face of familiar people)

Temporal Left Semantic cognition

o Cognitive problems

o Anomia (unable to recall the names of objects)

o Semantic deficits


o Lowered comprehension

Wernicke’s Area

Lack of comprehension

o Understanding spoken language impairment

o Understanding reading impairment

Table adapted from Wong and Gallate 2012 and Augustine, 2014, and Lewis, 2014

Parietal LobeThe parietal lobe is located in the back half of the brain. The parietal lobe is composed of

the somatosensory cortex and senses touch including pain and pressure (Goldstein, 2015). The

parietal lobe controls and interprets spatial information (Lewis, 2014). Current research data

supports parietal contributions to episodic memory retrieval. Episodic memory refers to every

day events held in conscious memory. Delineated regions of the parietal lobe contribute to

specific processes involved in memory (Wagner, Shannon, Kahn, & Buckner, 2005). Another

type of deficit a person may experience due to damage to the parietal lobe is alexia with

agraphia. According to Augustine (2014), “alexia, with agraphia, is acquired inability to read and

write, probably localized to the left angular gyrus of the parietal lobe” (p. 360). Damage to the

parietal lobes of the brain may result in many types of deficits. See the table below.

Parietal Lobe Damage

Parietal lobe damage results in numerous deficits. See summary table below.

Lobe Damage DeficitsParietal Neglect

Attentional deficit

Apraxia

Difficulty planning motor movements

Alexia with agraphiaTable adapted from Wagner, Shannon, Kahn, & Buckner, 2005; Augustine, 2014; and Lewis, 2014

Occipital Lobe


The occipital lobe is located in the back of the brain (Lewis, 2014). The occipital lobe is

the end where the neural fibers terminate that contain visual information from the retina

(Nehmad, 1998). According to Nehmad (1998), “Connections between the occipital lobes and its

adjacent parietal and temporal lobes also serve higher visual functions, such as reading, writing,

and recognition” (p.125). Some functions of the occipital lobe regarding vision are 1) integrate

sensory information with different areas of the brain, 2) integrating halves of the opposite visual

fields, and 3) visual memory (Nehmad, 1998).

Occipital Lobe DamageOccipital lobe damage results in numerous deficits. See summary table below.

Lobe Damage DeficitsOccipital Visual recognition

Visual orientation

Visual agnosia

o Cannot recall the name of an object

o Cannot demonstrate the use of an object

o Cannot remember seeing an object before

Voluntary eye movements

Visual field defects

Homonymous hemianopsia

Isolated visual symptoms

Alexia without agraphia

Optic Ataxia

Unable to complete color vision tests, maintain the ability to name

colors

BlindnessTable adapted from Augustine, 2014; Nehmad, 1998; and Lewis, 2014

Other Brain DisordersDyslexia


Dyslexia is the most common reading disability affecting children. According to

Augustine (2014), “dyslexia is characterized by the inability to learn to comprehend the sounds

related to the written language” (p.360). Typically children with dyslexia demonstrate difficulty

learning to read, but exhibit adequate intelligence for their age. Injury or abnormal development

of the temporo-parietio-occipital region, striate, or extrastriate cortex is associated with dyslexia

(Augustine, 2014).

Conclusion

Cognitive and motor deficits may be caused by brain damage, cerebrovascular disease,

swelling or inflammation, traumatic injury (head trauma), cancer (brain tumor), or abnormal

brain development. Depending on the region of the brain damaged or location of the abnormal

development, a person may experience various deficits ranging from mild to severe such as

impaired decision making skills, blindness, memory impairment, knowledge impairment, reading

impairment, language impairment, cognitive disruption, and motor deficits. The deficits affect a

person’s ability to acquire knowledge through learning activities and school attendance, as well

as participate in activities of daily living. Numerous advances in brain imaging and interventions

are being explored to discover early detection methods, prevention strategies, and treatment

options for abnormal brain development, brain disease, and injury.


References

Augustine, J.R., & ProQuest (Firm). (2014). Human neuroanatomy (2nd ed.). Hoboken, New

Jersey: John Wiley & Sons, Inc.

Bokde, A. L. W., Teipel S.J., Schwarz, R., Leinsinger, G., Buerger, K., Moeller, T., … Hampel,

H. (2005). Reliable manual segmentation of the frontal, parietal, temporal, and occipital

lobes on magnetic resonance images of health subjects. Brain Research Protocols, 14(3),

135-145. doi:10.1016/j.brainresprot.2004.10.001

Catani, M., Dell’Acqua, F., Vergani, F., Malik, F., Hodge, H., Roy, P.,… Thiebaut de Schotten,

M., (2012). Short frontal lobe connections of the human brain. Cortex, 48(2), 273-291.

doi:10.1016/j.cortex,2011.12.001

Curcio, G., Ferrara, M., and Gennaro, L. (2006). Sleep loss, learning capacity and academic

performance. Sleep medicine reviews, 10, 323-337.

Goldstein, E. B. (2015). Cognitive Psychology. Connecting mind, research, and everyday

experience. (4th ed.) Standford, CT: Cengage Learning.

Goldstein, R.Z., Leskovjan, A.C., Hoff, A.L., et al. (2004). Severity of neuropsychological

impairment in cocaine and alcohol addiction: Association with metabolism in the

prefrontal cortex. Neuropsychologia, 42(11), 1447-1458. Doi:

10.1016/jneuropsychologia.2004.04.002.

Harrison, Y., and Horne J. (1999). One night of sleep loss impairs innovative thinking and

flexible decision making. Organizational Behavior and Human Decision Processes,

78(2), 128-145.

Lewis, S.L., Dirksen, S., Heitkemper, M., & Bucher, L. (2014). Medical-surgical nursing:

Assessment and management of clinical problems (9th ed.). St. Louis: Mosby.


Lim, J., and Dinges, D. F.(2010). M meta-analysis of the impact of shrt-term sleep deprivation

on cognitive variables. Psychol Bull, 136, 375-389. Doi 10.1037/a0018883.

Muzur, A., Pace-Schott, E., and Hobson, J. A. (2002). The prefrontal cortex in sleep. Trends in

Cognitive Sciences, 6 (11), 475-481.

Nehmad, L. (1998). The end in sight: A look at the occipital lobe. Clinical Eye and Vision Care

10(3), 125-133. doi: 10.1016/S0953-4431(98)00013-7

Vartanian, O., Bouak, F., Caldwell, J. L., Cheung, B., Cupchik, G., Jobidon, M…. Smith, l.

(2014). The effects of a single night of sleep deprivation on fluency and prefrontal cortex

function during divergent thinking. Frontier in Human Neuroscience, 8, 214.

doi:10.3389/fnhm.2014.00214

Virag, M., Janacek, K., Horvath, A., Buidoso, Z., Fabo, D., & Nemeth, D. (2015). Competition

between frontonal lobe functions and implicit sequence learning: Evidence from the long-

term effects of alcohol. Experimental Brain Research, 233(7), 2081-2089.

Doi:htty://dx.doi.org/10.1007/s00221-015-4279-8

Wagner, A. D., Shannon, B. J., Kahn, I., & Buckner, R.L. (2005). Parietal lobe contributions to

episodic memory retrieval. Trends in Cognitive Sciences, 9(9), 445-453.

Doi:10.1015/j.tics.2005.07.001

Wong, C. and Gallate, J. (2012). The function of the anterior temporal lobe: A review of the

empirical evidence. Brain Research 1449, 94-116. Doi:10.1016/j.brainres.2012.02.017

Zeigler, D. W., Wang, C. C., Yoast, R.A., Dickinson, B D., McCaffree, M.A., Robinowitz, C.B.,

… Council on Scientific Affairs, American Medical Association (2005). The

neurocognitive effects of alcohol on adolescents and college students. Preventive

Medicine, 40 (1), 23-32. Doi:10.1016/j.ypmed.2004.04.044

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