Brain Regions/Functions - Cerebral Cortex Flashcards
Cerebral cortex components
Right and left hemispheres that contain:
1. Frontal lobes
2. Temporal lobes
3. Parietal lobes
4. Occipital lobes
5 frontal lobe components
- Broca’s area
- Prefrontal cortex
- Supplementary motor cortex
- Premotor cortex
- Primary motor cortex
Broca’s area functions
- Language
- Located in dominant frontal lobe (usually left)
Damage to Broca’s area
Broca’s aphasia
Prefrontal cortex (PFC) functions
- Executive function (planning, decision-making, social judgment, self-monitoring)
- Working memory
- Prospective memory
- Emotion regulation
PFC components
- Dorsolateral PFC (DLPFC)
- Orbitofrontal cortex (OFC)
- Ventromedial PFC (VMPFC)
Dorsolateral PFC (DLPFC) functions
- Executive function
Damage to dorsolateral PFC (DLPFC)
- Concrete thinking
- Impaired judgment and insight
- Poor planning
- Working memory deficits
- Perseverative responses
- Disinterest and apathy
Orbitofrontal cortex (OFC) functions
- Emotion regulation
- Response inhibition
- Social behaviors
Damage to orbitofrontal cortex (OFC)
- Poor impulse control
- Social inappropriateness (immaturity, offensive jokes)
- Lack of concern for others
- Aggressive and antisocial behavior
- Distractibility
- Affective lability
Ventromedial PFC (VMPFC) functions
- Decision-making
- Social cognition
- Memory
- Emotion regulation
Damage to ventromedial PFC (VMPFC)
- Impaired decision-making
- Impaired moral judgment
- Lack of insight
- Deficits in social cognition
- Confabulation
- Blunted emotional responses
Supplementary motor cortex functions
- Planning and coordinating self-initiated complex movements
- Somatotopically organized
3 scenarios in which the supplementary motor cortex or premotor cortex is active
- Engaging in complex movement
- Imagining engaging in complex movement
- Watching others engaging in complex movement
Premotor cortex functions
- Planning and coordinating complex movements triggered by external (sensory) stimuli
- Somatotopically organized
Primary motor cortex functions
- Sends signals from supplementary motor and premotor cortices to muscles
- Somatotopically organized
Damage to primary motor cortex
- Depends on location and extent of damage
- Ranges from weakness to paralysis in 1+ muscle(s) on the opposite side of body
Temporal lobe components
- Auditory cortex
- Wernicke’s area
Auditory cortex functions
- Processing sound
Damage to auditory cortex
- Auditory agnosia
- Auditory hallucinations
- Cortical deafness
Wernicke’s area functions
- Language
- Located in dominant temporal lobe (usually left)
Damage to Wernicke’s area
- Wernicke’s aphasia
Arcuate fasciculus
- Connects Broca’s area and Wernicke’s area
Damage to arcuate fasciculus
- Conduction aphasia
Parietal lobe components
- Somatosensory cortex
Somatosensory cortex functions
- Processes sensory information related to touch, pressure, temperature, pain, body position
Damage to somatosensory cortex
1+ somatosensory agnosia(s):
1. Tactile agnosia
2. Asomatognosia
3. Anosognosia
Damage to parietal lobe
- Somatosensory agnosia(s)
- Hemispatial neglect
- Ideomotor apraxia
- Ideational apraxia
- Gerstmann’s syndrome
Hemispatial neglect
- Also known as unilateral neglect and contralateral neglect
- Typically caused by damage to nondominant (right) parietal lobe
- Neglect of left side of body and stimuli on left side of body
Ideomotor apraxia
- Typically caused by damage to dominant (left) parietal lobe
- Inability to perform motor activity in response to a verbal command
Ideational apraxia
- Typically caused by damage to dominant (left) parietal lobe
- Inability to plan and execute a task that requires a sequence of actions
Gerstmann’s syndrome
- Typically caused by damage to dominant (left) parietal lobe
Symptoms:
1. Finger agnosia
2. Right-left disorientation
3. Agraphia
4. Acalculia
Occipital lobe components
- Visual cortex
Damage to visual cortex
- Visual agnosia
- Visual hallucinations
- Achromatopsia
- Cortical blindness
Cortical blindness
- Damage to visual cortex when eyes and optic nerves are intact
- Damage in one hemisphere affects vision on opposite side
- Can cause blindsight
Blindsight
Physiological and behavioral responses to stimuli a person cannot see
Examples:
1. Reaching for a glass they cannot see
2. Responding emotionally to (and accurately guessing) a picture of a facial expression they cannot see
Damage to occipitotemporal junction
- Bilateral lesions = prosopagnosia
Common left hemisphere functions
(95% of right-handed people, 50-70% of left-handed people)
1. Written and spoken language
2. Logical and analytical thinking
3. Positive emotions
Common right hemisphere functions
(95% of right-handed people, 50-70% of left-handed people)
1. Holistic thinking
2. Intuition
3. Understanding spatial relationships
4. Creativity
5. Negative emotions
Dominant hemisphere
Hemisphere dominant for language (left for most people)
Brain hemispheres and sensory information
- Left hemisphere controls right side of body (and vice versa)
- Exception = smell (left hemisphere processes smells in left nostril)
Corpus collosum
- Bundle of nerve fibers that allows two brain hemispheres to share information
Sperry et al. brain lateralization research
- Split-brain patients with severe epilepsy
- Severed corpus callosum
Presented spoon in right visual field, processed by left (dominant) hemisphere:
1. Could see spoon
2. Could identify spoon via touch with right hand only
Presented spoon in left visual field, processed by right (nondominant) hemisphere:
1. Could not see spoon
2. Could identify spoon via touch with left hand only
Newer research techniques to study brain lateralization
- Dichotic listening task
- Neuroimaging
Dichotic listening task
- Studies speech lateralization
- Presents two words simultaneously to each ear
- Most (especially right-handed people) recall word presented to right ear, processed in left auditory cortex
