59 Cortical Locations Flashcards
What is the front back division of the brain?
Front is MOTOR
Back is SENSORY
Using the words Convergent or Divergent, which is related to the Motor or Sensory hemispheres?
Front, Motor, Convergent
Back, Sensory, Divergent
Using the words Executive vs Sensory memory, which is related to the motor or sensory hemispheres?
Front Motor Convergent Executive Memory
Back Sensory Divergent Sensory Memory
Note: There are different areas of the cortex that are more ancient or more modern phylogenetically. Interestingly, these correspond to the age in a person’s life when the neurons of each section complete their myelination.
Ancient = earlier myelination = primary cortices
In between = unimodal cortices (premotor cortex and unimodal sensory area)
Modern = later myelination = multimodal association cortices
What is a multimodal cortex?
aka association cortex combines input from multiple sensory and motor areas of the brain and are used for memory, planning, language, math, logic, and awareness.
What are the three multimodal cortices that we learned about in class?
Parietal Association Cortex
Temporal Associate Cortex
Prefrontal Association Cortex
Where is the Parietal Association Cortex located?
Brodmann area 7 and 39 at the intersection of the somatosensory and visual cortex.
What is the function of the parietal association cortex?
Spatial localization and attention (attention proportional to the amount of neuron firing)
The sense of the body in space
The perception of “agency”aka sense of “self” (ie, the feeling that one is in charge of making decisions)
What deficits occur with lesions to the parietal association cortex?
Inability to recognize objects by touch (tactile agnosia)
Visuospatial deficits (eg optic ataxia)
Attention deficits
Contralateral Neglect Syndrome
Where are locations of “working” memory aka very short term memory?
Frontal and Parietal Cortices
What percentage of people are Right vs Left hemisphere dominant?
How is dominance defined?
5% are right dominant
95% are left dominant
Dominance is defined as what side of the brain a person’s language area is mostly located.
More on R/L balance later…
What is “Neglect” in neuroscience?
The inability to perceive objects in the environment.
What is Contralateral Neglect Syndrome?
Damage to the non-dominant parietal hemisphere which leads to non-perception of the contralateral visual field.
Explain why Contralateral Neglect Syndrome must be damage to the non-dominant side.
The non-dominant parietal lobe sees both sides of the visual field.
The dominant parietal lobe only sees the contralateral side of the visual field.
Therefore, if damage is done to the non-dominant side, then the patient only sees one side of the visual field.
If damage is done to the dominant side, then the patients can still see both sides of the visual field, although not perfectly.
What is Balint’s Syndrome?
Triad of symptoms…
SIMULTANAGNOSIA»_space; the inability to perceive the visual field as a whole; the inability to percieve more than one object at a time
OPTIC APRAXIA»_space; deficits in visual scanning through the visual field
OPTIC ATAXIA»_space; deficits in hand-eye coordination; the inability to move the hand to specific objects in the visual field.
What is SIMULTANAGNOSIA?
the inability to perceive the visual field as a whole; the inability to percieve more than one object at a time
What is OPTIC APRAXIA?
deficits in visual scanning through the visual field
What is OPTIC ATAXIA?
deficits in hand-eye coordination; the inability to move the hand to specific objects in the visual field.
What is TACTILE AGNOSIA aka ASTEREOAGNOSIA?
The inability to identify objects by touch despite normal sensory ability.
This task requires the interaction of somatosensory (touch) and visual (3D visualization of the object based on touch) and integration of those stimuli at the parietal multimodal cortex.
Where is the Temporal Association Cortex?
In the temporal lobe
Brodmann’s areas 21 and 22
What is the function of the Temporal Association Cortex?
Processes AUDITORY and VISUAL information.
Important for OBJECT RECOGNITION and LANGUAGE COMPREHENSION.
Important for FACIAL RECOGNITION.
What deficits occur with lesions to the temporal association cortex?
VISUAL AGNOSIA: Inability to recognize objects by sight.
PROSOPAGNOSIA: Inability to recognize faces (especially after lesions to the NON-DOMINANT inferior temporal lobe).
AUDITORY AGNOSIA: inability to recognize or make sense of complex sounds (such as words).
RECEPTIVE APHASIA (“Wernicke’s”): deficits in language comprehension.
ACULCULIA or DYSCALCULIA: impaired arithmetic functions. Damage to dominant temporal lobe including the inferior region (involved in recognizing numbers) and the angular gyrus. The non-dominant hemisphere can participate in higher order math functions that aren’t as well localized as the ability to do simple calculations.
What is PROSOPAGNOSIA?
Where is the lesion?
Inability to recognize faces (especially after lesions to the NON-DOMINANT inferior temporal lobe).
What is AUDITORY AGNOSIA?
Inability to recognize or make sense of complex sounds (such as words).
What is RECEPTIVE AGNOSIA akaWERNICKE’S?
Deficits in language comprehension.
What is ACULCULIA aka DYSCALCULIA?
What locations can this occur in?
Impaired arithmetic functions.
Damage to DOMINANT TEMPORAL LOBE including the INFERIOR REGION (involved in recognizing numbers) and the ANGULAR GYRUS.
The NON-DOMINANT hemisphere can participate in higher order math functions that aren’t as well localized as the ability to do simple calculations.
What are FACE CELLS?
Where are they located?
Face cells fire when they look at specific faces at a specific angle.
Located in the inferior temporal cortex.
Note: ppt vs notes had different level of detail for the Frontal Association Cortex.
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ppt: What Brodmanns’ areas is the Frontal Association Cortex?
9, 10, 11, 12, and 46
ppt: When does the Frontal Association Cortex finish developing?
Decades after birth.
ppt: What are the functions of the Frontal Association Cortex?
Executive function, inhibition of impulsivity, planning, personality, and mood.
ppt: What are afferents to the Frontal Association Cortex?
Limbic cortex, amygdala, septal nuclei, reciprocal connections with the medial dorsal nucleus of the thalamus.
ppt: What symptoms do lesions in the Frontal Association Cortext cause?
LACK OF INHIBITION.
Changes in personality and mood, loss of abstract reasoning, impulsivity, reduced working memory, and lack of foresight.
What are the two main portions of the PREFRONTAL CORTEX?
What Brodmanns’ areas are each?
Dorsolateral Prefrontal Cortex (DLPC) areas 9, 10, 46
Orbitomedial Prefrontal Cortex areas 11 and 12
What areas are the Dorsolateral Prefrontal Cortex (DLPC)?
What areas are the Orbitomedial Prefrontal Cortex?
9, 10, 46
11 and 12
What are the functions of the Dorsolateral Prefrontal Cortex (DLPC)?
Executive functions: working memory, judgment, planning, sequencing of activity, abstract reasoning, and dividing attention
What are the functions of the Orbitomedial Prefrontal Cortex?
Impulse control, personality, reactivity to surroundings and mood.
Where is the Anterior Cingulate Gyrus?
What Brodmann’s areas?
Subcallosal and Subgenual regions
24 and 25
What are the fucntions of the Anterior Cingulate Gyrus?
Mood, especially depression and mania
What are tests of executive function?
Wisconsin Card Sorting Task (may sort cards by color, shape, or number)
Stroop Task (remember color order, but if spell words mislabelled colors more difficult)
N-Back Task (test working memory of number ‘n’ steps back)
Oculomotor Delayed Response Task (see a target in periphery and look in that direction after a period of time)
Working memory is maintained by “reverberatory circuits.”
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What are the three types of neurons active in the Oculomotor Delayed Response Task?
Cue selection
Delay selection
Response selection
What is the perception action cycle?
Primary Sensory Cortex»_space; Unimodal Association Sensory Cortex»_space; Multimodal Association Sensory Cortex»_space; Prefrontal Cortex Multimodal Motor»_space; Premotor Cortex Unimodal Motor»_space; Primary Motor Cortex
Where is the “sense of agency” located, ie, we choose to move?
What other areas are necessary for voluntary movement?
Parietal cortex is the sensation of will or agency
The supplementary motor cortex precedes conscious awareness of movement
What is Abulia?
What brain area is lesioned?
Inability to initiate movement
Supplementary Motor Area
What cortices provide the “urge” to move, if stimulated?
Both the Parietal Cortex and/or the Supplementary Motor Area
What cortex, if stimulated, can produce the illusion that movement occurred?
Parietal Cortex
Where is the Supplementary Motor Cortex located?
What Brodmann’s area?
Dorsal area 6
Extending medially into the interhemispheric fissure
What afferents lead to the Supplementary Motor Cortex?
What efferents come from the Supplementary Motor Cortex?
Afferent:
Sensory Association Areas
Prefrontal Cortex
Efferent: Primary Motor Cortex Parietal Cortex Contralateral Supplementary Motor Cortex Basal Ganglia Thalamus Brainstem
What afferents lead to the the Supplementary Motor Cortex?
Sensory Association Areas
Prefrontal Cortex
What efferents come from the Supplementary Motor Cortex?
Primary Motor Cortex Parietal Cortex Contralateral Supplementary Motor Cortex Basal Ganglia Thalamus Brainstem
Voluntary Motor Behavior follows what cycle?
Inferior Posterior Parietal Cortex»_space; Frontal Lobe»_space; Presupplementary Motor Area and the Premotor Area »_space; Primary Motor Area
Note: the Presupplementary Motor Area and the Primary Motor Area send efferents to tell the Parietal Cortex that movement will happen.
Long form:
Experiments in awake humans have found that decisions regarding voluntary movements are reflected in increased activity in the frontal cortex occurring before the perception of decision making occurs (in the parietal cortex). This process involves projections from the supplementary motor cortex to the parietal cortex that inform the perceptual brain about decisions that have already been made. The perceptual brain, in response, generates the illusion of conscious decision.
What is Alien Hand Syndrome?
Hand acts autonomously with purpose without willful intent as if the hand were controled by an independent mind.
Purposeful hand movement without sense of agency.
When does Alien Hand Syndrome occur ie what lesions?
Lesions in projections that normally inform the parietal cortex of imminent movement.
Lesions in the Corpus Callosum (explained below)
What is Utilization Behavior?
Inability to resist impulses to handle objects.
Purposeful, but autonomous movements
What are the two communication points between the Left and Right Hemispheres?
Corpus Callosum and the Anterior Commisure
What is a Corpus Callostomy?
Severing of the corpus callosum
What is the definition of Dominant vs Non-Dominant hemisphere?
Defined as which hemisphere shows LANGUAGE SPECIALIZATION
What is the Wada Test?
How is it performed?
Identifies Dominant and Non-Dominant hemispheres
Anesthesia is injected into the internal carotid artery on one side, and determine if language ability is intact.
Explain Alien Hand Syndrome as it relates to Corpus Callostomy.
The dominant hemisphere feels no sense of agency over limb movements controlled by the non-dominant hemisphere.
It appears as if the split-brain patient is much like two separate individuals interacting independently with the world, only one of which has the capacity to communicate with language.
Therefore, the language-dominant hemisphere can report its frustration with the unexpected (but purposeful) actions of limbs controlled by the other hemisphere.
However, because it is not specialized for communication, little is known about how the non-dominant hemisphere interprets the actions of the “Alien Hand” controlled by the language-dominant hemisphere.
What type of thinking does the DOMINANT hemisphere control?
NON-DOMINANT hemisphere?
Dominant: Language, Math, Logic
Non-Dominant: Facial Recognition, Spatial Skills, Music, Visual Imagery
In split brain patients, the ability to verbally identify objects is better when perceived by the _____ hemisphere.
Dominant
ie, the object is felt in the contralateral hand or seen in the contralateral visual field
With FACIAL recognition of SELF vs OTHER, which hemisphere is responsible for each?
DOMINANT = SELF facial recognition NON-DOMINANT = OTHER facial recognition
In terms of DEPRESSION vs MANIA, which hemisphere is responsible for each?
DEPRESSION = DOMINANT lesion MANIA = NON-DOMINANT lesion
In terms of Wernicke’s and Broca’s areas, which hemisphere is responsible for each?
Both are on DOMINANT SIDE
Language ability is the definition of dominance
However, the NON-DOMINANT side helps to understand and generate inflections of voice that generate context.
Where is Wernicke’s area?
Where is Broca’s area?
What are the Brodmann’s areas of each?
W: Upper Temporal Lobe, extending back to the Supramarginal gyri and Angular Gyri. Areas 22, 40, and 39, respectively.
B: Opercular and Triangular portions of the Inferior Frontal Gyrus Areas 44 and 45
What is Wernicke’s Aphasia?
What is Broca’s Aphasia?
Wernicke’s aphasia is the inability to understand language, but the ability to produce language remains intact.
Broca’s is the inability to produce written or spoken language, but the ability to understand language remains intact.
What symptoms occur if the Wernicke’s and Broca’s areas are intact, but the tracts connecting them are injured?
Inability to create complex sentences (ie, sentences with clauses)
eg, no ifs, ands, or butts.
What are Transcortical Aphasias?
Damage to cortical areas around Wernicke’s and Broca’s areas.
Can repeat complex sentences, but have difficulty understanding complex sentences or generating meaningful language spontaneously self willed.
What areas of the brain are responsible for SIGN LANGUAGE?
Same areas as spoken language.
What areas of the brain are responsible for SECOND LANGUAGES…
Learned at birth?
Learned as adult?
At birth: same areas
As adult: different areas.
