Cerebral cortex 2 Flashcards
Function: Analyzing location and movement of visual objects in space
Parietal Association Cortex
Injury to what side results in hemineglect?
Damage to R parietal or frontal cortex
- Worse with acute injury
- Recovery can take weeks to months
- Some patients will have permanent deficit
Ignore visual, auditory or tactile stimuli from contralateral side
Sensory neglect - Tactile > Visual > Auditory Double simultaneous stimulation - Look for extinction - Bilateral - Proximal > distal
sensation on R reported as on L
Allesthesia
- In L sided neglect
Decreased spontaneous movement or akinesia; Ipsilateral gaze preference toward side of lesion; Motor impersistence (hold arms out, involved side drifts down), especially of contralateral limbs; Allokinesia (moves normal limb when told to move involved limb)
Motor-intentional neglect
Line bisection – to R; Cancellation tasks – ignore left side; Drawing a clock, they draw a circle but only put numbers on R side
Combined sensory-motor neglect
Involved with thought process; Anosognosia, anodiaphoria, and hemiasomatognosia
Conceptual neglect
lack of awareness of hemineglect
Anosognosia
seen in conceptual neglect and also seen in:
- Wernicke’s aphasia
- Frontal lobe dysfunction
Aware of disability, but no emotional concern or distress
Anosodiaphoria
Deny L body is part of them
Hemiasomatognosia
Damage can result in an inability to function in the real world;
Overall functions:
- Restraint – inhibition of inappropriate responses
- Initiative – motivation to pursue positive activities
- Order – sequencing tasks
Frontal cortex
What are the specific functions of the frontal cortex?
- Working Memory
- Learning New Materials
- Shifting Cognitive Set
- Selective Attention (also being able to switch attention)
- Integrate Information from Limbic and heteromodal Association areas in decision making
Functions:
- Self-awareness
- Motivation
- Goal oriented behavior - Deciding on a goal, Planning how to accomplish goal, and Executing the plan
- Monitoring the execution of the plan
- Abstract thought
- Problem Solving
Prefrontal cortex
AKA frontal association area
Where is the prefrontal cortex? where is connected to?
Location: rostral to motor planning areas;
Connections to Sensory Association Areas and Limbic areas
What occurs as a result to prefrontal cortex injury?
- Apathy
- Loss of goal-directed behaviors: Choosing goals, Planning , Executing plans, Monitoring execution
- Behavior may be misinterpreted as uncooperative or unmotivated - Difficulties with divergent thinking (thinking of possibilities; can choose a correct answer out of a list) - don’t ask open ended questions
What effects are seen with frontal lobe lesions (not including problems with prefrontal cortex)?
- Incontinence – more medial frontal regions
- Inability to suprress inappropriate responses (Go-no-go test)
- Attention impairments
- Problems with abstract reasoning (similarities; can assess normal or concrete)
What is Anton’s syndrome?
Cortical blindness due to Bilateral injury to primary visual cortex
- anosognosia (completely unaware of deficit)
What is the result of unilateral injury to the primary visual cortex?
Homonymous hemianopsia with macular sparing
Processes motion and spatial localization and integrating everything together; stream of visual analysis
Dorsolateral Parieto-occipital cortex
What are the characteristics are seen in Balint’s syndrome
- Simultanagnosia
- Optic Ataxia
- Ocular apraxia
inability to perceive parts of a visual scene as a whole; Describe parts, but do not see how the parts make up a whole
Simultanagnosia
- can see windows, door, siding, but can’t determine its a house
impaired ability to reach for or point to objects in space under visual guidance
Optic Ataxia
impairment in directing gaze towards an object in periphery of visual field through saccades; difficulty orienting eyes toward something; difficulty orienting eyes toward stimulus (problems with visual map)
Ocular apraxia
What area of the brain is injured in Balint’s syndrome
Dorsolateral parieto-occipital cortex
What brain regions are involved in attention/ awareness?
- Brainstem reticular formation
- Thalamus
- Basal forebrain
- Cerebral cortex
What are the three types of memory?
- Emotional
- Declarative
- Procedural
Memory of feelings; Memory for fear is in the amygdala (temporal lobe); Brain regions not known for other emotions
Emotional Memory
Memory for facts, events, concepts and locations; Requires attention during recall
Declarative memory
AKA conscious, explicit, cognitive memory
What are the 3 stages of declarative memory?
- Immediate (sensory register)
- 1 to 2 seconds
- Memories can be easily displaced
- Primary sensory and sensory association cortex - Short-term memory
- Brief storage
- Begins to be lost in 1 minute if not rehearsed - Long-term memory
- Relatively permanent
- Consolidation (ST LT)
What is the pathway of declarative memory?
- Sensory association area
- Anterior Temporal Lobe (memory lobe)
- Parahippocampal Cortex –> Hippocampus
- Basal forebrain, including basal nucleus of Meynert
- Cerebral cortex
AKA Skill, habit, nonconscious memory, implicit memory; Requires practice; Task can be done without conscious thought
Procedural memory
What are the three stages of procedural memory?
- Cognitive
- Beginning stages
- Person thinks about what they are doing – cognitive
- Step-by-step performance of task - Associative
- Movements refined and more efficient
- Less dependent on cognition - Autonomous stage
- Movements are autonomous, do not require attention or conscious thought
- Other activities can be done at the same time
Where is procedural memory located?
- Frontal cortex
- Thalamus
- Basal ganglia
What results from injury to the non-dominant side of the brain?
- Sensory neglect (visual, tactile, auditory)
- Motor-intentional neglect
- Combination of sensory and motor neglect
- Conceptual neglect
- Difficulty in tasks requiring visual/spatial analysis or constructional abilities
- Can have relatively severe personality and emotional changes
What pathway from the visual association cortex determines where the thing is we’re looking at?
Dorsal pathways to parieto-occipital association cortex
What pathway from the visual association cortex determines what the thing is we’re looking at?
Ventral pathways to occipitotemporal association cortex
What injury results in prosopagnosia?
Bilateral injury to inferior occipitotemporal cortex
Condition where a person can describe, but cannot identify; Generic recognition is intact, specific recognition is impaired
Prosopagnosia
- person can recognize a man vs. woman, but can’t ID someone by face - can recognize by voice, clothing, other factors
- also extends to animals
Function of stream of visual analysis; processes color and visual information
Inferior occipitotemporal association cortex
Where does visual-spatial analysis occur?
Parietal association cortex (Junction of P,T, and O lobes)
- non dominant side (R) more involved than dominant (L)
