Higher Cortical Functions & Cognitive / Behavioral Manifestations of Brain Disorders, Part 2 Flashcards
What are 7 examples of higher-order functions?
Language
Memory
Executive Functions
Perception
Spatial Behaviour
Attention
Skilled Movement
What are the 3 main division areas of the frontal lobe?
Motor,
Premotor
Prefrontal areas
Which areas of the frontal lobe are associated with executive functions?
Prefrontal areas (i.e., dorsolateral & orbitofrontal) associated with “executive functions”
What are executive functions?
Refers to “control systems that implement different behavioral strategies in response to both external and internal cues”
What does executive functions include?
An extensive variety of functions
What would be unlikely to occur from frontal damage?
Unlikely to produce impairment to all functions
Summary of Major symptoms of frontal lobe damage.
What are 3 FL symptom examples?
- Impaired social behavior and changes in personality
- Loss of behavioral spontaneity (decreased verbal fluency, loss of initiative, apathy)
- Poor strategy formation, loss of response inhibition & perseveration (Wisconsin Card Sorting Task)
What does the Phineas Gage show from FL symptoms?
- Impaired social behavior and changes in personality
What does this image show from FL symptoms?
Loss of behavioral spontaneity (decreased verbal fluency, loss of initiative, apathy)
What does this image show from FL symptoms? (2)
- Wisconsin Card Sorting Task
- Poor strategy formation, loss of response inhibition & perseveration
What examples of conditions from direct FL lesions? (3)
Direct FL lesions (e.g., TBI, stroke, degenerative conditions)
What examples of conditions from lesions to subcortical areas that project to FL ? (4)
Lesions to subcortical areas that project to FL (e.g., stroke, PD, HD, Korsakoff’s)
What is perception?
Refers to cognition resulting from the activity of the various sensory regions of the cortex beyond the primary sensory cortex
Which areas between primary/secondary/tertiary perform perceptual functions?
Secondary Areas
What is agnosia? (3)
- Refers to partial or complete inability to recognize sensory stimuli
- Typically affect a single sensory system (e.g., vision, audition, tactile)
- Not explained by a defect in primary sensory processes or reduced alertness
What are examples of visual associate agnosia? (3)
- Difficulty recognizing objects visually despite intact vision (i.e., shape, size, colour of objects are seen)
- Patients are able to describe visual features, copy and match objects
- May affect selected class of items (e.g., face agnosia = prosopagnosia)
Damage to which lobes causvisual associative agnosia? (2)
- Usually results from occipital and/or posterior temporal damage, often bilateral
What is auditory agnosia?
Difficulty recognizing sounds (i.e., hearing intact but unable to process what sounds mean)
What are the three subtypes of auditory agnosia?
- Linguistic type (aka pure word deafness)
- Non-verbal type
- Amusia
Describe the linguistic type of auditory agnosia. (2)
- Difficulty recognizing spoken words but reading comprehension & speech production are intact
- Results often from L temporal lesions (may disconnect auditory input & Wernicke’s area)
Describe the Non-verbal type of auditory agnosia. (2)
- Difficulty recognizing environmental sounds
- Results often from RH or bilateral temporal lesions
Describe the amusia type of auditory agnosia. (2)
Difficulty understanding music (e.g., pitch, rhythm)
Traditionally thought to follow right temporal lesions but actually depends on what specific aspect of music is impaired
What are spatial behaviors?
All behaviours with which we guide our bodies through space
What is topographic memory?
Ability to move from one place to another from memory
What is cognitive maps?
Mental representations of space
Which hemisphere plays a special role?
Right-hemisphere
Rh damage result in…
Spatial impairments
What is attention?
Refers to processes that either allow a selective awareness of an aspect of the sensory environment or allow selective responsiveness to one class of stimuli
Attention is related to…
to executive functions
Attention may be specific to…
sensory modality
Attention involves which neural networks? (5)
Brainstem (RAS)
Sensory regions
Parietal,
Cingulate
Prefrontal cortex
Can attention be affected by neurological disorders? If yes, explain: (3)
- Yes, especially TBI
- Deficits are typically bilateral
- Deficit that is especially severe on one side of space = hemi-inattention or sensory neglect
What is sensory neglect?
Characterized by a failure to report, or respond, or attend to, stimuli on the side of body opposite to lesion, despite adequate sensory and motor function
In which modality does sensory neglect may manifest?
May manifest in any modality (i.e., visual, auditory, somatosensory)
Sensory neglect is often accompanied by:
anosoagnosia
What is anosoagnosia?
Symptom of severe mental illness experienced by some that impairs a person’s ability to understand and perceive his or her illness
Sensory Neglect results from damage to:
Usually results from right parietal damage, causing left-sided neglect
What is the difference between Hemianopia and Neglect?
- Hemianopia is a visual field defect (i.e., primary sensory disorder)
- Neglect is an attentional disorder
What are the sequences in the cortex for movement?
What is apraxia?
Disorder of skilled movement not caused by muscle weakness or other primary motor disturbance (target movements can be carried out in some contexts)
What does apraxia involves?
Involves “high-level” motor functions (e.g., difficulties with goals, plans, sequences)
What is ideomotor apraxia? (2)
- Difficulty performing actions on command or imitating actions
- May be able to perform action spontaneously in actual situation (e.g., with object)
Ideomotor Apraxia often results from lesions to…
Left hemisphere lesions
Ideomotor Apraxia often accompanies which disorder?
Aphasia
What is ideational Apraxia?
Difficulty undertaking a series of movements involving some ideational or planning component (e.g., pretending to use a hammer)
What can we see from patients suffering from ideational apraxia? (2)
- Individual steps may be performed
- Objects often used inappropriately
Examples:
Person tries to light a candle by striking a match on it
Person tries to open a can of soup by hitting the can with the can opener
Ideational Apraxia results from lesions to:
Often results from diffuse bilateral lesions (e.g., in AD)
What is apraxia of speech? (4)
- Difficulty coordinating motor sequences of sounds
- Usually results from LH lesions
- Often accompanied by Broca’s aphasia
- Often accompanied by other apraxias
