Higher Order Cortical Functions - Left and Right Hemisphere Flashcards
In general, language functions are lateralized to the __ hemisphere
Left
The left hemisphere is better at
Linguistic processing
Local processing
The right hemisphere is better at
Paralinguistic processing
Facial recognition
Visuospatial processing
Global processing
What are split brain studies?
Studies that are performed on people that had the hemispheres split at corpus callosum to look at functions of the hemispheres
Split brain is typically done to treat epilepsy
Visual information presented to the left visual field goes to the ____ hemisphere
Right
Same for tactile information
What do split brain studies reveal about L/R brain function?
Lateralized nature of brain function
Verbal processing of information in the left visual field is hard to verbalize because the information cannot cross over to the right side of the brain for lang production
How were hemispheric differences originally identified?
Experimental tasks
What are dichotic listening tasks?
Different words are presented to both ears simultaneously
Expect the right ear to have an advantage because that will project information to the left hemisphere which is better at processing verbal information
Majority of auditory information is distributed to the ____ hemisphere
Contralateral
What experimental tasks have a left ear advantage?
Identifying song/tune
What experimental tasks have a right ear advantage?
Identifying letters, words
Both hemispheres process local and global information but differ in ___
efficiency
Left hemisphere is faster processing ____ while right hemisphere is faster at processing ____
Left: local
Right: global
Patients with left hemisphere lesions are slower at IDing ___ targets while those with right hemisphere lesions are slower at IDing ___ targets
Left lesion: local targets
Right lesion: global targets
Left hemisphere damage leads to
Aphasia
Associated with L MCA strokes
Left hemisphere damage effect on language
Impairment of language comprehension and production that affects all modalities of language (listening, speaking, reading, writing)
What is anomia?
From left hemisphere damage
Difficulty retrieving word
What is apraxia?
Difficulty sequencing motor movements (motor planning/programming problem)
Right hemisphere disorders can be heterogeneous. What does this mean?
Don’t always display all the characteristics
Right hemisphere disorders causes
Prosopagnosia: Difficulty IDing faces
Difficulty expressing (flat affect)
Prosodic deficit: montone, lack of prosody, miss differences from different stress (suprasegmental information)
Discourse deficits from right hemisphere disorder
Egocentric, verbose (using more words than needed), confabulate (trying to make sense of things)
Difficulty with turn taking
Comprehension deficits with right hemisphere disorder
Inferencing deficits (focus on details, no big picture)
Difficulty with sarcasm, idioms, literal interpretations
Difficulty with figurative language
What is hemispatial neglect?
Occurs with right hemisphere disorder
Difficulty attending to objects, people, body parts on contralateral side
Called left neglect
Where does damage typically occur with hemispatial neglect?
Right paretial-temporal-occipital area
What is egocentric hemineglect?
Related to own body
What is allocentric hemineglect?
External to the person, representation of things outside them
Does hemispatial neglect tend to recover?
Yes it tends to recover with time, not everyone recovers though
What are constructional impairments?
Neglect left side when copying drawings
Turn 3D to 2D, crowd objects/letters, displace to right of page
What is anosognosia?
Impaired awareness of deficits or how those deficits impact daily functioning
Inability to recognize that they have a problem
What is the frontal lobe responsible for? When does it mature?
Restraint, Initiative, Order
20s
What are the three surfaces of the frontal lobe?
Lateral
Medial
Orbitofrontal
What is the lateral frontal lobe responsible for?
Movement
What areas are part of the lateral frontal lobe?
Primary motor cortex
Premotor cortex
Supplementary motor cortex
Frontal eye fields
The corticospinal system projects to
Medial and superior portion of precentral gyrus
The corticonuclear system projects to
Lateral portion of precentral gyrus
What is the function of the frontal eye fields?
Sends signals for eye movements
Saccades
Flow of motor movement planning and sequences
Posterior cortex provides sensory information to frontal
Prefrontal cortex plans movements
Premotor cortex organizes movement sequences
Motor cortex produces specific movements
If a movement is relatively simple, the ____ and ___ cortex execute the action
Motor
If planning is required, the ____ cortices are involved
Prefrontal
More concentration for movement leads to ___ areas of the brain being activated for planning and execution
More
What areas are a part of the lateral frontal lobe?
Anything anterior to the motor areas
What are the functions of the lateral frontal lobe- prefrontal cortex?
Planning and problem solving
Attention
Keeping track (WM) and organizing
Emotional control
Social cognition
What are the causes of prefrontal cortex deficits?
Trauma, stroke, hydrocephalus, meningiomas, gliomas, infectious disorders, demyelinating disorder, degenerative diseases, psychological disorders, developmental disorders
What is the orbitofrontal cortex responsible for?
Impulse control
Maintenance of a goal
Monitoring ongoing and socially appropriate behaviors
Evaluating emotional experiences
Comparing expected reward/punishment with actual reward/punishment
Orbitofrontal damage leads to
Poor decision making
Impulsivity and disinhibition
Perseveration
Socially inappropriate/tactless
Impaired insight, empathy, and remorse
The medial frontal cortex contains
Cingulate gyrus
Micturition
What is the function of the anterior cingulate gyrus?
Part of limbic system
Connects emotional and cognitive, motivated attention
What is the function fo the posterior cingulate gyrus?
Motivated movement
What is the function of the micturition?
Sends signals to brainstem that the bladder is full
What happens with medial cortex damage?
Psychiatric: depression, OCD, schizophrenia
Apathy: loss of motivation and reduced goal-directed activities
Akinetic mutism: don’t speak, no motivation for anything, apathetic
