Cerebral Asymmetry & Plasticity Flashcards
Left hemisphere (LH) is important for: (2)
– Production and comprehension of language
– Controlling movement on right side of body
Right hemisphere (RH) is important for: (2)
– Perceiving and synthesizing nonverbal information
– Controlling movement on left side of body
What is meant by the fact that laterality is relative and not absolute?
– Both hemispheres participate in almost every
behaviour
Give an example of how site is as important as side on the brain.
For example, R and L frontal lobes more similar than R frontal and R occipital
Give examples to show that individual variability could show how the brain is asymmetrical. (2)
– E.g., cerebral organization may be more asymmetrical
in right-handers and males
– E.g., RH is “dominant” for language in some people
What are physical differences of the RH and the LH? (2)
- Right hemisphere (RH) is slightly larger and
heavier than left hemisphere (LH), - There is more gray matter in LH
What are the physical differences between Planum temporale (Wernicke’s area in LH) and Heschl’s gyrus (primary auditory cx)?
Planum temporale (Wernicke’s area in LH) is larger in LH, but Heschl’s gyrus (primary auditory cx) is larger in RH
What is special about the visibility of the Frontal operculum (Broca’s area in LH)?
It is organized differently, with more visible cortex in RH and more hidden cortex in LH
What is special about the neurons in Broca’s area (LOP)?
The neurons in this area tend to have more dendritic branches because Broca’s area is doing a lot more language processing in the left hemisphere/
What can we say about the distribution of neurotransmitters between hemispheres?
The distribution is asymmetrical
Is the visual system symmetrical?
No, asymmetrical
What are the Tachistocscopic findings related to our perception of our right and left visual fields? (3)
- Shows asymmetry in the visual system
- RVF advantage for verbal material (e.g., letters, words)
- LVF advantage for visual-spatial material (e.g., 2-D point localization, dot and form enumeration, matching of slanted lines, depth perception, faces)
Is the auditory system symmetrical?
No, bilateral dichotic, and it is contralaterally dominant
How do dichotic listening findings show that the auditory system is asymmetric? (2)
- R ear advantage for verbal material (e.g., words, digits, backward speech) (left hemisphere)
- L ear advantage for nonverbal material (e.g., music, tones, environmental sounds) (Right Hemisphere)
What are common deficits after lateralized lesions in the LH? (2)
- Language (esp. production & syntax)
- Verbal memory
What are common deficits after lateralized lesions in the RH? (3)
- Some linguistic functions (e.g., prosody, pragmatics, high-level comprehension)
- Visual memory and spatial abilities
- Some music components (e.g., temporal aspects)
Explain handedness differences anatomical asymmetry between people who are right and left handed. (2)
- More L-handers than R-handers show no anatomical asymmetry or reversal of asymmetry
- More L-handers than R-handers have RH or bilateral representation of language
Prosody is more dominant in which hemisphere?
Right Hemisphere based
What is considered the dominant vs. the non-dominant hemisphere? (2)
- Dominant hemisphere” = hemisphere that contains language
- “Non-dominant hemisphere” = hemisphere that does not contain language
What are tasks favoring women? (5)
What are tasks favoring women? (5)
What are tasks favoring men? (5)
What is neural plasticity?
Ability of brain to change as a result of experience
What are characteristics of neural plasticity? (2)
- Changes are structural (e.g., organization & size of different areas & circuits) and chemical (e.g., distribution & amount of neurotransmitters).
- Networks are strengthened &/or weakened.
When does neural plasticity occur? (2)
Occurs especially in development and after injury
The extent of anatomical asymmetry may be greater in___________ than____________
males than females
Corpus callosum may be larger in ______________ than __________
females than males
Females & males may (on average) have different cognitive strengths:
(F > M in some verbal, STM, perceptual detail tasks; M > F in some visual-spatial & mathematical tasks)
What are effects of Environment on Brain Development of a child in the evidence of plasticity?
The fact that severely neglected children may develop behavioral and cognitive abnormalities
What are effects of environment on brain development of early exposure in the evidence of plasticity?
Exposure early in life increases brain size and connectivity (esp. occipital cortex)
Explain perceptual specialization in humans related to plasticity. (2)
- Systems become specialized for types of stimuli they are exposed to but at the cost of losing ability to process less frequently perceived stimuli types
- Speech and face perception
Explain the recovery of the brain after damage. (3)
- Some recovery of function typically occurs (depends on function)
- Amount of recovery is very variable
- Nature and mechanism of such recovery is poorly understood
What are characteristics of recovery? (3)
- Return of function is usually gradual with slow re-emergence of skills
- Rate of impairment-based recovery typically declines over time
- Rate of functional- and participation-based recovery?
What are variables that may affect recovery on average? (6)
- Lesion size (smaller > larger)
- Age (younger > older)
- Sex (females > males)
- Handedness (LH > RH)
= Cognitive skills/Intelligence (high > low) - Personality/Motivation
