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