Functional Localization in Brains I: Topography Flashcards
Name scientific paradigms used for the localization of brain function.
- Lesion studies
- Neuroanatomical tracing
- Electrophysiology mapping
- Imaging
- Stimulation
What does this 3D homunculus tell you about the mapping of the motor and somatosensory cortices?
The homunculus visually displays how the motor and somatosensory cortices are mapped. The larger the body part in the diagram, the more of the cortex is dedicated to its movement or sense of touch.
- Note that*
- more of your brain is dedicated to the movement and feeling of your face and hands than to the rest of your body combined.
What is a retinotopic map?
Retinotopy means that spatially close patches of visual cortex respond to spatially close bits of visual input.
The primary visual cortex has a retinotopic structure.
What is a somatotopic map?
Maps are referred to as ‘somatotopic’ when cortical spaces are related to locations on the body, such that adjacent neurons in the neural tissue respond selectively to stimuli presented to adjacent locations on the body.
What is meant by divergence and convergence in the brain?
A group of neurons projects to a single neuron (convergence)
A single neuron projects to a group of neurons (divergence)
Name some of the methods of electrophysiological mapping.
EEG - electroencephalography
ECOG - electrocorticography
What is the goal of electrophysiological mapping?
To record from sites of the brain during stimulation or movement in order to map the responsiveness of specific regions.
Why does topography occur in the brain?
Topography occurs as a result of self-organization and genetic underpinnings of neuronal growth and migration.
Why is the “somatosensory homunculus” representation of body parts disproportionate to the body?
What takes up more space on the cortex needs more ‘resolution’ in perception.
What is the evolutionary underpinning of neuronal diversity in the brain?
Neuronal diversity follows the need. The goal is to solve the problems the neurons need to solve in the most efficient way.
Different types of neurons and receptors are perfectly made to solve the particular problems they encounter.
Injection of Pseudorabies virus, Herpes virus, and Cholera toxin into a neuron are methods of________
neuroanatomical tracing
How are horizontal cells involved in vision?
Horizontal cells are involved in lateral inhibition and underly on/off responses in the retinal ganglion cells.
