Paul - Function of Topographic Brain Maps

Question 1

Define a receptive field and provide examples.

Answer 1

Receptive field: Area of sensory stimulation that affects a neuron’s response.
* Example: Zone of tactile sensitivity on skin
* Key principle: Smaller receptive field = Higher spatial resolution

Question 2

Explain the organization of topographic brain maps

Answer 2

In a brain map darker = more blood = more neural activity.
The somato-sensory cortex is the area of the brain used in touch pathways. The neurons in it are arranged by body part input and the cortical size area is correlated with innervation density and sensory actuity.
Primary somatosensory cortex - (Spatial representation of touch-sensitivity: Somatotopy)

Question 3

Describe the plasticity of topographic maps

Answer 3

Sensory deprivation triggers cortical remapping - like if a finger is cut off (that part of the brain shrinks and neurons from neighbouring fingers take its place) or glued together (area of the brain is the same size but neurons get mixed up and overlap).
Finger use correlates with cortical map size and after using one finger more than the rest then the map for that finger can increase in size (like reading braille).
Repetitive synchronous movement of fingers can merge cortical finger map (and cause focal hand dystonia)

Question 4

Analyze the functions of topographic brain maps in neural processing and behaviour

Answer 4

Efficient information processing:
* Reduces neural wiring costs
* Minimizes signal transmission delays
* Optimizes use of cortical space
Preserves spatial relationships:
* Enables accurate localization of stimuli
* Supports coherent perception of the environment
* Facilitates coordinated motor responses
Facilitates local computations:
* Allows rapid comparison of adjacent inputs
* Enhances feature detection and discrimination
* Supports integration of related information