Week 3.9 - Encoding and Decoding Part I

Question 1

What is a receptive field?

Answer 1

For a given neuron, it is the part of the input (sensory, cognitive, motor) space that, when activated, can elicit/inhibit spikes.

Question 2

What is a tuning curve?

Answer 2

A tuning-curve shows the response of a neuron (in spike frequency) for some feature dimension of input (orientation of a bar, e.g.).

Question 3

What is transduction?

Answer 3

Transduction is the conversion of a physical source of energy (light, sound,touch,…) into spikes. Sensory receptor neurons convert a type of stimulus energy (e.g. photon, sound wave) into an electrical impulse that can be interpreted by the brain. So, transduction is the process by which some type of information is encoded into spikes.

Question 4

What is a topographic map?

Answer 4

A topographic map is a map of something that retains spatial relationshiops (neighborhoods). For example, the map of the sensory surface is topographical because the neighborhood in the skin is like the neigborhood in the somatosensory cortex.

Topographic is to be constrasted with topological map, where relationships are kept, but not necessarily spatial arrangement.

Sensation is topographically organised in the brain, meaning that neural activity appears as a map. For example, the neurons that respond to stimuli on your fingers are grouped and not randomly peppered throughout the brain.

Question 5

Sensation is ______ organised in the brain

Answer 5

topographically

Question 6

What are mirror neurons?

Answer 6

Neurons that fire both when an animal performs an action as well as when observing an action from someone else. These neurons “mirror” the behaviour of others, and seem important for understanding someone else’s intentions or have empathy.

Question 7

What is the pathway for interpreting sound?

Answer 7

Receptors > Spiral ganglion > brainstem and midbrain nuclei > Thalamus > Primary Auditory Cortex

Question 8

What are common shapes of tuning curves?

Answer 8

Most often tuning curves can look like gaussians or sigmoids.

Question 9

What is the pathway for most forms of sensory perception?

Answer 9

Receptors > Ganglia > Brainstem > Thalamus > Cortex