week 1

Question 1

What are motor invariants and how do they manifest in human movements?

Answer 1

Motor invariants refer to the highly stereotyped patterns in eye and arm movements. Humans tend to follow a specific path (the sequence of spatial positions) and maintain a characteristic velocity profile when executing these movements

Question 2

Describe the neuromuscular junction and its functional significance

Answer 2

The neuromuscular junction is the connection between the brain and muscles where an axon terminal sends signals to activate a muscle. It features a convoluted surface that increases the available receptors for neurotransmitter binding, facilitating effective muscle activation.

Question 3

What role does the retina play in vision?

Answer 3

The retina contains cells sensitive to light and color. These cells convert visual stimuli into signals that form the optic nerve, which then passes information to higher visual centers for reconstruction of the visual scene.

Question 4

Explain why the strawberries in the illusion appear red even though the overall image is cyan

Answer 4

The brain performs a white balance correction by subtracting the pervasive cyan tint from the scene. Since red is the complementary color to cyan, the strawberries are perceived as red

Question 5

Why is compression important in the visual system?

Answer 5

Compression reduces the vast amount of information and energy needed to process a static scene by transmitting only the important, changing information rather than redundant, unchanging details

Question 6

How do simultaneous contrast illusions influence color perception

Answer 6

These illusions occur when the appearance of horizontal bars is altered by the background colors. The surrounding colors affect the target color’s perception via processes like lateral inhibition

Question 7

What is lateral inhibition and why is it beneficial for sensory processing?

Answer 7

Lateral inhibition is a process where an excited cell reduces the activity of its neighboring cells, enhancing the contrast between different signals. This mechanism improves the localization and clarity of visual or tactile stimuli

Question 8

How does temporal inhibition differ from lateral inhibition?

Answer 8

Temporal inhibition suppresses cells that remain active for extended periods, adapting slowly over time, whereas lateral inhibition is a rapid spatial process that enhances contrast between neighboring cells

Question 9

How do neurons encode the intensity of a stimulus?

Answer 9

Neurons use a rate code where the firing frequency indicates the stimulus intensity. Typically, this involves comparing the contrast between two levels of stimulation

Question 10

What is sensory adaptation and why is it useful?

Answer 10

Sensory adaptation allows neurons to adjust their sensitivity to a wide range of input intensities, emphasizing changes over constant stimulation. This process compensates for the limited dynamic range of individual neurons

Question 11

Describe how the Craik-O’Brien-Cornsweet illusion demonstrates the brain’s filling-in process

Answer 11

In the illusion, the brain completes the image by using information from active central photoreceptors at the boundary and spreading it to neighboring areas, creating a complete perception even if not all the corresponding cells are activated