PSC 100: Visual Perception (Exam #1)

How is perception constructed?

Sensory filters based on our receptor types and system computations.

What is akinetopsia?

The inability to perceive motion (i.e. parked cars vs moving cars).

What is light?

A form of electromagnetic radiation that includes waves and a stream of photons.

In a stream of photons, one photon particle equals to…

One unit of light energy when light is absorbed.

In what sequence does light pass through the eye?

Light → cornea → lens → retina

In the retina, what are the two types of photoreceptors?

Rods and cones

Rods are ________ to low levels of light. Cones ________ in dim light.

sensitive/cannot function

Which has a higher acuity, rods or cones?

Cones

In terms of color, rods are color-_____ whereas cones are color-_____

blind/sensitive

In the fovea, is there rods or cones?

Cones. There is none in the periphery.

What is a wavelength?

The spatial distance between two consecutive positive (or negative) peaks. The lower the frequency, the longer the wavelength.

What is the visual pathway from the retina to V1 (visual cortex)?

Eye (retina) → Thalamus (LGN) → Optic Nerve → Occipital Lobe (V1)

What is Area V1?

The primary visual projection area, or primary visual cortex, which is located in the occipital lobe.

In the visual pathway from the retina to V1, what other features are included in the eye?

• Photoreceptors

• Bipolar cells

• Ganglion cells

What is lateral inhibition?

When cells are stimulated, they inhibit the activity of neighboring cells (Winner take all architecture).