Chapter 3: sensation and perception

Question 1

What is transduction?

Answer 1

The process of converting outside stimuli, such as light, into neural activity.

Question 2

Levels of processing?

Answer 2

Bottom-up processing:
- data driven (something loud or from the outside environment).
Top-down processing:
- conceptual driven (how your expectations impact the level of attention and effort you give)
- can lead to visual illusions and perceptions being arbitrary.

Question 3

What is habituation and sensory adaptation?

Answer 3

Habituation:
- The tendency of the brain to stop attending to unchanging information.
Sensory adaptation:
- The tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging.

Question 4

Anatomy of the eye?

Answer 4

Pupil:
- where the light enters
Iris:
- coloured muscle that controls pupil and responds to light
Lense:
- focuses incoming light
Retina:
- tissue with photoreceptors
Optic nerve:
Transmits visual info from retina to the brain
Blind spot:
- (optic disc) Where the optic nerve leaves the eye (to the optic tract); there are no photoreceptor cells here
Cornea:
- Curved, transparent dome that bends incoming light waves so the image can be focused on retina

Question 5

Vision

Answer 5

Visual field:
- the whole area you can see without moving head or eyes.
Visual acuity:
- sharp in direct vision
- falls off towards periphery

Question 6

Photoreceptors within the retina?

Answer 6

Rods:
- visual sensory receptors found at the back of the retina (except fovea) responsible for non-color sensitivity to low levels of light.
Cones:
- visual sensory receptors found at the back of the retina (most concentrated in fovea (middle of retina) responsible for color vision and sharpness of vision.
- trichromatic theory (theory of color vision that proposes three types of cones red blue and green three colors theory.)
- opponent-process theory (theory of color vision that proposes visual neurons (or groups of neurons) are stimulated by light of one color and inhibited by light of another color.

Question 7

Visual agnosia?

Answer 7

• in the inferior temporal lobe.
  Prosopagnosia:
• visual agnosia specific to to facial recognition.

Question 8

How is pure sound described?

Answer 8

Amplitude:
- perceived as loudness, measured in decibels.
Frequency:
- measured in hertz.

Question 9

Outer ear?

Answer 9

• Pinna (auricle)
• ear canal (external auditory canal)
• ear drum (tympanic membrane)
  Major function:
• protect, amplification, sound localisation.

Question 10

Inner ear?

Answer 10

• structures convert sound into neural activity.

- mammals has fluid filled cochlea (contains hair cells)

Question 11

Seeing or hearing are both top down processes!

Answer 11

!

Question 12

Bodily senses: somatosensory cortex?

Answer 12

• laid out like a map
• cells arranged according to body surface.
• larger to sensitive regions.

Question 13

What pain do we feel first?

Answer 13

Sharp as these a delta fibres are covered in myelin sheath. Dull are c fibres.

Question 14

Congenital analgesia?

Answer 14

• no c fibres or a delta fibres.

- hereditary

Question 15

Gate control theory?

Answer 15

• involves activating other pain receptors to stop or dull pain.
• stimulates sensory input
• reduces perception of pain

Question 16

Taste and smell receptors can be replaced!

Answer 16

!

Question 17

Taste

Answer 17

• ta