PSYC1101 - PERCEPTION

How do we see light?

brain turning some light waves intro neutral signal

what range of wavelength in nanometres can we see and what is it called?

400-700nm

White light

PHOTORECEPTORS

convert light wave energy into neutral signal (to the brain)

Rods

cells in the photoreceptor layer that work in good lighting and are sensitive to fine detail and colour. Usually found in the periphery

Cones

cells in the photoreceptor layer that work in dim lightning and are sensitive to movement but not fine detail or colour. Predominantly found in the fovea

What cell in the photoreceptor layer would mostly be in use when you want to pee at night and its dark?

Cones

Where is our blind spot?

Near the nose, which is why our brain can see the nose but chooses to ignore it

JUDGING POSITION: distance

ability to judge depth begins in infancy (visual cliff)

monocular depth cues

if you shut one eye it is harder to determine close/far something is

JUDGING POSITION: occlusion

depth cues, If one object covers part of another object, we assume the covering object is in front.

Relative Height

we look at the horizon, which is why then left image looks 3D because we know that above, looks further away, that's how the horizon works, SAME APPLIES TO LIGHT, further away is less clear

Binocular Depth cues (3D

our two eyes have slightly different views of the world

Sound

pressure waves in air, water or some other medium

Frequency

the number of sound waves, or cycles, per second

Amplitude

the vertical size of the sound waves

Decibels (dB)

a measure of the physical pressures that occur at the eardrum

STEPS TO HEARING: 1

Soundwave pressure distorts the eardrum

STEPS TO HEARING: 2

the soundwave pressure causes physical movement in a small bone set

STEPS TO HEARING: 3

bones push on the cochlear, causing fluid inside to move

STEPS TO HEARING: 4

The movement of fluid in the cochlear bends hair cells and this triggers the neuronal signal

Frequency theory

we sense sound frequency depending on the fluid movement

Place theory

we sense sound frequency according to the locations of fluid activity in the cochlear

Localising sound: how do we locate sound?

Sound will be perceived first and loudest by the closest ear

how are the ears used for balance?

Key mechanisms of the vestibular system also lie in the ear

The semi-circular canals lie along distinct planes

Fluid movement creates neural signals that signal movement

Gustation

Taste buds on tongue react to chemical compounds in food

What does gustation also work often with?

Smell because they are both chemical sense as they process the chemicals in substances

Olfaction

smell by processing odours, which are air borne chemicals

How to smell: 1

chemicals bind to receptor cells (hair) in the nasal passage

How to smell: 2

Each receptor will only bind to specific chemicals (substrate and enzyme)

How to smell: 3

Smells are processed by Olfactory cortex, which activate the amygdala

TOUCH (RECEPTORS)

embedded in outer layer (epidermis) and underlying layer (dermis) of skin

types of touch receptors

- pain

- pressure

- temperature

Kinaesthetic receptors

mechanoreceptors in muscles, tendons and joints

important sense of where our limbs are and our movements

Homonculus

map-like representation of regions of the body in the brain (big lips)