PSY100 - Ch 5 Sensation and perception

agnosia

neurological disorder characterized by an inability to recognize and identify objects or persons using one or more of the senses

sensation

The process of detecting environmental stimuli or stimuli arising from the body

perception

The process of interpreting sensory information

psychophysics

The study of relationships between the physical qualities of stimuli and the subjective responses they produce

signal detection theory

The analysis of sensory and decision-making processes in the detection of faint, uncertain stimuli

absolute threshold

The smallest amount of stimulus that can be detected

difference threshold

The smallest detectable difference between two stimuli

sensory adaptation

The tendency to pay less attention to a nonchanging source of stimulation

audition

The sense of hearing

binocular cue

A depth cue that requires the use of both eyes

bottom-up processing

Perception based on building simple input into more complex perceptions

top-down processing

A perceptual process in which memory and other cognitive processes are required for interpreting incoming sensory information

cochlea

The structure in the inner ear that contains auditory receptors

cones

A photoreceptor in the retina that processes colour and fine detail

cornea

The clear surface at the front of the eye that begins the process of directing light to the retina

depth perception

The ability to use the two-dimensional image projected on the retina to perceive three dimensions

difference threshold

The smallest detectable difference between two stimuli

fovea

An area of the retina that is specialized for highly detailed vision

somatosensory homunculus

a map along the cerebral cortex of where each part of the body is processed

mechanoreceptors

a type of somatosensory receptors which relay extracellular stimulus to intracellular signal transduction through mechanically gated ion channels

nocireceptors

pain receptors activated by damaged stimuli

gate control theory

The theory that suggests that input from touch fibres competes with input from pain receptors, possibly preventing pain messages from reaching the brain

gustation

The sense of taste

gestalt principles

similarity, continuation, closure, proximity, figure/ground, and symmetry & order

iris

The brightly coloured circular muscle surrounding the pupil of the eye

lens

The clear structure behind the pupil that bends light toward the retina

monocular cue

A depth cue that requires the use of only one eye

motion parallax

objects that are farther away seem to move more slowly than objects that are closer

olfaction

The sense of smell

olfactory bulb

One of two structures below the frontal lobes of the brain that receive input from the olfactory receptors in the nose

olfactory nerve

A nerve carrying olfactory information from the olfactory receptors to the olfactory bulbs

opponent process theory

A theory of colour vision that suggests we have a red-green colour channel and a blue-yellow colour channel in which activation of one colour in each pair inhibits the other colour

optic nerve

The nerve exiting the retina of the eye

pupil

An opening formed by the iris

retina

Layers of visual processing cells in the back of the eye

retinal disparity

The difference between the images projected onto each eye

rod

A photoreceptor specialized to detect dim light

taste bud

A structure found in papillae that contains taste receptor cells

transduction

The translation of incoming sensory information into neural signals

trichromatic theory

A theory of colour vision based on the existence of different types of cones for the detection of short, medium, and long wavelengths

vestibular system

The system in the inner ear that provides information about body position and movement

synesthesia

A condition where the stimulation of one sensory pathway leads to the simultaneous and automatic stimulation of another sensory pathway

temporal pathway (ventral stream)

The “what” visual pathway that extends from the occipital lobe into the temporal lobe

parietal pathway (dorsal stream)

The “where” visual pathway that extends from the occipital lobe into the parietal lobe

split brain

patients in whom the corpus callosum has been cut for the alleviation of medically intractable epilepsy

contralateral organization

the arrangement whereby the motor cortex of each cerebral hemisphere is mainly responsible for control of movements of the contralateral (opposite) side of the body

figure ground relationship

whatever isn’t the focus of visual field is automatically assigned as background

illusory contours

tendency to perceive contours even when they don’t exist

interpreter

left hemisphere process that attempts to make sense out of events

fusiform face area

area of the brain that becomes particularly active when people look at faces