Psyc 1100 Week 5: Sensation and Perception

Flashcards for Psyc 1100 Week 5: Sensation and Perception

Sensation

Stimulation of a sense organ; occurs in the body.

Perception

Organization, identification, and interpretation of a sensation in order to form a mental expression; occurs in the brain.

Transduction

Process in which sensory receptors convert physical signals from the environment into neural signals that are sent to the central nervous system.

Sensory Adaptation

Process where sensitivity to prolonged stimulation declines over time as organism adapts to current conditions.

Psychophysics

Methods that systematically relate the physical characteristics of a stimulus to an observer's perception.

Absolute Threshold

Minimum intensity needed to just barely detect a stimulus in 50% of trials.

Just Noticeable Difference (JND)

Minimum change in a stimulus that can just barely be detected.

Weber's Law

For every sensory domain, the change in a stimulus that is just noticeable is a constant ratio of the standard stimulus over a range of standard intensities.

Signal Detection Theory

Way of analyzing data from psychophysics experiments that measures an individual's perceptual sensitivity while also taking noise, expectations, motivations, and goals into account.

Retina

Layer of light-sensitive tissue lining back of eyeball.

Accommodation

Process by which eye maintains a clear image on the retina.

Cone cells

Detect colour, focus on fine detail; operate in normal light conditions.

Rod cells

Operate in low-light conditions, allow night vision.

Opponent-Process Theory

Pairs of cones work in opposition, vision treats pairs of colours as opposites.

Fovea

Area in retina where vision clearest, no rods, lots of cones.

Blind spot

Location in visual field that produces no sensation on retina.

Area V1

Primary visual processing area.

Ventral Stream (the "What" pathway)

Represents shape and identity of object.

Dorsal Stream (the "Where" pathway)

Identify location of object and how it is moving; also plays a role in guiding actions (reaching/tracking with eyes/etc).

The Binding Problem

How brain links features together so we see unified objects in our vision rather than free-floating features.

Illusory Conjunction

Perceptual mistake where brain incorrectly combines features from multiple objects.

Feature Integration Theory

Argues focus not required to detect individual features of a stimulus, but is needed to bind those individual features together in perception; attention as "glue" that binds features together.

Perceptual Organization

Process of grouping and segregating features to create whole objects organized in meaningful ways.

Simplicity

Visual system tends to select simplest interpretation of stimuli.

Closure

Tend to fill in missing elements of visual scene, perceive edges that are interrupted as complete objects.

Continuity

Edge/contours with same orientation tend to be grouped together perceptually.

Similarity

Regions of similar colour/texture/lightness/shape perceived as belonging to same object.

Proximity

Objects close together tend to be grouped together.

Common Fate

Elements of visual image that move together perceived as parts of a single moving object.

Familiar Size

How big is object usually vs how big does it appear now?

Linear Perspective

Parallel lines seem to converge as they recede into distance.

Texture Gradient

Textures more detailed the closer they are.

Interposition

When one object blocks view of another.

Relative Height in Image

Higher objects usually further away.

Binocular Disparity (aka Retinal Disparity)

Difference in the retinal images of the two eyes.

Sound waves

Changes in air pressure over time.

Area A1

Primary auditory cortex in the brain.

Conductive Hearing Loss

Eardrum or ossicles damaged, no longer fully functional.

Sensorineural Hearing Loss

Cochlea, hair cells (cilia), or auditory nerve damaged and no longer fully functional.

Haptic Perception

Active exploration of environment through touching/grasping objects with hands.

Tactile Receptive Field

Small patch of skin that relates information about pain, pressure, texture, patterns, or vibrations to a specific receptor.

Proprioception

Sense of bodily position.

Vestibular System

Three fluid- filled semicircular canals and adjacent organs located next to cochlea.

Olfactory Bulb

Brain structure located above nasal cavity, beneathe frontal lobe.

Pheromones

Biochemical odourants emitted by other members of a species that can affect the behaviour or physiology of an animal.