Sensation and Perception

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Sensory Adaptation

The diminished sensitivity to a constant stimulus over time, allowing our senses to focus on changes in the environment.

Sensory Deprivation

The condition in which an individual is deprived of sensory input, often leading to alterations in perception and cognitive functioning.

bottom-up processing

Starting with the sensory input, the brain attempts to understand/make sense.

top-down processing

Guided by experience and higher-level processes, we see what we expect to see.

selective attention

Our tendency to focus on just a particular stimulus among the many that are being received. Allows us to prioritize information, filter out distractions and enhance relevant stimuli.

selective inattention

The failure to notice a stimulus because attention is focused on another stimulus, often leading to missing important details.

Psychophysics

The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation

absolute threshold

The minimum intensity of a stimulus that can be detected 50% of the time.

difference threshold

The minimum difference between two stimuli required for detection 50% of the time. (JND)

Weber’s law

To be able to tell the difference between degrees of stimulation, two stimuli must differ by a constant minimum percentage.

subliminal stimuli

stimuli that are below the absolute threshold (50%) of conscious awareness, yet can still influence thoughts and behaviors.

priming

The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.

gestalt psychology

organized whole perceived as more than sum of parts

proximity grouping

objects close together are viewed together visually

similarity grouping

items that share attributes are visually grouped together

continuity grouping

a line will always appear to continue traveling the same way

connectedness grouping

elements visually connected are perceived as single unit

closure grouping

brain’s ability to fill gaps/make sense of image

figure ground

figure: main object of focus

ground: background that supports figure

perceptual constancy

perception of object as constant even though sensation changes

shape/size constancy

shape/size perception constant despite changes

color constancy

color perception same despite various lighting changes

perceptual sets

mental predisposition to perceive things a certain way - schema (pattern)

depth perception

interpret visual cues (how far/close)

binocular cues

cues on distances, based on retinal disparity

retinal disparity

left/right eyes view slightly different images

monocular cues

perceive depth using one eye

relative size

further = higher

relative size

equal size means further is smaller looking

interposition

see two overlapping objects in one line of vision

light/shadow

dimension with depth/perception