Perception, Thresholds and Receptor Processes

Sensation

stimulation of sense organs

Perception

The act of becoming aware through the senses

Psychophysics

The study of how physical stimuli are translated into psychological experience

.Absolute Threshold

the weakest amount of a stimulus that a person can detect half the time

Gustav Fechner

early German psychologist credited with founding psychophysics, absolute threshold

Detection Thresholds

the smallest amount of sound, pressure, taste, or other stimuli that an individual can detect

Signal Detection Theory

theory regarding how stimuli are detected under different conditions

Discrimination Threshold

the ability to distinguish the difference between two stimuli

Hit

signal presented and participant detects it

Miss

PA fails to detect it

False Alarm

PA detects a signal that was not presented

.Correct Rejection

Signal not detected and PA does not detect it

.just noticeable difference (JND)

the minimal change in a stimulus that can just barely be detected

Ernest Weber

Concluded that he difference threshold is a constant fraction ot proportion of the specific stimulus

Webers Law

to be perceived as different, two stimuli must differ by a constant minimum percentage

Subliminal Perception

the processing of information by sensory systems without conscious awareness

Priming

the activation, often unconsciously, of particular associations in memory

Tip of the tongue phenomenon

the temporary inability to remember something you know, accompanied by a feeling that it's just out of reach

Receptor cells

Specialized cells in every sensory system of the body that can turn other kinds of energy into action potentials (neural impulses) that the brain can process

.Receptive Field

the stimulus region and features that affect the activity of a cell in a sensory system

Transduction

conversion of one form of energy into another

Contralateral Shift

neural impulse goes to the thalamus, which sends it to the appropriate brain area

Cornea

the clear, dome-shaped outer layer of the eye that allows light to enter and helps the eye focus