PSY Perception Chapter 1

Transduction

Converting physical energy into neural signals

Vestibular System

Helps perceive balance, movement, acceleration, and physical orientation

Introspection

Sensing information from inside the body

Absolute Threshold

Minimal stimulus needed for detection

Difference Threshold

Minimum difference between two stimuli that can be detected

Scaling

Measures perceived intensity, differences between people, and changes across a stimulus range

Signal Detection Theory

Sometimes perception requires a question. Performance depends on sensitivity and decision criterion.

The Time Course of Perception

Stimulus begins>Perception>Response

Researchers can measure, accuracy, reaction time, and the effects of stimulus duration

Sensory Neuroscience

Researchers can study sensory receptors, individual neurons, brain regions, and patterns of brain activity

Computational Models

Sensory input>Processing>Representation>Perception

Can describe how info is processed, make quantitative predictions, incorporate prior experiences, and be tested against human behavior.

Gustav Fetchner

Asked: Can subjective experience be measured scientifically? His goal was to connect physical energy to sensation. Basically: Physical World>Sensory stimulation>Mental experience.

Psychophysics

The quantitative study of the relationship between physical events and mental experiences

Absolute Threshold

Minimum intensity of a stimulus that can be detected

Ex: Hearing Test!

Method of Constant Stimuli

Goal: Estimate the intensity detected at a specific percentage of the time. Multiple trials are needed because perception is variable. The more trials, the better the estimate.

Method of Adjustment

The participant controls the stimulus intensity. Task: Adjust the stimulus until it is just detectable

Ernst Weber & the JND

How much must a stimulus change before we notice? The JND depends on the starting intensity.

Weber’s Law

The JND is a constant proportion of the original stimulus.

Δi/I=K

Δi= just noticeable difference

I= original stimulus intensity

K= constant proportion