PSYC 1010 Lecture Notes - Detection Theory, Psychophysics, Retina
Sensation: The process whereby our sensory organs gather information from the outside world.
Perception: The process whereby the brain interprets and organizes these sensations.
The study of how physical stimuli are translated into psychological experience.
Absolute Threshold: The point at which a person can detect the lowest intensity of light 50% of
Difference Threshold (jnd): Is the smallest difference in stimulation required to discriminate 1
stimulus from another, 50% of the time.
People are able to perceive very small changes if the magnitude of reference stimulus is small,
but as that magnitude increases, a greater change is necessary before one can perceive a
Signal Detection Theory
Proposes that the detection of stimuli is based on:
1. The actual intensity of the stimulus
3. Decision-process or response-criterion
3 Types of Perceptual Organization
1. Depth & Distance Perception
- Binocular Cues
- Monocular Cues
2. Form Perception
3. Perceptual Constancies
Binocular Cues Result from 2 Processes
1. Convergence: Eyes move more inward as an object gets close.
2. Retinal Disparity: A slightly different view of object falls on each retina.
Cues can be registered by each eye independently
Form Perception (Gestalt)
How stimuli are organized into meaningful patterns and shapes.
We perceive familiar objects as being of a fixed size even if the size of the retinal image changes when
our distance from the object changes.
The registration of sensory input without conscious awareness.