Sensation & Perception

Psychophysics

The study of how physical stimuli are translated into psychological experience (the study of sensation and perception)

Sensation

the passive process by which sensor receptors and the nervous system receives and represents stimulus energy from our environment.

Perception

The brain’s process of organizing and interpreting sensory information to give it meaning.

Bottom-Up processing

analysis that begins with the sensory receptors and works up to the rain’s integration of sensory info (think using the parts to get the whole)

Top-Down processing

info processing that is guided by higher-level thinking, influenced by our experiences and expectations (think using the whole to understand)

absorb, brain, organizes

sensation: Sense organs _____ energy, sense receptors converts the energy into a neural impulse and send it to the ______. Perception: brain _______ and translates it to give it meaning.

Transduction

is the conversion of one form of energy into another. In sensation, the transformation of stimulus energies (light, sound, chemical, mechanical) into neural impulses to send to the brain.

Selective Attention

picking up and choosing among all various available inputs. your senses take in 11,000,000 bits of info per second, we consciously only process about 40.

Cocktail Party effect

your ability to attend to only one voice among many

inattentional blindness

failing to see visible objects when our attention is directed elsewhere.

Change blindness

failing to notice changes in the environment

Absolute Threshold

The weakest level of a stimulus that can be correctly detected at least half of the time (the dividing line between what has detectable energy and what dos not).

Subliminal messages

receiving of messages that are below one’s absolute threshold for conscious awareness

Difference threshold (Just Noticeable Difference, JND)

the minimum difference that a person can detect between two stimuli (at least half of the time).

Weber’s Law (Fechner-Weber’s Law)

The principle that, to perceive a difference, two stimuli must differ by a constant minimum percentage. The change needed is proportional to the stimulus - the larger the stimulus, the larger the change needed to detect JND.

Sensory Adaptation

one becomes less sensitive to a stimulus with the passing of time.

Prosopagnosia

the condition where people have face ‘blindness’ due to damage of fusiform gyrus (part of the right temporal lobe)

Synesthesia

a condition in which one sense is simultaneously perceived as if by one or more additional senses. Another form joins objects such as letters, shapes, numbers or people’s names with a sensory perception such as small, color or flavor.