Psychology 1000-001

Chapter 5-Sensation & Perception

Sensory receptor cells

Specialized neurons to convert (sensory transduction) specific stimuli into neural impulses.

Sensation

The act using our sensory systems to detect enviornmental stimuli

Transduction

Transformation of physical energy into electrical signals

Psychophysics

The study of the effects of physical stimuli on sensory perceptions and mental state (Gustav Fechner)

Absolute threshold

Smallest amount of stimulus that one can detect

Signal detection analysis

Technique to determine the ability to separate true signals from background noise

Sensitivity

True ability to detect presence or absence of signal

Response bias

Behavioural bias to respond yes

Weber’s law (Ernst Weber 1795-1878)

JND is constant proportion of original intensity

Absolute threshold

The point where we become aware of a faint stimulus

Subliminal stimuli

Events that occur below the absolute threshold; not consciously aware of

Karremans & Colleagues (2006)

1. Dutch college students viewed a series of trials where a string of letters were presented on the screen

2. Students were asked to note whether the strings contained a small b

3. Before each letter string, researchers quickly presented either the name of a popular drink in Holland or a control string containing the same letters

4. Trappey’s (1996) meta-analyses of 23 studies suggests otherwise

Perception

The conscious recognition and identification of a sensory stimulus, involves both bottom-up and top-down processing

Bottom-up processing

Outside-in, sensory information from environment driving the process of understanding

Top-down processing

Inside-out, knowledge and expectancy driving the process of understanding

Sensation adaptation

A process whereby repeated stimulation of a sensory cell leads to reduced response

Inattentional blindness

Failure to notice something obvious because you were focused on something else