Sensation and Perception Flashcards
Sensation
The stimulus-detection process by which our sens organs respond to and translate environmental stimuli into nerve impulses (transduction) that are sent to the brain
Perception
- Making ‘sense’ of what our senses tell us
- This is the active process of organizing and identifying the stimulus and giving it meaning
Psychophysics
Scientific field relating the physical characteristics of stimuli to sensory capabilities
Stimulus
Refers to any physical entity that transfers energy to sensory organs
e.g. light waves (vision), sound waves (hearing), airborne particles (smell), dissolved particles (taste), physical force (touch), temperature (pain)
Absolute threshold
The lowest stimulus intensity at which a stimulus can be detected 50% of the time
Psychometric function
Express sensory capability as a function of stimulus intensity
Intra-individual variability
Sensivity can fluctuate within an individual
Influenced by fatigue, expectation, significanc, of stimulus
Inter-individual variability
Individuals can have different decision criteria: how certain they need to feel before reporting that they detect a stimulus
JND
Just Noticable Difference
The difference that can be discriminated 50% of the time
Corea
Where the light enters the eye
Pupil
Adjustable aperture that controls the amount of light entering the eye
Iris
The pigmented region surrounding the pupil
Lens
An elastic structure that becomes thinner to focus on distant objects and thicker to focus on near objects
Sensory cells retina
Cells are called photoreceptors:
1) Rods
2) Cones
Rods
Largely color insensitive, but more sensitive to lower intensities of light
