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
Cones
Each cell is sensitive to wavelengths in blue, green, or red bands
Fovea
Small area in the center of the retina that contains a high density of cones but few rods
Foveation
Directing your gaze at something
Bottom-up processing
How our brain constructs perceptions by binding together primitive representations into complex object representations
Top-down processing
Refers to the ways in which existing knowledge, expectations, emotional states, arousal, attention can bias bottom-up signals get processed, and what representations they are assigned to
Law of similarity
Similar objects are grouped together
Law of proximity
Objects are grouped together based on their proximity to one another
Law of closure
We ted to fill in gaps in incomplete figures
Law of continuity
We link individual elements together in patters that make sense
