Sensation

Translation of information from outside the nervous system into neural activity giving nervous system knowledge of the world

Transduction

what takes place when many sensors in the body convert physical signals (energy) from the environment into encoded neural (electrochemical) signals sent to the central nervous system.

Perception

Interpretation, identification and organization a sensation in order to form a mental representation that is meaningful

Absolute Threshold

minimal intensity (physical energy) needed to just barely detect a stimulus

Just Noticeable Difference (Difference
Threshold

Minimal change in a stimulus that can just barely be detected

Multitasking

Multitasking involves paying attention to more than one stimulus at the same time

Sensory Adaptation (Change vs Consistent Stimuli

Sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions.

Visual Acuity

Ability to see fine detail (it is the smallest line of letters that a typical person can read from a distance of 20 feet

20/20 Vision

perfect/normal vision

Light Wave (Wavelength)

Color is our perception of light wavelengths on the visible spectrum.

Cornea

transparent bulge on the front of eye; light enters here

Pupil

an opening in the iris; light passes through

Lens

elastic membrane capsule; thinner - focus on distant objects; thicker - focus on nearby objects.

Retina

Light-sensitive multilayered tissue lining the back of the eyeball (contains rods and cones)

Accommodation

Process by which the eye maintains
a clear image on the retina

Nearsightedness

see clearly what’s nearby, but distant objects are blurry because light from
them is focused in front of the
retina, a condition called myopia

Farsightedness

Distant objects are clear, but those objects nearby are blurry because their point of focus falls beyond the
surface of the retina a condition
called hyperopia.

Cones

Detect color, operate under normal daylight conditions, and allow us to focus on fine detail

Rods

Become active under low-light conditions for night vision

Fovea

a small depression within the neurosensory retina where visual acuity is the highest.

Blind Spot

Light sensitive receptor cells in the retinal surface excited by or inhibited by spots of light causes the optic nerve to develop a blindspot.

Primary Colors (Red, Green, Blue)

these 3 colors make up the entire color spectrum.

Color Deficiency

Color blindness (one or more cone types missing)

Ventral (What)

temporal lobe that allows us to perceive shape and identity.

Dorsal (Where)

to the parietal lobe that allows us to spatial relations.

Simplicity

When confronted with two or more
possible interpretations of an object’s, the visual systems tends to select the simplest or most likely interpretation

Closure

We tend to fill in missing elements of a
visual scene

Continuity

When edges or contours have same
we tend to group together edges or contours that have the same orientation

Similarity

Regions that a similar in shape, color, or texture are perceived as belonging to the same object.

Proximity

Things that are close together tend to be grouped together

Common Fate

Elements of a visual image that move
together are perceived as part of a single moving
object.

Figure-Ground

a human's ability to visually differentiate between an object and its background.