AP Psychology 1.6a/1.6b

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception

The process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful.

Bottom-Up Processing

Information processing that begins with the sensory receptors and works up to the brain's integration of sensory information.

Top-Down Processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Transduction

Conversion of one form of energy into another.

Absolute threshold

The minimum stimulus energy needed to detect a particular stimulus 50% of the time.

Just-noticeable difference

The minimum difference between two stimuli required for detection 50% of the time. Also called difference threshold.

Sensory adaptation

Diminished sensitivity as a consequence of constant stimulation.

Weber's law

The principal that, to be perceived as different, two stimuli must differ by a constant minimum percentage.

Wavelength

determines hue, the color we experience, such as a tulip's red petals or green leaves.

Retina

structure is on the back of the eye, contains the receptor rods and cones, and begins the processing of visual information

Blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

Visual nerve

carries the visual impulse out the back of the eye and into the brain for further processing.

Lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

Accommodation

the process by which the eye's lens changes shape to focus images of near or far objects on the retina.

Nearsightedness

a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina

Farsightedness

a condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina

Photoreceptors

respond to light, rods and cones

Rods

Retinal receptors that detect black, white, and gray

Cones (red, blue, green)

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

Trichromatic theory

The theory that the retina contains three different types of color receptors which can produce the perception of color.

Opponent-process theory

The theory that opposing retinal processes. enable color vision.

Afterimages

An effect that occurs when someone stares at an image for a while and then looks away.

Ganglion cells

The axons of these cells twine together to form the optic nerve.

Dichromatism

A form of colorblindness where a person only has two color receptors.

Monochromatism

A form of colorblindness where a person only has one color receptor.

Prosopagnosia

A condition where a person cannot recognize others by looking at their face.This answer is correct.