Perceptions ID Terms

Definitions from AMSCO Book

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Difference threshold

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

Just Noticeable Difference (JND)

The minimum difference between two stimuli required for detection 50% of the time. (same thing as difference threshold.)

Weber’s Law

The principle that, to be perceived as different, two stimuli must differ by a constant percentage (rather than a constant amount).  

Absolute thresholds

The minimum stimulation needed to detect a particular stimulus 50% of the time. Our lowest levels of awareness of faint stimuli with no competing stimuli present.

Subliminal perception

Perception of a stimulus below the threshold for conscious perception.

Signal Detection theory

Your ability or likelihood to detect some stimulus is affected by the intensity of the stimulus (e.g., how loud a noise is) and your physical and psychological state (e.g., how alert you are).

Top-down processing

We form perceptions (or focus our attention) by starting with the larger concept or idea (it can even be the concept or idea of an object) and then working our way down to the finer details of that concept or idea. The use of pre-existing knowledge to organize individual features into a unified whole.

Bottom-up processing

(also known as Feature Analysis); Information processing that starts by noticing individual elements and then zooms out to appreciate the whole picture. Begins with sensory inputs and works up to mentally organizing them into a whole.

Deductive reasoning

An approach to logical thinking that begins with a general idea, such as a hypothesis, and then develops specific evidence to support or refute it.

Inductive reasoning

An approach to logical thinking that begins with specific details or observations and forms broad perceptions or generalizations based on them.

Feature detectors

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

Divided attention

Focusing on two or more tasks or stimuli.

Selective attention

The process of directing our awareness to relevant stimuli while ignoring irrelevant stimuli.

Cocktail Party effect

The ability to focus your hearing on one specific thing even though noise is all around you.

Stroop Effect

Our brains recognize the color of the word first, which interferes with our ability to read the word aloud.

Selective inattention

The expression “you hear what you want to hear” describes this; The screening out of unwanted stimuli because it causes anxiety or feels threatening or because it is thought to be of no importance.

Inattentional blindness

Failing to see visible objects when our attention is directed elsewhere.  

Change blindness

 A type of inattentional blindness; the inability to see changes in our environment when our attention is directed elsewhere.

Perceptual adaptation

The ability of the body (and brain) to adapt to an environment and filter out distractions.

Sensory adaptation

Diminished sensitivity as a consequence of constant stimulation.

Habituation

Occurs when we stop having an interest in a stimulus or lack attention to it; decreasing response to a stimulus with repeated exposure to it.

Gestalt

A movement/school of thought in psychology founded in Germany in 1912, seeking to explain perceptions in terms of gestalts (or an organized whole) rather than by analyzing their constituents (or individual parts).

Figure-ground pattern

The figure is what is focused on and the ground is the blurry background which is likely ignored.

Grouping

Elements that are grouped together within the same region of space tend to be grouped together; Gestalt psychologists posited that our brains have a tendency to organize stimuli into groups.

Proximity principle

Things that are near each other seem to be grouped together.

Similarity principle

Similar things tend to appear grouped together (both visual and auditory stimuli).

Continuity principle

Points that are connected by straight or curving lines are seen in a way that follows the smoothest path.

Closure principle

Things are grouped together if they seem to complete some entity.

Connectedness principle

Things that are physically connected by lines or other linking features are perceived as a single, unified group rather than as separate individual parts.

Depth perception

The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

Visual cliff

A laboratory device for testing depth perception in infants and young animals. Used by Eleanor Gibson and Richard Walk to determine whether crawling infants could perceive depth.

Binocular cues

(We use BOTH of our eyes) that help us to judge distance.

Convergence

A binocular cue when looking at a close-up object, your eyes angle inwards towards each other (you become slightly cross-eyed).

Monocular cues

(Depth perception that requires only ONE eye; more limited but still possible) that help use judge distance.

Linear perspective

A monocular cue that when parallel lines appear to converge at a vanishing point on the horizon. The closer the lines are, the greater the distance.

Interposition

A monocular cue when the partial blocking of one object by another object, leaving the viewer with the perspective that the blocking object is closer. 

Relative size

A monocular cue that if two objects are roughly the same size, the object that looks the largest will be judged as being the closest to the observer. 

Relative height

A monocular cue when we perceive objects higher in our field of vision as farther away.

Relative clarity

A monocular cue when clear objects appear closer than blurry or fuzzy objects. The further something is from us, the less detail it conveys.

Light and Shadow

A monocular cue when nearby objects reflect more light to our eyes than distant ones. If there are two identical objects, the dimmer one seems farther away.

Texture gradient

A monocular cue when you're looking at an object that extends into the distance, such as a grassy field, the texture becomes less and less apparent the farther it goes into the distance.

Motion parallax

Objects closer to use appear to move faster than those farther away.

Stroboscopic movement/phi phenomenon

An illusion of movement created when two or more adjacent lights blink on and off in quick succession, like Christmas lights.

Relative motion

As we move, objects that are actually stable may appear to move.

Perceptual constancy

Our ability and need to perceive objects as unchanging even as changes may occur in distance, point of view, and illumination. Our brain makes adjustments and interpretations without our awareness to perceive the objects as the same, because otherwise our world view would not make sense.

Color constancy

Perception that the color of an object remains the same even if lighting conditions change

Size constancy

The tendency to interpret an object as always being the same actual size, regardless of its distance.

Unconscious inference

The brain’s automatic process of interpreting sensory information based on prior knowledge and contextual cues, allowing us to perceive objects accurately despite changes in their appearance.

Shape constancy

When our viewing angle changes or an object rotates and we still perceive the object as staying the same shape.

Lightness constancy

When our perception of the whiteness, blackness, and grayness of objects remains constant no matter how much the illumination has changed (we see a constant proportion of lightness)

Muller-Lyer Illusion

An optical illusion where two lines of equal length appear to be different in length due to the orientation of the arrow-like protrusions at their ends.

Ponzo illusion

An optical illusion where people perceive the top gray line as wider than the bottom gray line, even though they are the same size.

Moon illusion

An optical illusion in which the moon appears to be larger when it is on or near the horizon than when it is high in the sky.

Perceptual set

A mental predisposition to perceive or notice some aspects of the available sensory data and ignore others.

Schemas

Mental filters or maps that organize our information about the world (also associated with Piaget and Development)

Parapsychology

The study of paranormal phenomena.

Extrasensory perception (ESP)

The ability to perceive information about the outside world without using the known senses.

Telepathy

The idea that one person can perceive or communicate with another person's thoughts without using physical signals or sensory channels.

Clairvoyance (ESP)

talking to dead people

Precognition (ESP)

The ability to predict future events

Psychokinesis

The ability to move or change the state of a physical object using only the mind.