Chpt. 4 - Sensation and Perception

Absolute Threshold

The amount of stimulation necessary for a stimulus to be detected. In practice, this means that the presence or absence of a stimuli is detected correctly half the time over many trials

Afterimages

Sensations that linger after the stimulus is removed. Most visual ___ are negative ___, which appear in reversed colors

Ambiguous Figures

Images that are capable of more than one interpretation. There is no "right" way to see an ___ ___

Amplitude

The physical strength of a wave. This is usually measured from peak (top) to valley (bottom) on a graph of the wave

Basilar Membrane

A thin strip of tissue sensitive to vibrations in the cochlea. The ___ ___ contains hair cells connected to neurons. When a sound wave causes the hair cells to vibrate, the associated neurons become excited. As a result, the sound waves are converted (transduced) into nerve activity

Binding Problem

Refers to the process used by the brain to combine (or "bind") the results of many sensory operations into a single percept. This occurs, for example, when sensations of color, shape, boundary, and texture are combined to produce the percept of a person's face. No one knows exactly how the brain does this. Thus the ___ ___ is one of the major unsolved mysteries in psychology

Binocular Cues

Information taken in by both eyes that aids in depth perception, including binocular convergence and retinal disparity

Blind Spot

The point where the optic nerve exits the eye and where there are no photoreceptors. Any stimulus that falls on this area cannot be seen

Bottom - Up Processing

Perceptual analysis that emphasizes characteristics of the stimulus, rather than our concepts and expectations. "Bottom" refers to the stimulus, which occurs at step one of perceptual processing

Brightness

A psychological sensation caused by the intensity of light waves

Closure

The Gestalt principle that identifies the tendency to fill in gaps in figures and to see incomplete figures as complete

Cochlea

The primary organ of hearing; a coiled tube in the inner ear, where sound waves are transduced into nerve messages

Color

Also called hue. ___ is not a property of things in the external world. Rather it is a psychological sensation created in the brain from information obtained by the eyes from the wavelengths of visible light

Color Blindness

Typically a genetic disorder (although sometimes a result of trauma) that prevents an individual from discriminating certain colors. The most common from is red - green ___ ___

Conduction Deafness

An inability to hear resulting from damage to structures of the middle or inner ear

Cones

Photo-receptors in the retina that are especially sensitive to color but not to dim light. You may have guessed that the ___ are cone shaped

Difference Threshold

The smallest amount by which a stimulus can be changed and the difference be detected half the time

Electromagnetic Spectrum

The entire range of electromagnetic energy, including radio waves, X rays, microwaves, and visible light

Feature Detectors

Cells in the cortex that specialize in extracting certain features of a stimulus

Fechner's Law

The magnitude of a stimulus can be estimated by the formula S=k log R, where S= sensation, R = stimulus, and k = a constant that differs for each sensory modality (sight, touch, temperature)

Figure

The part of a pattern that commands attention. The ___ stands out against the ground

Fovea

The tiny area of sharpest vision in the retina

Frequency

The number of cycles completed by a wave in a given amount of time, usually a second

Gate - Control Theory

An explanation for pain control that proposes we have a neural "gate" that can, under some circumstances, block incoming pain signals

Gestalt Psychology

From a German word that means "whole" or "form" or "configuration." The ___ psychologists believed that much of perception is shaped by innate factors built into the brain

Ground

The part of a pattern that does not command attention; the background

Gustation

The sense of taste - from the same word root as "gusto' - also called the gustatory sense

Illusion

You have experienced an ___ when you have demonstrably incorrect perception of a stimulus pattern, especially one that also fools others who are observing the same stimulus

Just Noticeable Difference (JND)

Also known as the difference threshold

Kinesthetic Sense

The sense of body position and movement of body parts relative to each other

Law of Common Fate

The Gestalt principle that we tend to group similar objects together that share a common motion or destination

Law of Continuity

The Gestalt principle that we prefer perceptions of connected and continuous figures to disconnected and disjointed ones

Law of Pragnanz

The most general Gestalt principle, which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure. Our perceptual system prefers to see a fully developed Gestalt, such as a complete circle - as opposed to a broken circle

Law of Proximity

The Gestalt principle that we tend to group objects together when they are near each other

Law of Similarity

The Gestalt principle that we tend to group similar objects together in our perceptions

Laws of Perceptual Grouping

The Gestalt principles of similarity, proximity, continuity, and common fate. These "laws" suggest how our brains prefer to group stimulus elements together to form a percept

Learning - Based Inference

The view that perception is primarily shaped by learning (or experience,) rather than by innate factors

Loudness

A sensory characteristic of sound produced by the amplitude (intensity) of the sound wave

Monocular Cues

Information about depth that relies on the input of just one eye - includes relative size, light and shadow, interposition, relative motion, and atmospheric perspective

Nerve Deafness (Sensorineural Deafness)

An inability to hear, linked to a deficit in the body's ability to transmit impulses from the cochlea to the brain, usually involving the auditory nerve or higher auditory processing centers

Olfaction

The sense of smell

Opponent - Process Theory

The idea that cells in the visual system process colors in complementary pairs, such as red or green or as yellow or blue. This explains color sensation from the bipolar cells onward in the visual system

Optic Nerve

The bundle of neurons that carries visual information from the retina to the brain

Percept

The meaningful product of perception - often an image that has been associated with concepts, memories of events, emotions, and motives

Perception

A process that makes sensory patterns meaningful. it is ___ that makes these words meaningful, rather than just a string of visual patterns. To make this happen, ___ draws heavily on memory, motivation, emotion, and other psychological processes

Perceptual Constancy

The ability to recognize the same object as remaining "constant" under different conditions, such as change in illumination, distance, or location

Perceptual Set

Readiness to detect a particular stimulus in a given context - as when a person who is afraid interprets an unfamiliar sound in the night as a threat

Pheromones

Chemical signals released by organisms to communicate with other members of their species

Photoreceptors

Light - sensitive cells (neurons) in the retina that convert light energy to neutral impulses. The ___ are as far as light gets into the visual system

Pitch

A sensory characteristic of sound produced by the frequency of the sound wave

Placebo Effect

A response to a placebo (a fake drug) caused by subject's belief that they are taking real drugs

Retina

The thin, light sensitive layer at the back of the eyeball. The ___ contains millions of photoreceptors and other nerve cells

Rods

Photoreceptors in the retina that are especially sensitive to dim light but not to colors. Strange as it may seem, they are rod-shaped

Sensation

The process by which stimulation of a sensory receptor produces neural impulses that the brain interprets as a sound, a visual image, an odor, a taste, a pain, or other sensory image. ___ represents the first series of steps in processing incoming information

Sensory Adaptation

Loss of responsiveness in receptor cells after stimulation has remained unchanged for a while, as when a swimmer becomes adapted to the temperature of the water

Signal Detection Theory

Explains how we detect "signals," consisting of stimulation affecting our eyes, ears, nose, skin, and other sense organs. ___ ___ ___ says that sensation is a judgment the sensory system makes about incoming stimulation. Often, it occurs outside of the consciousness. This also takes observer characteristics into account

Skin Senses

Sensory systems for processing touch, warmth, cold, texture and pain

Steven's Power Law

A law of magnitude estimation that is more accurate than Fechner's law and covers a wider variety of stimuli

Timbre

the quality of a sound wave that derives from the wave's complexity (combination of pure tones.) ___ comes from the Greek word for "drum" as does the term tympanic membrane or eardrum

Top - Down Processing

Perceptual analysis that emphasizes the perceiver's expectations, concept memories, and other cognitive factors, rather than being driven by the characteristics of the stimulus. "Top" refers to a mental set in the brain - which stands at the "top" of the perceptual processing system

Transduction

Transformation of one form of energy into another - especially the transformation of stimulus information into nerve signals by the sense organs. Without ___, ripe tomatoes would not appear red

Trichromatic Theory

The idea that colors are sensed by three different types of cones sensitive to light in the red, blue and green wavelengths. The ___ ___ explains the earliest stage of color sensation

Tympanic membrane

The eardrum

Vestibular Sense

The sense of body orientation with respect to gravity. The ___ ___ is closely associated with the inner ear, and in fact, is carried to the brain on a branch of the auditory nerve

Visible Spectrum

The tiny part of the electromagnetic spectrum to which our eyes are sensitive

Weber's Law

This concept says that the size of a just noticeable difference (JND) is proportional to the intensity of the stimulus; the JND is larger when the stimulus intensity is high and is small when the stimulus intensity is low