Unit 3 - Sensation and Perception Flashcards
Sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
Perception
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
Bottom-Up Processing
Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information. Ex. Stubbing toes on a chair.
Top-Down Processing
Information processing guided by higher-level mental processes, as when we construct perception drawing on our experience and expectations. Ex. Interpreting an image’s meaning
Selective Attention/Cocktail Party Effect
The focusing of conscious awareness on a particular stimulus.
Inattentional Blindness
Failing to see visible objects when our attention is directed elsewhere.
Change Blindness
Failing to notice changes in the environment.
Transduction
Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
Absolute Threshold
The minimum stimulation needed to detect a particular stimulus 50% of the time.
Signal Detection Theory
A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes that there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness.
Subliminal Threshold
When stimuli are below one’s absolute threshold for conscious awareness. Ex. dog whistle
Priming
The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.
Difference Threshold/Just Noticeable Difference (JND)
The minimum difference between two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference.
Weber’s Law
The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).
Figure and Ground
The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Phi Phenomenon
An illusion of movement created when two or more adjacent lights turn on and off in quick succession.
Perceptual Constancy
Perceiving objects as unchanging (having consistent shapes, size, brightness, and color) even as illumination and retinal images change.
Color Constancy
Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.
Perceptual Adaption
In vision, the ability to adjust to an artificially displaced or even inverted visual field.
Visual Cliff
A laboratory device for testing depth perception in infants and young animals.
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.
Monocular Cues
Depth cues, such as interposition and linear perspective, available to either eye alone.
Binocular Cues
Depth cues, such as retinal disparity, that depend on the use of two eyes.
Retinal Disparity
A binocular cue for perceiving depth: By comparing images from the retinas in the two eyes, the brain computes distance- the greater the disparity (difference) between the two images, the closer the object.
Convergence
Allows us to perceive distance; eye move inward and outward.
Gestalt
An organized whole, Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.
Grouping
The perceptual tendency to organize stimuli into coherent groups.
Proximity
A type of grouping tendency where we group nearby figures together.
Continuity
A type of grouping tendency where we perceive smooth, continuous patterns rather than discontinuous ones.
Closure
A type of grouping tendency where we fill in gaps to create a complete, whole object.
Motion Perception
Objects traveling towards us (appear to) grow in size and those moving away (appear to) shrink in size.
Motion Parallax
A depth cue whereby objects closer to us seem to move at a faster pace than those that are farther away.
Relative Size
Perceive the one that casts a smaller retinal image to be farther away.
Interposition
Closer objects block distant objects.
Relative Clarity
Hazy objects are perceived to be more distant.
Texture Gradient
Indistinct texture signals have increased distance.
Relative Height
We perceive objects that are higher in our field of vision to be farther away.
Linear Perspective
Parallel lines appear to converge in the distance; perceived distance.
Sensory Adaptation
Diminished sensitivity as a consequence of constant stimulation.
Perceptual Set
A mental predisposition to perceive one thing and not another.
Schemas
Concepts that organize and interpret unfamiliar information (mental file cabinet); built upon from the moment we are born.
Context Effects
Context can drastically alter perception.
ESP
The controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition.
Parapsychology
The study of paranormal phenomena, including ESP and psychokinesis.
Psychophysics
The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.
Relative Brightness
The closer the object is, the brighter it will be.
