(4) Sensation and Perception Flashcards
Sensation
the process of detecting external events with sense organs and turning those stimuli into neural signals
Perception
involves attending to, organizing, and interpreting stimuli that we sense
Transduction
when specialized receptors transform the physical energy of the outside world into neural impulses
Doctrine of specific nerve energies
first proposed in 1826 by the German physiologist Johannes Muller, the doctrine states that the different senses are separated In the brain
Sensory Adaptation
the reduction of activity in sensory receptors with repeated exposure to a stimulus
Psychophysics
the field of study that explores how physical energy such as light and sound and their intensity relate to psychological experience
Absolute Threshold
the minimum amount of energy or quantity of a stimulus required for it to be reliably detected at least 50% of the time it is presented
Difference Threshold
the smallest difference between stimuli that can be reliably detected at least 50% of the time
Weber’s Law
states that the just noticeable difference between two stimuli changes as a proportion of those stimuli
Signal Detection Theory
Whether a stimulus is perceived depends on both the sensory experience and the judgment made by the subject
Subliminal Perception
perception below the threshold of conscious awareness
Priming
which previous exposure to a stimulus can influence that individual’s later responses, either to the same stimulus or to one that is related to it
Top-down Processing
when our perceptions are influenced by our expectations or by our prior knowledge
Bottom-up Processing
occurs when we perceive individual bits of sensory information (e.g. sounds) and use them to construct a more complex perception (e.g. a message)
Perceptual Set
a filter that influences what aspects of a scene we perceive or pay attention to
Divided Attention
paying attention to more than one stimulus or task at the same time
Selective Attention
involves focusing on one particular event or task
Inattentional Blindness
a failure to notice clearly visible events or objects because attention is directed elsewhere
Sclera
the white, outer surface of the eye
Cornea
the clear layer that covers the front portion of the eye and also contributes to the eye’s ability to focus
Pupil
regulates the amount of light that enters the eye by changing its size; it dilates (expands) to allow more light to enter and constricts (shrinks) to allow less light into the eye
Lens
a clear structure that focuses light onto the back of the eye
Retina
lines the inner surface of the eye and consists of specialized receptors that absorb light and send signals related to the properties of light to the brain
Optic Nerve
a dense bundle of fibres that connect to the brain
Rods
are photoreceptors that occupy peripheral regions of the retina; they are highly sensitive under low light levels
Cones
photoreceptors that are sensitive to the different wavelengths of light that we perceive as colour
Fovea
the central region of the retina
Dark Adaptation
the process by which the rods and cones become increasingly sensitive to light under low levels of illumination
Trichromatic Theory
(young-helmholtz theory) maintains that colour vision is determined by three different cone types that are sensitive to short, medium, and long wavelengths of light
Opponent-process Theory
a theory of colour perception stating that we perceive colour in terms of opposing pairs; red to green, yellow to blue, and white to black
Optic Chiasm
the point at which the optic nerves cross at the midline of the brain
Feature Detection Cells
a set of cells in the visual cortex that respond selectively to simple and specific aspects of a stimulus, such as angles and edges
Ventral Stream
a neural circuit for vision that extends from the visual cortex to the lower part of the temporal lobe
Dorsal Stream
a neural circuit for vision that extends from the visual cortex to the parietal lobe
Prosopagnosia
an inability to recognize faces or face blindness
Perceptual Constancy
the ability to perceive objects as having constant shape, size, and colour despite changes in perspective
Binocular Depth Cues
distance cues that are based on the differing perspectives of both eyes
Convergence
occurs when the eye muscles contract so that both eyes focus on a single object
Retinal Disparity
(binocular disparity) the difference in relative position of an object as seen by both eyes, which provides information to the brain about depth
Monocular cues
Depth cues that we can perceive with only one eye
Pitch
the perceptual experience of sound wave frequencies
Cochlea
a fluid-filled membrane that is coiled in a snail-like shape and contains the structures that convert sound into neural impulses
Sound Localization
the process of identifying where sound comes from
Place Theory of Hearing
how we perceive pitch is based on the location (place) along the basilar membrane that sound stimulates
Frequency Theory
the perception of pitch is released to the frequency at which the basilar membrane vibrates
Primary Auditory Cortex
a major perceptual centre of the brain involved in perceiving what we hear
Vestibular System
a sensory system in the ear that provides information about spatial orientation of the head as well as head motion
Vestibular Sacs
structures that influence your ability to detect when your head is no longer in an upright position
Semicircular Canals
three fluid-filled canals found in the inner ear that respond when the head moves in different directions (up-down, left-right, forward-backward)
Haptics
the active, exploratory aspect of touch sensation and perception
Kinesthesis
the sense of bodily motion and position
Nociception
the activity of nerve pathways that respond to uncomfortable stimulation
Gate-control Theory
explains our experience of pain as an interaction between nerves that transmit pain messages and those that inhibit these messages
Phantom Limb Sensations
frequently experienced by amputees, who report pain and other sensations coming from the absent limb
Gustatory system
functions the sensation and perception of taste
Olfactory System
involved in smell—the detection of airborne particles with specialized receptors located in the nose
Olfactory Epithelium
a thin layer of cells that are lined by sensory receptors called cilia
Olfactory Bulb
a structure on the bottom surface of the frontal lobes that serves as the brain’s central region for processing smells
Multimodal Integration
the ability to combine sensation from different modalities such as vision and hearing into a single integrated perception
Autonomous Sensory Meridian Response
(ASMR) a phenomenon in which specific auditory or visual stimuli trigger tingling sensations in the scalp and neck, sometimes extending across the back and shoulders
