Chapter 4: Sensation and perception Flashcards
Modalities
Sensory brain regions that process different components of the perceptual world.
Sensation
Simple awareness due to the stimulation of a sense organ.
Perception
The organization, identification and interpretation of a sensation in order to form a mental representation.
Transduction
What takes place when many sensors in the body convert physical signals from the environment into neural signals sent to the central nervous system.
Psychophysics
Methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus.
Absolute threshold
The minimal intensity needed to just barely detect a stimulus.
Just noticeable difference (JNB)
The minimal change in a stimulus that can just barely be detected.
Weber’s law
The just noticeable difference of a stimulus is a constant proportion despite variation in intensity.
Signal detection theory
An observation that the response to a stimulus depends on a person’s sensitivity to the stimulus in the presence of noise and on a person’s respons criterion.
D-prime (D’)
A statistic that gives a relatively pure measure of the observer’s sensitivity or ability to detect signals.
Sensory adaptation
Sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions.
Retina
Light-sensitive tissue lining the back of the eyeball.
Accommodation
The process by which the eye maintains a clear image of the retina.
Cones
Photoreceptors that detect colour, operate under normal daylight conditions and allow us to focus on fine detail.
Rods
Photoreceptors that become active only under low light conditions for night vision.
Fovea
An area of the retina where vision is the clearest and there are no rods at all.
Blind spot
An area of the retina that contains neither rods nor cones and therefore has no mechanism to sense light.
Receptive field
The region of the sensory surface that, when stimulated, causes a change in the firing rate of that neuron.
Trichromatic colour representation
The pattern of responding across the three types of cones that provides a unique code for each colour.
Area V1
The initial processing region of the primary visual cortex.
Topographic visual organization
Adjacent neurons process adjacent portions of the visual field.
Visual form agnosia
The inability to recognize objects by sight.
Binding problem
How features are linked together so that we see unified objects in our visual world rather than free-floating or miscombined features.
Illusory conjunction
A perceptual mitake where features from multiple objects are incorrectly combined.
Feature integration theory
A theory that proposes that attention binds individual features together to comprise a composite stimulus.
Synaesthesia
The perceptual experience of one sense that is evoked by another sense.
Modularization
The process of relatively encapsulated function
Perceptual constancy
A perceptual principle stating that even an aspect of sensory signals change, perception remains consistent.
Template
A mental representation that can be directly compared to a viewed shape in the retinal image.
Monocular depth cues
Aspects of a scene that yield information about depth when viewed with only one eye.
Binocular disparity
The difference in the retinal images of the two eyes that provides information about depth.
Motion parallax
A depth cue based on the movement of the head over time.
Apparent motion
The perception of movement as a result of alternating signals appearing in rapid succession in different locations.
Pitch
How high or low a sound is
Loudness
A sound’s intensity
Timbre
A listener’s experience of sound quality and resonance.
Cochlea
A fluid-filled tube that is the organ of auditory transduction.
Basilar membrane
A structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid.
Hair cells
Specialized auditory receptor neurons embedded in the basilar membrane.
Area A1
A portion of the temporal lobe that contains the primary auditory cortex.
Place code
The cochlea encodes different frequencies at different locations along the basilar membrane.
Temporal code
The cochlea registers low frequencies via the firing rate of action potentials entering the auditory nerve.
Visual orienting
A behavioral response to move the eyes towards a target.
Multisensory integration
The perceptual representation of events from more than one sensory modality.
Haptic perception
The active exploration of the environment by touching and gasping objects with our hands.
Referred pain
Feeling of pain when sensory information from internal and external areas converge on the same nerve cells in the spinal cord.
Gate-control theory
A theory of pain perception based on the idea that signals arriving from pain receptors in the body can be stopped, or gated, by interneurons in the spinal cord via feedback from two directions.
Vestibular system
The three fluid-filled semicircular channels and adjacent organs located next to the cochlea in each inner ear.
Olfactory receptor neurons (ORN)
Receptor cells that initiate the sense of smell.
Olfactory bulb
A brain structure located above the nasal cavity beneath the frontal lobes.
Pheromones
Biochemical odorants emitted by other members of their species that can affect an animal’s behavior or physiology.
Taste buds
The organ of taste transduction.
