Synaesthesia- The perceptual experience of one sense that is evoked by another sense.
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.
Just Noticeable Difference (JND)-The minimal change in a stimulus that can just barely
Weber’s Law-The JND of a stimulus is a constant property despite variations in intensity.
Signal Detection Theory-An observation that the response to a stimulus depends both
on a person’s sensitivity to the stimulus in the presence of noise and on a person’s
Sensory Adaptation-Sensitivity to prolonged stimulation tends to decline over time as an
organism adapts to certain conditions.
Visual Acuity-The ability to see fine detail.
Retina-Light sensitive tissue lining the back of the eyeball.
Accommodation-The process by which the eye maintains a clear image on the retina.
Cones-Photoreceptors that detect color, 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
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 Color Representation-The pattern of responding across the three types of
cones that provides a unique code for each color.
Color-Opponent System-Pairs of visual neurons that work in opposition.
Area V1-The part of the occipital lobe that contains the primary visual cortex.
Visual-Form Agnosia-The inability to recognize objects by sight.
Perceptual Constancy-A perceptual principle stating that even as aspects 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 or 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
Temporal Code-The cochlea registers low frequencies via the firing rate of action
entering the auditory nerve. Haptic Perception-The active exploration of the environment by touching and grasping
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 canals and adjacent organs located
next to the cochlea in each inner ear.
Olfactory Receptor Neurons (ORNS)-Receptor cells that initiate the sense of smell.
Olfactory Bulb-A brain structure located above the nasal cavity beneath the frontal
Pheromones-Biochemical odorants emitted by other membranes of their species that
can affect an animal’s behaviour or physiology.
Taste buds-The organ of taste transduction. Summary for Chapter 4:
The Doorway to Psychology:
Sensation and perception are separate events that, from the vantage point of the
perceiver, feel like one single process. Sensation is simple awareness due to the
stimulation of a sense organ, whereas perception is a brain activity that
organizes, identifies, and interprets a sensation in order to form a mental
Transduction is the process that converts physical energy in the world into neural
signals in the central nervous system. All senses rely on transduction, although
the types of energy being sensed differ (e.g., light waves for vision, sound waves
Psychophysics was a field of study during the mid- to late- 1800s that sought to
understand the link between properties of a physical stimulus and people’s
psychological reactions to them.
Psychophysics researches developed the idea of an absolute threshold, the
minimal intensity needed to just barely detect a stimulus, and the difference
threshold, the minimal change in a stimulus that can just barely be detected. The
difference threshold is also referred to as the just noticeable difference (JND).
Signal detection theory represents a refinement of these basic approaches and
takes into account a perceived hit, miss, false alarm, and correct rejection rates.
Sensory adaptation occurs when sensitivity to prolonged stimulation tends to
decline over time as an organism adapts to current conditions. This adaptive
process illustrates that the perceptual system is more sensitive to changes in
stimulation than to constant levels of stimulation.
Vision: More Than Meets the Eye:
Vision takes place when light waves are transduced by cells in the eye. Light
waves have the properties of length, amplitude, and purity. These physical
properties are perceived as color, brightness, and saturation, respectively.
Light enters the eye through the cornea and pupil, landing on the retina, tissue
that lines the back of each eyeball. The retina is composed of three layers of cells:
photoreceptors, bipolar cells, and ret