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.