Chapter 3: Quiz Flashcards
the minimum amount of energy in a sensory stimulus detected 50 percent of the time.
absolute threshold
A theory that assumes that the detection of faint sensory stimuli depends not only upon a person’s physiological sensitivity to a stimulus but also upon his decision criterion for detection, which is based on non sensory factors.
signal detection theory
The minimum difference between two sensory stimuli detected 50 % of the time.
difference threshold
for each type of sensory judgement that we can make, the measured difference threshold is a constant fraction of the standard stimulus value used to measure it. This constant fraction is different for each type of sensory judgement.
Weber’s Law
The perceived magnitude of a stimulus is equal to its actual physical intensity raised to some constant power. The constant power is different for each type of sensory judgement.
Stevens’s power law
Our sensitivity to unchanging and repetitious stimuli disappears over time.
sensory adaptation
The conversion of physical energy into neural signals that the brain can understand.
transduction
the focusing of light waves from objects of different distances directly on the retina
accommodation
the light sensitive layer of the eye that is composed of three layers of cells- ganglion, bipolar, and receptor (rod and cones)
retina
Receptor cells in the retina that are principally responsible for dim light and achromatic vision.
rods
Receptors cells in the retina that are principally responsible for bright light and color vision.
cones
A condition in which a blind person has some spared visual capacities in the absence of any visual awareness.
blindsight
The receptor cells for hearing. They line the basilar membrane inside the cochlea.
hair cells
The interpretation by the brain of sensory information.
sensation
The processing of incoming sensory information as it travels up from the sensory structures to the brain.
bottom-up processing
The brain’s use of knowledge, beliefs, and expectations to interpret sensory information.
top-down processing
the interpretation of ambiguous sensory information in terms of how our past experiences have set us to perceive it.
perceptual set
The use of the present context of sensory information to determine its meaning
contextual effect
the Gestalt perceptual organizational principle that the brain organizes sensory information into the center of attention and the less distinct background
figure-and-ground principle
the Gestalt perceptual organizational principle that the brain completes (closes) incomplete figures to form meaningful objects.
closure
a line or shape that is perceived to be present but does not really exist. The brain creates it during perception.
subjective contour
The perceptual stability of the size, shape, brightness, and color for familiar objects seen at varying distances, different angles, and under different lighting conditions.
perceptual constancy
Our ability to perceive the distance of objects from us.
depth perception
What does psychophysical research focus on?
the relationship between the physical and psychological world
