sensation and perception Flashcards
sense
a system that translates data from outside the nervous system into neural activity
sensations
raw information from the senses
perception
the process through which people take raw sensations from the environment and give them meaning using knowledge, experience, and understanding of the world
accessory structures
structures, such as the outer part of the earr, that modify a stimulus
transduction
the process of converting incoming physical energy into neural activity
neural receptors
cells that are specialized to detect certain types of energy and convert it into neural activity
sensory adaptation
decreasing responsiveness to an unchanging stimulus
encoding
translation of the physical properties of a stimulus into a specific pattern of neural activity
specific energy doctrine
the discovery that stimulation of a particular sensory nerve provides codes for that sense, no matter how the stimulation takes place
absolute threshold
the minimuum amount of stimulus energy that can be detectted 50 percent of the time
noise
the spontaneous random firing of nerve cells that occurs because the nervouse system is always active
response bias
the internal rule a person uses to decide whether or not to report a stimulus
signal detection theory
a mathematical model of what determies a person’s report of a near-threshold stimulus
sensitivity
the ability to detect a stimulus
Weber’s law
a law stating that the smallest detectable difference in stimulus energy is a constant fraction of the intensity of the stimulus
just-noticeable difference
the smallest detectable difference in stimulus energy
wavelength
the distance between peaks in a wave of light or sound
frequency
the number of complete waves, or cycles that pass a given point per unit of time
amplitude
the distance between the peak and the baseline of a wave
figure
the part of the visual field that has meaning
ground
the contourless part of the visual field
figure ground discrimination
the ability to organize a visual scene so that it contains meaningful figures set against a less relevant ground
depth perception
perception of distance, allowing us to experience the world in three dimensions
motion parallax
a depth cue whereby a difference in the apparent rate of movement of different objects provides information about the relative distance of those objects
eye convergence
a depth cue that results when the eyes rotate to project the image of an object on each retina
retina desparity
a depth cue based on the difference between the retinal images by each eye
looming
a motion cue whereby rapid expansion in the size of an image fills the available space on the retina
stroboscopic illusion
an illusion of motion that is created when we see slightly different images or slightly displaced lights flashed in rapid succession
perceptual constancy
the perception that objects retain the same size, shape, color and other properties despite changes in their retinal image
top-down processing
aspects of recognition guided by higher-level cognitive processes and by psychological factors such as expectations
bottom-up processing
aspects of recognition that depend first on information about stimuli that come up to the brain from the sensory system
schemas
mental representations of what we know and expect about the world
