Sensation & Perception Flashcards
Sensation
The process by our sensory receptors and nervous system receive and represent stimulus energies from our environment (PNS)
Perception
Process of organizing and interpreting sensory information, enabling us to recognize meaningful events (CNS)
Sensory adaptation
Sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current (unchanging) conditions [stop noticing]
Habituation
Decrease in response to a stimulus after repeated presentation [stop reacting]
Psychophysics
Methods that ensure the strength of a stimulus and the observer’s sensitivity to the stimulus
Sensitivity
How responsive to faint stimuli
Acuity
How well we can distinguish two very similar stimuli
Absolute threshold
Minimum stimulus energy needed to detect a particular stimulus 50% of the time
Just noticeable difference (JND)
Minimal change in a stimulus that can just barely be detected
Weber’s law
Magnitude needed to detect physical change in a stimulus is proportional to the absolute magnitude of that stimulus
Signal detection theory
Psychological theory predicting how and when we detect a faint stimulus (signal) amid background stimulation (noise)
Perceptual set
Readiness to perceive a stimulus in a particular way
Myopia (nearsightedness)
Faraway objects are focused in front of retina
Hyperopia (farsightedness)
Nearby objects are focused beyond retina
Cones
Center of retina, cells sensitive to fine detail and color
Rods
Periphery of retina, cells sensitive to low light and black-and-white
Blindspot
Location in the visual field that produces no sensation on the retina
Trichromatic theory
Thomas Young & Hermann von Helmholtz - Color perception is produced by red, green, and blue color receptors
Perceptual constancy
Even as aspects of sensory signals change, perception remains constant (door opening)
Perceptual contrast
Although two things may be similar we perceive them as different (blue/black dress vs white/gold dress)
Gestalt perceptual grouping rules
Simplicity, closure, continuity, similarity, proximity, common fate
Monocular depth cues
Linear perspective, texture gradient, interposition, relative height
Binocular depth cues
Retinal disparity (retinas receive different images) & convergence (Cue caused by the way our eye muscles turn our eyes inward)
Outer ear
Pinna, auditory canal
Middle ear
ossicles, eardrum, oval window
Inner ear
Cochlea, auditory nerve, hair cells, basilar membrane
Place theory
Pitch we perceive depends on which parts of cochlea are stimulated
Frequency theory
Perception of pitch depends on frequency of vibration of cochlea
Sensorineural hearing loss
Damage to cochlea or hair cells
Conduction hearing loss
Damage to outer or middle ear
Vestibular sense
Awareness of body balance and movement (sense of equilibrium) Thanks to semicircular canals and vestibular sacs
Kinesthesis
Sense that provides info through receptors in muscles, tendons, joints
Haptic perception
Active exploration of environment by touching and grasping objects
Tactile receptive field
Small patch of skin that relates information about pain, pressure, warmth, and cold
Smell (olfaction)
Includes nose, mouth, upper part of throat
Nociceptors
Sensory receptor for painful stimuli (C fibers, slow/small, A fibers, fast/large)
