Week 7: Introduction to Sensation and Perception Flashcards
Sensation and Perception, Hearing, Touch and Pain,
Sensation
The physical processing of environmental stimuli by the sense organs
During sensation, our sense organs are engaging in TRANSDUCTION; After our brain receives the electrical signals, we make sense of all this stimulation and begin to appreciate the complex world around us (PERCEPTION)
Transduction
A process in which physical energy converts into neural energy
Perception
The psychological process of interpreting sensory information
Absolute Threshold
The smallest amount of stimulation needed for detection by a sense
Signal Detection
Method for studying the ability to correctly identify sensory stimuli (the way we measure absolute thresholds)
Method of limits - effort to determine the point, or threshold, at which a person begins to hear a stimulus
Ascending/Descending trials
Hit - correct identification
Miss - incorrect identification
Additionally, indicating that a sound was heard when one wasn’t played is called a FALSE ALARM, and correctly identifying when a sound wasn’t played is a CORRECT REJECTION.
Differential Threshold
The smallest difference needed in order to differentiate two stimuli
Just Noticeable Difference (JND)
The smallest differenced needed in order to differentiate two stimuli
Weber’s Law
States that just noticeable difference is proportional to the magnitude of the initial stimulus
Bottom-up Processing
Building up to perceptual experience from individual pieces
Top-down Processing
Experience influencing the perception of stimuli
Sensory Adaptation
Decrease in sensitivity of a receptor to a stimulus after constant stimulation
Retina
Cell layer in the back of the eye containing photoreceptors
Once past the pupil, light passed through the lens, which focuses an image on a thin layer of cells in the back of the eye (the retina)
It is in the retina that light is transduced, or converted into electrical signals, by specialized cells called photoreceptors - RODS and CONES
Binocular Disparity
Difference in images processed by the left and right eyes
Binocular Vision
Our ability to perceive 3D and depth because of the difference between the images on each of our retinas
Primary Visual Cortex
Area of the cortex involved in processing visual stimuli
Agnosia
Loss of the ability to perceive stimuli
Ventral Pathway
Pathway of visual processing; the “What” pathway (processing visual recognition)
Dorsal Pathway
Pathway of visual processing; the “where” pathway (processing location and movement)
Dark Adaptation
Adjustment of eye to low levels of light
Light Adaptation
Adjustment of eye to high levels of light
Opponent-Process-Theory
Theory proposing colour vision as influenced by cells responsive to pairs of colours
Colour deficient vision can result from issues with the cones/retinal ganglion cells involved in colour vision
Someone stares at a yellow piece of paper for 30 seconds, and then he quickly looks at a white wall. The blue afterimage he sees supports OPT
The Trichromatic Theory
Theory proposing colour vision as influenced by three different cones responding preferentially to red, green, and blue
Sound Waves
Changes in air; physical stimulus for audition
the AMPLITUDE of a sound wave codes for the loudness of a stimulus (higher amplitude sound waves result in louder sounds)
the PITCH of a stimulus is coded in the FREQUENCY of the sound wave (higher frequency sounds are higher pitched)
allows us to tell difference between bright and dull sounds as well as natural and synthesized instruments
Audition
Ability to process auditory stimuli; also called hearing
Pinna
Outermost portion the ear
Auditory Canal
Tube running from the outer ear to the middle ear
Tympanic Membrane
Thin, stretched membrane in the middle ear that vibrates in response to sound; also called the eardrum
Ossicles
A collection of three small bones in the middle ear that vibrate against the tympanic membrane
Cochlea
Spiral bone structure in the inner ear containing auditory hair cells
Primary Auditory Cortex
Area of the cortex involved in processing auditory stimuli
Vestibular System
Parts of the inner ear involved in balance - comprised of three semicircular canals (fluid-filled bone structures containing cells that respond to changes in the head’s orientation in space) - info from vestibular system sent through vestibular nerve to muscles involved in movement of parts of body
Info allows us to maintain our gaze on an object while we are in motion - disturbances in the system can result in issues w balance including vertigo
Somatosensation
Ability to sense touch, pain and temperature
Mechanoreceptors
Mechanical sensory receptors in the skin that respond to tactile stimulation - allow for conversion of one kind of energy into a form the brain can understand
Primary Somatosensory Cortex
A strip of cerebral tissue just behind the central sulcus engaged in sensory reception of bodily sensations