Behavioral Sciences Ch 2. Sensation and Perception Flashcards
Sensation
The conversion, or transduction, a physical, electromagnetic, auditory, and other information from the internal and external environment into electrical signals in the nervous system, performed by receptors in the PNS
Perception
The processing of sensory information to make sense of its significance, includes both external sensory experience and the internal actives of the brain and spinal cord
Sensory receptors
Nerves that respond to stimuli and trigger electrical signals, stimuli transmitted to projection areas in the brain
Sensory ganglia
Collections of cell bodies outside the central nervous system that are associated with sensory neurons
Projection areas
Areas in the brain that further analyze sensory input
Common sensory receptors
Photo receptors, hair cells, nociceptors, thermoreceptors, osmoreceptors, olfactory receptors, and taste receptors
Threshold
The minimum stimulus that causes a change in signal transduction, aka limina
Absolute threshold
The minimum of stimulus energy that is needed to activate a sensory system, may not be significant enough to be converted to an action potential through transduction
Threshold of conscious perception
The minimum of stimulus energy that will create a signal large enough in size and long enough and duration to be brought into awareness, can be tested with discrimination testing
Difference threshold
aka just noticeable difference, the minimum difference in magnitude between two stimuli before one can perceive the difference
Just-noticeable difference
jnd - aka difference threshold, the minimum difference in magnitude between two stimuli before one can perceive the difference
Weber’s Law
States that the just noticeable difference for stimulus is proportional to the magnitude of the stimulus, and that this proportion is constant or most of the range of possible stimuli
Signal detection theory
Refers to the effects of non-sensory factors, such as experiences, motives, and expectations, and perception of stimuli, experiences allow us to look at response bias
Response bias
The tendency of subjects to systematically respond to a stimulus in a particular way due to non-sensory factors
Adaption
A decrease in response to a stimulus over time, one way the mind and body try to focus attention on only the most relevant stimuli
Eye
An organ specialized to detect light in the form of photons
Cornea
Gathers and filters incoming light, clear, domelike window in the front of the eye
Iris
Divides the front of the eye into the anterior and posterior chambers, it contains two muscles, the dilator and the constrictor pupillae, which open and close the pupil
Anterior chamber of the eye
Lies in front of the iris
Posterior chamber of the eye
Lies between the iris and the lens
Dilator pupillae
Muscle in the iris that is responsible for dilating the pupil during sympathetic stimulation
Constrictor pupillae
Muscle in the iris that is responsible for constricting the pupil during parasympathetic stimulation
Pupil
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Lens
Refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to the ciliary muscle, right behind the iris
Suspensory ligament
Connected to the ciliary muscle, holds the lens in place
Ciliary muscle
Connects to the suspensory ligaments in the eye that holds the lens in place, part of the ciliary body, under parasympethetic control, changes shape of lens when it contracts during accommodation
Aqueous humor
Produced by the ciliary body, drains through the canal of Schlemm, bathes the front part of the eye
Retina
Contains the actual photoreceptors that transduce light into electrical information the brain can process, most cones are in the macula, innermost layer of the eye, like a screen consisting of neural elements and blood vessels, considered part of the CNS and develops from an outgrowth of brain tissue
Rods
Detect light and dark, contain pigment called rhodopsin, low sensitivity to details, permit night vision
Cones
Come in three forms (short, medium, and long wave length) to detect colors, sense fine details, most effective in bright light
Macula
Corresponds to the central vision field, the center is the fovea, high concentration of cones
Fovea
Center of the macula, contains only cones, visual acuity is the best
Bipolar cells
Where rods and cones synapse, synapse themselves on ganglion cells
Ganglion cells
Where bipolar cells synapse, integration of the signals and those from horizontal and amacrine cells where edge-sharpening is performed, group together to form the optic nerve
Horizontal and amacrine cells
Receive input from multiple retinal cells in the same area, integrate signals before reaching ganglion cells, important for edge-sharpening
Vitreous
Supports the bulk of the eye on the inside, transparent gel that supports the retina
Sclera
Supports the bulk of the eye on the outside, thick structural layer, the white of the eye
Choroid
Supports the bulk of the eye on the outside, continuous with the iris and the ciliary body
Visual pathway
Starts at the eye, travels through the optic nerves, optic chiasm, optic tracks, lateral geniculate nucleus (LGN) of the thalamus, and visual radiations to get to the visual cortex
Optic nerves
Forms by the grouping of ganglion cells, brings signal from eyes to brain
Optic chiasm
Fibers from the nasal half (temporal visual fields) of each retina crosses paths, temporal fibers do not cross, left visual field goes to right side of brain and vice versa
Optic tracks
Pathway of optical signal leaving the optic chiasm
Laternal geniculate nucleus
LGN - in the thalamus
Visual radiations
Vision path which runs through the temporal and parietal lobes
Visual cortex
Within the occipital lobe, where vision processing occurs
Parallel processing
The ability to simultaneously analyze and combine information regarding color, shape, and motion
Visual processing
Parallel processing:
Color is detected by cones
Shape is detected by parvocellular cells
Motion is detected by magnocellular cells
Parvocellular cells
Detect shape in vision, have high spatial resolution and low temporal resolution
Magnocellular cells
Detect motion in vision, with low spatial resolution and high temporal resolution
Ear divisions
Outer, middle, and inner ear
Outer ear
Consists of the pinna (auricle), external auditory canal, and tympanic membrane
Pinna
aka auricle, cartilaginous outside part of the ear, channels sound waves into the external auditory canal
External auditory canal
Pinna channels sound waves down this structure to the tympanic membrane (eardrum)
Tympanic membrane
aka eardrum, vibrates in phase with incoming sound waves and vibrates with an amplitude proportional to the volume of the sound, divides the outer and middle ear
Middle ear
Consists of the ossicles: malleus, incus, stapes, the footplate of the stapes rests on the oval window of the cochlea, the middle ears connected to the nasal cavity by the eustachian tube
Ossicles
Middle ear bones: malleus, incus, and stapes, smallest bones in the body, goal to transmit and amplify vibrations from the tympanic membrane to the inner ear
Malleus
hammer- affixed to the tympanic membrane, acts on the incus, transmit and amplifies vibrations
Incus
anvil - acts on the stapes, transmit and amplifies vibrations
Stapes
Stirrup - baseplate rests on the oval window of the cochlea where it transmits and amplifies vibrations to the inner ear
Oval window
Part of the cochlea, where the footplate of the stapes rests, entrance to the inner ear from the middle ear
Eustachian tube
Connects the middle ear to the nasal cavity, equalizes pressure between the middle ear and the environment
Inner ear
Contains the bony labyrinth, within which is the membranous labyrinth
Bony labyrinth
In the inner ear, filled with perilymph, surrounds the membranous labyrinth
Membranous labyrinth
In the inner ear, filled with endolymph, surrounded by the bony labyrinth
Cochlea
Spiral shaped organ divided into three parts called scalae, middle scala in membranous labyrinth, is tonotopically organized
Utricle and saccule
Within the vestibule in the bony labyrinth, detects linear acceleration, have hair cells covered with otoliths, otoliths resist motion during acceleration, bending the hair cells, which generates an electrical signal
Semicircular canals
Within the membranous labyrinth, detects rotational acceleration, canals arranged perpendicularly with ampullae on the ends with hair cells, hair cells detect rotation because endolymph resisting the movement bends hair cells, hair cells generate electrical signal
Auditory pathway
Starts from the cochlea and travels through the vestibulocochlear nerve and medial geniculate nucleus of the thalamus to get to the auditory cortex in the temporal lobe
Vesibulocochlear nerve
aka auditory nerve, carries electrical signals from hair cells to the CNS
Medial geniculate nucleus
MGN - within the thalamus, routes sound electrical signals
Auditory cortex
In the temporal lobe, where sound is processed
Superior olive
Some sound information also sent to here, localizes sound
Inferior colliculus
Sound is also routed here, involved in the startle reflex
Olfactory chemoreceptors
aka olfactory nerves, in the olfactory epithelium, detect smell, smell must bind to its respective chemoreceptor to cause a signal
Olfactory pathway
Starts from the olfactory nerves and travels through the olfactory bulbs and olfactory tract to get to the higher order brain areas, such as the limbic system
Smell
The detection of volatile or aerosolized chemicals, only sense that does not pass through the thalamus
Pheromones
Chemicals given off by animals that have an affect on social, foraging, and sexual behavior in other members of that species
Olfactory bulb
Place where smell signals are routed after receptor cells are activated
Olfactory tract
Routes smell signals from the olfactory bulb to higher regions of the brain, including the limbic system
Taste
The detection of dissolved compounds by taste buds in papillae, comes in five modalities, detected by chemoreceptors
Five modalities of taste
Sweet, sour, salty, bitter, and umami (savory)
Taste bubs
Receptors for taste, groups of cells found in little bumps on the tongue
Papillae
Little bumps on the tongue where taste buds are
Somatosensation
Refers to the four touch modalities: pressure, vibration, pain, and temperature, at least five different types of receptors
Two-point threshold
The minimum distance necessary between two points of stimulation on the skin such that the points will be felt as two distinct stimuli
Physiological zero
The normal temperature of the skin to which objects are compared to determine if they feel warm or cold
Nociceptors
Possible for pain perception
Gate theory of pain
States that there is a special “gating” mechanism that can turn pain signals on and odd, also that pain sensation is reduced when others somatosensory signals are present, not the best theory out there
Proprioception
aka kinesthetic sense, refers to the ability to tell where one’s body is in three-dimensional space
Kinesthetic sense
aka proprioception, refers to the ability to tell where one’s body is in three-dimensional space
Bottom-up processing
aka data-driven, refers to recognition of objects by parallel processing and feature detection, it is slower but less prone to mistakes
Top-down processing
aka conceptually driven, refers to recognition of an object by memories and expectations, with a little attention to detail, it is faster but more prone to mistakes
Perceptual organization
Refers to our synthesis of stimuli to make sense of the world, including integration of depth, form, motion, and constancy
Gestalt principles
The way the brain can infer missing pieces of a picture when a picture is incomplete, includes the law of proximity, the lost similarities, the law of good continuation, subjective contours, and the law of closure, governed by the law of pragnanz
The law of proximity
States that elements close to one another tend to be perceived as a unit
The law of similarity
States that elements that are similar appear to be grouped together
The law of good continuation
States that elements that appear to follow the same path tend to be grouped together
Subjective contours
First to the perception of nonexistent edges and figures, based on surrounding visual cues
The law of closure
States that when a space is enclosed by a group of lines, it is perceived as a complete or closed line, also refers to the fact that certain figures tend to be perceived is more complete than they really are
The law of pragnanz
Says that perceptual organization will always be as regular, simple, and as symmetric as possible, governs all Gestalt principles
Distal stimuli
Stimuli that originate outside of the body
Proximal stimuli
Directly interact with and affect the sensory receptors, and inform the observer about the presence of distal stimuli
Psychophysics
Studies the relationship between physical nature stimuli in the sensations and perceptions that evoke
Subliminal perception
Refers to the perception of a stimulus below a given threshold, usually the threshold of conscious perception
Discrimination testing
aka psychophysical discriminating testing, tests thresholds of conscious perception
Signal detection experiments
Use catch trials and noise trials, for outcomes include hits, misses, false alarms, and correct negatives
Catch trials
Trial of a signal detection experiment, the signal is actually presented
Noise trials
Trial of a signal detection experiment, the signal is not presented
Hits
When a subject correctly identifies a catch trial
Misses
When is subject incorrectly misses a catch trial
False alarms
When is subject incorrectly assumes the signal was presented
Correct negatives
When is subject to correctly identifies a noise trial
Choroidal vessels
A complex intermingling of blood vessels between the sclera and the retina, provide the eye with nutrients
Eye nutrients
From the choroidal vessels and the retinal vessels
Retinal vessels
Provide the eye with nutrients
Ciliary body
Produces aqueous humor, part of it is the ciliary muscle
Accommodation vision
When the ciliary muscle contracts under parasympathetic control and pulls on the suspensory ligaments to change the shape of the lens
Duplexity
aka duplicity theory of vision, states that the retina is composed of two kinds of photoreceptors: cones and rods
Duplicity theory of vision
aka duplexity, states that the retina is composed of two kinds of photoreceptors: cones and rods
Rhodopsin
Pigment found in rods
Superior colliculus
Vision also routed here, controls some responses to visual stimuli and reflexive eye movements
Feature detection
Similar idea to parallel processing in neuroscience
Vestibular sense
Senses rotational and linear acceleration
Ear
Complex organ responsible for hearing and vestibular sense
Perilymph
Thin layer of fluid that suspends the membranous labyrinth within the bony labyrinth, simultaneously transmits vibrations from the outside world and cushions the inner ear structures
Endolymph
Potassium rich fluid that bathes the membranous membrane
Cochlea middle scala
aka the organ of Corti, the actual hearing apparatus, rests on the basilar membrane, composed of thousands of hair cells bathed in endolymph, above is the tectorial membrane
Cochlea outside scala
Filled with perilymph, surround the hearing apparatus and are continuous with the oval and round windows of the cochlea
Basilar membrane
Thin, flexible membrane where the organ of Corti (or middle scala) rests
Organ of Corti
aka the cochlea middle scala, the actual hearing apparatus, rests on the basilar membrane, composed of thousands of hair cells bathed in endolymph, above is the tectorial membrane, stereocilia on hair cells sway back in forth because of sound vibrations, this opens ion channels, which generates an electrical signal
Tectorial membrane
Relatively immobile membrane on the top of the organ of corti/middle scala, hair cells directly connected to this membrane are involved in sound amplification
Round window
A membrane covered hole in the cochlea, permits the perilymph to actually move within the cochlea
Hair cells
Receptors in the auditory system capable of generating electrical signals, covered in stereocilia on their top surface
Stereocilia
On the top surface on of hair cells, sways in response to sound vibrations
Vestibule
Portion of the bony labyrinth that contains the utricle and saccule
Ampulla
Swellings at the ends of semicircular canals where the hair cells are located
Place theory
States that the location of a hair cell on the basilar membrane determines the perception of pitch when that hair cell is vibrated
Tonotopical
The way in which the cochlea is organized, means that which hair cells are vibrating gives the brain an indication of the pitch of the sound
Taste pathway
Starts at taste buds, travels to taste center in the thalamus, travels then to higher-order brain regions
Taste center
Part of the thalamus with the job of routing taste signals
Pacinian corpuscles
Responds to deep pressure and vibration
Meissner corpuscles
Responds to light touch
Merkel cells (discs)
Respond to deep pressure and texture
Ruffini endings
Respond to stretch
Free nerve endings
Respond to pain and temperature
Somatosensation pathway
Transduction in the receptors, signal travels to CNS and eventually to the somatosensory cortex
Somatosensory cortex
Within the parietal lobe, where somatosensory information is processed
Depth perception
Can rely on both monocular and binocular cutes
Monocular cues
Involves one eye, include the relative size of objects, partial obscuring of the object by another, the convergence of parallel lines at a distance, position of an object in the visual field, and lighting and shadowing
Binocular cues
Include two eyes and the slight differences in images projected on the two retinas and the angle required between the two eyes to bring an object into focus
Form determination
Usually determined through parallel processing in feature detection
Constancy
Refers to the idea that we perceive certain characteristics of objects to remain the same, despite differences in the environment
