Psych test #2
Terms
undefined, object
copy deck
- sense
-
a system that translates info from outside the nervous system into neural activity
must detect, encode, and transfer info - sensation
- message received from the senses
- accessory structures
-
first step in sensation
modifies energy
ex. outer part of ear, lens of eye - transduction
-
-converts incoming energy into neural activity
-takes place at sensory receptors
-detect certain forms of energy and respond by firing action potential
-ex. change light waves to color - coding
- allows neural impulses to be changed into certain properties
- doctrine of specific nerve endings
- stimulation of a particular sensory nerve provides codes for that sense no matter how stimulation takes place (ex. pressure on eye)
- temporal code
- changes in the timing of firing
- spatial code
- location of firing neurons relative to others
- absolute threshold
- the minimum amount of stimulus energy that can be detected 50% of the time
- subliminal stimuli
- stimuli too weak or brief to be perceived
- supraliminal stimuli
- stimuli that fall about the absolute threshold and are consistently perceived
- signal-detection theory
- predicts how and when a signal will be detected amid background noise
- sensitivity
-
-the ability to detect a stimulus from background noise
-influenced by intensity of signal, capacity of sensory system, amount of background noise - response criterion
-
-internal rule used to decide whether or not to report a stimulus
-affected by motivation, wants, needs, and expectancies (ex. airport security) - just-noticeable difference
-
-the smallest detectable difference in stimulus energy that can be detected 50% of the time
-the weaker the stimuli, easier to detect small differences - Weber's Law
-
-the more intense the stimulus, the greater the increase in stimulus intensity required for the increase to be perceived
-two stimuli must differ by a constant minimum percentage, rather than a constant amount - Light-electromagnetic radiation
-
-visable light
-electromagnetic radiation of a wavelenght between 400 and 750 nanometers
-does not need a medium to pass through - sensation of light
-
-light intensity (how much energy the light contains, determines brightness of light)
-light wavelenght (provides color, defferent wavelenghts produce different colors) - Eye
-
-cornea (light enters the curved, transparent, protective layer)
-pupil (light passes through an opening in the eye)
-iris (adjusts the amount of light allowed into the eye)
-lens (lies behind the pupil and bends light rays, focusing them on the retina)
- retina (surface at the back of the eye where light rays are focused) - photoreceptors
-
-specialized cells in the retina that convert light energy into neural activity
-contain photopigments (chemicals that respond to light)
-two types, rods and cones - rods
-
-has only one pigment
-distributed throughtout the retina, except at the fovea
-faciliatate peripheral vision
-mediate nighttime vision
-receive all colors as shades of gray - cones
-
-concentrated in center of the retina at the fovea
-mediate daytime vision
-mediate color vision
-provide a sharper image than rods - interactions in the retina
-
-rods and cones synapse with bipolar cells
-following this, it synapses with ganglion cells
-axons of the ganglion cells gather together to form the optic nerve (carries visual impulses from the retina to the brain) - trichromatic theory
-
-3 types of color receptors that are each receptive to a different primary color (red, blue, green)
-the ration of the activites of the 3 types of cones indicate what color will be sensed
-color vision is coded by the pattern of activity of the different cones - opponent-process theory
-
-3 distinct receptors (red green, yellow blue, white black)
-each element signals one color or the other, but never both
-gray results when lights of the 2 colors are mixed together
-supported byt he phenomenon of negative afterimages - trichromats
-
-people with normal color vision
-have 3 distinct visual pigments - dichromats
-
-lack one of the 3 pigments
-most are red green blind - monochromats
-
-have no color vision
-receive visual info through rods only - sex linked recessive trait
-
-associated with a gene on the X chromosome
-males are more prone to color blindness than females - sound
-
-repetitive fluctuation in the pressure of a medium like air
-vibrations produce the fluctuations in pressure that constitute sound
-Speech (vocal cords produce vibration into the air, creates waves) - Optic nerve
- blind spot
- optic chiasm
-
-half the fibers cross over to the opposite side of the brain
-info from the inner (nasal) half of the retina cross to the opposite side of the brain
-info from the outer (temporal) half of the retina remain on same side
-info from both eyes reaches both sides of the brain
-visual info transmitted to thalamus and then to primary visual receiving area in occipital lobe - loudness
-
-determined by amplitude of the sound wave
-waves with greater amplitude produce louder sounds
-measured in decibels (dB) - pitch
-
-depends on frequency of sound waves
-high frequency = high pitch
-humans can hear between 20-20,000 Hz - timbre
-
-quality of sound
-determined by complex wave patterns - wavelength
- distance from one peak to the next
- frequency
-
-number of complete waveforms that pass by a given point in space every second
-measured in hertz (Hz) - amplitude
-
-intensity
-difference between peak and baseline of a waveform - pinna
-
-the crumpled part
-funnels down through the ear canal
-sound waves collect in outer ear - tympanic membrane
-
-eardrum
-sound waves cause eardrum to vibrate - ossicles
-
-hammer, anvil, stirrup
-amplify changes in pressure - oval window
-
-membrane that seperates middle and inner ear
-vibration is up to 90 times greater at this point - cochlea
-
-amplified vibration transmitted to fluid in the cochlea
-movement of fluid in the cochlea bend the auditory receptor cells (hair cells)
-results in neural impulses in the adjacent auditory nerve
-nerve transmits signals through the medulla and thalamus to the auditory cortex of the temporal lobe - Place theory
-
-describes a spatial code for frequency
-proposed that pitch is determined by the part of the basilar membrane stimulated
-explains the ability to perceive high frequency tones, but does not explain the ability to perceive lower ones - frequency matching theory
-
-for low frequency sounds, the frequency of nerve impulses matches the frequency of the stimulus
-temporal code - volley theory
-
-differnt sets of fibers within the auditory nerve fire in successive rounds, with the pattern determining the pitch
-explains the perception of frequencies between 1000-4000Hz - touch
-
-energy detected from deformation of tissue, ususally the skin
-receptors in or below the skin transduce this info into neural activity
-changes in touch constitute the most important sensory info - coding of touch
-
-intensity (heaviness) coded by the firing rate and number of neurons stimulated
-location: coded by the spatial organization of the info
-topographical map of brain: differentially sensitive - skin senses
-
-pressure (only one with identifiable receptors)
-warmth
-cold
-pain
-not clear how receptors work together (wetness develops from touching adjacent cold and pressure spots, cold and warm spots produce a feeling of hot) - pain
-
-receptors are free nerve endings
-A-delta fibers carry sharp pain (myelinated to carry messages quickly)
-C fibers carry chronic, dull aches and burning sensations - gate control theory
-
-nervous system can process only a limited amount of sensory info at any one time
-when too much info is being received, cell sin the spinal cord act as a gate, blocking some pain signals
-ex. massaging area, distracting activity, hot or cold, can reduce pain - referred pain
- -pain sensation in one part of the body is perceived as coming from another part
- phantom pain
- -pain sensation felt in missing limb
- taste
-
-taste buds are the receptors, grouped together in stuctures called papillae
-10,000 taste buds in mouth
-discriminates between sweet, salty, sour, bitter, umami (enhances other tastes), and astringent (produced by tannins, tea)
-each taste bud responds best to 1-2 of these categories - sweet and bitter
- signaled when chemicals fit into specific receptor sites
- sour and salty
- more direct effects on the ion channels in membranes of taste buds
- flavor
-
-smell and taste converge to produce flavor
-food tastes good due to olfactory system more so than the taste system
-olfactory and taste pathways converge in the orbitofrontal cortex, where they also respond to sight and texture of food - olfaction
-
-sense odor in upper part of nose
-odor molecules readch olfactory receptors by either passing directly through the nostrils or rising through an opening in the palate
-molecules bind to dendrites in the nose, which leads to action potentials - proprioception
- allow us to know the position of body and what each part is doing
- vestibular sense
-
-provides info about the position of the head in space and its movements
-sense of balance
-vertigo - vestibular sacs
-
-organs in the inner ear that connect the semicircular canals and the cochlea
-contribute to the body's sense of balance - semicircular canals
- tubes in the inner ear whose fluid, when shifted by head movements, stimulates nerve cells
- vestibular system has neural connections:
-
-cerebellum (helps coordinate body movement
-digestive part of ANS (responsible for nausea)
-muscles of the eye (create vestibular-ocular reflexes (when head moves in one direction eyes more in opposite direction, allows us to fixate on one point)) - perception
- the process through which sensations are interpreted, using knowledge experience, and understanding of the world, to create meaningful experiences
- bottom up processing
-
-aspects of recognition that depend of the info about the stimulus that comes up to the brain from the sensory receptors
-certain cells respond to certain stimuli
-the brain then recombines this data to create the perceptual experience
-certain features are more important than others (rely on large scale features, such as hair and head shape) - top down processing
-
-use knowledge in making inferences to recognize objects, especially when sensory info is vague
-experiences creat schemas, which then can bias our perception
-can create a perceptual set, a predisposition to perceive a stimulus in a certain way
-makes educated guesses (can lead to wrong conclusions) - network processing
-
-utilize both top down and bottom up processing
-parallel distributed processing models (various elements of the object are believed to be simultaneously analyzed by a number of widely distributed, but connected, neural units in the brain. Units work in parallel) - attention
-
-the process of directing and focusing certain psychological resources to enhance perception, performance, and mental experience
-used to direct our sensory and perceptual systems, select specific info for further processing, ignore unwanted stimuli - directing attention
-
-Voluntary control (purposely focus attention in order to perform a task, reflects top down processing, overt orienting)
-Involuntary attention (bottom up process, abrupt changes in lighting or movement, covert orienting) - ignoring information
- inattentional blindness: dont pay attention to certain stimuli in the environment
- divided attention
-
-easy if one task is automatic
-more difficult if both require attention (but if tap different kinds of attentional resources, it is possible)
-if 2 tasks require same kind of attention, performance on both tasks will be poor - parallel processing
-
-the ability to search for targets rapidly and automatically
-filter out irrelevant info
-stroop test - stroop test
-
-a measure to assess the ingibition of automatic responses
-it is automatic for us to read words, compared to naming colors, need to inhibit automatic response - gestalt laws
-
-proximity
-similarity
-continuity
-closure (fill in missing contours of shape)
-common fate
-texture
-simplicity - synchrony
- stimuli that occur at the same time are likely to be perceived as belonging together