Chapter 5 Flashcards
what is sensation
the detection of physical stimuli and transmission of that info to the brain
what are examples of physical stimuli
light or sound waves, molecules of food or odour, temp and pressure changes.
what is perception
where the brain processes and organizes and interprets sensory info.
what is bottom up processing
based on the physical features of the stimulus - its like gluing pieces of sand together to get the full sculpture and understand what you are seeing
what is top down processing
how knowledge, expectations, or past experiences shale the interpretation of sensory information. what we anticipate and expect to see influences what we actually perceive.
what is transduction
the translation of stimuli into patterns of neural impulses.
what are sensory receotors
they receive physical and chemical stimulation and then pass the resulting impulses to the brain in the form of neural impulses
where does all sensory info (except smell) go
thalamus, then cerebral cortex.
what are the stimuli, receptors, pathway to the brain for vision
lightwaves, rods and cones, optic nerve
what are the stimuli, receptors, pathway to the brain for hearing/audition
sound waves, hair cells in cochlea, auditory nerve
what are the stimuli, receptors, pathway to the brain for taste
molecules dissolved in fluid on tongue, taste bud cells, some facial glossopharyngeal and vagus nerves
what are the stimuli, receptors, pathway to the brain for smell
momecules dissolved in fluid in the mucous membrane, olfactory nerve
what are the stimuli, receptors, pathway to the brain for touch
pressure on skin, sensitive ends of touch neurons, cranial nerves for touch above neck - spinal nerves for all other touch pathways below neck
what is qualitative info about a stimulus
most basic qualities of a stimulus. we can detect this info because diff sensory receptors respond to qualitatively different stimuli
what is quantitative info about a stimulus
the degree/magnitude of those qualities. this is coded bu the rate of a particular neurons firing or the number of neurons firing.
what is the absolute threshold «just noticeable differenfe»
the level of intensity at which participants can correctly detect a stimulus on 50% of the trials in which it is presented. also called a “just noticeable difference”
what is Webers law
the just noticeable difference between two stimuli is based on a proportion of the original stimulus rather than a fixed amount of difference
what are internal vs external stimuli
internal - mood, emotion, memory, physical states
external - sound, temperature, visual clutter
what is signal detection theory
detecting a stimulus is not an objective process - it is a subjective decision with two components 1) sensitivity to stimulus in the presence of noise 2) criteria used to make the judgement from ambiguous info.
what are the four possible outcomes with signal detection
hit, miss, false alarm, correct rejection.
what is sensory adaptation
decrease in sensitivity to a constant level of stimulation
what are the two types of receptor cells on the retina
rods and cones.
wgat do rods respond do
bright vs darkness, white and black light
wgat do cones respond to
colours, three types of cones red, blue, green
where are cones tightly packed vs diffuse
tightly packed at the fovea, diffuse on the outside edge.
where are rods concentrated vs diffuse
concentrated at retinas edge, and none are in the fovea
how does light go through the eyeball
cornea, lens, pupil, retina,
how do rods and cones work
decomposition of the photopigments alters the membrane potential of the photoreceptors and triggers action potentials in downstream neurons
where does visual information go
visual area of the thalamus, travels to the primary visual cortex, and then the cortical areas in the occipital lobes at the back of the head
what does the ventral stream do
projects from occipital lobe to temporal lobe, specialized for perception and recognition of objects (colours and shapes)
what does the dorsal stream do
projects from occipital to parietal lobe. important for spatial perception. (WHERE)
what is object agnosia
inability to recognize objects, when the what (ventral) stream is imapired
what is the trichromatic colour theory
colour vision results from activity in three types of cones that are sensitive to diff wavelengths
what is hue
consists of the distinctive characteristics that place a particular colour in the spectrum - a colours greeness or ornateness
what is saturation
the purity of the colour
what does Gestalt mean
shape and form
what do gestalt psychologists think
theorized that perception is more than the result of a collection of sensory data. the whole is different than the sum of its parts
what are Gestalt grouping laws (6)
proximity, similarity, good continuity, closure, illusory contours, common fate.
why are faces special, who is responsible for face theory
faces are special as a class of objects because we have developed significant expertise in identifying the small variations in features that distinguish individual faces
what are binocular depth cues
available from both eyes together present only when viewing the three dimensional world, provides internal cues of how far away something is
what are monocular depth cues
available from each eye alone and provide organizational info that is used to infer depth.
how is binocular disparity caused
the distance between humans two eyes
what is stereoscopic vision
the ability to determine an objects depth based on that objects projections to each eye
what is motion parallax
arises from relative speed with which objects move across the retina as a person moved
high vs low amplitude and pitch
high amplitude - loud
low amplitude - soft
High frequency - high pitch
low frequency - low pitch
how is wave frequency measured
hertz HZ
how do sound waves travel through ear
arrive at ear, travel down auditory canal, eardrum, ossicle bones, oval window (cochlea), hair cells, auditory nerve, thalamus, primary auditory cortex
what is the vestibular system, how does it work
helps us maintain balance, uses info from receptors in the semi-circular canals of the inner ear.
what is temporal coding
used to encode low frequencies
place coding
used to encode high frequency sounds
how does taste move through the body
fluid stimulates taste buds, send signals to thalamus, routed to frontal lobe.
what are the 5 basic qualities of taste
sweet, sour, salty, bitter, umami
how does smell pass through the nose into the brain?
we smell something when chemical particles (odourants) pass into the nose and into the nasal cavity’s upper and back portions. then odorants come into contact with the olfactory epithelium (thin layer of tissue with smell receptors), smell signals bypass the thalamus and go straight to the olfactory bulk then brain
what are pheromones
chemicals released by animals that trigger physiological or behavioural reactions in other animals and insects.
what is touch
a haptic sense, conveys sensations of temperature, pressure, and pain. perceived through the skin, our largest sense organ.
what are endorphins
chemical signals that promote a sense of pleasure or well being
what are the haptic receptors for temperature and pressure
sensory neuron’s that reach to the skins outer layer. the axons reach to the CNS by the spinal or cranial nerves.
how does touch info get to the brain
touch info goes to thalamus, thalamus sends it to primary somatosensory cortex in parietal lobe, electrical stimulation of the primary somatosensory cortex evokes the sensation of touch in different regions of the body
what are the two types of nerves identified for pain
fast fibres for sharp immediate pain (myelinated) , slow fibres for chronic dull and steady pain (nonmyelinated)
how does fast vs slow pain help us
fast pain leads us to recoil from harmful objects and therefore is protective - slow pain keeps us from using the affected body parts and helps in recuperation
gate control theory of pain
we experience pain when pain receptors are activated and a neural gates in the spinal cord allow the signal through to the brain.
