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