ch2: sensation and perception Flashcards
(108 cards)
sensation
transduction: conversion of physical, electromagnetic, auditory, and other info from our in and external envir. to electrical signals in the nervous system
performed by receptors in PNS, stimuli sent to CNS in the form of action potentials and neurotransmitter.
RAW SIGNAL
perception
processing of sensation info to make sense of the sig
sensory receptors
neurons that respond to stimuli and tigger electrical signals.
stimuli could be distal (outside, indirect) or proximal (directly interact and affect sensory receptors)
psychophysics
study of the physical nature of the stimuli and the sensations and perceptions that evoke
ganglia
collections of neuron cell bodies found outside the central nervous system
photoreceptors
respond to electromagnetic waves in the visible spectrum (sight)
hair cells
respond to movement of fluid in the inner ear structures
hearing, rotational and linear acceleration
nociceptors
respond to painful or noxious stimuli
somatosensation
thermoreceptors
respond to chgs in temp
thermosensation
osmoreceptors
respond to the osmolarity of the blood
water homeostasis
olfactory receptors
respond to volatile compounds
smell
taste receptors
respond to dissolved compounds
taste
absolute threshold/limina
minimum of stimulus energy that is needed to activate ta sensory system
threshold in SENSATION NOT PERCEPTION
a stimulus below the absolute threshold will not be transducer and thus never reaches CNS
Subliminal Perception
perception of a stimulus below a given threshold
the threshold of conscious perception.
a stimulus below the threshold of conscious perception arrives at the CNS, but doesn’t reach the higher order brain regions that control attention and consciousness
discrimination testing=psychophysical discrimination testing
participant is presented with a stimulus this is varied slightly, and asked to identify difference.
until a change is noticed, the chg btw the two is increased
difference threshold=just-noticeable difference (jnd)
minimum difference in magnitude between 2 stimuli before one can perceive difference
webers law
constant ration between chgs in stimulus magnitude needed to produce a jnd and the magnitude of the original stimulus.
signal detection theory
perception of stimuli is affected by non sensory factors, experiences (memory), motives, and expectations.
focuses on the chgs in out perception of the same stimuli depending on in and external context
response bias
tendency of subjects to systematically respond to a stimulus in a particular way due to non sensory factors
catch trials- signal present
noise trails- signal not present
subject could respond in such a way, creating 4 diff situas
adaptation
signal detection of stimulus can change over time thru adaptation
what entire lobe of the brain is devoted to vision?
occipital lobe (out of Fpot)
eye
specialized organ used to detect light in the form of photons
sclera
white of the eye
most of the exposed potion the eye is covered by this thick structural layer
provides structural support
does not cover the front most part for he eye, the cornea
choroidal vessels
a complex intermingling of blood vessels between the sclera and retina
one of two blood vessels that supplies the nutrients to the eye