Chapter 2: Sensation and Perception Flashcards
Sensation
the conversion, or transduction of physical, electromagnetic, auditory, and other information from the internal and external environment into electrical signals
Perception
the processing of sensory information to make sense of its significance
Sensory Receptors
neurons that respond to stimuli and trigger electrical signals
Projection Area
areas in the brain which further analyze sensory input
Threshold
the minimum amount of a stimulus that renders a difference in perception
Absolute Threshold
the minimum of stimulus energy that is needed to activate a sensory system
Just Noticeable difference
refers to the minimum difference in magnitude between two stimuli before one can perceive this diffeence
Weber’s Law
there is a constant ratio between the change in stimulus magnitude needed to produce a jnd and the magnitude of the original stimulus
Signal Detection Theory
refers to the effects of nonsensory factors such as experiences, motives, expectations, on perception of stimuli
Adaption
refers to a decrease in response to a stimulus over time
response bias
tendency of subjects to systematically respond to a stimulus in a particular way due to nonsensory factos
catch vs noise trials
catch trials are trials in which the signal is presented and noise trials are trials where the signal is not presented
sclera
a thick structural layer that covers the most of the exposed portion of the eye, also known as the white of the eye.
blood vessels in the eye
choroidal and retinal
retina
the innermost layer of the eye which contains the photoreceptors that transduce light into electrical information for the brain
cornea
this is where light passes through first when entering the eye and is a clear domelike window in the front of the eye
iris
the colored part of the eye
muscles of the eye
dilator pupillae (opens the pupil under sympathetic stimulation) and constrictor pupillae (constricts the pupil under parasympathetic stimulation)
ciliary body
continuous with the choroid and the iris and produces aqueous humor which bathes the front part of the eye before draining into the canal of Schlemm
lens
lies behind the iris and helps control the refraction of incoming light
ciliary muscle
contraction under parasympathetic control and it pulls on the suspensory ligaments and changes the shape of the lens in a process known as accomodation
vitreous
a transparent gel that supports the retina behind the lens
retina
in the back of the eye and is functioning to convert incoming photons of light to electrical signals.
duplicity theory of vision
states that the retina contains two kinds of photoreceptors: those specialized for light-and-dark detection and those specialized for color detection.
cones
retina made up of approximately 6 million cones and they are used for color vision and to sense fine details most effective in bright light and come in three forms
rods
retina made up of 120 million rods and they are more functional and only allow sensation of light and dark because they all contain rhodopsin (night vision)
fovea
the very center of the central section of the retina (macula) contains exclusively cones in the fovea
connection between rods and cones to optic nerve
rods and cones connect with bipolar cells, which highlight gradients between adjacent rods or cones, bipolar cells synapse with ganglion cells which group together to form the optic nerve
amacrine and horizontal cells
receive input from multiple retinal cells in the same area before the information is passed on to ganglion cells. These cells are important for edge detection as they increase our perception of contrasts
visual pathways
starts from the eye and travels through the optic nerves, optic chiasm, optic tracts, later geniculate nucleus of the thalamus, and visual radiations to get to the visual cortex
parallel processing
the ability to simultaneously analyze and combine information regarding color, shape, and motion
parvocellular cells
high spatial resolution and low temporal resolution allowing us to detect shape
magnocellular cells
low spatial resolution and high temporal resolution allowing us to detect motion
pathway of sound
soundwave reaches the pinna (auricle) and then channels the sound wave to the external auditor canal which directs sound to the tympanic membrane (eardrum)
tympanic membrane
the eardrum which vibrates in phase with the incoming sound waves and the frequency of the sound wave determines the rate at which the tympanic membrane vibrates. moves faster for high frequency sounds and more slowly for low frequency sounds louder sounds have greater intensity corresponding to an increased amplitude of this vibration
