6A: Sensing the environment Flashcards
(110 cards)
Sensation
conversion of physical, electromagnetic, auditory, and other info from our internal and external environment to electrical signals in the nervous system
threshold
min amount of a stimulus that renders a difference in perception
absolute threshold
min amount of stimulus energy that is needed to activate a sensory system
Weber’s Law
there is a constant ratio between the change in stimulus magnitude needed needed to produce a jnd (just noticeable difference) and the magnitude of the original stimulus
difference threshold (just noticeable difference, JND)
min difference in magnitude between two stimuli before one can perceive this difference
signal detection theory
changes in perception of the same stimuli depending on both internal (psychological) and external (environmental) context
reponse bias
tendency of subjects to systematically respond to a stimulus in a particular way due to nonsensory factors
adaptation
two parts: physiological (sensory) component - when pupils of the eyes will dilate in the dark and contract in the light, psychological (perception) component - once we have clothes on, we stop feeling the clothes on us
psychophysics
the branch of psychology that deals with the relationships between physical stimuli and mental phenomena
sensory receptors
neurons that respond to the stimuli and trigger electrical signals
sensory pathways
signals from stimuli must pass through specific sensory pathways: different types of receptors, nerve endings or specific sensory cells, receive stimulus, transmit data to CNS through sensory ganglia (collection of neuron cell bodies found outside CNS), once transduced, electrochemical energy is sent along neural pathways to projection areas
photoreceptors
respond to EM waves in visible light: sight
hair cells
respond to movement of fluid in inner ear structures: hearing, rotational, linear acceleration
Nocireceptors
respond to painful or noxious stimuli: somatosensory
thermoreceptors
respond to changes in temp: somatosensory
osmoreceptors
respond to osmolarity of blood: water homeostasis
olfactory receptors
respond to volatile compounds: smell
taste receptors
respond to dissolved compounds: taste
eye
specialized organ used to detect light in the form of photons
sclera
exposed portion of eye is covered by this, thick structural layer (white of the eye); does not cover cornea (front most portion of eye)
choroidal vessels/retinal vessels
supplies nutrients to eyes
retina
innermost layer of eye, contains photoreceptors that transduce light into electric info. considered part of CNS. has two types of photoreceptors: light/dark, color detection
cornea
light passes through here first; clear domelike window in front of eye and it focuses and gathers light
anterior chamber
one division of the front of the eye, lies in front of the iris and posterior chamber


