Sensing the Environment Flashcards
Content Category 6A: sensory processing, vision, hearing, perception, and other senses
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 (i.e.: trigger an action potential). present in sensation, but not perception.
subliminal perception
perception of a stimulus below a given threshold (i.e.: a threshold of conscious perception)
difference threshold
just-noticeable difference (JND). the minimum difference in magnitude between two stimuli before one can perceive the difference between them.
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
perception of the same stimuli can differ based on both internal and external contexts. example: the volume required to respond to your name in a crowded room vs. the volume required in a quiet room
sensory adaptation
how our sensory system adapts to and focuses attention on the most relevant stimuli, usually changes in our environment.
psychophysics
the study of the relationship between the physical nature of stimuli and the sensations and perceptions they evoke.
distal stimuli
stimuli that originate outside the body
proximal stimuli
stimuli that directly interact with and affect sensory receptors
photoreceptors
respond to electromagnetic waves in the visible spectrum (sight)
hair cells
respond to movement of fluid in the inner ear structure (hearing, rotational and linear acceleration)
nociceptors
respond to painful or noxious stimuli (somatosensation)
thermoreceptors
respond to changes in temperature (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)
describe how sensory pathways work.
different types of sensory receptors (nerve endings or sensory cells) receive stimuli and transmit data to the CNS through sensory ganglia. once transduction occurs, the electrochemical energy is sent along neural pathways to various projection areas in the brain, which further analyze the sensory input.
ganglia
collections of neuron cell bodies found outside the CNS