Chapter 2: Sensation and Perception Flashcards
What is transduction?
conversion of physical, electromagnetic, auditory information from internal or external environment to electrical signals in the nervous system (sensory information)
What is perception?
Processing sensory information to make sence of its significance
What are sensory receptors?
neurons that respond to stimuli and trigger electrical signals
Distal Stimuli
stimuli that originate from outside of the body
Proximal Stimuli
interact/affect sensory receptors, and inform the observer about the presence of distal stimuli
Ganglia
neuron cell bodies round outside central nervous system
receptors receive stimuli and transmit information to the nervous system through the ganglia
Photoreceptors
respond to electromagnetic waves in visible light spectrum (sight)
Hair Cells
respond to movement of fluid in inner ear structure (hearing)
Nociceptors
respond to pain or noxious stimuli (somatosensation)
Thermoreceptors
respond to changes in temperature
Osmoreceptors
respond to osmolarity (water homeostasis)
Olfactory Receptors
Respond to volatile compounds (smell)
Taste Receptors
respond to dissolved compounds (taste)
Threshold
The minimum amount of a stimulus that renders a difference in perception
What is absolute threshold?
- minimum of stimulus energy needed to activate a sensory system
- threshold in SENSATION
What is the threshold of Conscious Perception?
- Threshold by which a stimuli not only reaches the CNS, but reaches high order brain regions that control attention and consciousness
What is the difference threshold ?
minimum difference in magnitude between two stimuli before one can perceive a difference
Describe Weber’s Law
There is a constant ratio between change in stimulus and and the original magnitude of the stimulus
Signal Detection Theory
changes of perception of the same stimuli depending on internal and external context
Response Bias
Tendency to respond to a stimulus in a particular way
Sclera
White of the eye, covers most of the exposed region of the eye
Choroidal and retinal vessels
provide nutrients to the eye
Retina
innermost layer of the eye, contains photoreceptors
converts incoming photons of light to electrical signals
Cornea
Gathers and focuses incoming light
The front of the eye is divided into the :
anterior and posterior chamber
Which two muscles make up the pupil?
Dilator and constrictor pupillae
ciliary body
produces aqueous humor that bathes the front part of the eye