Sensation and Perception Flashcards
What is the difference between sensation and perception ?
Sensation is the ability to take in physical, auditory, electromagnetic, and etc. info form the internal and external environment & convert this info into electrical signals in the nervous system. Perception would be processing this info in the nervous system in order to make sense of the significance of the info.
Neurons that respond to sensory receptors by triggering electrical signals that carry info to the CNS is termed?
Sensory receptors
How do proximal and distal stimulus’ work cooperatively?
Proximal stimuli affect sensory receptors and in turn inform the body of the presence of the distal stimuli
Collections of neuron cell bodies found outside the CNS are ?
Ganglia
What are the most essential receptors and their functions?
Photoreceptors: respond to electromagnetic waves in the visible spectrum (sight)
Mechanoreceptors: respond to pressure or movement (auditory)
Nociceptors: respond to painful or noxious stimuli (somatosensation)
Thermoreceptors: respond to changes in temp (thermosensation)
Osmoreceptors: respond to osmolarity of blood (H2O homeostasis)
Olfactory receptors: respond to volatile compounds: (smell)
Taste receptors: respond to dissolved compounds (taste)
The min energy of a stimulus needed to activate a sensory system is termed ?
Absolute Threshold
-Threshold in sensation and not perception
The level of intensity that a stimulus must have in order to be concisely perceived by the brain is the_____?
Threshold of conscious perception
-Info received by CNS but does not pass this threshold is termed subliminal perception
What is the difference between absolute threshold and the threshold of conscious perception ?
A stimulus below the absolute threshold will not transduce (never reaches CNS), but a stimulus below the threshold of conscious perception will still arrive at CNS but will not be strong enough to reach the regions of the brain that will elicit a reaction/response
The min change in magnitude required for an observer to perceive that 2 different stimuli are in fact different is the ______?
Difference threshold (just noticeable difference) -Basis for discrimination testing (change in stimulus/magnitude of original stimulus)
The idea that difference thresholds are proportional and must be computed as percentages is termed ?
Weber’s Law
The study of how internal and external factors influence thresholds of sensation and perception is termed ?
Signal Detection Theory
Trials in which the signal is presented are _____, and those where it’s not present are _______?
Noise trials and catch trials (respectively)
- Hit: signal presented and correctly detected
- Miss: signals presented but not detected
- False alarm: signal not presented but claimed to be detected
- Correct negative: no signal presented and correctly identified that it was not present
Most of the exposed portion of the eye is covered by a thick structural layer known as the_____
Sclera (white of the eye)
The eye is supplied w/ nutrients by 2 sets of blood vessels: _____ & ______
Choroidal vessels (between sclera and retina) Retinal vessels
The innermost layer of the eye that contains the photoreceptors that transduce light into chemical info the brain can process is the _____
Retina
Light 1st passes through the _____ which gathers and focuses incoming light
Cornea
The front of the eye is divided into the ______ & the _______
Anterior chamber (in front of the iris) Posterior chamber (between the iris and the lens)
The colored part of the eye (iris) is composed of which 2 muscles ?
Dilator pupillae (opens the pupil under sympathetic stimulation) Constrictor pupillae (constricts the pupil under parasympathetic stimulation)
The vascular layer of connective tissue that provides supports and nourishment to the retina is termed ?
Choroid
What produces the aqueous humor of the eye and where does it drain ?
Ciliary body & Canal of Schlemm
The ____ controls the refraction of incoming light.
Lens
The transparent gel that lies behind the lens and supports the retina is termed ?
Vitreous humor
The process of the ciliary muscles contracting and pulling the suspensory ligaments to change the shape of the lens to focus on an image is termed ?
Accommodation
Which 2 photoreceptors compose the duplexity theory of light ?
Cones (detect color)
Rods (detect light and dark)