MCAT Psych #2 Flashcards
(180 cards)
sensation (transduction)
conversion of physical, electromagnetic, auditory, and other information from our internal and external environment to electrical signals in the NS.
o Goes from PNS to CNS, raw signal.
perception
the processing of information to make sense of its significance. Includes external sensory experience and internal activities of the brain and spinal cord. How to make sense of the world.
sensation vs. perception
sensation is the process of sensing our environment while perception is how we interpret these sensations,.
sensory receptors
neurons that respond to stimuli and trigger electrical signals.
distal stimuli
stimuli that originate outside of the body (ex: campfire)
proximal stimuli
directly interact with and affect the sensory receptors, and inform the observer about the presence of distal stimuli.
Ex: heat from campfire or photons from the light of the campfire.
psychophysics
the relationship between the physical nature of stimuli and the sensations and perceptions they evoke.
ganglia
collections of neuron cell bodies found outside the central nervous system.
o Transmit the data to the CNS
projection areas
location that the electrochemical energy signal is sent to in the brain which will then be further analyzed.
name the types of sensory receptors
o Photoreceptors: respond to electromagnetic waves in the visible spectrum (sight)
o Hair cells: respond to movement of fluid in the inner ear structures (hearing, rotational, and linear acceleration)
o Nociceptors: respond to painful or noxious stimuli (somatosensation)
o Thermoreceptors: respond to changes in temperature (thermosensation)
o Osmoreceptors: respond to the osmolarity of the blood (water homeostasis)
o Olfactory receptors: respond to volatile compounds (smell)
o Taste receptors: respond to dissolved compounds (taste)
photoreceptors
respond to electromagnetic waves in the visible spectrum (sight)
hair cells
respond to movement of fluid in the inner ear structures (hearing, rotational, and linear acceleration)
nocireceptors
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
Olfactory receptors: respond to volatile compounds (smell)
taste receptors
Taste receptors: respond to dissolved compounds (taste)
threshold
the minimum amount of a stimulus that renders a difference in perception.
o Ex: temperature changes throughout the day but it is not noticed until a big change (threshold is hit)
o Ex: temperature changes throughout the day but it is not noticed until a big change (threshold is hit)
absolute threshold
o the minimum of stimulus energy that is needed to activate a sensory system. The minimum intensity at which a stimulus will be transduced.
Threshold in sensation, not in perception.
How bright, loud, or intense a stimulus must be before it is sensed converted to an action potential.
Threshold of Conscious Perception
sensory systems send signals to the CNS without a person perceiving them (too small of stimulus or too brief)
A stimulus below the threshold of conscious perception arrives at the central nervous system but does not reach the higher-order brain regions that control attention and consciousness.
discrimination testing
what is the synonym of limina
threshold
what is the synonym for subliminal perception
threshold of conscious perception
discrimination testing
participant is shown one stimulus and then asked to identify if there is a difference in the second stimulus. Repeat until the participant reports noticing a change.
difference threshold
just noticeable difference (jnd)
the minimum difference in magnitude between two stimuli before one can perceive this difference.
Ex: sound frequency: the jnd is 3 hz, between sound waves at 440 Hz and 443 Hz.
Can also look at the jnd as a %, which would be 3/440 = 0.68%
• 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.
o Thus, for higher magnitude stimuli, the actual difference must be larger to produce a jnd.
o Holds for all sensory modalities except for at the extremely high or low ends of each range.