Basics + Psychophysics Flashcards
attempt 1
Cell body
contains nucleus
Nucleus
all computation for cell
Dendrites
important for computation
Axon
transmits electron activity
Axon terminal
transmits information to another neuron
Myelin sheath
insulation so electron signal is faster
Synapses
“The junction between neurons that permits information transfer.”
Neurotransmitter
“A chemical substance used in neuronal communication at synapses.”
Cerebellum
used to believe it was exceptionally important in movement but we now know that it is also important for perception & sensation
Occipital- primary visual cortex
First place where the visual information goes
Occipital- secondary visual cortex
Where the processed information go
Temporal- Primary auditory cortex
First place where auditory information go
temporal- secondary auditory cortex
Also important for motion and visual information (sensory processing)
Parietal
parts of the body are represented by adjacent parts of the brain & assist in spatial info and sophisticated motion processing
Frontal
Known for impulse control, judgment, motor control & sensory processing
Synaptic transmission
Connection needs to be strong enough to excite the next neuron so sometimes it needs multiple neurons to signal it.
Psychophysics
the science of defining quantitative relationship b/w physical and psychological (subjective) events
Sensation
lowest level of processing; physical energy translated into informational signal (ie. transduction)
Perception
usually “interpretation” of the information, but the distinction is irrelevant
Goal of psychophysics
psychophysics quantifies
Absolute thresholds
the minimum intensity of a stimulus that can be detected, sigmoid function, probability of detection increases with the signal intensity
Sigmoid function
a graph with a curved shaped S, right side
Difference thresholds
the smallest detectable diff between two stimuli OR the minimum change in a stimulus that enables it to be correctly judged as diff from a reference stimulus
JND
Just noticeable difference or how different two stimuli must be for the subject to notice that they are not the same
Method of Constant stimuli
in which many stimuli, ranging from rarely to almost always perceivable (or rarely to almost always perceivably different from a reference stimulus), are presented at a time. Participants respond to each presentation: “yes/no” “same/diff” and so on.
Method of Limits
in which the particular dimension of a stimulus, or the difference between two stimuli, is varied incrementally until the participants responds differently
Method of Adjustment
a method in which the participant controls the change in the stimulus
Weber’s Law
the principle describing the relationship between stimulus and resulting sensation that says that just noticeable difference (JND) is a constant fraction of the comparison stimulus
Fechner’s Law
a principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation increases proportionally to the log of the stimulus intensity
Steven’s Law
a principle describing the relationship b/w stimulus and resulting sensation that says the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an exponent.
Compression
the slope of the line is less than a 1:1 ratio (light)
Veridical
The slope of the line is equal to a 1:1 ratio (pencil length)
Exaggerated
he slope of the line is greater than a 1:1 ratio (electric shock)
Magnitude estimation
a psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli
Signal detection theory
a psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of noise. Measures obtained from a series of presentations are sensitivity (d’) and criterion of the observer.
Criterion
in reference to SDT, an internal threshold that is set by the observer. If the internal response is above criterion the observer gives on response and if below gives another.
Sensitivity
in reference to SDT, a value that defines the ease with which an observer can tell the diff b/w the presence and absence of a stimulus or the diff b/w stimulus 1 and stimulus 2