Chapter 1-introduction Flashcards
sensation
the ability to detect a stimulus and, perhaps, to turn that detection into a private experience, getting info in
perception
act of giving meaning to a detected sensation, internal endpoint, manifestation
transduction
conversion, neural energy
who studies sensations and perceptions
multidisciplinary-psychology, biology, computer science, linguists, etc.
study of sensations and perceptions is a _____ pursuit and requires _____ methods
scientific
thresholds
finding the limits of what can be perceived, tool
scaling
measuring private experience, report of “more” or “less”
are your qualia (private experiences) the same as others
signal detection theory
decision making in the presence of noise (neuronoise, external noise)
sensory neuroscience
the biology of sensation and perception, sensory receptors and nerves
neuroimaging
image of the mind, tool
relationship between mind and body using math-who?
Fechner
psychophysics
the science of defining quantitative relationships between physical and psychological (subjective) events
perceive motion/change with more or less luminance
high
psychophysics example
2 point touch threshold
just noticeable difference
smallest detecable difference between 2 stimuli, or the minimum change in a stimulus that can be correctly judged as different from a reference stimulus. are they the same or different?
another term for JND
difference threshold
absolute threshold
minimum amount of stimulation necessary for a person to detect stimulus 50% of the time
is the absolute threshold fixed
no, varies slightly based on noise (neural, sensory)
who discovered that they smallest change in astimulus that can be detected is a constant proportion of the stimulus level
Ernst Weber
Weber’s law
the principle describing the relationship between stimulus and resulting sensation that says the JND is a constant fraction of the comparison stimulus
JND example
lifting weights, 1 stays the same while the other increases. better at detecting a difference when the standard weight is lighter
what stimulus values have larger JNDs?
what stimulus values have smaller JNDs?
larger
smaller
weber’s law is constant ____ difference
relative; fraction 1:100
as the stimulus increases, need to ____ different weights to detect difference
increase
method of constant stimuli
many stimuli, ranging from rarely to almost always perceivable, are presented one at a time. controlled by researcher
show stimuli equal number of times
method of adjustment
participant controls the stimulus directly, increasing or decreasing values until it switches between being perceivable and not perceivable. subjective, spend more time in the middle
magnitude estimation
participant assigns values according to perceived magnitudes of the stimuli
stevens power law
describes the relationship between stimulus and resulting sensation; describes magnitude estimates
sevens power law formula
S=aI^b
S=scaling strength
I=stimulus intensity
^b=exponent, depend on type of stimulus
a=personal/subjective scaling, varied from person to person
magnitude
present stimuli, rate on scale
y=x^b, what happens to JND if
b>1
b=1
0<b></b>
JND shrinks
JND is constant absolute difference
Webers law-JND is constant relative difference
signal detection theory
the brains response to a stimulus is variable; quantifies response of observer to the presentation of a signal in the presence of noise
criterion for signal
decisions on the presence or absence of a stimulus or for same or different judgments use criteria; internal threshold set by the observer; changing it changes the hits and false alarms
receiver operating characteristic curve (ROC curve)
graphical plotting of hit rate as a function of false alarm rate
doctrine of specific nerve energies
formulated by johannes muller stating that the nature of sensation depends on WHICH sensor fibers are stimulated, not how they are stimulated
polysensory areas
information from several senses combined
synapse
junction between neurons that permits information transfer
neurotransmitter
chemical substance used in neuronal communicatino at synapses
EPSP
excitatory postsynaptic potential, causes action potential
IPSP
inhibitory postsynaptic potential, inhibits the action potential
layout of neuron
D -dendrite C -cell B body A -axon Synapse D C B A
action potential
depolarize axon with Na+
EPSP depolarized, less different from 0
IPSP hyperpolarized, more different from 0
electroencephalography (EEG)
space resolution
time resolution
invasive?
technique that, using many electrodes on the scalp, measures electrical activity from populations of many neurons in the brain
low
high (ms)
no
event related potential (ERP)
measure of electrical activity from a subpopulation of neurons in response to particular stimulus that requires AVERAGING many EEG recordings
computerized tomography (CT)
space resolution
time resolution
invasive?
imaging technology that uses xrays to create images of slices through volumes of material, structural
high
very low (years)
no
functional magnetic resonance imaging(fMRI)
space resolution
time resolution
invasive?
variant of MRI that makes it possible to measure localized patterns of activity in the brain. activated neurons provoke increased blood flow, which can be quantivied by measuring changed of oxygenated and deoxygenated blood to strong magnetic fields
medium
medium (sec)
no
lesion
space resolution
time resolution
invasive?
high/med
low (before/after)
very
single unit
space resolution
time resolution
invasive?
Electrophysiology, what neurons are doing
very high
very high (ms)
yes
clinical
space resolution
time resolution
invasive?
med
low (before/after)
yes
sense: sight/vision
stimulus info
receptor type
brain area
light/photons
photoreceptor
occipital lobe
sense: touch/somatosensation
stimulus info
receptor type
brain area
temperature, pressure/vibration
thermoreceptor, mechanoreceptor, nociceptor
parietal lobe
sense: hearing/audition
stimulus info
receptor type
brain area
sound/pressure wave
mechanoreceptor
temporal lobe
sense: taste/gestation
stimulus info
receptor type
brain area
chemicals
chemoreceptor
insular cortex
sense: smell/olfaction
stimulus info
receptor type
brain area
odor molecules
chemoreceptor
piriform cortex
sense: vestibuluar/balance orientation
stimulus info
receptor type
brain area
fluid pressure
mechanoreceptor
cerebellum, temporal lobe
sense: proprioception
stimulus info
receptor type
brain area
muscle and joint stretch/pressure
mechanoreceptor
cerebellum, parietal lobe
