Chapter 1 Flashcards
sensation
The ability to detect a stimulus and, perhaps, to turn that detection into a private experience.
perception
The act of giving meaning to a detected sensation.
qualia
In reference to philosophy, private conscious experiences of sensation or perception.
dualism
The idea that the mind has an existence separate from the material world of the body.
materialism
The idea that the only thing that exists is matter, and that all things, including the mind and consciousness, are the results of interaction between bits of matter.
panpsychism
The idea that the mind exists as a property of all matter, that is that all matter has consciousness.
psychophysics
The science of defining quantitative relationships between physical and psychological (subjective) events.
two-point touch threshold
The minimum distance at which two stimuli are just perceptible as separate.
just noticeable difference (JND) / difference threshold
The smallest detectable difference between two stimuli, or the minimum change in a stimulus that enables it to be correctly judged as different from a reference stimulus.
Weber fraction
The constant of proportionality in Weber’s law.
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.
Fechner’s law
A principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity.
absolute threshold
The minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time.
method of constant stimuli
A psychophysical method in which many stimuli, ranging from rarely to almost always perceivable (or rarely to almost always perceivably different from a reference stimulus), are presented one at a time. Participants respond to each presentation: “yes/no,” “same/different,” and so on.
method of limits
A psychophysical method in which the particular dimension of a stimulus, or the difference between two stimuli, is varied incrementally until the participant responds differently.
method of adjustment
A method of limits in which the participant controls the change in the stimulus
magnitude estimation
A psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli.
Steven’s power law
A principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an exponent.
cross-modality matching
The ability to match the intensities of sensations that come from different sensory modalities. This ability allows insight into sensory differences. For example, a listener might adjust the brightness of a light until it matches the loudness of a tone.
supertaster
An individual who experiences the most intense taste sensations. Some stimuli are dramatically more intense for supertasters than for medium tasters or nontasters. Supertasters also tend to experience more intense oral burn and oral touch sensations.
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 signal detection theory, an internal threshold that is set by the observer. If the internal response is above criterion, the observer gives one response (e.g., “yes, I hear that”). Below criterion, the observer gives another response (e.g., “no, I hear nothing”).
sensitivity
In reference to signal detection theory, a value that defines the ease with which an observer can tell the difference between the pres- ence and absence of a stimulus or the difference between Stimulus 1 and Stimulus 2.
receiver operating characteristic (ROC) curve
In reference to studies
of signal detection, the graphical plot
of the hit rate as a function of the false alarm rate. If these are the same, points fall on the diagonal, indicating that
the observer cannot tell the difference between the presence and absence of the signal. As the observer’s sensitivity increases, the curve bows upward toward the upper left corner. That point represents a perfect ability to distinguish signal from noise (100% hits, 0% false alarms).
sine wave
A simple, smoothly changing oscillation that repeats across space.
wavelength
The distance required for one full cycle of oscillation for a sine wave.
period
In reference to hearing, the time required for a full wavelength of an acoustic sine wave to pass by a point in space.
phase
A fraction of the cycle of the sine wave described in degrees (0° to 360°) or radians (0π to 2π). In reference to hearing, phase can be used to describe fractions of a period that relate to time.
Fourier analysis
A mathematical procedure by which any signal can be separated into component sine waves at different frequencies. Combining these sine waves will reproduce the original signal.
spatial frequency
The number of cycles of a grating (e.g., changes in light and dark) per unit of visual angle (usually specified in cycles per degree).
cycles per degree
The number of pairs of light and dark bars (cycles of grating) per degree of visual angle.
doctrine of specific nerve energies
A doctrine, formulated by Johannes Müller, stating that the nature of a sensation depends on which sensory fibers are stimulated, rather than how they are stimulated.
cranial nerves
Twelve pairs of nerves (one for each side of the body) that originate in the brain stem and reach sense organs and muscles through openings in the skull.
olfactory (I) nerves
The first pair of cranial nerves. The axons of the olfactory sensory neurons bundle together after passing through the cribriform plate to form the olfactory nerve, which conducts impulses from the olfactory epithelia in the nose to the olfactory bulb.
optic (II) nerves
The second pair of cranial nerves, which arise from the retina and carry visual information to the thalamus and other parts of the brain.
vestibulocochlear (VIII) nerves
The eighth pair of cranial nerves, which connect the inner ear with the brain, transmitting impulses concerned with hearing and spatial orientation. The vestibulocochlear nerve is composed of the cochlear nerve branch and the vestibular nerve branch.
oculomotor (III) nerves
The third pair of cranial nerves, which innervate all the extrinsic muscles of the eye except the lateral rectus and the superior oblique muscles, and which innervate the elevator muscle of the upper eyelid, the ciliary muscle, and the sphincter muscle of the pupil.
trochlear (IV) nerves
The fourth pair of cranial nerves, which innervate the superior oblique muscles of the eyeballs.
abducens (VI) nerves
The sixth pair of cranial nerves, which innervate the lateral rectus muscle of the eyeballs.
polysensory
Referring to blending multiple sensory systems.
vitalism
The idea that there is a force in life that is distinct from physical entities.
synapse
The junction between neurons that permits information transfer.
neurotransmitter
A chemical substance used in neuronal communication at synapses.
neuroimaging
A set of methods that generate images of the structure and/or function of the brain. In many cases, these methods allow us to examine the brain in living, behaving humans.
electroencephalography (EEG)
A technique that, using many electrodes on the scalp, measures electrical activity from populations of many neurons in the brain.
event-related potential (ERP)
A measure of electrical activity from a subpopulation of neurons in response to particular stimuli that requires averaging many EEG recordings.
magnetoencephalography (MEG)
A technique, similar to electroencephalography, that measures changes in magnetic activity across populations of many neurons in the brain.
computed tomography (CT)
An imaging technology that uses X-rays to create images of slices through volumes of material (e.g., the human body).
magnetic resonance imaging (MRI)
An imaging technology that uses the responses of atoms to strong magnetic fields to form images of structures like the brain. The method can be adapted to measure activity in the brain, as well.
functional magnetic resonance imaging (fMRI)
A variant of magnetic resonance imaging that makes it possible to measure localized patterns of activity in the brain. Activated neurons provoke increased blood flow, which can be quantified by measuring changes in the response of oxygenated and deoxygenated blood to strong magnetic fields.
blood oxygen level-dependent (BOLD) signal
The ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain neurons that are most involved in a task.
positron emission tomography (PET)
An imaging technology that enables us to define locations in the brain where neurons are especially active by measuring the metabolism of brain cells using safe radioactive isotopes.
