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Psychological Research Sep 2018The displacement of the final position of a moving object in the direction of the observed motion path, i.e. an overestimation, is known as representational momentum. It...
The displacement of the final position of a moving object in the direction of the observed motion path, i.e. an overestimation, is known as representational momentum. It has been described both in the visual and the auditory domain, and is suggested to be modality-independent. Here, we tested whether a representational momentum can also be demonstrated in the somatosensory domain. While the cognitive literature on representational momentum suggests that it can, previous work on the psychophysics of tactile motion perception would rather predict an underestimation of the perceived endpoint of a tactile stimulus. Tactile motion stimuli were applied on the left and the right dorsal forearms of 32 healthy participants, who were asked to indicate the subjectively perceived endpoint of the stimulation. Velocity, length and direction of the trajectory were varied. Contrary to the prediction based on the representational momentum literature, participants in our experiment significantly displaced the endpoint against the direction of movement (underestimation). The results are thus compatible with previous psychophysical findings on the perception of tactile motion. Further studies combining paradigms from classical psychophysics and cognitive psychology will be needed to resolve the apparently paradoxical predictions by the two literatures.
Topics: Female; Humans; Male; Middle Aged; Motion Perception; Psychophysics; Touch Perception
PubMed: 28597136
DOI: 10.1007/s00426-017-0879-1 -
The Neuroscientist : a Review Journal... Apr 2002There have been three main ideas about the basic law of psychophysics. In 1860, Fechner used Weber's law to infer that the subjective sense of intensity is related to... (Review)
Review
There have been three main ideas about the basic law of psychophysics. In 1860, Fechner used Weber's law to infer that the subjective sense of intensity is related to the physical intensity of a stimulus by a logarithmic function (the Weber-Fechner law). A hundred years later, Stevens refuted Fechner's law by showing that direct reports of subjective intensity are related to the physical intensity of stimuli by a power law. MacKay soon showed, however, that the logarithmic and power laws are indistinguishable without examining the underlying neural mechanisms. Mountcastle and his colleagues did so, and, on the basis of transducer functions obeying power laws, inferred that subjective intensity must be related linearly to the neural coding measure on which it is based. In this review, we discuss these issues and we review a series of studies aimed at the neural mechanisms of a very complex form of subjective experience-the experience of roughness produced by a textured surface. The results, which are independent of any assumptions about the form of the psychophysical law, support the idea that the basic law of psychophysics is linearity between subjective experience and the neural activity on which it is based.
Topics: Animals; Humans; Models, Neurological; Neural Conduction; Perception; Psychophysics
PubMed: 11954556
DOI: 10.1177/107385840200800207 -
The Journal of Neuroscience : the... Nov 2006
Review
Topics: Animals; Neural Pathways; Psychophysics; Rats; Sensory Deprivation; Vibrissae
PubMed: 17139795
DOI: 10.1523/jneurosci.4148-06.2006 -
Current Biology : CB Oct 2004
Review
Topics: Humans; Odorants; Olfaction Disorders; Olfactory Receptor Neurons; Perception; Psychophysics; Receptors, Odorant; Smell
PubMed: 15498475
DOI: 10.1016/j.cub.2004.09.066 -
The British Journal of Ophthalmology Aug 1993
Topics: Electrophysiology; Glaucoma; Humans; Psychophysics; Retina
PubMed: 8025040
DOI: 10.1136/bjo.77.8.471 -
Pain Medicine (Malden, Mass.) Sep 2020To examine psychophysical and brain activation patterns to innocuous and painful thermal stimulation along a continuum of healthy older adults.
OBJECTIVE
To examine psychophysical and brain activation patterns to innocuous and painful thermal stimulation along a continuum of healthy older adults.
DESIGN
Single center, cross-sectional, within-subjects design.
METHODS
Thermal perceptual psychophysics (warmth, mild, and moderate pain) were tested in 37 healthy older adults (65-97 years, median = 73 years). Percept thresholds (oC) and unpleasantness ratings (0-20 scale) were obtained and then applied during functional magnetic resonance imaging scanning. General linear modeling assessed effects of age on psychophysical results. Multiple linear regressions were used to test the main and interaction effects of brain activation against age and psychophysical reports. Specifically, differential age effects were examined by comparing percent-signal change slopes between those above/below age 73 (a median split).
RESULTS
Advancing age was associated with greater thresholds for thermal perception (z = 2.09, P = 0.037), which was driven by age and warmth detection correlation (r = 0.33, P = 0.048). Greater warmth detection thresholds were associated with reduced hippocampal activation in "older" vs "younger" individuals (>/<73 years; beta < 0.40, P < 0.01). Advancing age, in general, was correlated with greater activation of the middle cingulate gyrus (beta > 0.44, P < 0.01) during mild pain. Differential age effects were found for prefrontal activation during moderate pain. In "older" individuals, higher moderate pain thresholds and greater degrees of moderate pain unpleasantness correlated with lesser prefrontal activation (anterolateral prefrontal cortex and middle-frontal operculum; beta < -0.39, P < 0.009); the opposite pattern was found in "younger" individuals.
CONCLUSIONS
Advancing age may lead to altered thermal sensation and (in some circumstances) altered pain perception secondary to age-related changes in attention/novelty detection and cognitive functions.
Topics: Aged; Brain; Cross-Sectional Studies; Healthy Aging; Humans; Magnetic Resonance Imaging; Pain Perception; Pain Threshold; Psychophysics
PubMed: 31769853
DOI: 10.1093/pm/pnz281 -
Vision Research Mar 2004The bubbles method is a recently developed variant of reverse correlation methods that have been used in psychophysics and physiology. We show mathematically that for...
The bubbles method is a recently developed variant of reverse correlation methods that have been used in psychophysics and physiology. We show mathematically that for the broad and important class of noisy linear observers, the bubbles method recovers much less information about how observers process stimuli than reverse correlation does. We also show experimentally that the unusual type of noise used in the bubbles method can drastically change human observers' strategies in psychophysical tasks, which reduces the value of the information that is obtained from a bubbles experiment. We conclude that reverse correlation is generally preferable to the bubbles method in its present form, but we also give suggestions as to how the bubbles method could be modified to avoid the problems we discuss.
Topics: Humans; Models, Psychological; Photic Stimulation; Psychometrics; Psychophysics; Visual Perception
PubMed: 14680771
DOI: 10.1016/j.visres.2003.10.006 -
Vision Research Dec 2019Although faces can be recognized from different viewpoints, variations in viewpoint impair face identification ability. The present study quantified the effect of... (Review)
Review
Although faces can be recognized from different viewpoints, variations in viewpoint impair face identification ability. The present study quantified the effect of changes in viewpoint on sensitivity to face identity. We measured discrimination thresholds for synthetic faces presented from several viewpoints (same viewpoint condition) and the same faces shown with a change in viewpoint (5°, 10° or 20°) between viewing and test. We investigated three types of viewpoint change: (i) front-to-side (front-view matched to 20° side-view), (ii) side-to-front (20° side-view matched to front) and (iii) symmetrical (10° left to 10° right). In the same viewpoint condition, discrimination thresholds were lowest for faces presented from 0° and increased linearly as the viewing angle was increased (threshold elevations: 0° = 1.00×, 5° = 1.11×, 10° = 1.22×, 20° = 1.69×). Changes in viewpoint between viewing and test led to further reductions in discrimination sensitivity, which depended upon the magnitude of viewpoint change (5 = 1.38×, 10 = 1.75×, 20 = 2.07×). Sensitivity also depended upon the type of viewpoint change: while a 20° front-to-side viewpoint change increased discrimination thresholds by a factor of 2.09×, a symmetrical change in viewpoint, of the same magnitude, did not significantly reduce sensitivity (1.26×). Sensitivity to face identity is significantly reduced by changes in viewpoint. Factors which determine the extent of this reduction include the magnitude of viewpoint change and symmetry. Our results support the premise of viewpoint-dependent encoding of unfamiliar face identities, and suggest that symmetry may be used to recognize identities across different viewpoints.
Topics: Face; Humans; Pattern Recognition, Visual; Photic Stimulation; Psychophysics; Recognition, Psychology
PubMed: 31610285
DOI: 10.1016/j.visres.2019.09.006 -
Scandinavian Journal of Work,... 1999Psychophysics is a very old branch of psychology that is concerned with the relationship between physical stimuli that occur in the "outside world", and the sensations... (Review)
Review
Psychophysics is a very old branch of psychology that is concerned with the relationship between physical stimuli that occur in the "outside world", and the sensations they produce in the body's "inside world". According to modern psychophysical theory, the strength of a sensation is directly related to the intensity of its physical stimulus by means of a power function. The history and development of psychophysics is briefly reviewed, and the application of psychophysics to manual handling tasks and repetitive hand and wrist motion is described. The advantages and disadvantages of psychophysics are discussed. The following 4 directions for future research are suggested: further validation of the data, expansion into other areas of concern (eg, other body parts, jobs, and postures), broadening of the subject base by including symptomatic subjects, and greater inclusion of psychophysical measures (eg, pain, fatigue, and discomfort) in studies of musculoskeletal disorders.
Topics: Ergonomics; Forecasting; Humans; Lifting; Musculoskeletal Diseases; Occupational Diseases; Occupational Health; Psychophysics; Reproducibility of Results; Research; Risk Factors
PubMed: 10628435
DOI: No ID Found -
Vision Research Apr 2015In this paper, studies into the tactual perception of two liquid material properties, viscosity and wetness, are reviewed. These properties are very relevant in the... (Review)
Review
In this paper, studies into the tactual perception of two liquid material properties, viscosity and wetness, are reviewed. These properties are very relevant in the context of interaction with liquids, both real, such as cosmetics or food products, and simulated, as in virtual reality or teleoperation. Both properties have been the subject of psychophysical characterisation in terms of magnitude estimation experiments and discrimination experiments, which are discussed. For viscosity, both oral and manual perception is discussed, as well as the perception of the viscosity of a mechanical system. For wetness, the relevant cues are identified and factors affecting perception are discussed. Finally, some conclusions are drawn pertaining to both properties.
Topics: Cues; Discrimination, Psychological; Humans; Psychophysics; Surface Properties; Touch Perception; Viscosity; Wettability
PubMed: 25128819
DOI: 10.1016/j.visres.2014.08.002