Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Time Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed2000

Older listeners' use of temporal cues altered by compression amplification.

This study compared the ability of younger and older listeners to use temporal information in speech when that information was altered by compression amplification. Recognition of vowel-consonant-vowel syllables was measured for four groups of adult listeners (younger normal hearing, older normal hearing, younger hearing impaired, older hearing impaired). There were four conditions. Syllables were processed with wide-dynamic range compression (WDRC) amplification and with linear amplification. In each of those conditions, recognition was measured for syllables containing only temporal information and for syllables containing spectral and temporal information. Recognition of WDRC-amplified speech provided an estimate of the ability to use altered amplitude envelope cues. Syllables were presented with a high-frequency masker to minimize confounding differences in high-frequency sensitivity between the younger and older groups. Scores were lower for WDRC-amplified speech than for linearly amplified speech, and older listeners performed more poorly than younger listeners. When spectral information was unrestricted, the age-related decrement was similar for both amplification types. When spectral information was restricted for listeners with normal hearing, the age-related decrement was greater for WDRC-amplified speech than for linearly amplified speech. When spectral information was restricted for listeners with hearing loss, the age-related decrement was similar for both amplification types. Clinically, these results imply that when spectral cues are available (i.e., when the listener has adequate spectral resolution) older listeners can use WDRC hearing aids to the same extent as younger listeners. For older listeners without hearing loss, poorer scores for compression-amplified speech suggest an age-related deficit in temporal resolution.

Adult↗
PubMed1998

Temporal course of graviperception in intermittently stimulated cress roots.

Gravitropic bending of Lepidium roots caused by intermittent stimulation lasting approximately 1 h was the same for a particular sum of stimulation intervals and was independent of (i) the length of a single stimulation interval (from 1 to 12.2 s) during which the roots were exposed unilaterally and horizontally, and (ii) rest intervals (from 60 to 300 s) during which roots were horizontally rotated at two revolutions per minute on a clinostat. The same effectiveness of equal sums of short stimulations separated by relatively long rest intervals indicates that the signals into which the stimuli are transduced are: (i) additive; (ii) proportional to the duration of a single stimulation; and (iii) stable for at least 5 min. The perception time is shorter than 1 s, the presentation time is approximately 10 s. The effects of intermittent stimulation fit the hypothesis that the gravity-induced movement of statoliths changes asymmetrically the stress in cytoskeletal actin filaments, thereby inducing gravitropic bending.

Brassicaceae↗
PubMed1982

The perception of causality in infants.

The problem of the origins of the perception of causality in infancy has received relatively little attention in the literature despite its obvious importance. Two experiments with infants 4 1/2 and 8 months old are reported which seek to investigate sensitivity to spatiotemporal continuity in simple causal events with a differential dishabituation-of-looking technique. In the first experiment inanimate events of the familiar 'billiard-ball launching' type were used, while in the second animate events involving a hand/object pick-up were presented. The results suggest that both age groups of infants were sensitive to certain changes in spatiotemporal continuity in both types of event, although in the case of the inanimate stimuli the younger infants reacted less positively. It is suggested that infants in the first year of life are sensitive to certain spatiotemporal event configurations and that this sensitivity could be regarded as at least a required component of a perception of causality.

Age Factors↗
PubMed1993

Quantitative perceptual estimates: verbal versus nonverbal retrieval techniques.

Examples of the inaccessibility of mental processes by means of verbal recall are described with particular reference to the accuracy of quantitative estimates of size, distance, and duration. Evidence is presented in support of the hypothesis that nonverbal retrieval techniques are more accurate than quantitative verbal estimates. Implications for the judicial process are considered.

Adolescent↗
PubMed1998

Spatial-frequency discrimination, brain lateralisation, and acute intake of alcohol.

The effect of alcohol (breath-alcohol level of 0.1%) on perceptual discrimination of low (1.5 cycles deg-1) and high (8 cycles deg-1) spatial frequencies in the left and right visual field was measured in eighteen right-handed males, in a double-blind, balanced placebo design. Discrimination thresholds for briefly (180 ms) presented sinusoidal gratings were determined by two-alternative forced-choice judgments with four interleaving psychophysical staircases providing random trial-to-trial variation of reference spatial frequency and visual field, in addition to a random (+/- 10%) jitter of reference spatial frequency. Alcohol produced overall higher discrimination thresholds but did not alter the visual-field balance: no main effect of visual field was observed, but in both placebo and alcohol conditions spatial frequency interacted with visual field in the direction predicted by the spatial-frequency hypothesis of hemispheric asymmetry in visual-information processing, with left-visual-field/right-hemisphere superiority in discrimination of low spatial frequencies and right-visual-field/left-hemisphere superiority in discrimination of high spatial frequencies.

Adult↗
PubMed2004

Creating noisy stimuli.

A method for creating a variety of pseudo-random 'noisy' stimuli that possess several useful statistical and phenomenal features for psychophysical experimentation is outlined. These stimuli are derived from a pseudo-periodic function known as multidimensional noise. This class of function has the desirable property that it is periodic, defined on a fixed domain, is roughly symmetric, and is stochastic, yet consistent and repeatable. The stimuli that can be created from these functions have a controllable amount of complexity and self-similarity properties that are further useful when generating naturalistic looking objects and surfaces for investigation. The paper addresses the creation and manipulation of stimuli with the use of noise, including an overview of this particular implementation. Stimuli derived from these procedures have been used successfully in several shape and surface perception experiments and are presented here for use by others and further discussion as to their utility.

Algorithms↗
PubMed2003

Cortical modulation of whole body movements in brain-damaged patients.

The aim of the present study was to assess whether the consistent bias in reproducing distances and lengths on visual tasks that characterizes hemispatial neglect is also present when whole body displacements have to be calculated and reproduced. Two different experiments were proposed to participants with right brain lesions and neglect syndrome (RN+), right (RN-) and left brain lesions (LN-) without neglect and to participants without brain damage (C). In Experiment 1, participants actively reproduced passive linear displacements in the same or in a different direction. This task could be performed using only vestibular and somatosensory input, since no relevant visual input was available. In Experiment 2, relevant visual information had to be integrated with vestibular and somatosensory information in order to make the active reproduction. In Experiment 1, all brain-damaged groups reproduced the horizontal displacements similarly to the control group and without any spatial asymmetry. In Experiment 2, when vestibular, somatosensory and visually remembered information was required to produce an integrated mental representation, RN+ processed contralesional displacements differently from ipsilesional ones. Rectilinear displacements of the whole body in space were not affected by focal left and right brain lesions, suggesting that the computation of nonvisual information can be accomplished by brain structures different from those involved in spatial visual processes. However, when body displacements in space required a mental representation based on visual and nonvisual sensory information, a significant asymmetry appeared only in patients with hemispatial neglect. Some attempts are made to identify the neural substrates involved in this integration.

Aged↗
PubMed2003

Effects of accenting and regularity on the detection of temporal deviations: does regularity facilitate performance?

In an experiment on the effect of intensity accents on the perception of time intervals between tones, H. G. Tekman (2001) found that the regular placement of deviant time intervals in short sequences of tones reduced detection, especially if intensity accents marked the deviant time intervals. That was the opposite of what one would have expected on the basis of the dynamic attending theory of M. R. Jones (1976). The effect might have occurred because temporally deviant tones create cumulative onset shifts that affect all the subsequent tones. If the deviations were randomly placed, then they could follow each other in close succession and change the local tempo. In the present study, the changes of local tempo, which might have acted as a cue for the detection of temporal deviations in the random sequences, were eliminated by compensating for deviant time intervals with equal deviations in the opposite direction in the interval that followed. That change in the stimuli eliminated the negative main effect of regularity, and the accenting interacted with regularity in favor of detection in the regular sequences. However, a simple advantage of regular over random sequences was not observed. The author discusses possible reasons for the lack of a facilitatory effect of regularity.

Attention↗
PubMed1998

Enhancement of spatial-temporal reasoning after a Mozart listening condition in Alzheimer's disease: a case study.

Several recent studies have investigated the effectiveness of various behavioral interventions on the cognitive performance of subjects with Alzheimer's disease (AD). Simulations of Shaw's structured model of the cortex led to the predictions that music might enhance spatial-temporal reasoning. A subsequent behavioral study in college students documented an improvement in scores on a spatial-temporal task after listening to a Mozart piano sonata. In this study, we investigated the enhancement of scores on a spatial-temporal task after a Mozart listening condition in a set of twins who are discordant for AD. After listening to an excerpt from a Mozart piano sonata, the AD twin showed considerable improvement on the spatial-temporal task when compared with pretest scores. Furthermore, no enhancement of scores was seen following either of the control conditions (i.e., silence or 1930s popular tunes). This finding suggests that music may be used as a tool to investigate functional plasticity in Alzheimer's disease and to better understand the underlying pathophysiology.

Aged↗
PubMed1989

Memory disorder and subjective time estimation.

Time disorientation is a common feature of anterograde memory disorder caused by brain illness. This observation suggests that the subjective time constructions used to organize events are strongly dependent upon memory storage processes. This study evaluated one prominent cognitive theory of time estimation from the point of view of organic memory disorder. A severely amnesic subject and 10 unimpaired subjects were asked to estimate time intervals using methods gleaned from the cognitive study of subjective time estimation. Results strongly suggest that the ability to remember new information is required in order to maintain an accurate time perspective. The time context for this subject essentially resided in the past, roughly corresponding to the time of her original brain surgery for a dermoid cyst near the third ventricle. Her ability to estimate time intervals and general time perspective was constrained by her impoverished store of knowledge for personal experiences.

Female↗
PubMed2003

Oculomotor control and the maintenance of spatially and temporally distributed events in visuo-spatial working memory.

Previous studies have demonstrated that working memory for spatial location can be significantly disrupted by concurrent eye or limb movement (Baddeley, 1986; Smyth, Pearson, & Pendleton, 1988). Shifts in attention alone can also interfere with spatial span (Smyth & Scholey, 1994), even with no corresponding movement of the eyes or limbs (Smyth, 1996). What is not clear from these studies is how comparable is the magnitude of effect caused by different forms of spatial disrupter. Recently, it has been demonstrated that limb movements produce as much interference with spatial span as do reflexive saccades (Lawrence, Myerson, Oonk, & Abrams, 2001). In turn this has led to the hypothesis that all spatially directed movement can produce similar effects in visuo-spatial working memory. This paper reports the results of five experiments that have contrasted the effect of concurrent eye movement, limb movement, and covert attention shifts on participants' working memory for sequences of locations. All conditions involving concurrent eye movement produced significantly greater reduction in span than equivalent limb movement or covert attention shifts with eyes fixated. It is argued that these results demonstrate a crucial role for oculomotor control processes during the rehearsal of location-specific representations in working memory.

Adult↗
PubMed2005

The perception of empty and filled time intervals by pigeons.

Pigeons were trained in a within-subjects design to discriminate durations of a filled interval (2 s and 8 s of light) and durations of an empty interval (2 s and 8 s bound by two 500-ms light markers). Filled intervals required a response to one set of comparisons (e.g., blue vs. yellow), whereas empty intervals required a response to a different set of comparisons (e.g., red vs. green). Psychophysical testing indicated that empty intervals were judged to be longer than equivalent durations of a filled interval. This finding was replicated when the anchor durations used during training were changed to 1 s and 4s, or 4s and 16s. The difference between the point of subjective equality (PSE) for the empty intervals and the PSE for filled intervals increased as the magnitude of the anchor duration pairs increased. In addition, the difference limens (DL) for empty intervals were smaller than those for filled intervals, and they also increased as the magnitude of anchor duration pairs increased. An analysis of the Weber fractions (WF; i.e., DL/PSE) provided evidence for superimposition of the empty and filled timing functions across the different sets of anchor durations. These results suggest that the accumulation of subjective time was greater for empty intervals than for filled intervals. Within the framework of scalar timing theory, this difference in timing appeared to be the result of a clock rate difference rather than a switch latency difference.

Animals↗