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 883 records · Page 49Linked to original sources
PubMed1977

Higher cortical dysfunction associated with long term alcoholism.

A number of studies during the past decade have described deficits associated with chronic alcoholism. Although several of these studies have used neuropsychological tests, no study has comprehensively surveyed all recognized neuropsychological skills in a single population. The present study compared 41 chronic alcoholics to 41 matched controls during a two-day battery of neuropsychological tests, including the Halstead-Reitan, Wechsler Memory Scale, and other major tests. It was hypothesized that tests reflecting right and anterior brain function would differentiate between the groups. A factor analysis of the tests which differentiated between the groups indicated five primary deficits in chronic alcoholism: spatial conceptual skills, associative conceptual skills, flexibility, spatial-motor integration, and serial integration. The last factor demonstrated a small but significant verbal loss in the alcoholics. The implications of these factors for understanding and treating chronic alcoholism were discussed.

Adult↗
PubMed1997

Cutaneous senses for detection and localization of environmental sound sources: a review and tutorial.

A review and tutorial on the potential use of the skin for sound localization are presented. Some basic physical and psychophysical properties are reviewed; special properties and phantom perceptions associated with cutaneous stimulation are presented; experiments by Békésy, Gescheider, Frost, Richardson and Weisenberger on different instrumentation for/and results on localization of sound sources with skin stimulation are analysed. The best results have been obtained using intensity differences between two vibrators. Sound source localization precision approaching that of the auditory sense in quiet surroundings has been obtained, particularly when free head movements are allowed. Significant results have also been obtained with temporal differences, provided the natural sound delay between the ears is increased to fit the coding characteristics of the skin. As yet, no portable equipment has been designed and tested in realistic environments.

Auditory Perception↗
PubMed1998

Amplitude compression in cochlear implants artificially restricts the perception of temporal asymmetry.

This paper presents a study in which five cochlear implantees were asked to discriminate the timbre of stimuli with temporally asymmetric envelopes. Stimuli were damped and ramped sinusoids presented acoustically. They were transformed by the speech processor of the implant and were presented through one electrode. All cochlear implantees could discriminate the damped and ramped sinusoids when the half-life was 4 ms, the carrier frequency was 400 Hz, and the period of the envelope was 50 ms. In a second experiment, timbre discrimination performance was measured as a function of half-life for two cochlear implantees. Both showed that timbre discrimination was possible over the range 1-24 ms. In normal-hearing listeners, the range is 1-64 ms and in cochlear implantees, stimulated directly without the speech processor, the range is 1-300 ms. At long half-lives, the decrease in discrimination performance observed with the speech processor appears to be due to the amplitude compression applied by the device. The present results suggest that it may be important to ensure that cochlear implants do not restrict temporal asymmetry unduly when applying compression to control level.

Adult↗
PubMed1985

Frequency selectivity and temporal resolution in normal and hearing-impaired listeners.

Methods of measuring the frequency selectivity of the auditory system using masking techniques are outlined and described in terms of the concept of the auditory filter. The relationship between the auditory filter shape and excitation patterns is described. Evidence is reviewed showing that frequency selectivity is usually reduced in people with cochlear hearing losses. Methods of measuring the temporal resolution of the auditory system are also reviewed, and results are compared for normally hearing and hearing-impaired subjects. Temporal resolution is impaired in most but not all cases of sensorineural hearing loss. It is concluded that the loss of frequency and temporal resolution accompanying cochlear hearing loss is a major cause of the difficulties encountered by the hearing impaired in understanding speech in noisy situations.

Auditory Threshold↗
PubMed2005

Effects of visual and auditory short-term memory tasks on the spatiotemporal dynamics and variability of postural sway.

The authors measured postural sway while participants (N = 20 in each experiment) stood on a rigid or a compliant surface, with their eyes open or closed, and while they did or did not perform a short-term memory (STM) task. In Experiment 1, the STM stimuli were presented visually; in Experiment 2, the stimuli were presented auditorily. In both experiments, fine-scaled, mediolateral postural-sway variability decreased as the cognitive load imposed by the STM task increased. That effect was independent of support surface and vision manipulations. The spatiotemporal profile of postural sway was affected by both visual and auditory STM tasks, but to a greater degree by the auditory task. The authors discuss implications of the results for theories and models of postural control.

Adolescent↗
PubMed2002

Hemispheric asymmetries in categorical judgments of direction versus coordinate judgments of velocity of motion.

Three experiments on visual field differences in motion perception are reported. Experiment 1 employed circular stimuli that grew or shrank either quickly or slowly. Experiments 2 and 3 employed circles that moved upward or downward either quickly or slowly. Judgments based on categorical equivalence classes (i.e., grow/shrink, upward/downward) generally yielded small and nonsignificant right visual field advantages. Judgments based on the precise coordinates of motion (i.e., quickly/slowly) yielded significant left visual field advantages across all three experiments. Results are interpreted in light of Kosslyn's (1987) model of hemispheric differences in the processing of categorical versus coordinate spatial relations.

Attention↗
PubMed2004

The accuracy of spatial information from temporally and spatially organized mental maps.

The way a space is learned can result in a mental map that is either temporally or spatially organized (Curiel & Radvansky, 1998). The present study examined the availability of spatial information under map learning conditions where either temporal or spatial organization has been previously observed. The finding was that people were fairly accurate in tasks that explicitly required the use of spatial information. However, there was a particular advantage for having a spatially organized mental map in a direction judgment task, especially for short distances where fine-grained knowledge was required. In contrast, there was no clear advantage for either group in a distance estimation task. These data are interpreted in the context of Huttenlocher's category adjustment model.

Cognition↗
PubMed2000

Analyzing human random time generation behavior: a methodology and a computer program.

In the present article, it is argued that in addition to the traditional random generation tasks discussed by Towse and Neil (1998), random time interval generation tasks should be considered as useful alternatives, because they allow a better empirical control of the executive task component in dual-task situations. First, a framework for discussing randomness over time is presented. Then, the article goes on to present three methods for the analysis of such tasks. A first method is based on the correlation between the intervals produced. The second method calculates the approximate entropy, and the third method converts the time sequences into binary sequences and estimates the statistical properties of the sequence on the basis of these binary data. A principal components analysis on 19 different measures based on 1,381 sequences produced in a number of single-task and dual-task experiments shows that the proposed measures form two general clusters, one related to output probability, perseveration, and alternation, and one related to sequential commonalities. The article also briefly describes a computer program that implements these methodologies.

Humans↗
PubMed1993

An information integration approach to phenomenal causality.

Phenomenal causality was studied by using Michotte's launch event, in which successive motion of two objects evokes an immediate perception that the first motion causes the second. Information integration theory was used to address the complementary issues of invariant perceptual structure and individual differences in phenomenal causality. Three informational cues were varied conjointly: temporal and spatial contiguity of the two motions, and the ratio of their speeds. The dependent measure was a judgment of degree of causality or naturalness. The results showed that individual differences were related to these instruction conditions; the subjects showed five distinctive response patterns. Two were the modal patterns elicited by the instructions, and the others fell in between. The averaging model gave a good account of the data, with meaningful parameter estimates. Individual differences were localized in cue evaluation, whereas their integration into a unified judgment followed an invariant averaging rule. The results allow some reconciliation between Michotte and his critics.

Causality↗
PubMed1995

Repetition blindness under minimum memory load: effects of spatial and temporal proximity and the encoding effectiveness of the first item.

Repetition blindness (RB) refers to the reduced performance in reporting a repeated as opposed to a nonrepeated item in rapid serial visual presentation. In Experiment 1, we found RB for two-item stimuli in uncertain locations. The magnitude of RB decreased significantly with increases in interstimulus interval, but not with increases in spatial separation, indicating that RB is determined primarily by temporal factors. In Experiment 2, we found RB when subjects were required to report only the second of two successively presented items. The magnitude of RB increased with the duration of the first item, indicating that RB is determined by the encoding effectiveness of the first item. The results of this study collectively indicate that RB is not a memory or a sensory phenomenon, but rather a perceptual phenomenon occurring at the stage of identity encoding. The findings also undermine the arguments (Kanwisher, 1987) that have been offered in favor of the type-token binding failure hypothesis and indicate instead that type-node refractoriness may be the cause of RB.

Humans↗
PubMed1998

Interactions between spatial and spatiotemporal information in spatiotemporal boundary formation.

The surface and boundaries of an object generally move in unison, so the motion of a surface could provide information about the motion of its boundaries. Here we report the results of three experiments on spatiotemporal boundary formation that indicate that information about the motion of a surface does influence the formation of its boundaries. In Experiment 1, shape identification at low texture densities was poorer for moving forms in which stationary texture was visible inside than for forms in which the stationary texture was visible only outside. In Experiment 2, the disruption found in Experiment 1 was removed by adding a second external boundary. We hypothesized that the disruption was caused by boundary assignment that perceptually grouped the moving boundary with the static texture. Experiment 3 revealed that accurate information about the motion of the surface facilitated boundary formation only when the motion was seen as coming from the surface of the moving form. Potential mechanisms for surface motion effects in dynamic boundary formation are discussed.

Analysis of Variance↗
PubMed2005

Contributions of temporal and place cues in pitch perception in absolute pitch possessors.

Pitch perception is determined by both place and temporal cues. To explore whether the manner in which these cues are used differs depending on absolute pitch capability, pitch identification experiments with and without pitch references were conducted for subjects with different absolute pitch capabilities and musical experience. Three types of stimuli were used to manipulate place and temporal cues separately: narrowband noises, which provide strong place cues but less salient temporal cues; iterated rippled noises, which provide strong temporal cues but less salient place cues; and sinusoidal tones, which provide both. The results indicated that absolute pitch possessors utilize temporal cues more effectively when they identify musical chroma With regard to the judgment of height, it was indicated that place cues play an important role for both absolute and nonabsolute pitch possessors.

Adolescent↗
PubMed2005

A spatial explanation for synchrony biases in perceptual grouping: consequences for the temporal-binding hypothesis.

If two images are shown in rapid sequential order, they are perceived as a single, fused image. Despite this, recent studies have revealed that fundamental perceptual processes are influenced by extremely brief temporal offsets in stimulus presentation. Some researchers have suggested that this is due to the action of a cortical temporal-binding mechanism, which would serve to keep multiple mental representations of one object distinct from those of other objects. There is now gathering evidence that these studies should be reassessed. This article describes evidence for sensitivity to fixational eye and head movements, which provides a purely spatial explanation for the earlier results. Taken in conjunction with other studies, the work serves to undermine the current body of behavioral evidence for a temporal-binding mechanism.

Brain↗