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PubMed1983

The filled-duration illusion: limits of duration of interval and auditory fillers.

Two experiments were conducted to explore parameters of the filled-duration illusion, i.e., intervals filled with stimuli are perceived as longer than empty intervals of equal physical duration. It was hypothesized that the illusion would be found only for intervals of short duration, i.e., a few seconds, and that filled intervals would vary in perceived duration as a function of the type of "filler." Auditory tones were used as boundary and filler stimuli in a counterbalanced (Exp. I) and randomized (Exp. II) design that covered 9 intervals ranging from 1 to 60 sec. A psychophysical method of verbal estimation with single stimuli was employed. The first hypothesis was supported in that only with the short intervals (1 and 3 sec.) was there any evidence of a filled-duration illusion. The type of filler stimulus was important only in the 1-sec. intervals. Results are interpreted in terms of information-processing models for time perception.

Adolescent↗
PubMed2002

Deficits in auditory and visual temporal perception in schizophrenia.

INTRODUCTION: Characteristics of time perception have not been well documented in patients with schizophrenia. The current study investigated time estimation to (1) test whether visual and auditory time perception varied between patients and controls, (2) assess the degree to which patients and controls can differentiate changes in experimental intervals, and (3) explore whether the temporal deficits suggest a general time perception deficit versus modality-specific differences. METHODS: Participants were asked to decide whether temporal intervals were shorter or longer than standard intervals on computer-based auditory and visual temporal perception tasks. Data are presented for a sample of 10 patients with schizophrenia and 10 normal controls. RESULTS: Data suggest that patients with schizophrenia exhibit deficits in differentiating subtle differences in intervals in the tens of milliseconds range, compared to their normal control peers on both auditory (p < .01) and visual perception tasks (p < .01). CONCLUSIONS: Preliminary data suggest that there is a general temporal processing deficit in schizophrenia. However, future research using complementary techniques may provide useful information regarding the specific types of temporal deficits that affect patients with schizophrenia and the physiology of the dysfunction.

Journal Article↗
PubMed1996

Alpha brainwave training and perception of time passing: preliminary findings.

The ability to generate alpha brainwaves has been associated with the self-regulation of stress. It has been suggested that generation of these brainwaves, above what is to be expected in a normal 24-hour EEG, contributes to an expanded state of consciousness. This study attempted to test Newman's theory that expansion of consciousness could be observed in perception of time passing. Twenty female college students were randomly assigned to an alpha brainwave training or beta (mock) brainwave training group. Following ten 30-minute training sessions over a five-week period of time, each subject in each group was asked to produce ten randomly assigned time intervals. Mean scores were obtained for each of the ten intervals for each group. An analysis of variance with repeated measures was used to analyze the time interval perceptions of each group. According to results obtained, both main effects and interaction effects were highly significant (p < .0001). This study offers a beginning effort to examine the consciousness altering capability of alpha brainwave generation.

Acoustic Stimulation↗
PubMed1996

Effects of actual waiting time, perceived waiting time, information delivery, and expressive quality on patient satisfaction in the emergency department.

STUDY OBJECTIVE: To determine the effects of actual waiting time, perception of waiting time, information delivery, and expressive quality on patient satisfaction. METHODS: During a 12-month study period, a questionnaire was administered by telephone to a random sample of patients who had presented to a suburban community hospital emergency department during the preceding 2 to 4 weeks. Respondents were asked several questions concerning waiting times (ie, time from triage until examination by the emergency physician and time from triage until discharge from the ED), information delivery (eg, explanations of procedures and delays), expressive quality (eg, courteousness, friendliness), and overall patient satisfaction. RESULTS: There were 1,631 respondents. The perception that waiting times were less than expected was associated with a positive overall satisfaction rating for the ED encounter (P < .001). Satisfaction with information delivery and with ED staff expressive quality were also positively associated with overall satisfaction during the ED encounter (P < .001). Actual waiting times were not predictive of overall patient satisfaction (P = NS). CONCLUSION: Perceptions regarding waiting time, information delivery, and expressive quality predict overall patient satisfaction, but actual waiting times do not. Providing information, projecting expressive quality, and managing waiting time perceptions and expectations may be a more effective strategy to achieve improved patient satisfaction in the ED than decreasing actual waiting time.

Adolescent↗
PubMed1996

Characterization of hydrotropism: the timing of perception and signal movement from the root cap in the agravitropic pea mutant ageotropum.

In this study, ageotropum pea mutant was used to determine the threshold time for perception of an osmotic stimulation in the root cap and the time requirement for transduction and transmission of the hydrotropic signal from the root cap to the elongation region. The threshold time for the perception of an osmotic stimulation was compared to current estimates of threshold times for graviperception in roots. The time required for transduction and transmission in the hydrotropic response of ageotropum was compared to the time requirement in the gravity response of Alaska pea roots. We determined that threshold time for perception of an osmotic stimulation in the root cap is very rapid, occurring in less than 2 min following the application of sorbitol to the root cap. Furthermore, a single 5 min exposure of sorbitol to the root cap fully induced a hydrotropic response. We also found that transduction and transmission of an osmotic stimulus requires 90-120 min for movement from the root cap to more basal tissues involved in differential growth leading to root curvature. The very rapid threshold time for perception of root hydrotropism is similar to those times reported for root gravitropism. However, the time required for the transduction and transmission of an osmotic stimulation from the root cap is significantly longer than the time required in gravitropism. These results suggest that there must exist some differences between root hydrotropism and gravitropism in either the rate or mechanisms of transduction and transmission of the tropistic signal from the root cap.

Gravitropism↗
PubMed2004

Driver perception response time during the signal change interval.

The importance of perception response time (PRT) values for traffic signal change interval design, and the need to monitor the design PRT value, are challenges facing transportation professionals. However, current methods used to validate the design PRT value from on-site observational studies have failed to yield convincing proof that the 1 second design value is adequate. A modification to on-site data capture and extraction, using a transitional zone (TZ), is used to overcome this deficiency. The TZ allows the systematic identification and exclusion of those drivers who have time to delay their responses. Their inclusion in past studies inflated PRT values. Their exclusion in this study provides a more accurate value.

Automobile Driving↗
PubMed1978

Effect of density and environmental noise on perception of time, the situation, oneself and others.

The effects of density, intrusion of one's personal space, sex of subject, group composition, and environmental noise on the perception of time, the situation, oneself and others were investigated in this study. Generally, the results indicated that (1) both density and the intrusion of personal space concurrently affect the perception of crowding, (2) the physical factors interacted with the social and personal factors to affect the perception of several aspects of the situation, and (3) the environmental noise did not, for the most part, affect the perception of the situation.

Crowding↗
PubMed2006

Post-traumatic stress disorder and illness perceptions over time following myocardial infarction and subarachnoid haemorrhage.

OBJECTIVES: This study investigated post-traumatic stress disorder (PTSD) symptoms and illness perceptions in people who suffered the acute medical trauma of a myocardial infarction (MI) or a subarachnoid haemorrhage (SAH). The study tested hypotheses regarding changes in PTSD symptoms and illness perceptions over time, associations between PTSD and illness perceptions and cognitive predictors of PTSD. DESIGN AND METHOD: The study employed a longitudinal design and measured the illness perceptions and PTSD symptoms of an MI group (N=17) and a SAH group (N=27). Data were collected within 2 weeks of admission (T1), 6 weeks after admission (T2) and 3 months after admission (T3). Statistical analysis was undertaken to examine associations between illness perceptions and PTSD and to examine cognitive predictors of PTSD. RESULTS: The prevalence of PTSD within the total acute medical trauma sample was 16% at 2 weeks, 35% at 6 weeks and 16% at 3 months. Illness perception factors of identity, timeline (acute/chronic), consequences and emotional representation were strongly correlated with PTSD at all three time points. PTSD symptoms and illness perceptions were shown to have changed over time. The results also showed that several illness perception factors are significant predictors of PTSD. CONCLUSIONS: Both PTSD symptoms and illness perceptions changed significantly over time following an MI or SAH. Illness perception factors are significant predictors of PTSD.

Attitude to Health↗
PubMed1976

Facilitation of stereopsis from a large disparity random-dot stereogram by various monocular features: further findings (a short note).

This experiment examined the effects of adding five different kinds of prominent monocular features to a large-disparity random-dot stereogram. It was found that features which enclosed the disparate area produced the shortest initial perception times for fusion. The longer initial perception times for stimuli containing features without this enclosing property are explained in terms of less-helpful guidance of saccadic eye movements prior to the establishment of fusion. Subsequent reductions in perception times for these latter stimuli could be due to perceptual learning within the eye movement control system.

Depth Perception↗
PubMed2003

A right hemispheric frontocerebellar network for time discrimination of several hundreds of milliseconds.

Debate still surrounds the nature of the role of the dorsolateral prefrontal gyrus (DLPFC) in time perception. This region is frequently associated with working memory and is thus implicated as a so-called "accumulator" within a hypothesized internal clock model. However, we hypothesized that this region may have a more primary role in time perception. To test this hypothesis we used functional magnetic resonance imaging (fMRI) to examine the neural correlates of relatively pure time perception with a temporal discrimination task where intervals of 1 s had to be discriminated from those of 1.3, 1.4, and 1.5 s. Time perception in this particular time domain within the "perceived present" has not previously been investigated using fMRI. By using relatively short time periods to be discriminated and also contrasting activation with an order judgment task, we aimed to minimize the confounding aspects of sustained attention and working memory. In a group of 20 healthy right-handed adult males, neural activation associated with time discrimination was found in a predominantly right hemispheric network of right dorsolateral and inferior prefrontal cortices, right supplementary motor area, and left cerebellum. We conclude that right DLPFC, rather than having a purely working memory function, might be more centrally involved in time perception than previously thought.

Adult↗
PubMed1999

Perception of time: delay of estimation under auditory and visual tasks with type-A measures.

The perception of time is likely to be lengthened when estimates of duration are delayed rather than given immediately as reported by Vitulli and Crimmins in 1999. The present study sought boundary conditions for this robust effect. A multivariate analysis of variance showed a reliable main effect for delay of estimation, yet comparisons between auditory versus visual short-term memory tasks showed no differences in time estimations. The analysis showed weak interactions between sex and delay of estimation and between sex and delay of estimation on Jenkins Activity Survey-Job Involvement scores.

Auditory Perception↗
PubMed2002

Auditory chronostasis: hanging on the telephone.

The perception of time can be illusory: we have all waited anxiously for important seconds to tick away slowly at the end of a football game and have experienced the truth of the adage "time flies when you're having fun." One illusion of time experience that has recently been investigated, the apparent slowing of the movement of the second hand on the clock when one first looks at it, has been termed "chronostasis," and it has been suggested that the effect is unique to vision and is dependent on eye movements. We sought to test whether the effect is really unique to vision or whether it can also be produced with auditory stimuli. Subjects were asked to judge the length of a silent gap between two tones presented through headphones. When the tones were presented to one ear, subjects judged the duration of the gap veridically. When subjects were required to shift concentration from one ear to the other, however, the judgement of time showed that the auditory system is also susceptible to chronostasis. We suggest that this generalization of chronostasis to another sensory system is consistent with theories of time perception that emphasize a single, multimodal clock for duration estimation rather than a mechanism that is dependent on motor acts.

Auditory Perception↗
PubMed1994

Managing the perceptions of patient wait time.

Patients' perception of waiting time in the dental office can greatly affect their satisfaction of service. Traditional approaches to managing patient perceptions of wait time are discussed, and some new strategies are explored.

Appointments and Schedules↗
PubMed2003

Accuracy of sleep perceptions among insomnia sufferers and normal sleepers.

OBJECTIVE: To examine the distribution, consistency, and correlates of sleep time perceptions in primary insomnia sufferers and normal sleepers across settings (laboratory and home). METHODS: Fifty-two middle-aged and older insomnia sufferers and 49 matched normal sleepers underwent multiple nights of laboratory and home polysomnography (PSG) and provided concurrent subjective estimates of their sleep. Descriptive statistics, cluster analyses, and inferential tests were used to examine the nature of sleep time perceptions, identify subgroups with distinctive patterns such as perceptions, and explore factors that may contribute to these subgroups' distinctive sleep perceptions. RESULTS: Consistent with previous studies, the insomnia sufferers, as a group, showed a greater tendency to underestimate the time they slept than did the normal sleepers, but the accuracy of sleep time perceptions varied widely within each sample. Correlational analyses showed that study participants in each sample showed a moderate level of consistency in how accurately they estimated sleep time across nights. Subsequent cluster analyses conducted to identify subgroups with distinctive patterns of sleep time perceptions yielded four subgroups within the insomnia sample and three subgroups within the normal sleeper sample. Although the sleep setting significantly affected sleep perceptions for one insomnia subgroup, both laboratory and home objective-subjective sleep comparisons provided similar impressions regarding the relative accuracy of each subgroup's nocturnal sleep/wake perceptions. Finally, varying patterns of subgroup differences were noted across several common psychometric measures. CONCLUSIONS: The underestimation of sleep time is not a generic characteristic that separates all insomnia sufferers from normal sleepers. Sleep setting, personality traits, and perhaps constitutional factors appear to influence perceptions of sleep and wake time duration.

Analysis of Variance↗
PubMed2002

Perception of timing is more context sensitive than sensorimotor synchronization.

In three experiments, the effects of contextual temporal variation on the perception of timing and on sensorimotor synchronization were examined. Experiment 1 showed that exposure to a variably timed auditory precursor sequence reduces the detectability of deviations from isochrony in a musical test sequence. By contrast, in Experiment 2 there was only a small and transient effect of identical precursor sequences on the variability of finger taps that were synchronized with a similar test sequence. Moreover, the precursor did not impede phase error correction following deviations from isochrony in the test sequence. Experiment 3 employed a within-subjects design that required simultaneous detection of irregularities in and synchronization with nonmusical auditory sequences. Precursor variability impaired only detection, not synchronization performance. These results suggest that perception of deviations from regularity engages context-sensitive tining processes, probably related to conscious awareness, that are not involved in sensorimotor synchronization.

Adult↗
PubMed1997

The development and evaluation of the hypertension temporal orientation (HTO) scale.

Temporal orientation is a multidimensional concept that describes the perception of time among individuals. Time perception is structured by life experiences and can vary depending upon the particular context involved. Whether a person is past-, present- or future-oriented has been shown to influence his/her approach and reaction to health situations. Because the management of hypertension is based on achieving some future health state, hypertension provides a context in which an individual's time perspective may be particularly influential. One purpose of this study was to develop and evaluate a scale to measure temporal orientation that was specific to hypertension, namely the hypertension temporal orientation (HTO) scale. Data were collected via telephone interviews with 300 people who had been diagnosed by a physician as having hypertension. Principal components factor analysis revealed three dimensions of hypertension temporal orientation: (1) a nonexperiential domain; (2) an experiential disease domain; and (3) an experiential treatment domain with coefficient alpha estimates of 0.76, 0.66, and 0.63, respectively. The HTO scale was significantly discriminant of African Americans and whites on the experiential treatment domain whereby African Americans were more present-oriented regarding the daily management (or treatment) of hypertension as compared to whites. Additional evidence for the validity of the HTO scale was found with temporal orientation group comparisons on health perceptions. The findings provide early support for the reliability and validity of the HTO scale for measuring temporal orientation among people with hypertension.

Adult↗
PubMed2001

From physical time to the first and second moments of psychological time.

After examination of the status of time in experimental psychology and a review of related major texts, 2 opposite approaches are presented in which time is either unified or fragmented. Unified time perception views, usually guided by Weber's law, are embodied in various models. After a brief review of old models and a description of the major contemporary models of time perception, views on fragmented time perception are presented as challenges for any unified time view. Fragmentation of psychological time emerges from (a) disruptions of the Weber function, which are caused by the types of interval presentation, by extensive practice, and by counting explicitly or not; and (b) modulations of time sensitivity and perceived duration by attention and interval structures. Weber's law is a useful guide for studying psychological time, but it is also reasonable to assume that more than one so-called central timekeeper could contribute to perceiving time.

Attention↗