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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.
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.
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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.
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.
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.
The time perception mechanism in anticipatory timing control was investigated in a synchronization tapping task. An especially negative asynchrony phenomenon in which the tap onset precedes the stimulus onset was used as an anticipatory response. In this experiment, to clarify the effects of higher brain functions, such as attention, a dual-task method was applied and a word memory task was used as a secondary task. The results revealed two types of anticipatory mechanisms from the standpoint of attentional resources involved in time perception. One is the anticipatory tapping that is influenced by attention and seen in the interstimulus-onset interval (ISI) range of 1,800 to 3,600 ms. In this region, the magnitude of synchronization error (SE) between tap onset and stimulus onset was scaled by the ISI. The other is the automatic anticipation that is not affected by attention and is seen in the 450 to 1,500 ms range. SE in this region was constant and independent of the ISI. Accordingly, this anticipatory timing mechanism in synchronous tapping is thought to be a dual process including the attention processing of temporal information and the embodied automatic anticipation.
Naive observers of random-dot stereograms depicting complex surfaces often find that they require several tens of seconds before the impression of depth emerges. With practice, however, perception times often decrease markedly: perceptual learning occurs. Current explanations of these effects were assessed in two experiments. In the first experiment the perception times of naive observers for random-dot stereograms which depicted the same complex shape but contained different ranges of disparity were measured. In the second experiment the minimum times required by experienced observers to perceive a given complex shape in stereograms that contained different ranges of disparity were determined. Perception times for the naive observers were all very fast (<3 s) and showed no evidence of perceptual learning. There was no effect of disparity range on perception times in either experiment. It was found that very large-disparity (80 min arc) complex stereograms could be perceived quickly, even by naive observers. It is concluded that the long initial latencies previously reported are not due to surface complexity nor to the range of disparities present. Other factors. such as dot size, dot density, and the correlation of the stereo images, appear to be important determinants of efficient stereoscopic performance when viewing complex random-dot stereograms.
Time and again a lack of staff in the field of people's nursing is discussed (chronic lack of nursing staff); this means that there are not enough people to do the available work) (1). However, the time factor is also an important sociological dimension in old people's stationary care. First of all, this article points out the time dimension throughout life. This is followed by people's varying perceptions of the present and the related upsets and misunderstandings. Hereby the contradictory abundance and limitation in time as felt by the elderly also becomes apparent. The old people's awareness of the dwindling remainder of their own lifespans conflicts with the seemingly endless time of each day that passes.
A study is reported on the perception of empty time intervals marked by auditory signals. Nakajima's supplement hypothesis, which states that the subjective duration of a subjectively empty time interval is proportional to its physical duration plus a constant of approximately 80 ms, was examined quantitatively. Although this hypothesis has been used to explain various general aspects of time perception, from a global viewpoint, it has lacked the quantitative data necessary to describe the shape of the psychophysical functions mathematically. In the present study, subjects used two positive numbers to estimate the subjective ratio (m:n) between the durations of two serial or separate empty intervals. The psychophysical functions for empty durations 50-600 ms long could be approximated by a straight line with a positive gamma-intercept, as predicted by the hypothesis. The effective range of the hypothesis could be extended to approximately 1200 ms. A power function (without any modifications) also gave good approximations. The reliability and validity of the supplement hypothesis are discussed.
Temporal processing of durations in the range of seconds or more (i.e. time estimation) is cognitively mediated, whereas processing of brief durations in the range of milliseconds (i.e. time perception) appears to be beyond cognitive control and based on neural counting mechanisms. Although there is some evidence from animal and human studies suggesting that the internal timing mechanism underlying time perception is modulated by the effective level of brain dopamine, the findings are not conclusive. Therefore, the effects of pharmacologically induced changes in D2 receptor activity on temporal information processing were evaluated. In a double-blind design, either 3 mg of haloperidol, 150 mg of remoxipride, or placebo were administered in a single oral dose. Performance on time estimation was significantly impaired by both haloperidol and remoxipride as compared with placebo. Both drugs obviously affected cognitive mechanisms underlying temporal processing of durations in the range of seconds. On the other hand, only haloperidol produced a significant decrease in performance on time perception as compared with placebo and remoxipride, whereas the remoxipride and placebo groups did not differ significantly. The differential effects of haloperidol and remoxipride on performance on time perception suggest that D2 receptor activity in the basal ganglia may play a critical role in timing of brief durations in the range of milliseconds.
This study investigates, in young nonobese healthy athletes, the consequences of a 3-day fast coupled, or not, to enhanced physical activity. Eight male subjects, aged 21+/-2 years, fasted for 3 days on two separate occasions, 4 weeks apart. On the first occasion, subjects continued their daily training activities. On the second occasion, a daily physical exercise program was added to these activities. Subjects were evaluated before and after 24 hours and 72 hours of fasting. Evaluation consisted of body composition, basal respiratory exchange ratio, plasma metabolic parameters, perception-reaction time (both simple and discriminant), hand grip strength, and physical work capacity at 170 beats per minute (PWC170). Fasting determined significant reductions in body weight, body fat, and muscle mass. These reductions were not affected by enhanced physical activity. Basal respiratory exchange ratio decreased with fasting but was not influenced by increased training activities. Fasting determined a significant decrease in blood glucose levels, while plasma proteins, urea, uric acid, and free fatty acids increased. Perception-reaction time and hand grip strength were unmodified during fasting. By contrast, PWC170 was significantly and progressively reduced during fasting, and this decrease was not reversed by an increase in training activities.
Many types of behavior slow with age, and older drivers require more time to process information and make decisions. How greater response time requirements relate to the design of the highway environment and to features of new in-vehicle technologies is discussed. The design requirements for many different aspects of roadway geometrics and traffic control devices are based on design driver perception-reaction times. However, without knowing how much slower older drivers are than the design driver, it is difficult to determine whether they are adequately protected by current design practice and, if not, what the desired change in design should be. Attempts to address this have been hampered by the lack of directly relevant data, the situation-specific nature of certain findings, and the older driver's ability to compensate for declines in basic skills. Also discussed are the promise and problems of new in-vehicle technologies for providing the older driver with adequate time to act. These intelligent vehicle highway systems (IVHS) may speed navigational decision making and recognition of hazards and maneuver requirements. However, the possibility for interfering with quick responding also arises, and IVHS systems might disadvantage the older driver in other ways.
This study investigated the acute effects of delta(9)-tetrahydrocannabinol (THC) on four behavioral measures of impulsivity in recreational marijuana users. Although impulsive behavior has been studied using several different measures of impulsivity, few studies have utilized more than one of these measures on a single cohort. In this study, 37 healthy men and women participated in three sessions, in which they received capsules containing placebo, 7.5, or 15 mg THC in randomized order under double-blind conditions. Subjects were tested on the following four tasks: the Stop task, which measures the ability to inhibit a prepotent motor response; a Go/no-go task; a Delay discounting task, which measures the value of delayed or uncertain reinforcers; and a time estimation task, which measures alterations in time perception through a time reproduction procedure. Subjects also completed mood questionnaires and general measures of performance. THC produced its expected effects on subjective measures including increases in ARCI euphoria and marijuana scales. THC increased impulsive responding on the Stop task but did not affect performance on either the Go/no-go or Delay or Probability discounting tasks. On the time reproduction task, THC increased estimates of the duration of short intervals while not affecting estimates of longer intervals. There were no significant correlations between the four tasks either before or after drug administration. These results suggest that THC may increase certain forms of impulsive behavior while not affecting other impulsive behaviors. The dissociations between the four measures of impulsivity suggest that impulsivity is an assemblage of distinct components rather than a unitary process.
The acute behavioral effects of atropine sulfate were assessed using a battery of complex food-reinforced operant tasks that included: temporal response differentiation (TRD, n = 7); delayed matching-to-sample (DMTS, n = 6), progressive ratio (PR, n = 8), incremental repeated acquisition (IRA, n = 8), and conditioned position responding (CPR, n = 8). Performance in these tasks is thought to depend primarily upon specific brain functions such as time perception, short-term memory and attention, motivation, learning, and color and position discrimination, respectively. Atropine sulfate (0.01-0.56 mg/kg iv), given 15-min pretesting, produced significant dose-dependent decreases in the number of reinforcers obtained in all tasks. Response rates decreased significantly at greater than or equal to 0.03 mg/kg for the learning and discrimination tasks, at greater than or equal to 0.10 mg/kg for the motivation and short-term memory and attention tasks, and at greater than or equal to 0.30 mg/kg for the time perception task. Response accuracies were significantly decreased at doses greater than or equal to 0.10 mg/kg for the learning, discrimination, and short-term memory and attention tasks, and at greater than or equal to 0.30 mg/kg for the time perception task. Thus, the order of task sensitivity to any disruption by atropine is learning = color and position discrimination greater than time perception = short-term memory and attention = motivation (IRA = CPR greater than TRD = DMTS = PR). Thus in monkeys, the rates of responding in operant tasks designed to model learning and color and position discrimination were the most sensitive measures to atropine's behavioral effects. Accuracy in these same task was also disrupted but at higher doses. These data support the hypothesis that cholinergic systems play a greater role in the speed (but not accuracy) of performance of our learning and discrimination tasks compared to all other tasks. Accuracy of responding in these and the short-term memory task, all of which involve the use of lights as visual stimuli, was more sensitive to disruption by atropine than those tasks which did not utilize such strong visual stimuli.
We measured perception time of the vibratory stimulus from a 128 cps tuning fork in 96 male and 96 female normal subjects equally subdivided into 8 age decades. The following sites were examined: clavicula, olecranon, styloid apophysis of ulna and radius, anterosuperior spina of ilium, rotula (patella), internal and external malleolus. Reproducibility between different examiners and between tests by the same examiner on different days was good. There was a marked regional variation with longer perception times at the distal regions of upper limbs. A non linear age-related decrease in vibration sense was found in all regions. Males had longer perception times at clavicula, females at distal limbs; the latter finding might be explained by shorter stature in females. Perception times at distal limbs were longer in subjects with higher education levels. The study provides normative data for vibration sense in different regions and defines the effects on it of age, gender, height and education.
Outbred rats (n = 60) were trained to count 20-s intervals (by the technique developed by J. Bures) with drinking reinforcement. The animals were divided in three groups, which were subjected to conditioning from 7.00 to 9.00 a.m, from 1.00 to 3.00 p.m., and from 8.00 to 10.00 p.m, respectively. Conditioning was most efficient in the morning and least efficient in the day-time. Thus, the better capability of rats for time perception and conditioning on the basis of time perception in transitional phases of a day (from light to darkness and on the contrary) is in agreement with circadian rhythm of locomotion of these nocturnal animals.
In this study, we investigated when visual perception begins in fixations. During picture viewing, the picture was degraded at the beginning of selected saccades and changed back to the original after varying intervals. Participants manually responded whenever they detected changes. The change-backs were undetected when they occurred <6 msec after the end of the saccade, marked by the peak of the overshoot in dual Purkinje image eyetracker data, and detection reached asymptote 32 msec after that marker. Eye velocity at the change-back time also affected detection likelihood. Apparently, perception begins around the time at which the eyes stop rotating at the end of a saccade, giving a psychological justification for measuring fixation durations from then. This also specifies the deadline for gaze-contingent display changes to occur without detectable image motion. Investigators using the dual Purkinje image eyetracker should consider the peak of the overshoot as the fixation onset time and measure intrafixational presentation times from then.