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Simple motor reaction time and judgment of temporal order are commonly recognized as two methods for estimation of perceptual latency. Unfortunately, the results obtained by the methods under the same conditions do not agree. We review hypotheses attempting to explain the disagreement. Although some of these seem to be promising, no one at present could be fully accepted.
BACKGROUND: Time management in ambulatory patient visits is increasingly critical. Do patients who perceive a longer visit with internists report increased satisfaction? METHODS: Prospective survey of 1486 consecutively encountered ambulatory visits to 16 primary care physicians (PCPs) in an academic primary care clinic. Patients were queried regarding demographics, health status, perception of time spent before and after ambulatory visits, whether the physician appeared rushed, and visit satisfaction. Physicians were queried regarding time spent, estimated patient satisfaction, and whether they felt rushed. RESULTS: In 69% of 1486 consecutive visits, patient previsit expectation of visit duration was 20 minutes or less. Patient and PCP postvisit estimates of time spent significantly exceeded patient previsit time expectation. Patients who estimated that they spent more time than expected with the PCP were significantly more satisfied with the visit. When patient postvisit estimate of time spent was less than the previsit expectation, visit satisfaction was significantly lower independent of time spent. Patient worry about health and lower self-perceived health status were significantly associated with patient expectation for longer visits. Primary care physicians felt rushed in 10% of encounters. Although PCPs estimated patient satisfaction was significantly lower when they felt rushed, patient satisfaction was identical when PCPs did and did not feel rushed. Patients indicated that PCPs appeared rushed in 3% of encounters, but this perception did not affect patient satisfaction. CONCLUSION: Perceived ambulatory visit duration and meeting or exceeding patient expectation of time needed to be spent with the physician are determinants of patient satisfaction in an ambulatory internal medicine practice.
An evaluation of time perception in drug addicts was carried out in 12 s intervals, using 10 attempts with up to 0.1 s precision. Eighty-two heroin addicts in abstinent and post abstinent periods have been observed, the results being compared to 52 healthy controls. During the first two days after admission to the hospital (abstinent syndrome development), time intervals values were lower in patients than in controls, reaching a precision of recalling 12s, with a following exceeding of this index. On day 15-16, time perception returned to precise level (post abstinent period). Depending on drug addiction duration and individual features of brain hemisphere asymmetry, changes in subjective time perception were revealed in the study.
BACKGROUND: Timeliness of care is 1 of 6 dimensions of quality identified in Crossing the Quality Chasm. We compared patient and physician perceptions of appropriate timing of visits for common medical problems. METHODS: This study was conducted at 2 internal medicine clinics at the University of Colorado Health Sciences Center. Adult patients and companions, and outpatient General Internists were surveyed. The survey contained 11 clinical scenarios of varying urgency. Respondents indicated how soon the patient in each scenario should be seen. Responses ranged from that day to 1 to 3 months. Responses were analyzed using the Mann-Whitney U test. RESULTS: Two hundred and sixty-two patients and 46 of 61 physicians responded. For 8 of the 11 scenarios patients felt they should be seen significantly earlier than physicians. Scenarios involving chronic knee and stomach pain, routine diabetes care, and hyperlipidemia generated the greatest differences. Patients and physicians agreed on the urgency of scenarios concerning wheezing in an asthmatic, an ankle injury, and acute pharyngitis. CONCLUSIONS: Patients expected to be seen sooner than physicians thought necessary for many common chronic medical conditions, but are in agreement about timeliness for some acute problems. Understanding patient expectations may help physicians respond to requests for urgent evaluation of chronic conditions.
In a previous paper we showed that community children with hyperactive behavior were more inconsistent than controls in the temporal organization of their motor output. In this study we investigated: (1) various aspects of motor timing processes in 13 clinically diagnosed boys with attention deficit hyperactivity disorder (ADHD) who were compared to 11 community boys with hyperactive behavior and to a control group and (2) the effect of methylphenidate on the motor timing processes in the clinical group with ADHD in a double blind, cross-over, medication-placebo design, including 4 weeks of medication. The clinical group with ADHD, like the community group with hyperactivity, showed greater variability in sensorimotor synchronization and in sensorimotor anticipation relative to controls. The clinical group was also impaired in time perception, which was spared in the community group with hyperactivity. The persistent, but not the acute dose, of methylphenidate reduced the variability of sensorimotor synchronization and anticipation, but had no effect on time perception. This study shows that motor timing functions are impaired in both clinical and community children with hyperactivity. It is the first study to show the effectiveness of persistent administration of methylphenidate on deficits in motor timing in ADHD children and extends the use of methylphenidate from the domain of attentional and inhibitory functions to the domain of executive motor timing.
Four questions concerning the perceptual source of information about time to contact (tc) are addressed: (a) What conditions are required for the optic variable tau to play a role in the perception of tc? (b) When these conditions are met, does tau alone provide sufficient information for accurate timing of interceptive actions? (c) Does a distance divided by velocity account of tc perception provide a convincing alternative to an account that is based on tau? (d) Is there any empirical evidence that distinguishes the two accounts? A "global" type of tau variable and a "local" type of tau variable are distinguished, each with different limitations. The discussion is largely concerned with local tau variables, 2 versions of which are identified. It is concluded that tau alone cannot provide sufficient information for skilled timing. An extended tau-based account presented in an earlier article (Tresilan, 1990) is discussed. It is argued that no extant empirical data can distinguish the extended account from the distance divided by velocity account.
The literature on time perception is discussed. This is done with reference both to the "cognitive-timer" model for time estimation and to the subjective experience of apparent duration. Three assumptions underlying the model are scrutinized. I stress the strong interplay among attention, arousal, and time perception, which is at the base of the cognitive-timer model. It is suggested that a multiplicative function of two key components (the number of subjective time units and their size) should predict apparent duration. Implications for other cognitive domains are drawn, and in particular an analogy is suggested between apparent duration and apparent movement.
To support the idea that temporal information processing may depend on an internal clock, Treisman et al. proposed a pacemaker model (Treisman, M., Faulkner, A., Naish, P.L.N., Brogan, D., 1990. The internal clock: Evidence for a temporal oscillator underlying time perception with some estimates of its characteristics frequency. Perception 19, 705-743.) and a technique for interfering with it by introducing an external periodic phenomenon. Experimental results obtained by these authors on time estimation and production tasks support this model. In another study, Treisman et al. established that the pacemaker also affects reaction times (RT) (Treisman, M., Faulkner, A., Naish, P.L.N., 1992. On the relation between time perception and the timing of motor action: Evidence for a temporal oscillator controlling the timing of movement. Quarterly Journal of Experimental Psychology 45A, 235-263.). In the present study, we addressed the question as to which information processing stage (Sanders, A.F., 1980. Stage analysis of reaction process, In: Stelmach, G.E., Requin, J. (Eds.). Tutorials in motor behavior. North-Holland, Amsterdam, pp. 331-354.) is affected by this internal clock. For this purpose, we used the Additive Factors Method (Sternberg, S., 1969. The discovery of processing stages: Extension of Donder's method. In: Koster, W.G. (Ed.). Attention and Performance II. Acta Psychologica 30, 276-315.). To vary sensorial processing time, we used two visual stimulus intensities. Stimulus-response mapping was manipulated to enhance central processing time. To modify the duration of the motor stages, the two responses could be given by two fingers on the same hand (right ring vs. middle finger) or by two fingers of the different hands (right ring vs. left middle finger). Intensity of the stimulus, stimulus-response mapping, and repertoire of responses were found to be additive. We obtained RT modulations similar to those obtained by Treisman et al. in 1992. No first order interactions were observed between the periodical phenomenon and the other manipulated factors but only a third order one. Two possible interpretations of these results are proposed.
A reading time and an ERP experiment conducted in Italian investigated the parser's responses to a syntactic violation (subject-verb number agreement) and to a semantic violation (subject-verb selectional restriction), examining the time course of comprehension processes until sentence end. The reading-time data showed that the syntactic violation was detected earlier than the semantic one and that the two violations differed in the time-course. The ERP data fully supported the reading time data: Syntactic anomalies elicited a left anterior negativity (LAN) and a P600. Semantic anomalies elicited a N400 centred on the parietal sites which started 90 ms later (latency 430 ms) than the LAN. Furthermore, the N400 evoked by the words that followed the target word continued and increased until sentence end. The results are discussed with respect to the hypotheses that the parser constructs distinct syntactic and semantic analyses of a sentence and that this characteristic holds cross-linguistically. The appropriateness of different methodologies to the study of sentence processing is also evaluated.
The time course of audiovisual information in speech perception was examined using a gating paradigm. VCVs that evoked the McGurk effect were gated visually and auditorily. The visual gating yielded a McGurk effect that increased in strength as a linear function of amount of visual stimulus presented. The acoustic gating revealed a more nonlinear function in which the VC information was considerably weaker than the CV portion of the VCV. The results suggest that the flow of cross-modal information in quite complex during audiovisual speech perception.
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It is well recognized that sleep time misperceptions are common among insomniacs, but little is known about the distribution and clinical significance of these subjective distortions. The current investigation was conducted to examine the distribution of sleep time misperceptions among a large (n = 173), diverse group of insomniacs and to determine if such misperceptions might relate to the patients' clinical characteristics. Consistent with previous studies, our subjects, as a group, produced sleep estimates that were significantly (p < 0.0001) lower than polysomnographically determined sleep times. However, patients' sleep time perceptions were widely distributed across a broad continuum, which ranged between gross underestimates and remarkable overestimates of actual sleep times. Results also showed that subgroups, formed on the basis of presenting complaints and diagnostic criteria (i.e. International Classification of Sleep Disorders nosology), differed in regard to the magnitude and direction of their sleep distortions. Moreover, these differences appeared consistent with the types of objective sleep disturbances these subgroups commonly experience. Hence, the tendency to underestimate actual sleep time is not a generic attribute of all insomniacs. Furthermore, it appears that the accuracy and nature of sleep time perceptions may relate to the type of sleep pathology underlying insomniacs' presenting complaints.
PURPOSE: To document immediate and short-term biobehavioral effects of therapeutic touch (TT), estimate the magnitude of TT effects, and compare TT effects to placebo responses. DESIGN: A repeated measures, pretest-posttest quasi-experimental design. TT and mimic TT were administered using standardized protocols to 11 adults in a controlled setting. METHODS: Four physiological (total pulse amplitude, blood pressure, pulse, temperature) and three subjective (stress, self-assessment of health, time perception) variables were evaluated over 24 hours. FINDINGS: Total pulse amplitude and time perception decreased significantly immediately after TT intervention, indicating vasoconstriction and time passing "faster," with large and medium effect sizes significantly greater than were placebo responses. Vasodilation, a relaxation response, was expected instead of vasoconstriction. CONCLUSIONS: TT may have adverse and positive outcomes.
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People with learning disabilities often have difficulties understanding abstract concepts such as the concept of time yet research in this area is scarce. Not only does the development of an understanding of the concept of time enable us to predict future events, order past events and give us a sense of control over current events, it also serves to contribute to the very essence of our understanding of a sense of ourselves. It seems reasonable to suggest that the converse may be true for people who are not able to develop this concept. Time perception and understanding are complex cognitive processes. It is suggested that facilitating this development and managing associated difficulties may be achieved by focusing on the practical applications of time in everyday life. Improving time perception abilities may reduce feelings of powerlessness and anxiety and increase feelings of self-efficacy but research is needed to evaluate this.
Visual perception consists of early preattentive processing and subsequent attention-demanding processing. Most researchers implicitly treat preattentive processing as a domain-dependent, indivisible stage. We show, however, by interrupting preattentive visual processing of color before its completion, that it can be dissected both temporally and spatially. The experiment depends on changing easy (preattentive) selection into difficult (attention-demanding) selection. We show that although the mechanism subserving preattentive selection completes processing as early as 200 msec after stimulus onset, partial selection information is available well before completion. Furthermore, partial selection occurs first at locations near fixation, spreading radially outward as processing proceeds.
This study examines the public's and physicians' willingness to support deception of insurance companies in order to obtain necessary healthcare services and how this support varies based on perceptions of physicians' time pressures. Based on surveys of 700 prospective jurors and 1617 physicians, the public was more than twice as likely as physicians to sanction deception (26%versus 11%) and half as likely to believe that physicians have adequate time to appeal coverage decisions (22%versus 59%). The odds of public support for deception compared to that of physicians rose from 2.48 to 4.64 after controlling for differences in time perception. These findings highlight the ethical challenge facing physicians and patients in balancing patient advocacy with honesty in the setting of limited societal resources.