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 343 records · Page 19Linked to original sources
PubMed2006

Unlocking the riddle of time in learning disability.

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.

Adult↗
PubMed2000

Tracking visual search over space and time.

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.

Adult↗
PubMed2004

Lying to insurance companies: the desire to deceive among physicians and the public.

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.

Deception↗
PubMed2005

Creativity: self-perceptions over time.

This study explores creativity and motivation in the second half of life. While many quantitative studies on creativity show decline with advancing age, there is some evidence that creativity may change qualitatively over time. The purpose of this study is to elucidate self-perceived changes in creativity over the life span. The participants included visual artists, both working and retired. A total of 21 adults, ages 53 to 75, participated in the study. Ten of the artists were interviewed in depth regarding the perception of their own creativity over time. Another 11 artists participated in two separate focus groups. All of the participants represented their perceived creativity using an adaptation of the Creative Life-Line Curve (CLLC; Romaniuk, Romaniuk, Sprecher, & Cones, 1983). Findings indicated that participants do not perceive a decline in creativity with age. In-depth analysis of the interviews included qualitative coding to establish a number of themes that permeated the self-perceptions regarding changes in creativity over time. These themes were found to exemplify many of the concepts inherent in the life-span developmental perspective.

Aged↗
PubMed1997

Comparative effects of alcohol and marijuana on mood, memory, and performance.

This study compared subjective and behavioral effect profiles of alcohol and smoked marijuana using technology that controlled puffing and inhalation parameters. Male volunteers (n = 5) with histories of moderate alcohol and marijuana use were administered three doses of alcohol (0.25, 0.5, or 1.0 g/kg), three doses of marijuana [4.8, or 16 puffs of 3.55% delta 9-tetrahydrocannabinol (THC)], and placebo in random order under double blind conditions in seven separate sessions. Blood alcohol concentration (10-90 mg/dl) and THC levels (63-188 ng/ml) indicated that active drug was delivered to subjects dose dependently. Alcohol and marijuana produced dose-related changes in subjective measures of drug effect. Ratings of perceived impairment were identical for the high doses of alcohol and marijuana. Both drugs produced comparable impairment in digit-symbol substitution and word recall tests, but had no effect in time perception and reaction time tests. Alcohol, but not marijuana, slightly impaired performance in a number recognition test. These data are useful for understanding the relative performance impairment produced by alcohol and marijuana at the delivered doses and the relationship between their subjective and behavioral effects.

Adolescent↗
PubMed1984

The relationship between space and time in the perception of stimuli moving behind a slit.

When a shape defined by a set of dots plotted along its contour is presented in a sequence of frames within the boundaries of a slit, and in each frame only one dot (featureless frame) or two dots (feature frame) are displayed, a whole moving dotted shape is perceived. Masking techniques and psychophysical measures have been used to show that a dynamic random-dot mask interferes with shape identification, provided the interframe interval is greater than about 15 ms, and there are no stimulus features for recognition in individual frames. A similar pattern of results was obtained when the observer had only to detect the movement of a single dot or a pair of dots against a dynamic-noise background. It is concluded that the visual system can resolve the correspondence problem in both apparent movement (one moving dot) and aperture viewing (featureless-frame condition) by extracting motion before the extraction of features in each frame. However, the results also show that where feature identification in each frame is possible, it can also be used to identify the moving targets.

Female↗
PubMed1999

Maternal perception of lactogenesis time: a clinical report.

A study evaluating the time between delivery and the surge in milk production (lactogenesis time) determined whether lactogenesis time (LT) is affected by parity, factors in pregnancy and delivery, and especially cesarean section. Forty-six primiparous mothers and 81 multiparous mothers reported the time of sensation of milk production after delivery. The mean LT in the entire sample was 50 +/- 15 hours. The mean LT in 46 primiparous mothers was 59 +/- 14 hours, and in 81 multiparous mothers 45 +/- 12 hours (by student t test, p < 0.01). Mean LT did not decrease as parity increased in the multiparous mothers. By multivariate analysis, mean LT was 44 hours in multiparous mothers who delivered vaginally without medication, 11 hours longer if primiparous, 6 hours longer if delivery by cesarean section, and 13 hours longer if sedative or pain medication were given during labor.

Adult↗
PubMed1979

Variations in perception of short time intervals during menstrual cycle.

The hypothesis that women experience heightened sensitivity and responsivity premenstrually was tested by asking 10 women to produce short time intervals at four phases of the menstrual cycle. 10 men were assigned to "pseudo-cycles" and tested as a control. The test was based on the assumption that a greater sensitivity to stimuli is reflected in a "slowing down" of subjective time. The women produced the shortest time intervals three to four days before menses, confirming the hypothesis.

Adult↗
PubMed1979

Carbon monoxide and human time discrimination: failure to replicate Beard-Wertheim experiments.

Beard and Wertheium described a dose-related deficit in human time perception during low level CO exposure. Two other laboratories were unable to replicate this finding, although methodological differences could explain these failures. This study more precisely repeated the original experiment, but failed again to obtain any CO-related deficit. The bulk of evidence, therefore, does not indicate any adverse effect of low level CO exposure on time perception in healthy young adults.

Acoustic Stimulation↗
PubMed2003

First-time mothers' perceptions of efficacy during the transition to motherhood: links to infant temperament.

This investigation examined associations between pre- and postnatal reports of 1st-time mothers' depression, anxiety, and marital quality and postnatal reports of infant temperament and changes in feelings of efficacy. Maternal efficacy measured prenatally was associated with concurrent measures of depression, anxiety, marital conflict, and levels of previous child-care experience. Mothers' perception of infant temperament postnatally accounted for a significant proportion of variance in postnatal reports of maternal efficacy. Although individual differences in women's feelings of efficacy were fairly stable, significant increases in maternal efficacy were also observed over time. Findings suggest that 1st-time mothers' beliefs about their ability to perform nurturing routines may changes from a global sense of self-competence to more differentiated perceptions of nurturing efficacy.

Adult↗
PubMed2005

Cumulative blood oxygenation-level-dependent signal changes support the 'time accumulator' hypothesis.

We studied time-related changes in the blood oxygenation-level-dependent signal during a time reproduction task. Nine healthy study participants retained and reproduced stimuli of varying durations in the multi-second range. During the encoding phase of the task, activity in the left dorsolateral prefrontal cortex inversely correlated with the interval duration, while an adjacent region in the dorsolateral prefrontal cortex showed positive correlation with duration in the reproduction phase. Cumulative signal increase during the reproduction phase, as found in the primary motor and supplementary motor areas, may also reflect the time-sensitive behavior. Signal accumulation in the right caudate nucleus is in agreement with presumed role of basal ganglia in time perception. These results support the 'time accumulator' hypothesis.

Adult↗
PubMed1993

Temporal bisection in rats: the effects of high-peak-power pulsed microwave irradiation.

The effects of high-peak-power, pulsed microwaves on a time perception and discrimination task were studied in rats. Exposures were performed with the TEMPO exposure system, which produces an 80 nanosecond pulse with peak-power levels in excess of 700 megawatts. The ability to expose animals to such fields within a controlled environment is unique. As determined by calorimetry, a maximal, whole-body-averaged, specific-absorption rate of 0.072 W/kg was produced. Thus exposures were well below a recommended SAR limit of 0.4 W/kg. Power levels of transmitted microwaves were varied over a 50 dB range to obtain ascending and descending dose-response functions for each of the behavioral measures. Measures of time perception, response bias, and total trials did not change with power level. Dose-response effects were observed for discriminability (ability to distinguish between durations), session time, and trial completions (null responses, failures to respond on a trial). Covarying sound and X-ray exposures produced by TEMPO did not reliably correlate with the observed microwave effects. The observation of repeatable dose-response effects on discriminability and null responses indicates that the microwave exposures were affecting cognitive function in the rats, particularly the decision-making process.

Animals↗
PubMed2005

Effects of smoking urge on temporal cognition.

The authors examined temporal aspects of smoking urge. In Experiment 1, smokers assigned to high- or low-urge conditions were informed they would be allowed to smoke in 2.5 min. They next completed measures of time perception. High-urge smokers reported 45 s to pass significantly more slowly than did low-urge smokers. In Experiment 2, the high-urge smokers from Experiment 1 anticipated that their urges would climb steadily over the next 45 min if they were not permitted to smoke. Another group of high-urge smokers actually reported their urges over 45 min. These urge ratings did not show the steady rise anticipated by the first group. Results suggest that smoking urge may affect time perception and that craving smokers overpredict the duration and intensity of their own future smoking urges if they abstain.

Adolescent↗
PubMed1991

Effects of morphine sulfate on operant behavior in rhesus monkeys.

The acute effects of morphine sulfate were assessed using a battery of complex food-reinforced operant tasks that included temporal response differentiation (TRD, n = 5), delayed matching-to-sample (DMTS, n = 6), progressive ratio (PR, n = 9), incremental repeated acquisition (IRA, n = 9), and conditioned position responding (CPR, n = 7) tasks. Performance in these tasks is thought to depend upon specific brain functions such as time perception (TRD), learning (IRA), short-term memory and attention (DMTS), color and position discrimination (CPR), and motivation to work for food (PR). Morphine sulfate (0.1-5.6 mg/kg IV), given 15 min presession, produced significant dose-dependent decreases in the number of reinforcers obtained in each task. Response accuracy was significantly decreased at doses greater than or equal to 1.0 mg/kg for TRD when compared to saline injections. Accuracy was not consistently affected in any other task in the test battery. Response rates decreased or response latencies increased significantly at doses of 1.0 mg/kg and above for the PR task, at 3.0 mg/kg and above for the IRA and TRD tasks, and only at the highest dose 5.6 mg/kg in the CPR and DMTS tasks. Percent task completed was decreased following doses of 1.0 mg/kg and higher for the IRA, PR and TRD tasks, at doses of 3.0 mg/kg and higher for the DMTS task, and at the high dose of 5.6 mg/kg for the CPR task. These results indicate that in monkeys, the performance of operant tasks designed to model learning ability (IRA), time perception (TRD) and motivation (PR) are more sensitive to the disruptive effects of morphine than is performance in tasks designed to model short-term memory and attention (DMTS). The task which models color and position discrimination (CPR) was the least sensitive to disruption by morphine.

Animals↗