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PubMed1992

The perception of time as a factor in Rogers' Science of Unitary Human Beings: a literature review.

This literature review examines an operationalization of Martha Rogers' Science of Unitary Human Beings. The principle of helicy and the theory of accelerating evolution has been used by a number of authors as a theoretical framework for the exploration of how patients, particularly those who are elderly, perceive the passage of time. Although there is no conclusive evidence to support the aspect of Rogers' theory of accelerating evolution that suggests that as people grow older they perceive time as passing more quickly, there is evidence that suggests that different elderly patients can have a variable perception of the passage of time. For example, some patients perceive the passage of time as rapid and will be happy to sit quietly. Others may perceive the passage of time as occurring more slowly and will require diversional therapy. A conclusion is reached that nurses should include individual assessments of the patients' perception of the passage of time in order to identify accurately the degree of need for diversional activities.

Aged↗
PubMed1992

Perception of timing of movement-onset in a simple reaction time task.

Subjects judged verbally on temporal order between pressing a switch and a marking sound (MS) in a simple reaction time paradigm. They were uncertain when sound preceded movement by less than about 60 ms or followed it by less than 130 ms (transient zone--TZ). The point of subjective equality (defined by 0.5 probability of correct judgements of temporal order of sound and switching onsets) and the median of TZ were shifted about 60 and 35 ms prior movement onset, respectively. Estimating mutual timing of movement preparation and execution and sensory delays, these shifts correspond to the simultaneity of onsets of MS and proprioceptive feedback in the brain. Thus the results suggest about proprioceptive origin of perception of active movement onset.

Adult↗
PubMed1991

Empirical and theoretical issues in the perception of time to contact.

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.

Acceleration↗
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↗
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↗
PubMed1978

The clinical utility of the hand-held tachistoscope.

A hand-held tachistoscope for use at the bedside was constructed and used to examine 40 normal controls and 170 psychiatric and neurological patients. This instrument quickly provided an index (perception time) which distinguished between idiopathic psychiatric illness and delirium, and between cortical and subcortical neuropathology. Slow perception time was seen in patients with delirium or cortical neuropathology.

Adolescent↗
PubMed1978

Methadone maintenance: an assessment of potential fluctuations in behavior between doses.

Thirty methadone maintenance outpatients were measured 1 and 25 hours after ingestion of methadone on auditory threshold, distance perception, simple and differential reaction time, time perception, attention span, and short-term memory. The results revealed a small but statistically significant difference between the two tests for distance perception. In addition, treatment interacted with preparatory interval on differential reaction time and with sex on attention span.

Adolescent↗
PubMed1975

Delayed decrement of the nerve impulse propagation during induced limb ischaemia in chronic hepatic failure.

Sensory thresholds for vibrations and electrical shocks and the sensory nerve conduction velocity (median nerve) were measured during 30 minutes of induced limb ischaemia in 10 normal subjects and 15 patients with chronic hepatic failure. Sensory action potentials were recorded simultaneously at the wrist and elbow. Seven patients (group A) had a normal perception time for vibrations. As in normal subjects, the potential amplitude decreased from the onset of ischaemia, more pronounced at the elbow than at the wrist, and the conduction velocity became reduced more rapidly in the wrist-elbow than the first digit-wrist segment, indicating impulse propagation with decrement. Eight patients (group B) had a markedly prolonged perception time for vibrations. The reduction of potential amplitude and conduction velocity was considerably delayed, and the impulse propagation showed no evidence of decrement for 20-25 minutes of ischaemia. A rise of the threshold for electrical shocks was absent or very delayed. As in the two other groups, the rise was abrupt and occurred at the moment when the potential below the occluding cuff (elbow) was extinct. In both groups of patients there was an increasing temporal dispersion of action potentials and in patient group A a desynchronization of the late phase of the potential took place early in the course of ischaemia. Differences between groups A and B could not be predicted from the pre-ischaemic nerve conduction data.

Adult↗
PubMed1977

The development of children's understanding of cyclic aspects of time.

Developmental psychological approaches to the study of time have fallen into 3 categories: studies of time perception; studies of logical, reconstructive abilities; and studies of the understanding of conventional time systems. The present work examines problems spanning the latter 2 categories--the development of children's understanding of temporal cycles and the relationship between cyclic concepts and cognitive development. 62 children, ranging in age from 4 to 10 years, were administered Piagetian tests of classification and seriation and a variety of specially designed cyclic tasks. Results show major progress in the representation of cyclic order and recurrence during the age period examined. For a variety of particular cycles, order responses were shown before continuity responses. The ability to produce a correct order is related to seriation performance but not classification performance when the variance attributable to age is partialed out. Continuity responses appear to be unrelated to performance on either of the Piagetian tasks tested when age is controlled.

Age Factors↗
PubMed1979

Inverse relationship of the velocities of perceived time and information processing events in the brain: a potential bioassay for neural functions: a hypothesis.

The velocity of elapsing time is not a constant but a relativistic component in the space-time continuum as postulated by Albert Einstein in his general and special relativity theories. The hypothesis presented here is that there is a biological corollary to relativity theory. It is postulated that biological time perception is also not a constant but is related by an inverse relationship between the velocities of neural processing events and perceived elapsing time. A careful analysis of this relationship may potentially offer a sensitive bioassay to determine the integrity of regional brain function under normal conditions and in the presence of specific disease processes. The mechanism for the biological basis of this theorem depends on the presence of a neural circuit developed through evolution which monitors overall brain efficiency and is coordinately linked to neural time perceiving circuits. Several test approaches are presented to validate the hypothesis of biologic time relativity compared to the rate of neural processing.

Adult↗
PubMed1977

Localization of disappearance of a light target during tracking eye movements. I.

A light target moving at a constant velocity in horizontal direction and disappearing at a locus determined by the experimenter is presented to the subjects in the experiments. The task of the subjects is to track its movement with their eyes and to determine the place of its disappearance using a scale fixed on the screen. Under these conditions they systematically mislocate the locus of disappearance in the direction of the eye movement. The mislocation is in linear dependence on the velocity of tracking and, moreover, it depends on the locus of disappearance of the target. The error is smaller when the target disappears at the end of tracking. The theory that mislocation is due to perception time is rejected.

Adult↗
PubMedDate not supplied

[Generalized transformation of subjective time assessment].

The subjects were given false information on the results of their estimation of time intervals in one of the experimental situations (they assessed time intervals filled up with different kinds of mental activity or free of them, as well as reproduced from memory 1-sec. interval). The observed changes in the accuracy of time estimation were typical of all situations, i.e. they were of generalized and coordinated character and pertained throughout 5 days. It is suggested that different specific forms of time perception typical of certain conditions form a unified system.

Adult↗
PubMed1977

Effects of degree of obesity, age of onset, and weight loss on responsiveness to sensory and external stimuli.

Four experiments tested responsiveness to external and sensory stimuli in female human subjects who differed in degree of overweight and in age of onset of their obesity. The effects of weight loss upon external responsiveness were assessed by testing subjects before and after weight reduction in order to determine the role of energy deficit and deprivation in mediating heightened responsiveness to external cues. There was no significant positive correlation between degree of overweight and degree of external responsiveness. In general, the age of onset of the obesity was also not a relevant factor in the degree of externality. Weight loss did not change responses to visual and cognitive cue salience manipulations in measures of feeding, emotionality, time perception, and short-term recall, whereas responsiveness to variations in palatability increased following weight reduction. While external cue responsiveness does not appear to result from adiposity per se or from deprivation, responsiveness to taste stimuli may reflect these parameters. The role of external and sensory cues in the development and maintenance of obesity is discussed.

Adolescent↗
PubMedDate not supplied

Psychedelic effects of a subanesthetic concentration of nitrous oxide.

The subjective effects of nitrous oxide were examined by administering questionnaires to volunteers (16 men and 16 women) breathing 30% nitrous oxide or 100% oxygen. Nitrous oxide produced a variety of subjective effects, including some that are characteristic of psychedelic drugs, such as happy, euphoric mood changes, changes in body awareness and image, alterations of time perception, and experiences of a dreamy, detached reverie state. The subjective effects, including those of a psychedelic nature, were very similar to the subject effects we observed in a previous study of nitrous oxide. However, euphoric mood changes were more pronounced, and adverse effects were less pronounced, in the present study, possibly due to the shorter duration of gas inhalation or the minimal tests of performance involved. Some other differences in subjective effects between the present and previous studies were identified by a discriminant analysis and seemed related to specific differences in experimental conditions. This suggests that the environment can influence which drug effects emerge, or at least their relative prominence. Clinicians should be familiar with the range of subjective effects that patients inhaling nitrous oxide may experience.

Adult↗
PubMed1978

The use of numerical and graphical statistical methods in the analysis of data on learning to see complex random-dot stereograms.

Several numerical and graphical statistical methods are illustrated in an analysis of data from an experiment that investigated a hypothesis of Julesz that giving a person a priori information about the structure of a complex random-dot stereogram reduces the time needed to perceive it when it is viewed. The data are divided into two groups, one consisting of those observers who received no cue or verbal cues (NV) and the other consisting of those who received verbal-visual cues (VV). A quantile-quantile plot shows that the NV times (mean = 7.6) are longer than the VV times (mean =5.6). By using probability plots, it is shown that the perception times have an exponential probability distribution. A hypothesis test based upon this distribution is used to show that the difference between the NV and VV times has significance slightly below 0.05.

Cues↗
PubMed1978

Binocular utilization of monocular cues that are undetectable monocularly.

The latency time of tracking dynamic random-dot stereograms can be shortened by as much as 100 ms when monocular cues are added by introducing a difference in dot density between target and surround. It has been tacitly assumed that perception time will be reduced only if the added monocular cues are above the detection threshold for each eye. However, the experiments reported here clearly show that stereoscopic performance as measured by an eye tracking task can be greatly enhanced by added monocular cues that cannot be detected. Observers were instructed to track a suddenly displaced vertical bar (portrayed as a dynamic random-dot stereogram) while their eye movements were recorded by EOG. The bar had either a given binocular disparity or zero binocular disparity with respect to its surround. For the target with a disparity (in a wide range), the latency time of tracking decreased by more than 30 ms (10%) as density difference increased from 0 to 4%, whereas in the control conditions with no stereoscopic cues (zero disparity) subjects were unable to track the bar at all within that range of density difference. Thus stereopsis is greatly aided by minimal monocular cues that by themselves elude monocular detection.

Cues↗