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PubMed1981

[Effect of alcohol on interhemispheric functional relations in patients with late sequelae of cranio-cerebral injuries].

Using the backward masking method the time of perception of visual stimuli in the right and the left field of vision was examined. It was found that in patients with craniocerebral injury sequelae, as well as in healthy subjects the time of perception of literal stimuli was shorter in the left field of vision, i.e. the information entering the right hemisphere was processed more rapidly. Under the action of alcohol the asymmetry of the perception time disappeared in the patients, and became inverse in the healthy subjects, i.e. the time of perceiving letters in the left field of vision got longer than in the right field. Under the action the right hemisphere seemed to lose its advantage in the speed of the stimuli perception. It is supposed that the right hemisphere is more sensitive to alcohol.

Adult↗
PubMed1983

[Lateralization factors in the vertebrate brain].

Conditioning in white rats and suppression of a hemisphere's cortex with spreading depression revealed that the right hemisphere prevailed in perception of space, in the simultaneous information processing, in perception of concrete signs and in deductive processing whereas the left hemisphere was predominant in perception of time, in successive information processing, in perception of abstract signs and in inductive processing. Induction and deduction are hypothetically assumed to be the main factors determining the lateralization of functions in the brain hemispheres.

Animals↗
PubMed2003

Physicians' perceptions of minimum time that should be saved to move a surgical case from one operating room to another: internet-based survey of the membership of the Association of Anesthesia Clinical Directors (AACD).

STUDY OBJECTIVE: Moving the last case of the day from one operating room (OR) to another OR can increase OR efficiency. However, there is a penalty cost for moving a case. The goal of the study was to measure perceptions of the minimum time that needs to be saved for it to be worthwhile to move a case from a late-running OR to another OR. DESIGN: Internet-based survey of the Association of Anesthesia Clinical Directors (AACD) and/or attendees at one of its courses. As subjects completed the computer-assisted survey, answers to test questions were checked immediately to ensure respondents understood the relevant concepts. MEASUREMENTS: Respondents were asked to complete the statement: "I would move the case if I would expect to save ____ hours of overutilized OR time." MAIN RESULTS: 234 E-mail invitations to complete the survey were transmitted. Of that number, 87 completed surveys were returned. Respondents were physicians, mostly from the United States. The 25th, 50th, and 75th percentiles of the penalty cost were 1.0 hour of overutilized OR time. The 95% confidence intervals were 0.5 to 1.0 hour for the 25th percentile, 1.0 to 1.0 hour for the 50th percentile, and 1.0 to 2.0 hours for the 75th percentile. There was no significant correlation between the penalty cost and the number of ORs at the respondent's facility, number of times the survey was submitted until it was completed correctly, or total number of errors in responses. CONCLUSIONS: Members of the AACD perceive the penalty cost for moving a case to be 1 hour.

Anesthesia Department, Hospital↗
PubMed2005

Long duration spinal cord injury: perceptions of functional change over time.

PURPOSE: To investigate perceptions of functional change over time held by individuals with long duration spinal cord injury (SCI) living in Queensland, Australia. METHOD: A retrospective telephone questionnaire was administered to 84 individuals who had sustained a SCI more than 20 years previously and were older than 15 at the time of injury. Motor subset scores of the Functional Independence Measure (FIM) and a single scale measuring mobility aids status (MAIDS), were collected for three points in time--post discharge from initial rehabilitation (D/C point); approximately 10 years post injury (Mid point) and currently (Current point). RESULTS: A significant number of participants perceived that their function had increased between the D/C and Mid points and had subsequently decreased between the Mid and Current points. Participants also reported an increasing dependence on mobility aids between the Mid point and the Current point. Those who reported functional decline between the Mid and Current points were significantly older than those who did not report functional decline but did not differ in duration of injury or age at onset. CONCLUSIONS: The results support the need for services that provide assessment and intervention for functional changes throughout the life span of people with SCI.

Activities of Daily Living↗
PubMed1999

Cortical representation of spatiotemporal pattern of firing evoked by echolocation signals: population encoding of target features in real time.

Target perception in echolocating bats entails the generation of an acoustic image of the target in the auditory cortex. By integrating information conveyed in the sequence of acoustic echoes, the population of cortical neurons in hypothesized to encode different target features based on its spatiotemporal pattern of neural-spike firing during the course of echolocation. A biologically plausible approach to the cortical representation of target features is employed by using electrophysiological data recorded from the auditory cortex of the FM bat, Myotis lucifugus. A single-neuron model of delay-sensitive neurons is first approximated by the formulation of a Gaussian function with different variables to represent the delay-tuning properties of individual cortical neurons. A cortical region consisting of delay-sensitive neurons organized topographically according to best frequency (i.e., tontopically organized) is then modeled with multiple layers of the single-neuron model. A mechanism is developed to represent and encode the responses of these neurons based on time-dependent, incoming echo signals. The time-varying responses of the population of neurons are mapped spatially on the auditory-cortical surface as a cortical response map (CORMAP). The model is tested using phantom targets with single and multiple glints. These simulation results provide further validation of the current auditory framework as a biomimetic mechanism for capturing time-varying, acoustic stimuli impinging in the bat's ears, and the neural representation of acoustic stimulus features by saptiotemporal-firing patterns in the cortical population.

Auditory Cortex↗
PubMed1992

Amplitude rise time and the perception of the voiceless affricate/fricative distinction.

Variation of amplitude envelope at stimulus onset has been considered to be of primary importance for distinguishing voiceless affricates from fricatives (e.g., [symbol: see text]). In earlier perceptual experiments, however, variation in amplitude rise time was confounded with variation in frication duration. In two experiments, these variables were independently manipulated, and their individual and combined effects for perception of magnitude of [symbol: see text] were examined. Variation in amplitude rise time alone was not sufficient to signal the voiceless affricate/fricative contrast in these experiments, but variation in frication duration alone was sufficient.

Humans↗
PubMed1988

The effect of focal interictal spikes on perception and reaction time. II. Neuroanatomic specificity.

By means of a computerized system of spike detection, presentation of visual stimuli, and timing of a button press, we showed previously that single posterior interictal spikes resulted in transient prolongation of reaction time and increased non-response rate in 3 subjects. By varying the response hand and the visual field of stimulus, conditions with maximum spike effect were defined more precisely, in relationship to the location of the spike. In general, spike-induced dysfunction was most pronounced when either response hand or visual field of stimulus was contralateral to the spike. This not only was true across all 3 subjects, but held even for independent right and left occipital spikes within the same subject. Also, perceptual versus motor aspects were differentially affected by the anterior-posterior location of the spike. These findings indicate that focal interictal spikes may transiently disrupt aspects of cortical functioning corresponding to their neuroanatomical location.

Action Potentials↗
PubMed1987

In search of paintings influence on time judgement.

The influence of paintings on short time interval perception was studied. Three methods for time estimation were tested: direct scaling and two modifications of the method of reproduction – with and without simultaneous presentation of the painting whose duration was, reproduced. The results show that short time interval perception is influenced by such complex stimuli as paintings. The motor reproduction with simultaneous presentation of the visual stimulus was the most effective in revealing the influence of paintings on short time interval perception.

Art↗
PubMed2002

Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time.

PROBLEM: Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. METHOD: Perception-reaction time and brake-movement time were measured at the onset of lights for 72 subjects in a simulator. The six experimental conditions were three levels of uncertainty conditions (none, some, and some + false alarms) and two types of transmission (manual and automatic). The 72 subjects, half male and half female, were further divided into three age groups (mean of 23, 30, and 62 years). Each subject had 10 trials in each of the three levels of uncertainty conditions. RESULTS: Transmission type did not significantly affect either perception-reaction time or brake-movement time. Perception-reaction time increased significantly from 0.32 to 0.42 s (P < .05) as uncertainty increased but brake-movement time did not change. Perception-reaction time increased (from 0.35 to 0.43 s) with age but brake-movement time did not change with age. Gender did not affect perception-reaction time but did affect brake-movement time (males 0.19 s vs. females 0.16 s). IMPACT ON INDUSTRY: At 90 km/h, a car travels 0.25 m in 0.01 s. Consequently, even such small effects multiplied by millions of vehicle-kilometers can contribute to significant savings in lives and damages.

Adolescent↗
PubMed1999

Taking time seriously. A theory of socioemotional selectivity.

Socioemotional selectivity theory claims that the perception of time plays a fundamental role in the selection and pursuit of social goals. According to the theory, social motives fall into 1 of 2 general categories--those related to the acquisition of knowledge and those related to the regulation of emotion. When time is perceived as open-ended, knowledge-related goals are prioritized. In contrast, when time is perceived as limited, emotional goals assume primacy. The inextricable association between time left in life and chronological age ensures age-related differences in social goals. Nonetheless, the authors show that the perception of time is malleable, and social goals change in both younger and older people when time constraints are imposed. The authors argue that time perception is integral to human motivation and suggest potential implications for multiple subdisciplines and research interests in social, developmental, cultural, cognitive, and clinical psychology.

Adult↗
PubMed2004

Auditory-visual temporal integration as a function of distance: no compensation for sound-transmission time in human perception.

In a psychophysical outdoor experiment with human subjects, the point of subjective simultaneity (PSS) of auditory and visual stimuli was measured for distances from 1 to 50 m. Repetitive sound and light pulses were presented with various stimulus-onset asynchronies, and subjects judged which modality came first. With increasing distance of the stimuli the PSS shifted in a linear relation toward delays of the light behind the sound. The slope of the regression line (3 ms/m) almost exactly corresponded to that of the temporal disparities resulting from the lower velocity of sound compared to light. These data refute the hypothesis proposed recently that there could be an 'implicit estimation' of sound-arrival time. The brain seems to eliminate such crossmodal temporal disparities by the integration of auditory and visual stimuli that fall into a time window, but not by specific compensatory processes that use an estimate of the sound delay.

Acoustic Stimulation↗
PubMed1989

A randomized clinical trial of home nursing care for lung cancer patients.

A randomized clinical trial was conducted to assess the effects of home nursing care for patients with progressive lung cancer. One hundred sixty-six patients were assigned to either an oncology home care group (OHC) that received care from oncology home care nurses, a standard home care group (SHC) that received care from regular home care nurses, or an office care group (OC) that received whatever care they needed except for home care. Patients were entered into the study 2 months after diagnosis and followed for 6 months. Patients were interviewed at 6-week intervals across five occasions. At the end of the study, there were no differences in pain, mood disturbance, and concerns among the three groups. There were significant differences in symptom distress, enforced social dependency, and health perceptions. The two home nursing care groups had less distress and greater independence 6 weeks longer than the office care group. In addition, the two home nursing care groups steadily reported worse health perceptions over time. Thus, it was remarkable that the office care group, which indicated more symptom distress and social dependency with time, also indicated perceptions of improved health with time. These results suggest that home nursing care assists patients with forestalling distress from symptoms and maintaining their independence longer in comparison to no home nursing care. Home care may also include assisting patients in acknowledging the reality of their situation.

Adult↗
PubMed1994

The effects of sex, target duration, and illumination on the production of time intervals.

An experiment is reported which examined the effects of illumination, sex, and the duration of target intervals on the perception of time. Six male and six female participants made repeated estimates of one, three, seven, and twenty seconds each, using the production technique. There were sixty trials per duration, half of which were performed with the lights on and half with the lights off. Order of administration of lighting condition and duration of target time was randomized. For estimates expressed as ratios of target times, results indicated significant main effects for participant sex and duration of target time on mean time estimates. However, manipulation of lighting condition did not produce a significant main effect. For the variability of response, there was a significant interaction between sex and light condition such that women were less variable in lighted conditions. These findings are discussed in terms of previous equivocal evidence for the influence of participant sex on time perception and the modification of such an influence through change in experimental conditions.

Adult↗