Time perception

About: Time perception is a research topic. Over the lifetime, 1918 publications have been published within this topic receiving 87020 citations.

Interval timing with a beat frequency model connecting phase resetting and network response.

Abstract: Time perception is essential for normal physiological and behavioral responses, e.g., recalling stored data and planning future actions, and is deregulated in a series of neuropathologies, e.g., Parkinson’s disease. It is commonly accepted that processing temporal information involves a neural mechanism mimicking a stopwatch such as in the Scalar Expectancy Theory [1]. Organisms have multiple neural timing mechanisms that can span more than 10 orders of magnitude form circadian (24 hours) to interval (minutes) to millisecond timing [2]. Our focus is on modeling neural networks responsible for interval timing. In designing any computational model of interval timing, we must acknowledge an experimentally observed fact: the plot of mean response time versus the standard deviation of the distribution for different timing intervals is linear (scalar property). The established paradigm assumes an internal clock model in which pulses that are emitted regularly by a pacemaker are temporarily stored in an accumulator. At the time of reward or feedback, the number of pulses stored in the accumulator is transferred to the reference memory for future use. During “peak-interval procedure” (in which the participants are asked to reproduce the criterion interval) it is assumed that the internal clock is reset and pulses stored into accumulator until the current count match the memorized value stored during the training. The model we used assumes that timing is an emergent activity originated in the thalamo-cortico-striatal loops [2,3]. In this striatal beat-frequency (SBF) model, timing is based on the coincidental activation of medium spiny neurons in the basal ganglia by cortical neural oscillators [2,3]. The cortical oscillators are assumed to be synchronized at the onset of a trial, and to oscillate at a fixed frequency throughout the criterion interval. In our computational model, the oscillator block is composed of independent spiking neurons with intrinsic frequencies fi which, due to varying factors (biological noise, background neural activity from other cortical areas, etc.), are randomly distributed according to a certain density probability function. The synchronization of cortical oscillations at trial onset and the experience-dependent changes in cortico-striatal transmission are thought to be modulated by the dopaminergic neurons in the substatia nigra pars compacta and ventral tegmental area. A memory block stores the criterion time value c memorized during the training process. However, both storage and retrieval of criterion time to and from memory units is affected by biological context (brain state) and is modeled by randomly distributing criterion time according to a certain density probability function [3]. All timing models must connect the objective time with the subjective time. The subjective time is strongly influenced by brain’s state through neuromodulators. For example, dopamine advances the response whereas achetylcholine can induce a delay of the response in a fixed interval experiment. The mechanism involved could be through a direct change in firing frequency due to neurotransmitter action and it was modeled as a separate clock block. The decision block is an essential component of any timing mechanism that relates internal perception of time intervals with external action. A straightforward mechanism of implementing decision-making uses a set of synaptic weights derived from the memorized criterion time [3]. The weights computed from the memorized criterion constitute the reference vector of weighs. The decision block estimates the projection of the current weights on the vector of weight reference weight. The model correctly reproduced measured behavioral data.

Gender differences in time perception during olfactory stimulation

Abstract: In this study, we conducted two experiments to evaluate the effect of different types of odors on a time reproduction task, comparing performances of males to those of females. In the first experiment, subjects had to estimate short (510, 600, 690 ms) and long (1700, 2000, 2300 ms) interval durations under three odor conditions: positive, negative and neutral. A gender specific effect of olfactory stimulation on time estimation was found only for short durations. Namely, females were less accurate (overestimated) in reproducing short time intervals during the unpleasant odor presentation. This effect was confirmed and strengthened in the second experiment in which the intensity of the negative odor was enhanced. The present findings suggest that the neural network underlying time estimation is more “sensitive” to context manipulations in females than in men. Practical Applications The first important point is that there might be relevant gender differences in the processing of time (time estimation) that are mediated by olfactory stimulation. This new evidence might have important implications and applications in health issues and especially in workplace safety, for example in jobs or contexts in which fast processing and rapid decisions or choices are required. Therefore, the knowledge that females are more influenced by unpleasant odors than males during time estimation should be seriously considered in situations in which time plays a crucial role such as during rapid decision-making, where automatic processes should be efficiently activated. Overall, the higher sensitivity to specific olfactory stimulation observed in women probably reflects individual differences in a complex process such as time processing.

Higher mental functions and time perception in Internet-addicted teenagers

Abstract: Statistical data about Internet users indicates that Russia ranks first in Europe in terms of its number of Internet users. Young people prevail among Russia’s Internet users. Internet dependence behaviour is given a definition. The behavioural peculiarities of Internet addicts are considered. Time perception is a background for psychical processes. The time focus of the human psyche reveals itself in the speed and duration of perception, impression, memory, thought and emotions peculiar to people with a certain temperament and of a certain age, sex and group. Time perception is an integral part of our mental processes. A human being is inclined to consider all events and processes taking place around him as a process which takes time. The time perception of every person is always specific, and it is reflected in his or her thought and behaviour. The results of studying higher mental functions and time perception in internet-addicted teenagers are given. The obtained results have revealed distraction at the end of the study due to the high exhaustiveness of the neuro-dynamic component of mental activity, as well as the poorer ability of Internet addicts to be conscious of themselves in time. Given the absence of a clear pattern of their roles in real life, Internet addicts may often find that their addiction results in mental conflicts and self-aggression. In turn, it may result in impulsion, confusion, certain problems with explaining personal actions, wishes and motives. Internetaddicted teenagers have a more pessimistic attitude towards their time and life activity. When running into hardship, their behavioural performance and incentives to overcome barriers may be limited.