Perception of time

The perception of time indicates the subjective Perception which one has of the flow of the Temps.

If we have eyes to see, ears to hear and a nose to feel, we do not have sensory receiving dedicated to the perception of time. However we are however able to perceive the flow of time. The study of the perception of time is thus confronted with a paradox which returns to the nature even of the Temps where meets the psychological experiments, the philosophical reflections and the fundamental mécansimes of the Cerveau.

Temporal perception was the work object many since the first studies Psychophysique S until explorations in cerebral Imagerie. The experimenters harnessed themselves to distinguish various types of phenomena which raise all of the perception of time:

the perception of the durations
the perception and production of rates/rhythms
the perception of the temporal order and simultaneity

The question remains posed to know if these various fields of temporal perception proceed of the same mechanisms or not, in particular of other distinctions were introduced on the basis of scale of time considered. Thus according to the French psychologist Paul Mills, it is advisable to distinguish perception (for relatively short durations until a few seconds) from the temporal estimate which east indicates the apprehension of long durations (higher than several seconds until hours or more).

Experimental studies of the perception of time

The scientific study of the perception of time goes up with work of the German psychologist Johann Czermak which in 1857, publishes a series of results on what it calls the " direction of the temps" ( Zeitsinn ). By means of the methods of the Psychophysical being born, it entrepend to measure:

the smallest perceptible time interval in different the sensory methods (vision, hearing, touch)
how the same duration is perceived by the various directions
how varies the perception the speed of an object according to the Perception of space

These questions pose the stakes of the study Psychophysique of psychological time.

To the same time and during all second half of the XIXe century, Ernst Mach, Karl Vierordt, Wilhelm Wundt or Gustav Fechner carries out them also experiments aiming at testing if the perception of time has common characteristics with the perception of other physical sizes, for example if she obeys or not the Loi of Weber. One of the first conclusion of this work was to show that temporal perception roughly follows a Loi of Weber on certain ranges of durations whose extent varies according to the authors.

During the XXe century, the experimental Psychologie continues the study of the perception of time at the man by means of new paradigms by comparing it with the data obtained in the animal. By means of adapted procedures, it was quickly shown that the animals of laboratory (Rat, Pigeon, Chat and Singe mainly) was sensitive to the temporal relations between the events. Already, the experiments of Pavlov on the Conditionnement indicated that a dog accustomed to receive a reward of a nourrissor to a fixed time after a ringing salivated in anticipation of this appetitive stimulus. With the peak procedure , by which an animal is involved to wait a certain duration before making a gesture given to receive a reward, it is proven that the animals have them also a direction of time. Although the sensitivities are different, it would seem that the perception of time in the man and the animal are founded on the same neurobiologic bases.

Currently, the experimental procedures evolved/moved much, in particular with the use of the data processing which allows:

on the one hand development of experiments (including different stimulis visual, auditive…) in a faster and easier way. The data analysis is immediate and easy.
in addition, the development of the data-processing modeling of the neural networks, which allows studies increasingly closer to the biological phenomena

Physiological mechanisms

One can disinguer several mechanisms of perception of time, according to the scale at which one places oneself:

Models of internal clock

In 1984, a model cognitivist was proposed by Gibbon, Church and Meck. In this model, a pacemaker provided a base of time by delivering impulses to regular intervals. ---> Currently several assumptions without clash to be contradictory.

on the one hand the model of the Pacemaker/Accumulateur, which is founded on the idea that there exist precise zones in the brain persons in charge of the perception of time. In this model, a pacemaker (network of neurons specialized) delivers impulses in a regular way. These impulses are " stockées" in an accumulator. When it is a question thereafter of using a temporal judgment (length of a stimulus for example), the accumulator communicates the pulse repetition frequency entered with the " memory of référence". The brain can then compare this number with a later stimulus, and thus compare the durations.
in addition the model of the space encoding of time, taking account of the dynamics of the neural networks. The principle is the following: when a stimulus is perceived, there will be activation of a certain number of neurons within a network. One can see the network of neurons like a grid. Thus temporal information is encodée by the number and the position of the activated neurons. Neurons " extérieurs" can decode this information thanks to a reinforcement of the specific synapses of the detected neurons. So that such a model is possible, it is necessary however that a stimulus always starts the same cascade of events, which seems to be the case according to studies of data-processing modeling.
of other assumptions is also taken into account, including " neurons oscillateurs" or of the differences in activation of the neurons.

References

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