# Introduction

Time perception refers to the subjective, individual experience or awareness of the passage of time. Time being a concept of major importance to people and their fear of fatality, time perception is a very widely studied issue, in multiple disciplines across both humanities and natural sciences.
As its evidence comprises subparts (primary or secondary, qualitative or quantitative), the study of time perception in any field seems complex. It is an intrinsically individual and subjective phenomenon and analysing different evidence from different perspectives is a complex process.

# Time perception in Neuroscience
## Research and evidence in neuro-scientific time perception

A range of research methods have been used to produce evidence relating to how humans perceive time, with a focus on the anatomy and physiology of the brain. These include electrophysiology, psychophysics, EEG (electroencephalogram), MRI, and computer modelling data which are used in conjunction with more qualitative evidence produced by asking subjects questions and recording their responses. The present consensus in the scientific community is that the mechanism of time perception lies in the connections within and between neural networks, as opposed to constrained to a single part of the brain.

## Emotions and time perception

The mechanism underlying the phrase ‘time flies when you are having fun’ has been scientifically examined and qualitative evidence has been found to support the hypothesis that emotion does affect time perception. A 2011 French study run by Professor Driot-Volet and Sandrine Gil involved showing subjects extracts of films intended to induce fear, sadness, or indifference (neutral clips like weather reports used for the latter). After viewing, subjects estimated the duration of a stimulus, and having seen a fear inducing clip, time seemed to slow down, as fear activates an internal response that increases the rate of the internal body clock. Surprisingly, sad clips were not seen to alter subjects sense of time, as the clips were not personal.

## Overcoming the subjectivity of evidence

The very nature of studying time perception is that it is subjective and individual, which contributes significant challenges to obtaining valid evidence. To overcome such issues, researchers utilise standardised tasks that allow for a more accurate comparison of the way individuals perceive the effect of emotions and experiences on time. It is important to separate the time perception in a neutral context to the time perception emotional situation. This ensures that it is the emotions of the emotional stimulus that affect the way time is perceived, rather than other factors involved in the emotional event.

# Time perception in Philosophy
## Particular evidence in philosophy

Contrary to scientific fields, philosophical evidence and the resulting thinking are not as obvious or quantitative. The main evidence available in our subjective and relative perception of time is individual experience : anything one feels, thoughts, memories or even physical feelings. German philosopher Martin Heidegger stresses that time “persists merely as a consequence of the events taking place in it”. Therefore, time is perceived through events that come in succession. Each and every individual experiences these events by means of their senses before perceiving them in time, in the way a flash of lightning is first perceived by vision and later by hearing. Philosophical evidence when it comes to time perception, with its regards to personal experience, is therefore most likely to be empirical, qualitative and primary.

## Memory as the major type of evidence in time perception

Such introspective evidence can allow a study of the perception of time’s duration. St-Augustine highlights the prevailing role of memory, being the evidence on which we base our understanding of the time we live in. The duration of a moment can only be assessed once it has passed and has been anchored in our memory. The memory of this moment, of what one felt and thought, is what allows us to place it in time. The only time in which we exist is the present, and our memories of events represent the evidence of time passing. Past and future are just existent in our minds, and only allow us to organize our memories of events chronologically. Evidence of time duration and passing, lying in memory, is evidently fully subjective. St-Augustine describes our conception of time as fully spontaneous, thus there is no need to try and explain it.

## How memory leads to a qualitative and individual perception of time according to philosophy

Sharpening St-Augustine’s argument, W. J. Friedman formulated two models. The strength model states that the more recent an event, the stronger its memory is. Based on empirical evidence, he counters it with the inference model, arguing that time is perceived by recalling characteristics of the events which date we are trying to gauge. Indeed, he tested how people would remember a list of words, given successively, considering they were told to remember some of them more than others. Experience shows that the best remembered words were not the last ones but the ones on which attention was drawn. Overall, philosophy provides evidence that individuals will remember events and therefore perceive time according to their personal experiences (interactions, orders received, striking feelings) impacting their memory. Thus time perception is a relative concept and not a universal one.

# Conclusion
## Tensions and common ground between the disciplines

The main basis of the existing tensions is the types of evidence used as it incorporates many sub-parts (such as objective and subjective evidence). Indeed, disciplines relying more on solid, quantitative and objective evidence such as neuroscience will have a different understanding from disciplines using more subjective evidence like philosophy does. Neuroscience and philosophy differ on the fact that neuroscience covers immediate time perception and the impact of emotions that are felt simultaneously whereas philosophy highlights the importance of past experiences and how they influence one’s time perception. However, they concord about the fact that time perception lies on a subjective basis and that individual profile – emotions and experience – is key to one’s time perception. Our interdisciplinary approach therefore challenges the generally acknowledged belief that objective evidence is more powerful than subjective.

## An interdisciplinary approach: the domain of psychology

Tackling the concept of time perception in an interdisciplinary way naturally leads to the field of psychology. Psychology – "the study of the mind and how it dictates and influences our behaviour" – strongly relies on neuroscientific evidence, theory and methods, which are the first tools used by psychologists to assess issues. For example, it was shown that the emotion of anxiety obstructs an accurate perception of time. However, psychology as a profession focuses as well on directly helping individuals to reach mental and behavioural stability. To reach this aim, a unique patient-psychologist relationship has to exist. Philosophical evidence enters here the process : an individual's time perception depends on their memory of personal experience. This means the evidence on which the therapist will work to help the patient will come out of their communication and the patient’s telling about their past : primary subjective evidence which could indicate what might provoke their anxiety. In this way, associating philosophy and neuroscience with their tensions and common ground altogether helps get a holistic approach and cope efficiently with time anxiety.

## References

* ↑ Eagleman DM. Human time perception and its illusions. Current Opinion in Neurobiology [Internet]. 2008 Apr [cited 2019 Sep 17];18(2):131–6. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866156/ ‌
* ↑ Fontes R, Ribeiro J, Gupta DS, Machado D, Lopes-Júnior F, Magalhães F, et al. Time perception mechanisms at central nervous system. Neurology International [Internet]. 2016 Apr 1;8(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4830363/
* ↑ Lake JI, LaBar KS, Meck WH. Emotional Modulation of Interval Timing and Time Perception. Neuroscience and biobehavioral reviews [Internet]. 2016 May 1 [cited 2020 Dec 2];64:403. Available from:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380120/#R168‌
* ↑ Heidegger M. Being and time. SCM Press; 1962.
* ↑ Le Poidevin, R. "The Experience and Perception of Time", The Stanford Encyclopedia of Philosophy (Summer 2019 Edition) [online], Edward N. Zalta (ed.), [4/12/2020] available from : https://plato.stanford.edu/archives/sum2019/entries/time-experience
* ↑ Augustine S. Confessions Of St. Augustine. S.L.: Bibliotech Press; 2020.
* ↑ Friedman, William J.. Memory – Remembrance of the times of things passed In : About Time: Inventing the Fourth Dimension, Cambridge, MA: MIT Press.1990.
* ↑ British Psychological Society. What is Psychology ?[online] BPS; 2020 [accessed 8 December 2020]. Available from : https://www.bps.org.uk/public/what-is-psychology
* ↑ Whyman, A. D., & Moos, R. H. Time Perception and Anxiety In : Perceptual and Motor Skills. Southern Universities Press; 1967, p.567-570