Time perception and the heart

The heart has held a central place in theories of human function for centuries. It was proclaimed as the seat of life in Ancient Greek and Byzantine medical literature, and the Ancient Egyptians embalmed their dead by carefully preserving the heart while unceremoniously discarding the brain1. This stands as a stark inversion of today’s physiological priorities. However, researchers have recently again been investigating human cognition and behaviour from the perspective of cardiac physiology.

My colleagues and I recently published a paper showing that temporal reproduction is associated with heart rate. In this post I will briefly discuss this paper, and review the literature on why heart rate — and autonomic nervous system function in general — is deeply connected to cognition.

Cardiac physiology

The idea that periodic physiological signals might constitute a biological clock is not new2. The most popular, recent account of this idea, endorsed by Marc Wittmann and Bud Craig, suggests that time perception is a function of integrated interoceptive signals34, which explains why physiological factors such as arousal5 and body temperature6 can affect time perception.

However, a simple linear relationship between heart rate and time perception is almost definitely an oversimplification. For instance, it’s clear that increasing heart rate (by exercise for instance) doesn’t affect time perception significantly7. But there are other elements of cardiac signals that provide a wider overview of the autonomic nervous system. This arises because the heart is innervated by both the sympathetic (SNS) and parasympathetic nervous system (PNS), and each of these arms have slightly different latencies (the PNS acts more rapidly on the heart). Thus, different components of the variability of heart rate can be attributed to the SNS and PNS. This means, for instance, that if analysed in the time-frequency domain, power in the high-frequency band of heart rate variability reflects the functioning of the PNS8.

Spectral components of heart rate variability. Power in different frequency bands corresponds to the function of the autonomic nervous system. VLF, very low frequency; LF, low frequency; HF, high frequency.
Spectral components of heart rate variability. Power in different frequency bands corresponds to the function of the autonomic nervous system. VLF, very low frequency; LF, low frequency; HF, high frequency.

Over the last decade or so, researchers have used these types of analysis techniques to link cardiac signals with different types of cognitive processes. This includes emotion regulation9, self-control10, and working memory11. Further to this, directly stimulating the ANS via the vagus nerve can also enhance memory processes12.

Temporal reproduction and heart rate variability

In our study, we assessed whether performance in a temporal reproduction task was associated with these different measures of cardiac activity. Healthy participants completed a standard temporal reproduction task with durations spanning from 2 – 15 seconds, while we recorded electrocardiogram (ECG). We characterised participants temporal reproductions with a two parameter psychophysical function (Steven’s power law), where the exponent parameter indicates the concavity of the function and thus whether participants tend to under-reproduce (exponent > 1), or over-reproduce (exponent < 1) intervals.

We found that that different frequency components of heart rate variability were associated with differences in participants’ reproductions. Specifically, we found that the high-frequency component was negatively associated with the exponent parameter of the psychophysical function. This suggests that individuals with higher PNS cardiac influence under-reproduced longer intervals compared with those with lower PNS cardiac influence. We also found a similar negative association between the low-frequency component and the exponent. The interpretation of the low-frequency component of heart rate variability is not as clear as that of the high-frequency component, as it reflects physiological processes other than purely SNS function13. However, increases in the low-frequency component have been previously been associated with decreases in attention and fatigue due to time-on-task14, thus it is possible that individuals who experienced more task-related fatigue performed more poorly on the reproduction task. Overall, these results show that time perception is associated with autonomic nervous system function.

Time reproduction function split by low-frequency heart rate variability (LF-HRV). Participants with high LF-HRV under-reproduced longer intervals.
Time reproduction function split by low-frequency heart rate variability (LF-HRV). Participants with high LF-HRV under-reproduced longer intervals.

Existing literature

This is not the first time that researchers have found links between time perception and heart rate. For instance, one study found that individuals have better absolute accuracy at reproducing durations when their heart rate slows down during the encoding of the sample interval15. Individuals with higher resting heart rate variability are also more accurate at reproducing durations16. Similarly, individuals with overall higher heart rate variability are also more accurate in a temporal bisection task17. As the PNS is responsible for slowing down heart rate, and is also the principle determinant of heart rate variability, this would suggest that individuals with higher PNS function are more accurate at duration reproduction in general.

However, other studies that have directly stimulated the vagus nerve (the main nerve of the PNS), have found that this can cause overestimations (under-reproductions) of time in the ranges of 34 – 230 seconds18. This is approximately consistent with our results showing that individuals with higher PNS function under-reproduced durations, however it conflicts somewhat with the results of the above studies. One possible discrepancy is that the above studies used absolute measures of accuracy, whereas we observed a directional effect. Whatever the reason for these differences, the relationship between autonomic nervous system function and temporal reproduction clearly merits further investigation.

In sum, this research seems to suggest that while the beats of the heart themselves are not analogous to a pacemaker, changes in the autonomic nervous system are either a corollary of a timing mechanism, or the autonomic nervous system directly plays role in how humans perceive time. Given the non-invasive nature of heart rate recordings, future research may be able to clarify exactly how signals from the heart inform our perception of time.


Source paper:

Fung, B. J., Crone, D. L., Bode, S., & Murawski, C. (2017). Cardiac Signals Are Independently Associated with Temporal Discounting and Time Perception. Frontiers in Behavioral Neuroscience, 11, 369. http://doi.org/10.3389/fnbeh.2017.00001

More reading on how cardiac signals relate to cognition:

Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61(3), 201–216. http://doi.org/10.1016/S0165-0327(00)00338-4

Thayer, J. F., & Lane, R. D. (2009). Claude Bernard and the heart–brain connection: Further elaboration of a model of neurovisceral integration. Neuroscience and Biobehavioral Reviews, 33(2), 81–88. http://doi.org/10.1016/j.neubiorev.2008.08.004


  1. Lykouras, E., Poulakou-Rebelakou, E., & Ploumpidis, D. N. (2010). Searching the seat of the soul in Ancient Greek and Byzantine medical literature. Acta Cardiologica, 65(6), 619–626. http://doi.org/10.2143/AC.65.6.2059857 ↩︎
  2. Goudriaan, J.C., 1921. Le rhythm psychique dans ses rapports avec les frequences cardiaques et respiratoires. Arch. Neerl. Physiol. 6, 77–110. ↩︎
  3. Craig, A. D. (2009). Emotional moments across time: a possible neural basis for time perception in the anterior insula. Philosophical Transactions of the Royal Society B-Biological Sciences, 364(1525), 1933–1942. http://doi.org/10.1098/rstb.2009.0008 ↩︎
  4. Wittmann, M. (2009). The inner experience of time. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 364(1525), 1955–1967. http://doi.org/10.1098/rstb.2009.0003 ↩︎
  5. Droit-Volet, S., & Meck, W. H. (2007). How emotions colour our perception of time. Trends in Cognitive Sciences, 11(12), 504–513. http://doi.org/10.1016/j.tics.2007.09.008 ↩︎
  6. Wearden, J. H., & Penton-Voak, I. S. (1995). Feeling the heat: Body temperature and the rate of subjective time, revisited. The Quarterly Journal of Experimental Psychology, 48(2), 129–141. http://doi.org/10.1080/14640749508401443 ↩︎
  7. Schwarz, M. A., Winkler, I., & Sedlmeier, P. (2012). The heart beat does not make us tick: The impacts of heart rate and arousal on time perception. Attention, Perception & Psychophysics, 75(1), 182–193. http://doi.org/10.3758/s13414-012-0387-8 ↩︎
  8. Berntson, G. G., Bigger, J. T., Eckberg, D. L., Grossman, P., Kaufmann, P. G., Malik, M., et al. (1997). Heart rate variability: origins, methods, and interpretive caveats. Psychophysiology, 34(6), 623–648. ↩︎
  9. Park, G., & Thayer, J. F. (2014). From the heart to the mind: cardiac vagal tone modulates top-down and bottom-up visual perception and attention to emotional stimuli. Frontiers in Psychology, 5, 278. http://doi.org/10.3389/fpsyg.2014.00278 ↩︎
  10. Segerstrom, S. C., & Nes, L. S. (2007). Heart Rate Variability Reflects Self-Regulatory Strength, Effort, and Fatigue. Psychological Science, 18(3), 275–281. http://doi.org/10.1111/j.1467-9280.2007.01888.x ↩︎
  11. Hansen, A. L., Johnsen, B. H., & Thayer, J. F. (2003). Vagal influence on working memory and attention. International Journal of Psychophysiology, 48(3), 263–274. http://doi.org/10.1016/S0167-8760(03)00073-4 ↩︎
  12. Clark, K. B., Naritoku, D. K., Smith, D. C., Browning, R. A., & Jensen, R. A. (1999). Enhanced recognition memory following vagus nerve stimulation in human subjects. Nature Neuroscience, 2(1), 94–98. http://doi.org/10.1038/4600 ↩︎
  13. Reyes Del Paso, G. A., Langewitz, W., Mulder, L. J. M., van Roon, A., & Duschek, S. (2013). The utility of low frequency heart rate variability as an index of sympathetic cardiac tone: A review with emphasis on a reanalysis of previous studies. Psychophysiology, 50(5), 477–487. http://doi.org/10.1111/psyp.12027 ↩︎
  14. Fairclough, S. H., & Houston, K. (2004). A metabolic measure of mental effort. Biological Psychology, 66(2), 177–190. http://doi.org/10.1016/j.biopsycho.2003.10.001 ↩︎
  15. Meissner, K., & Wittmann, M. (2011). Body signals, cardiac awareness, and the perception of time. Biological Psychology, 86(3), 289–297. http://doi.org/10.1016/j.biopsycho.2011.01.001 ↩︎
  16. Pollatos, O., Laubrock, J., & Wittmann, M. (2014). Interoceptive Focus Shapes the Experience of Time. PloS One, 9(1), e86934. http://doi.org/10.1371/journal.pone.0086934 ↩︎
  17. Cellini, N., Mioni, G., Levorato, I., Grondin, S., Stablum, F., & Sarlo, M. (2015). Heart rate variability helps tracking time more accurately. Brain and Cognition, 101, 57–63. http://doi.org/10.1016/j.bandc.2015.10.003 ↩︎
  18. Biermann, T., Kreil, S., Groemer, T. W., Maihöfner, C., Richter-Schmiedinger, T., Kornhuber, J., & Sperling, W. (2011). Time Perception in Patients with Major Depressive Disorder during Vagus Nerve Stimulation. Pharmacopsychiatry, 44(05), 179–182. http://doi.org/10.1055/s-0031-1280815 ↩︎

The benefits and costs of temporal attention

Attending to specific moments in time improves the quality of sensory information presented at these moments. Behavioural and neural benefits of temporal orienting have been shown in several contexts, including rhythmic regularities of the presented stimuli, cues informing about the relevance of specific time windows, and evolving probabilities of events occurring over time. However, it is not clear to what extent the effects and mechanisms of temporal attention are shared with other domains of attentional selection. For example, spatial attention not only improves the processing of stimuli presented at the attended location, but also has detrimental effects on processing stimuli presented elsewhere, as compared to neutral baseline conditions. This is exactly the focus of a recent paper by Denison, Heeger and Carrasco, who investigate whether similar perceptual trade-offs characterise temporal attention.

In a series of behavioural experiments, the authors present cues that inform participants of the latency of targets about which they will be most likely prompted for a response. Specifically, participants are asked to discriminate the visual orientation of gratings presented at various latencies after the auditory cue. In the simplest scenario (Experiment 1), the cue informs (with 75% validity) whether the orientation of the first (1000 ms after the cue) or the second target (250 ms later) will need to be reported. Crucially, 20% of the trials were left neutral and contained an uninformative cue, allowing for a baseline comparison. An analysis of accuracy and reaction times showed that when participants believe they will be asked about the first target, they are better and faster at discriminating its orientation than when they can’t predict which target will be relevant, and their performance is weakest if they are invalidly cued to the second target. This result suggests that participants attending a later time window will perform worse when asked about stimuli presented before this time window. But is this effect symmetric – i.e., is task performance worse for targets presented late if participants attend an earlier time window? While the behavioural effects show a pattern consistent with such an effect, the pairwise comparisons of the three experimental conditions (valid, neutral, and invalid cues) are not significant. This is not entirely surprising, given that at the moment of report the late targets might be accessed more easily since they are more recent and have not been interrupted by other irrelevant targets.

Thus, in a second experiment, the same task was administered but this time with three consecutively presented targets. However, the results were only partly consistent with the simpler version of the experiment. For example, attentional costs for targets presented before an attended time window were marginally significant or not observed. Interestingly, while attentional benefits of cueing were not observed for the intermediate latency, targets presented at this latency showed robust costs when participants attended an earlier time window, suggesting that in some contexts temporal attention might disrupt processing of targets presented after the attended time window, perhaps similar to an attentional blink.

To address the question whether temporal attention actually improves the quality of visual representations (as previously shown for rhythmic orienting) or can be explained by other factors such as missing the unattended targets (as in attentional blink) or mistakes in which targets are reported, another version of the task was run. This time, again using two targets, participants had to reproduce the orientation of targets instead of only reporting whether they were tilted clockwise or counter-clockwise. The results of these experiment suggested that attention primarily affected the precision of sensory representation but not the rates of guesses (expected if unattended targets were completely missed) or target swaps. However, as in the first experiment, these effects were largely confined to targets presented early, with no evidence of benefits or costs at longer latencies.

Taken together, while these studies provide further evidence for behavioural benefits of temporal attention and for the first time directly address attentional costs in the unattended time windows, the results aren’t always symmetric or consistent across experiments. Some of these differences can be explained by task specifics; however, it would be interesting to see whether similar effects can be identified in a more continuous version of the task, where the influence of each consecutively presented stimulus – attended or not – on the final orientation report could be quantified using established modelling techniques. Finally, the paper by Denison et al., does provoke further questions about the possible neural implementation of the observed perceptual trade-offs – where any differences that might be observed between the neural mechanisms of temporal and spatial attention will likely transform our understanding on attentional selection.

Ryszard Auksztulewicz, Oxford Centre for Human Brain Activity

Source article: Denison RN, Heeger DJ, Carrasco M (2017) Attention flexibly trades off across points in time. Psychon Bull Rev, Jan 4. doi: 10.3758/s13423-016-1216-1.

1st Conference of the Timing Research Forum, Strasbourg, France from October 23-25, 2017

We are pleased to invite you to attend the 1st Conference of the Timing Research Forum to be held in Strasbourg, France from October 23-25, 2017.
This international, multi-disciplinary meeting will encompass all aspects of timing research (duration, temporal resolution, rhythms etc.) from a variety of different approaches (experimental psychology, neuroscience, modeling, clinical, philosophy).  The emphasis will be on oral and poster presentations by young researchers, with interaction between junior and senior researchers strongly encouraged.

 

The conference will take place on the university campus in central Strasbourg:

Conference Center

Patio

22, rue Descartes

67000 Strasbourg

 

Strasbourg is located on the border of Germany, and is the symbol of peace between France and Germany. Together with Brussels, it is recognized as the capital of Europe. With its rich medieval history and multicultural influence, it was named a UNESCO world heritage site in 1998. It is an ancient University town, whose current research is recognized for its excellence.

 

 

 

 

Submission guidelines

The conference will include 3 keynote lectures from junior and senior researchers, and several themed symposia, oral sessions, and poster presentations. We invite you to submit abstracts for oral and poster sessions and/or proposals to organize symposia. All submissions will be peer-reviewed by members of the scientific committee, which will be composed by the TRF Committee members, and the conference organizers.

 

Symposia (deadline: May 1, 2017):

8 Symposia will be selected from submitted proposals. Each symposium must be themed around a single topic and will include 3 oral presentations of 20 minutes (+ 5 minutes questions) organized by a chairperson, who can also be a presenter. There can be 4 oral presentations if preferred, but the total duration of the symposium should not exceed 1 hour and 15 minutes. The chairperson is responsible for submitting the symposium proposal and for recruiting speakers. Symposia on current topics and of a multidisciplinary nature are encouraged.

Symposium proposals should include the following:

  • The name, contact information, and affiliation of the symposium chairperson.
  • A title
  • A brief abstract describing the symposium’s objective and topics to be covered (maximum 500 words, references included).
  • Up to 5 keywords.
  • The title of each presentation, with a listing of proposed speakers, their affiliations and contact information. For multi-author papers, please underline the presenter.
  • A short abstract for each presentation (max 150 words with references)
  • Abbreviations must be spelled out in full at their first use. Do not use abbreviations in the title. Use only standard abbreviations.

If your symposium proposal is not accepted, the abstracts will be automatically re-considered for poster or oral presentation.

 

Oral and Poster sessions (deadline: May 1, 2017)

There will be two short oral sessions, each containing 6 presentations of 12 minutes (+ 3 minutes for questions). There will be two poster sessions, and around 15 posters will be selected for oral blitz presentation (5 minutes). Abstracts for poster and oral presentations should include the following:

  • A title that clearly defines the work addressed.
  • Name and affiliation of the authors. For multi-author papers, please underline the presenter and provide their contact information.
  • An abstract describing the specific goal of the study, the methods used, a summary of the results, and a conclusion. The abstract should not exceed 300 words (references included).
  • Up to 5 keywords.
  • Abbreviations must be spelled out in full at their first use. Do not use abbreviations in the title. Use only standard abbreviations.
  • Do not add formatting. Italic, bold, tabs or extra spaces will not appear in the final program.
  • Your preference of oral or poster presentation.
  • Specify whether you wish to apply for a student travel grant (see below).

All selected abstracts and symposium proposals will be published in a special issue of the Timing and Time Perception Reviews journal.

 

Student travel grants:

We offer a small number of student grants. Please mention that you wish to apply for a grant at the end of your abstract. Grants will be awarded by the committee based on the quality and interest of the abstract.

 

Registration fees:

Early bird (deadline: June 30):

100 € for students

125 € for post-docs

200 € for PIs


Regular registration (deadline: September 23):

150 € for students

200 € for post-docs

300 € for PIs

 

Late/Onsite (deadline: October 23):

200 € for students

275 € for post-docs

400 € for PIs

 

Registration will be free for speakers/symposia organizers, as well as for students of the University of Strasbourg (who supports the conference). Registration fees will cover a buffet lunch for all 3 days of the conference, as well as coffee breaks and social events.

 

Conference website:

The website for the conference will be launched soon, and will provide more details about the program, venue, as well as practical information. Abstract submission and registration will be coordinated via the website. For any queries, please email Anne Giersch at trf.strasbourg@orange.fr.

 

Sincerely,

Anne Giersch, University of Strasbourg                   &

Jenny Coull, Aix-Marseille Université & CNRS

January 2017 Newsletter of the Timing Research Forum

Dear all,

Wish you all a wonderful New Year!

We are pleased to share the January 2017 Newsletter of the Timing Research Forum.

  1. TRF Membership Statistics

Website:               454 members (+9.4%)

ResearchGate:     154 followers (+92.5%)

Twitter:                  178 followers (+20.3%)

Facebook:             181 followers (+19.9%)

The statistics reveal that we have a highly active research community that continues to grow! Please join us on these platforms to discuss and share research on timing and time perception.

  1. 1st Conference of the Timing Research Forum (TRF1)

We are pleased to share details of the 1st Conference of TRF and announce the call for symposia and abstracts as below.

Date:          October 23-25, 2017

Venue:       University of Strasbourg, 22 Rue Descartes, Strasbourg, France

Organizers: Anne Giersch & Jenny Coull

Scientific committee:   TRF Committee Members & conference organizers

Contact: Anne Giersch – trf.strasbourg@orange.fr

Call for Symposia (deadline: May 1, 2017)

8 Symposia will be selected from submitted proposals. Each symposium must be focused on a single topic and will include 3 oral presentations of 20 minutes (+ 5 minutes questions) organized by a chairperson, who can also be a presenter. There can be 4 oral presentations if preferred, but the total duration of the symposium should not exceed 1 hour and 15 minutes.  The chairperson is responsible for submitting the symposium proposal and for recruiting speakers.  Symposia on current topics and of a multidisciplinary nature are encouraged.

Symposium proposals should include the following:

  • The name, contact information, and affiliation of the symposium chairperson.
  • A title
  • A brief abstract describing the symposium’s objective and topics to be covered (maximum 500 words, references included).
  • Up to 5 keywords.
  • The title of each presentation, with a list of proposed speakers, their affiliations and contact information. For multi-author papers, please underline the presenter.
  • A short abstract for each presentation (max 150 words with references)
  • Abbreviations must be spelled out in full at their first use. Do not use abbreviations in the title. Use only standard abbreviations.

If your symposium proposal is not accepted, the abstracts will be automatically re-considered for poster or oral presentation.

 

Call for Abstracts for Talks & Posters (deadline: May 1, 2017)

There will be two short oral sessions, each containing 6 presentations of 12 minutes (+ 3 minutes for questions).  

There will be two poster sessions, and around 15 posters will be selected for oral blitz presentation (5 minutes).

Abstracts for poster and oral presentations should include the following:

  • A title that clearly defines the work addressed.
  • Name and affiliation of the authors.  For multi-author papers, please underline the presenter and provide their contact information.
  • An abstract describing the specific goal of the study, the methods used, a summary of the results, and a conclusion.  The abstract should not exceed 300 words (references included).
  • Up to 5 keywords.
  • Abbreviations must be spelled out in full at their first use. Do not use abbreviations in the title. Use only standard abbreviations.
  • Do not add formatting. Italic, bold, tabs or extra spaces will not appear in the final program.
  • Your preference of oral or poster presentation.
  • Specify whether you apply for a student travel grant (see below).

All selected abstracts and symposium proposals will be published in a special issue of the Timing and Time Perception Reviews journal.

The website for the conference will be launched soon, and will provide more details about the program, venue, as well as practical information. Abstract submission and registration will be coordinated via the website. For any queries, please contact Anne Giersch at – trf.strasbourg@orange.fr.

III. TRF Blogs

We have a number of excellent blogs reviewing recent papers on timing and time perception by a number of promising early career researchers. Please read, share, comment and discuss! If you’d also like to contribute as a blogger, please get in touch: trf@timingforum.org.

Frequency tagging indexes cortical entrainment related to temporal prediction

Bronson Harry

MARCS Institute, University of Western Sydney

Controlling Time Perception using Optogenetics

Mukesh Makwana

Centre of Behavioural and Cognitive Sciences, University of Allahabad, India

Time-dependency in perceptual decision-making

Bharath Talluri

University Medical Centre, Hamburg-Eppendorf

Visual cortex responses reflect temporal structure of continuous quasi-rhythmic sensory stimulation

Molly Henry

University of Western Ontario

Temporal statistical regularity results in a bias of perceived timing

Bharath Talluri

University Medical Centre, Hamburg-Eppendorf

Mental context biases retrospective temporal judgements

Bronson Harry

MARCS Institute, University of Western Sydney

Society for Neuroscience 2016

Molly Henry

University of Western Ontario

 

Does Sense of Smell affect Sense of Time?

Mukesh Makwana

Centre of Behavioural and Cognitive Sciences, University of Allahabad, India

Do beta oscillations predict the timing of upcoming stimuli?

Ryszard Auksztulewicz

Oxford Centre for Human Brain Activity

Beat keeping in a Sea Lion as Coupled Oscillation: Implications for comparative understanding of human rhythm

Molly Henry

University of Western Ontario

 

  1. Blog your paper

We would like to invite TRF members to submit short summaries of their recently published articles on timing. Articles should be no longer than 500 words and not include more than one representative figure.

Please submit your entries after your paper is published by emailing us at trf@timingforum.org. Submissions are open anytime and will be featured on the TRF blog page – http://timingforum.org/category/blog/.

  1. Blog your conference

We would like to invite TRF members to write about their experience of a timing conference/meeting/workshop that they have recently attended. Submissions can highlight prominent talks/papers presented, new methods, trends and your personal views about the conference. Pictures may also be included. Submissions should be no longer than 1000 words.

Please submit your entries to trf@timingforum.org within two months from the date of the conference.

For example, see Molly Henry’s blog on the state of timing research at the Society for Neuroscience Annual Conference – Society for Neuroscience 2016.

 

  1. Timing projects on ResearchGate

We would like to invite all researchers to share links to their timing projects on ResearchGate with us. We will collate information about all projects in order to share them with the TRF community on ResearchGate and beyond.

Please email us your project link at trf@timingforum.org

 

VII. Timing Meetings in 2017

Experimental Psychology Society on Modularity in Time Perception and Timed Behavior

January 19; Liverpool, UK

 

Neurosciences and Music VI: Music, Sound and Health

June 15-18; Boston, USA

 

Rhythm Perception and Production Workshop

July 3-5; Birmingham, UK

 

European Society for Cognitive Science of Music

July 31 – Aug. 4; Ghent, Belgium

 

1st Conference of the Timing Research Forum

October 23 – 25; Strasbourg, France

 

For further details on these timing meetings, please visit – http://timingforum.org/timing-meetings/.

 

If you are organizing or aware of any other meetings focused on timing, please let us know at trf@timingforum.org.
VII. Contributions

TRF aims to host timing related resources, so that TRF‘s website will be the one stop for everything related to timing. Currently, the TRF website has these resources: all members’ publications, timing related special issues, and books on timing, a list of meetings focused on timing, a list of timing related societies/groups, as well as code and mentoring resources.

We ask all of you to contribute to these resources. Please send us (email at trf@timingforum.org) any omissions that we might have or any new information that should be added.

TRF is based on the idea of sharing information freely between its’ members so as to advance timing research and group collaborations. Thus, we encourage all of you to share with us any of the above resources that you might have and/or suggest new resources that we should add and circulate within the community.

VIII. Suggestions

We thank all of you for supporting this community and hope that you will continue to do so in the future. As we continuously emphasize, TRF is meant to be open to all timing researchers with the aim of sharing ideas and advancing the current state of the art. Thus, we are open to any suggestions or ideas that will help TRF grow and advance.

We have already established many ways (website, mailing list, resources etc.) to discuss the current state and the future of TRF and these tools will become more active in the coming months. We look  forward to your feedback!

With best wishes,

Sundeep Teki                                          

University of Oxford                                   

sundeepteki.org                                        

&

Argiro Vatakis

Cognitive Systems Research Institute

argirovatakis.com

 

Timing Research Forum

Web:            timingforum.org

Email:          trf@timingforum.org

Twitter:        twitter.com/timingforum

Facebook:   facebook.com/timingresearchforum

Frequency tagging indexes cortical entrainment related to temporal prediction

Listening to music typically induces a strong sense of an underlying beat. Although clearly related to periodicities contained in the stimulus, beat perception is internally generated since beat induction can occur in instances where no stimulation is present (i.e., in syncopated rhythms). Thus the capacity to extract a beat from periodic input provides an interesting phenomenon for examining the neural processes that temporally organise and ulitmately structure our perception of the world.

The neural mechanisms associated with beat-induction can be measured with a frequency tagging technique applied to EEG data recorded while participants listen to music. This approach involves examining the peaks in the frequency spectrum of EEG data that correspond to periodicities contained in the stimulus. By examining the activity evoked by syncopated rhythms (where the beat percept does not correspond to the sensory input), previous studies have shown that this technique indexes both periodic activity associated with the sensory input, and endogenous processes involved in extracting temporal structures from periodic input.

To further demonstrate the functional significance of this approach, Nozaradan, Peretz and Keller examined how neural entrainment measured with frequency tagging is correlated with individual differences in rhythmic motor control. The authors presented both unsyncopated and syncopated auditory rhythms whilst brain activity was recorded with EEG. Individual differences in ability to detect the beat in these rhythms were assessed offline with finger tapping tasks. In addition participants also completed another finger tapping task designed to assess temporal prediction. This stimulus comprised an aperiodic, predictable sequence of tones whereby the tempo continually varied between 400-600 ms (with a sinusoidal contour). This sequence was used to assess participants’ ability to anticipate the upcoming stimulus interval by quantifying the lag-1 and lag-0 correlation between the inter-stimulus interval and the inter-tap interval. Accurate prediction of the stimulus sequence would result in a larger lag-0 correlation than the lag-1 correlation, whereas tracking behaviour would be observed as a larger lag-1 correlation than lag-0 correlation.

The results showed that periodic stimulation produced peaks in the frequency spectrum of the recorded EEG data that corresponded to beat and non-beat frequencies. Importantly however, behavioural performance correlated selectively with the strength of entrainment in the beat frequencies. Tapping accuracy (mean asynchrony in the beat perception tasks) and the temporal prediction index (from the tempo change task) correlated positively with the height of the peaks for the beat induced frequencies, whereas the degree of entrainment in non-beat frequencies was negatively correlated with periodic tapping accuracy and was uncorrelated with prediction in tempo changing sequences. Together, these results highlight the functional significance of processes indexed by the frequency tagging approach, and show that beat perception is related to selective entrainment of neural activity to beat related frequencies.

The authors argue that the relationship between neural entrainment and temporal prediction is consistent with predictive coding models, whereby the brain optimises behaviour by forming internal models of the causes of sensory events. These internal models act as templates based on past experience that optimise sensory processing by providing predictions about the timing of upcoming sensory input. This argument is supported by another study published in 2016, which showed that temporal predictions associated with both periodic and aperiodic sequences lower sensory thresholds in a pitch discrimination task. Intriguingly, this study showed that isochronous stimulation also produced faster response times, whereas aperiodic stimulation did not. The authors of this paper argued that this dissociation may reflect the lowering of motor thresholds caused by simple sensory-motor coupling in the isochronous context, whereas changes in sensory processing may have been due to controlled processes that update internal models (i.e., linked to period correction). It remains to be seen whether the frequency tagging approach can be used to further dissociate the exogenous and endogenous processes involved in temporal prediction.

 

Bronson Harry

The MARCS Institute, Western Sydney University

Controlling Time Perception using Optogenetics

Imagine you have a device which can help you control your perception of time, so that you can speed up or slow down the subjective time at your will. Sounds like a science fiction but not in the near future. Yes a step has been taken to control time perception in mice using optogenetics. A recent study by Sofia Soares, Bassam Atallah, and Joseph Paton published in Science, not only measured the activity of the Dopaminergic (DA) neurons in substantia nigra pars compacta (SNc) in mice but also manipulated the activity of these neurons using optogentics resulting in altered timing behaviour.

They first trained mice to categorize variable interval between two tones (0.6, 1.05, 1.26, 1.38, 1.62, 1.74, 1.95 and 2.4 sec) as shorter or longer than 1.5 sec by touching the right or left port with their nose. The correct response was rewarded. After around 2 months of training mice were very accurate in performing this task.

Next, to confirm that the activity in SNc-DA neurons is essential for accurate timing, they used pharmacogenetic suppression approach. In this, they injected the SNc of a set of mice with the viral vector carrying the genes (hM4D(Gi)-mCherry). When hM4Di is expressed it does not affect the normal functioning of the neurons, but when an inert molecule like clozapine-N-oxide (CNO) is introduced it activates the hM4Di which then results in silencing of those neurons. They found that the timing behavior become very poor in the set of mice treated with CNO compared to the control set which were treated with saline. They also checked for timing accuracy before and after the CNO treatment showing that mice regained its timing accuracy.

Further, to establish a strong molecular basis for trial-by-trial variation in timing, they used the fiber photometry approach. In this, they measured the activity in the DA neurons while mice were performing the timing task. To accomplish this they injected SNc of a set of mice with the viral vector carrying the genes (GCaMP6f and tdTomato). When neurons are active there is lot of intake of Ca2+, which then binds with GCaMP6f and tdTomato protein leading to conformation changes and fluorescence. The amount of fluorescence is the indicator of activity of the cells. To assess whether trial-by-trial change in the activity within these neurons correlates with the timing behavior of mice, they distributed all the trials based on the measured activity of DA neurons into three categories i.e. low activity, medium activity, and high activity. They found that when the activity in the dopamine neurons was high, mice more often reported shorter response, whereas when the activity was low, mice more often reported longer response. Thus, the activity in the DA neurons of SNc could predict the mice behavioural response.

Finally, to establish a causal link between the activity of the DA neurons in SNc and timing behavior, they used optogenetic approach. They injected neurons in SNc with viral vectors carrying genes (ChR2-EYFP, and ArchT-GFP, or eNpHR3.0.EYFP). ChR2 codes for photo sensitive channel rhodopsin which when stimulated with 473nm (blue light) leads to influx of positive ions (cations) inside the cells thus activating the cell. On the other hand, eNpHR3 codes for halorhodopsin which when stimulated with 596nm (yellow light) leads to influx of chloride ions thus silencing the neurons by hyperpolarization. They found that when these neurons were optogentically activated using blue light, mice responded shorter response more often. Whereas when these neurons were optogentically silenced using yellow light, mice responded longer response more often. These changes in timing behavior were transient as mice timing accuracy was again restored in the absence of light. Thus, the authors were able to manipulate the timing behaviour of the mice using optogenetics.

The study explains the underestimation of time during fun or pleasurable activity where dopamine is supposedly high and overestimation of time during stress and fear where dopamine is low. Although, this study suggests that increased activity in the DA neurons leads to underestimation of time, however there are studies which suggest that increase in dopamine leads to overestimation of time (1,2,3).

Overall, this study happens to be the first to manipulate timing behaviour in mice using optogenetics, giving hope for the future where individuals could one day manipulate their own subjective time.

Source article: Soares, S., Atallah, B. V., & Paton, J. J. (2016). Midbrain dopamine neurons control judgment of time. Science, 354(6317), 1273-1277.

References:

  1. Buhusi, C. V., & Meck, W. H. (2002). Differential effects of methamphetamine and haloperidol on the control of an internal clock. Behavioral neuroscience, 116(2), 291.
  2. Failing, M., & Theeuwes, J. (2016). Reward alters the perception of time. Cognition, 148, 19-26.
  3. Terhune, D. B., Sullivan, J. G., & Simola, J. M. (2016). Time dilates after spontaneous blinking. Current Biology, 26(11), R459-R460.

—-Mukesh Makwana (Doctoral student), mukesh@cbcs.ac.in
Centre of Behavioural and Cognitive Sciences (CBCS), University of Allahabad, India.