Interval timing as function of methods of estimation – a study on cohorts of young Indians

Abstract

The present study is planned to study the pattern/variation in subjective estimation of an array of short-intervals using two popular methods, time reproduction (TR) and time production (TP) prospectively. In the first study, the subjects estimated the short-intervals 5 s, 10 s, 15 s, 30 s, 60 s, and 120 s with time reproduction (TR). In the second study, the same target intervals were estimated using time production (TP) method. The short-intervals were estimated with both TP and TR using the “TimeProd” software (Cajochen et al. 2011). In aggregate, 173 randomly chosen apparently healthy subjects including male and female voluntarily participated in these studies. Out of these, 110 subjects (median age = 23.0 y) participated in a time estimation task with TR method and 63 subjects (median age = 23.0 y) estimated the same intervals with TP method. In both methods, randomly selected subjects including females and males estimated the target intervals during 14:00–16:00 h. The target intervals were randomly presented to the subjects in triplicates. The average of two nearest estimates was converted to duration judgment ratio, “theta (θ)”. Results confirmed a significant methodological difference in estimation of 5 s, 10 s, 60 s, and 120 s. The estimates of all intervals were near to accuracy with TR method only. The frequencies of accurate estimates of 5 s and 120 s were higher with TR than TP method. Variance was found to be greater in estimation with TP than TR method for all target intervals. Coefficient of variance (CV) was increasing and decreasing in TR and TP methods. The gender difference was found in time production of 120 s only. It could be concluded that variations do exist in the pattern of interval timings in time production and time reproduction methods, on account of different underlying memory components. Short-intervals perceived accurately with the time reproduction method. The imperative finding is that the nature of CV may vary in interval timing as a function of method. It also seems that effects of gender and intervals are method dependent.

Keywords:

• interval timing
• time reproduction
• time production
• prospective paradigm

Acknowledgments

This work was supported by the Department of Science and Technology (DST), New Delhi, through the sanction of a Major Research Project under the scheme Cognitive Science Research Initiative (CSI) and the University Grants Commission, New Delhi, through its DRS-SAP Scheme sanctioned to the School of Life Sciences, Pt. Ravishankar Shukla University, Raipur, in the thrust area, Chronobiology. We are grateful to the subjects, who voluntarily participated in this study. We are obliged to Dr. Christian Cajochen, Department of Clinical Psychology and Psychotherapy, Faculty for Psychology, University of Basel, Basel, Switzerland, and his colleague Dr. Jakub Späti, Centre for Chronobiology, University Psychiatric Clinics, Basel, Switzerland, for providing us the software, “TimeProd”.