Time perception: the bad news and the good

Abstract

Time perception is fundamental and heavily researched, but the field faces a number of obstacles to theoretical progress. In this advanced review, we focus on three pieces of 'bad news' for time perception research: temporal perception is highly labile across changes in experimental context and task; there are pronounced individual differences not just in overall performance but in the use of different timing strategies and the effect of key variables; and laboratory studies typically bear little relation to timing in the 'real world'. We describe recent examples of these issues and in each case offer some 'good news' by showing how new research is addressing these challenges to provide rich insights into the neural and information-processing bases of timing and time perception. WIREs Cogn Sci 2014, 5:429-446. doi: 10.1002/wcs.1298 This article is categorized under: Psychology > Perception and Psychophysics Neuroscience > Cognition.

FIGURE 1

The effects of extended practice on the precision of temporal discrimination. Participants classified intervals as ‘short’ or ‘long’ according to whether the interval was shorter/longer than a given base duration. The top left panel shows data from one participant, Alfred Kristofferson, after extensive self-experimentation; it plots the variability in temporal representation (q, calculated according to a rather specific set of assumptions) as a function of base duration. The dashed line summarizes performance early in training; after prolonged practice, the data points ‘unfold’ from this line to give a staircase structure where both the height of the steps and the width of the treads double in magnitude with each successive step. Kristofferson interpreted this as evidence for a ‘time quantum’. The top right and bottom panels show similar data from two other participants (WM and FMS51). The eye of faith might discern some indication of a step pattern for these participants, but it is nowhere near as pronounced as for Kristofferson and the fit of Kristofferson's theoretically motivated step function is poor. (This function posits that the ‘treads’ of the staircase have the same near-horizontal slope but both their width and the step between them periodically doubles, corresponding to systematic doubling in the base of a triangular noise distribution; see Figure 4 of the paper by Matthews and Grondin51). Rather, for WM the variability in temporal representation is a quadratic function of base duration and for FMS the relation is linear. (Reprinted with permission from Ref 51)

FIGURE 2

The effects of stimulus spacing on temporal bisection by humans. The top panels show the proportion of ‘long’ responses for super logarithmic (high positive skew), logarithmic (moderate positive skew), arithmetic (no skew), and antilogarithmic (moderate negative skew) spacing of the comparison durations when the two standard intervals are widely separated (left panel) or differ by only a small ratio (right panel). As the skew becomes more negative, the bisection point shifts to the right. The bottom panels show that these context effects are well-described by temporal range-frequency theory. (Reprinted with permission from Ref 41)

FIGURE 3

Individual differences in the effect of stimulus repetition on duration discrimination. Participants saw two images and indicated whether the second was longer or shorter than the first. The graphs show the probability of a ‘longer’ response as a function of the duration of the second (comparison) stimulus when the comparison image is a repeat of the standard image (Rep) and when it is different (Novel). The top left panel shows data averaged across participants; the top right shows a participant with good discrimination who was little affected by repetition; the bottom left shows a participant with reasonable overall discrimination but who judged novel images to be much longer than repeats of the same duration; the bottom right shows a participant with the same tendency but whose discrimination was very poor. Data are from a study reported by Matthews.

FIGURE 4

Individual differences in beat perception. The top panel shows the stimulus sequences for the Control and Test trials, and the pattern of responses for weak and strong beat perceivers. In the control condition, listeners hear a pair of tones separated by 600 ms followed by another pair with a separation of 600 ms ±ΔT. Both strong and weak beat perceivers judge the sequence as ‘speeding up’ when the final separation is less than 600 ms and as ‘slowing down’ when it is more than 600 ms. On test trials, the first part of the sequence comprises a run of 3 tones separated by 300 ms so that the 600-ms periodicity is implicit. Strong beat-perceivers respond as for the control trials; weak beat-perceivers are insensitive to the 600-ms periodicity and judge all sequences as ‘slowing down’ because even the shortest final interval is longer than the 300 ms that separates the first 3 tones. The bottom panel shows the brain regions showing differential activity for the two groups of participants. Note that these neural differences arise even for the control sequences, where behavioral responses are identical. (Reprinted with permission from Ref 78)

FIGURE 5

The effects of sequence structure on the judged duration of tone sequences. The left panel shows judgments of decelerating (Dec), Accelerating (Acc) and Constant-tempo (Con) sequences of 5 tones as a function of physical duration. At short durations, accelerating sequences are judged longer than decelerating ones; at longer durations, this pattern reverses. Constant-tempo stimuli are consistently judged to be the longest of all. The right-hand panel shows the predictions of a weighted sum of segments model, which successfully captures this complex pattern (see text for details). (Reprinted with permission from Ref 33)