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Timing Rhythms: Perceived Duration Increases with a Predictable Temporal Structure of Short Interval Fillers.

Horr NK, Di Luca M - PLoS ONE (2015)

Bottom Line: One account to explain effects of temporal structure is a non-linear accumulator-counter mechanism reset at the beginning of every subinterval.No general over- or underestimation is registered for rhythmically grouped compared to isochronous intervals.Implications of these findings for a non-linear clock model as well as a neural response magnitude account of perceived duration are discussed.

View Article: PubMed Central - PubMed

Affiliation: Centre for Computational Neuroscience and Cognitive Robotics, Department of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.

ABSTRACT
Variations in the temporal structure of an interval can lead to remarkable differences in perceived duration. For example, it has previously been shown that isochronous intervals, that is, intervals filled with temporally regular stimuli, are perceived to last longer than intervals left empty or filled with randomly timed stimuli. Characterizing the extent of such distortions is crucial to understanding how duration perception works. One account to explain effects of temporal structure is a non-linear accumulator-counter mechanism reset at the beginning of every subinterval. An alternative explanation based on entrainment to regular stimulation posits that the neural response to each filler stimulus in an isochronous sequence is amplified and a higher neural response may lead to an overestimation of duration. If entrainment is the key that generates response amplification and the distortions in perceived duration, then any form of predictability in the temporal structure of interval fillers should lead to the perception of an interval that lasts longer than a randomly filled one. The present experiments confirm that intervals filled with fully predictable rhythmically grouped stimuli lead to longer perceived duration than anisochronous intervals. No general over- or underestimation is registered for rhythmically grouped compared to isochronous intervals. However, we find that the number of stimuli in each group composing the rhythm also influences perceived duration. Implications of these findings for a non-linear clock model as well as a neural response magnitude account of perceived duration are discussed.

No MeSH data available.


Related in: MedlinePlus

Results of Experiment 2.(A) Proportions of responses indicating the rhythmic interval to be longer than the isochronous interval as a function of physical duration difference. (B) Point of subjective equality (PSE) and just noticeable difference (JND) calculated from response proportions with the Spearman-Kärber method. Error bars are S.E.M.
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pone.0141018.g004: Results of Experiment 2.(A) Proportions of responses indicating the rhythmic interval to be longer than the isochronous interval as a function of physical duration difference. (B) Point of subjective equality (PSE) and just noticeable difference (JND) calculated from response proportions with the Spearman-Kärber method. Error bars are S.E.M.

Mentions: Fig 4 shows response proportions, PSE, and JND values. As in Experiment 1, the three group-of-2 patterns did not differ in terms of PSE or JND and were grouped together (one-way r.m. ANOVA on PSE: F(2,46) = 0.11, p = 0.90, ηp² = 0.08; on JND: F(2,46) = 2.07, p = 0.14, ηp² = 0.08). The PSE averaged across the four rhythmic conditions shows a tendency of rhythmic intervals to be perceived as shorter than isochronous intervals, however this underestimation is not statistically significant (33±20ms, t-test against 0, two-tailed: t(23) = 1.9, p = 0.07, d = 0.39). The duration required for an isochronous interval to perceptually match a rhythmic interval changes depending on the rhythm condition (one-way r.m. ANOVA on PSE: F(3,69) = 3.3, p = 0.027, ηp² = 0.13). For each individual rhythm condition the perceived duration of rhythms is not significantly different to the isochronous intervals (t-test of PSE against 0, two-tailed, Bonferroni-corrected: t(23) = 0.10, p>1, d = 0.02, group-of-3: t(23) = 2.43, p = 0.096, d = 0.49; group-of4: t(23) = 2.08, p = 0.192, d = 0.43, group-of-5: t(23) = 2.4, p = 0.112, d = 0.48). Visual inspection suggests that the main effect of rhythm condition on PSE is carried by the difference between group-of-2 rhythms and rhythms with more than two stimuli per group, but these differences cannot be confirmed statistically (paired sample t-test on PSE, two-tailed, Bonferroni-corrected between group-of-2 and: group-of-3 t(23) = 2.51, p = 0.112, d = 0.51; group-of-4 t(23) = 2.56, p = 0.054, d = 0.52; group-of-5 t(23) = 2.38, p = 0.078, d = 0.48). The average JND is similar to the one obtained in Experiment 1 (330±20ms) and does not vary across conditions (one-way r.m. ANOVA: F(3,69) = 2.00, p = 0.074, ηp² = 0.10). In sum, we do not observe a statistically significant difference in perceived duration between isochronous and fully predictable rhythmic intervals, but we register a change in perceived duration depending on the number of stimuli in the groups of the rhythmic interval.


Timing Rhythms: Perceived Duration Increases with a Predictable Temporal Structure of Short Interval Fillers.

Horr NK, Di Luca M - PLoS ONE (2015)

Results of Experiment 2.(A) Proportions of responses indicating the rhythmic interval to be longer than the isochronous interval as a function of physical duration difference. (B) Point of subjective equality (PSE) and just noticeable difference (JND) calculated from response proportions with the Spearman-Kärber method. Error bars are S.E.M.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4608791&req=5

pone.0141018.g004: Results of Experiment 2.(A) Proportions of responses indicating the rhythmic interval to be longer than the isochronous interval as a function of physical duration difference. (B) Point of subjective equality (PSE) and just noticeable difference (JND) calculated from response proportions with the Spearman-Kärber method. Error bars are S.E.M.
Mentions: Fig 4 shows response proportions, PSE, and JND values. As in Experiment 1, the three group-of-2 patterns did not differ in terms of PSE or JND and were grouped together (one-way r.m. ANOVA on PSE: F(2,46) = 0.11, p = 0.90, ηp² = 0.08; on JND: F(2,46) = 2.07, p = 0.14, ηp² = 0.08). The PSE averaged across the four rhythmic conditions shows a tendency of rhythmic intervals to be perceived as shorter than isochronous intervals, however this underestimation is not statistically significant (33±20ms, t-test against 0, two-tailed: t(23) = 1.9, p = 0.07, d = 0.39). The duration required for an isochronous interval to perceptually match a rhythmic interval changes depending on the rhythm condition (one-way r.m. ANOVA on PSE: F(3,69) = 3.3, p = 0.027, ηp² = 0.13). For each individual rhythm condition the perceived duration of rhythms is not significantly different to the isochronous intervals (t-test of PSE against 0, two-tailed, Bonferroni-corrected: t(23) = 0.10, p>1, d = 0.02, group-of-3: t(23) = 2.43, p = 0.096, d = 0.49; group-of4: t(23) = 2.08, p = 0.192, d = 0.43, group-of-5: t(23) = 2.4, p = 0.112, d = 0.48). Visual inspection suggests that the main effect of rhythm condition on PSE is carried by the difference between group-of-2 rhythms and rhythms with more than two stimuli per group, but these differences cannot be confirmed statistically (paired sample t-test on PSE, two-tailed, Bonferroni-corrected between group-of-2 and: group-of-3 t(23) = 2.51, p = 0.112, d = 0.51; group-of-4 t(23) = 2.56, p = 0.054, d = 0.52; group-of-5 t(23) = 2.38, p = 0.078, d = 0.48). The average JND is similar to the one obtained in Experiment 1 (330±20ms) and does not vary across conditions (one-way r.m. ANOVA: F(3,69) = 2.00, p = 0.074, ηp² = 0.10). In sum, we do not observe a statistically significant difference in perceived duration between isochronous and fully predictable rhythmic intervals, but we register a change in perceived duration depending on the number of stimuli in the groups of the rhythmic interval.

Bottom Line: One account to explain effects of temporal structure is a non-linear accumulator-counter mechanism reset at the beginning of every subinterval.No general over- or underestimation is registered for rhythmically grouped compared to isochronous intervals.Implications of these findings for a non-linear clock model as well as a neural response magnitude account of perceived duration are discussed.

View Article: PubMed Central - PubMed

Affiliation: Centre for Computational Neuroscience and Cognitive Robotics, Department of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.

ABSTRACT
Variations in the temporal structure of an interval can lead to remarkable differences in perceived duration. For example, it has previously been shown that isochronous intervals, that is, intervals filled with temporally regular stimuli, are perceived to last longer than intervals left empty or filled with randomly timed stimuli. Characterizing the extent of such distortions is crucial to understanding how duration perception works. One account to explain effects of temporal structure is a non-linear accumulator-counter mechanism reset at the beginning of every subinterval. An alternative explanation based on entrainment to regular stimulation posits that the neural response to each filler stimulus in an isochronous sequence is amplified and a higher neural response may lead to an overestimation of duration. If entrainment is the key that generates response amplification and the distortions in perceived duration, then any form of predictability in the temporal structure of interval fillers should lead to the perception of an interval that lasts longer than a randomly filled one. The present experiments confirm that intervals filled with fully predictable rhythmically grouped stimuli lead to longer perceived duration than anisochronous intervals. No general over- or underestimation is registered for rhythmically grouped compared to isochronous intervals. However, we find that the number of stimuli in each group composing the rhythm also influences perceived duration. Implications of these findings for a non-linear clock model as well as a neural response magnitude account of perceived duration are discussed.

No MeSH data available.


Related in: MedlinePlus