Does Sound Influence Perceived Duration of Visual Motion?

Multimodal perception is a key factor in obtaining a rich and meaningful representation of the world. However, how each stimulus combines to determine the overall percept remains a matter of research. The present work investigates the effect of sound on the bimodal perception of motion. A visual moving target was presented to the participants, associated with a concurrent sound, in a time reproduction task. Particular attention was paid to the structure of both the auditory and the visual stimuli. Four different laws of motion were tested for the visual motion, one of which is biological. Nine different sound profiles were tested, from an easier constant sound to more variable and complex pitch profiles, always presented synchronously with motion. Participants’ responses show that constant sounds produce the worst duration estimation performance, even worse than the silent condition; more complex sounds, instead, guarantee significantly better performance. The structure of the visual stimulus and that of the auditory stimulus appear to condition the performance independently. Biological motion provides the best performance, while the motion featured by a constant-velocity profile provides the worst performance. Results clearly show that a concurrent sound influences the unified perception of motion; the type and magnitude of the bias depends on the structure of the sound stimulus. Contrary to expectations, the best performance is not generated by the simplest stimuli, but rather by more complex stimuli that are richer in information.

Parallel processes of temporal control in the supplementary motor area and the frontoparietal circuit

Durations in the several seconds' range are cognitively accessible during active timing. Functional neuroimaging studies suggest the engagement of basal ganglia (BG) and supplementary motor area (SMA). However, their functional relevance and arrangement remain unclear because non-timing cognitive processes temporally coincide with the active timing. To examine the potential contamination by parallel processes, we introduced a sensory control and a motor control to the duration reproduction task. By comparing their hemodynamic functions, we decomposed the neural activities in multiple brain loci linked to different cognitive processes. Our results show a dissociation of two cortical neural circuits: the SMA for both active timing and motor preparation, followed by a prefrontal-parietal circuit related to duration working memory. We argue that these cortical processes represent duration as the content but at different levels of abstraction, while the subcortical structures including BG and thalamus provide the logistic basis of timing by coordinating temporal framework across brain structures.

Perceptual History Acts in World-Centred Coordinates

Serial dependence effects have been observed using a variety of stimuli and tasks, revealing that the recent past can bias current percepts, leading to increased similarity between two. The aim of this study is to determine whether this temporal integration occurs in egocentric or allocentric coordinates. We asked participants to perform an orientation reproduction task using grating stimuli while the head was kept at a fixed position, or after a 40° yaw rotation between trials, from left (−20°) to right (+20°), putting the egocentric and allocentric cues in conflict. Under these conditions, allocentric cues prevailed.

Music Tempo and Perception of Time: Musically Trained vs Nontrained Individuals

In this experiment we explored the effect of music tempo on the perception of time. Musically trained and nontrained participants carried out a reproduction task with music clips of various durations and tempos. Results revealed that the reproduced durations were longer for fast-tempo music clips than for slow-tempo music clips of equal duration. In addition, short clips were more accurately reproduced compared to longer stimuli. Notably, the error in reproducing the duration of a stimulus was overall lower for musically trained than nontrained participants, but more so for short than long clips. Finally, the accuracy in estimating the duration of the music clips correlated positively with years of musical training, further suggesting that musical training is a critical variable for time estimation.

Subjective time compression induced by continuous action

Increasing evidence indicates that voluntary actions can modulate the subjective time experience of its outcomes to optimize dynamic interaction with the external environment. In the present study, using a temporal reproduction task where participants reproduced the duration of an auditory stimulus to which they were previously exposed by performing different types of voluntary action, we examined how the subjective time experience of action outcomes changed with voluntary action types. Two experiments revealed that the subjective time experience of action outcomes was compressed, compared with physical time, if the action was performed continuously (Experiment 1), possibly enhancing the experience of controlling the action outcome, or if the action was added an extra task-unrelated continuous action (Experiment 2), possibly reflecting different underlying mechanisms from subjective time compression induced by the task-related continuous action. The majority of prior studies have focused on the subjective time experience of action outcomes when actions were performed voluntarily or not, and no previous study has examined the effects of differences in voluntary action types on the subjective time experience of action outcomes. These findings may be useful in situations in which people wish to intentionally compress their own time experience of daily events through their voluntary actions.

How does working memory store more information at larger set sizes? A composite code model.

A central feature of working memory is its limited capacity in terms of the amount of information that can be simultaneously maintained. Despite this, many studies observe an increase in the total amount when more items are maintained (set size), as measured by Shannon information. We propose the composite code model which maintains this fixed capacity assumption but demonstrates increasing observed information across set sizes. This relies on the hierarchical organisation of the visual system, in which higher-order information is abstracted about simple study displays. Using Bayesian inference, target responses can be inferred from knowledge about non-targets. We tested this model against our own data from a delayed reproduction task and those of published open data sets. We found initial support for the model, with its predictions matching those of the observed effects.

How does working memory store more information at larger set sizes? A composite code model.

A central feature of working memory is its limited capacity in terms of the amount of information that can be simultaneously maintained. Despite this, many studies observe an increase in the total amount when more items are maintained (set size), as measured by Shannon information. We propose the composite code model which maintains this fixed capacity assumption but demonstrates increasing observed information across set sizes. This relies on the hierarchical organisation of the visual system, in which higher-order information is abstracted about simple study displays. Using Bayesian inference, target responses can be inferred from knowledge about non-targets. We tested this model against our own data from a delayed reproduction task and those of published open data sets. We found initial support for the model, with its predictions matching those of the observed effects.

Running Fast and Standing Slow: a Study on the Effect of Gesture Posing on Time Perception

Everyone has 24 hours in a day, but this does not feel the same for everyone. Time perception can be subjective and is affected by a wide range of factors. Studies have shown that presenting pictures with actions can bias observers’ performance in a duration reproduction task. Instead of watching pictures of actions, this research explored the effect of gesture posing on such a time perception bias. Sixty participants were assigned into either a watching or posing group. Compared with the corresponding baseline performance, participants overestimated time duration when viewing or posing pictures suggesting action. A corresponding underestimation was observed when the pictures or gestures suggested inaction. The role of physical gestures and their potential effect on time perception based on the embodiment account is discussed. Further investigation is also proposed to examine the role of the embodiment effect on subsecond time intervals.

Abstracting time in memory

Planning the future relies on the ability to remember how long events last, yet, how durations are stored in memory is unknown. Here, we developed a novel n-item delayed duration reproduction task to assess whether elapsed time is stored as a continuous feature or as an abstract item in memory. In three experiments (N = 58), participants listened to non-rhythmic sequences composed of empty time intervals (durations), which they had to reproduce as precisely as possible following a delay period. We manipulated the number of time intervals (n-item) and the overall sequence duration to separate their effects on recall precision. The precision of temporal reproduction systematically decreased with an increasing number of items. Our results suggest that the number of time intervals, not their duration, determines recall precision. We interpret this as evidence towards an abstract representation of duration in working memory.