Showing papers on "Time perception published in 2006"

Time dilation in dynamic visual display

Abstract: How does the brain estimate time? This old question has led to many biological and psychological models of time perception (R. A. Block, 1989; P. Fraisse, 1963; J. Gibbon, 1977; D. L. I. Zakay, 1989). Because time cannot be directly measured at a given moment, it has been proposed that the brain estimates time based on the number of changes in an event (S. W. Brown, 1995; P. Fraisse, 1963; W. D. Poynter, 1989). Consistent with this idea, dynamic visual stimuli are known to lengthen perceived time (J. F. Brown, 1931; S. Goldstone & W. T. Lhamon, 1974; W. T. Lhamon & S. Goldstone, 1974, C. O. Z. Roelofs & W. P. C. Zeeman, 1951). However, the kind of information that constitutes the basis for time perception remains unresolved. Here, we show that the temporal frequency of a stimulus serves as the "clock" for perceived duration. Other aspects of changes, such as speed or coherence, were found to be inconsequential. Time dilation saturated at a temporal frequency of 4-8 Hz. These results suggest that the clock governing perceived time has its basis at early processing stages. The possible links between models of time perception and neurophysiological functions of early visual areas are discussed.

Neurophysiology of Implicit Timing in Serial Choice Reaction-Time Performance

Abstract: Neural representations of time for the judgment of temporal durations are reflected in electroencephalographic (EEG) slow brain potentials, as established in time production and perception tasks. Here, we investigated whether anticipatory processes in reaction-time procedures are governed by similar mechanisms of interval timing. We used a choice reaction task with two different, temporally regular stimulus presentation regimes, both with occasional deviant interstimulus intervals. Temporal preparation was shown in the form of adjustments in time course of slow brain potentials, such that they reached their maximum amplitude just before a new trial, independent of the duration of the interstimulus interval. Preparation was focused on a brief time window, demonstrated by a drop in amplitude of slow potentials as the standard interval had elapsed in deviant interstimulus intervals. Implicit timing influencing perceptual processing was shown in reduced visual-evoked responses to delayed stimuli after a deviant interstimulus interval and in a reduction of EEG alpha power over the visual cortex at the time when the standard interval had elapsed. In contrast to explicit timing tasks, the slow brain potential manifestations of implicit timing originated in the lateral instead of the medial premotor cortex. Together, the results show that temporal regularities set up a narrow time window of motor and sensory attention, demonstrating the operation of interval timing in reaction time performance. The divergence in slow brain potential distribution between implicit and explicit timing tasks suggests that interval timing for different behaviors relies on qualitatively similar mechanisms implemented in distinct cortical substrates.

Embodied temporal perception of emotion.

Abstract: The role of embodiment in the perception of the duration of emotional stimuli was investigated with a temporal bisection task. Previous research has shown that individuals overestimate the duration of emotional, compared with neutral, faces (S. Droit-Volet, S. Brunot, & P. M. Niedenthal, 2004). The authors tested a role for embodiment in this effect. Participants estimated the duration of angry, happy, and neutral faces by comparing them to 2 durations learned during a training phase. Experimental participants held a pen in their mouths so as to inhibit imitation of the faces, whereas control participants could imitate freely. Results revealed that participants overestimated the duration of emotional faces relative to the neutral faces only when imitation was possible. Implications for the role of embodiment in emotional perception are discussed.

The supplementary motor area in motor and perceptual time processing: fMRI studies.

Abstract: The neural bases of timing mechanisms in the second-to-minute range are currently investigated using multidisciplinary approaches. This paper documents the involvement of the supplementary motor area (SMA) in the encoding of target durations by reporting convergent fMRI data from motor and perceptual timing tasks. Event-related fMRI was used in two temporal procedures, involving (1) the production of an accurate interval as compared to an accurate force, and (2) a dual-task of time and colour discrimination with parametric manipulation of the level of attention attributed to each parameter. The first study revealed greater activation of the SMA proper in skilful control of time compared to force. The second showed that increasing attentional allocation to time increased activity in a cortico-striatal network including the pre-SMA (in contrast with the occipital cortex for increasing attention to colour). Further, the SMA proper was sensitive to the attentional modulation cued prior to the time processing period. Taken together, these data and related literature suggest that the SMA plays a key role in time processing as part of the striato-cortical pathway previously identified by animal studies, human neuropsychology and neuroimaging.

Role of the olivo-cerebellar system in timing

Abstract: Timing has been proposed as a basic function of the cerebellar cortex (particularly the climbing fiber afferents and their sole source, the inferior olive) that explains the contribution of the cerebellum to both motor control and nonmotor cognitive functions. However, whether the olivo-cerebellar system mediates time perception without motor behavior remains controversial. We used event-related functional magnetic resonance imaging to dissociate the neural correlates of the perceptual from the motor aspects of timing. The results show activation of multiple areas within the cerebellar cortex during both perception and motor performance of temporal sequences. The results further show that the inferior olive was activated only when subjects perceived the temporal sequences without motor activity. This finding is most consistent with electrophysiological studies showing decreased responsiveness of the inferior olivary neurons to sensory input during expected, self-produced movement. Our results suggest that the primary role of the inferior olive and the climbing fiber system in timing is the encoding of temporal information independent of motor behavior.

When do auditory/visual differences in duration judgements occur?

Abstract: Four experiments examined judgements of the duration of auditory and visual stimuli. Two used a bisection method, and two used verbal estimation. Auditory/visual differences were found when durations of auditory and visual stimuli were explicitly compared and when durations from both modalities were mixed in partition bisection. Differences in verbal estimation were also found both when people received a single modality and when they received both. In all cases, the auditory stimuli appeared longer than the visual stimuli, and the effect was greater at longer stimulus durations, consistent with a "pacemaker speed" interpretation of the effect. Results suggested that Penney, Gibbon, and Meck's (2000) "memory mixing" account of auditory/visual differences in duration judgements, while correct in some circumstances, was incomplete, and that in some cases people were basing their judgements on some preexisting temporal standard.

Temporal processing deficits in the pre-senescent auditory system.

Abstract: This study tested the hypothesis that temporal processing deficits are evident in the pre-senescent (middle-aged) auditory system for listening tasks that involve brief stimuli, across-frequency-channel processing, and/or significant processing loads. A gap duration discrimination (GDD) task was employed that used either fixed-duration gap markers (experiment 1) or random-duration markers (experiment 2). Independent variables included standard gap duration (0, 35, and 250 ms), marker frequency (within- and across-frequency), and task complexity. A total of 18 young and 23 middle-aged listeners with normal hearing participated in the GDD experiments. Middle age was defined operationally as 40-55 years of age. The results indicated that middle-aged listeners performed more poorly than the young listeners in general, and that this deficit was sometimes, but not always, exacerbated by increases in task complexity. A third experiment employed a categorical perception task that measured the gap duration associated with a perceptual boundary. The results from 12 young and 12 middle-aged listeners with normal hearing indicated that the categorical boundary was associated with shorter gaps in the young listeners. The results of these experiments indicate that temporal processing deficits can be observed relatively early in the aging process, and are evident in middle age.

Visual onset expands subjective time

Abstract: We report a distortion of subjective time perception in which the duration of a first interval is perceived to be longer than the succeeding interval of the same duration. The amount of time expansion depends on the onset type defining the first interval. When a stimulus appears abruptly, its duration is perceived to be longer than when it appears following a stationary array. The difference in the processing time for the stimulus onset and motion onset, measured as reaction times, agrees with the difference in time expansion. Our results suggest that initial transient responses for a visual onset serve as a temporal marker for time estimation, and a systematic change in the processing time for onsets affects perceived time.

The Crossed-Hands Deficit in Tactile Temporal-Order Judgments: The Effect of Training

Abstract: Several recent studies have shown that judgments of temporal order for tactile stimuli presented to the two hands are greatly affected by crossing the hands. The size of the threshold for judging temporal order may be up to four times larger with the hands crossed as compared to the hands uncrossed. The results from these recent studies suggest that with crossed hands, contrary to many situations involving the integration of tactile and proprioceptive information, subjects have difficulty in adjusting their perception of tactile inputs to correspond with the spatial positions of the hands. In the present study we examined the effect of training in judging temporal order on the size of this crossed-hands deficit--the difference in the thresholds for temporal-order judgments when the hands are crossed and uncrossed. All training procedures produced significant declines in the size of the deficit. With training, the difference between crossed-hands and uncrossed-hands temporal-order thresholds dropped from several hundred milliseconds to as little as 19 ms. A group of percussionists with experience in playing with crossed hands showed the same crossed-hands effects as non-musicians. The results were consistent in showing that the crossed-hands deficit was never completely eliminated but was greatly reduced with training. The implication is that subjects are able to adjust to the crossed-hands posture with modest amounts of training. The results are discussed in terms of the explanations that have been offered for the crossed-hands deficit.

Time Perception and Time-Based Prospective Memory

Abstract: In this chapter, we review experimental psychology research in two domains: time perception and time-based prospective memory (ProM). Intuition suggests that these domains are connected, that they involve at least some of the same high-level cognitive processes or mechanisms. In view of this intuition, it is surprising that only a small number of empirical investigations have focused directly on the processes or mechanisms that link time perception and time-based ProM. Why? In order to answer this question, in the first part of this chapter, we summarize recent empirical and theoretical work on time perception, and on how this ability changes across the adult lifespan. In the second part, we review empirical and theoretical work on time-based ProM and on how this cognitive function changes across the adult lifespan. In addition, we examine the manner in which timeand event-based ProM tasks have been defined, in order to identify where — under what kinds of study/testing conditions — time-related processes might be recruited in support of performance on time-based tasks.

Delay period activity of monkey prefrontal neurones during duration-discrimination task.

Abstract: Evidence from brain imaging studies has indicated involvement of the prefrontal cortex (PFC) in time perception; however, the role of this area remains unclear. To address this issue, we recorded single neuronal activity from the PFC of two monkeys while they performed a duration-discrimination task. In the task, two visual cues (a blue or red square) were presented consecutively followed by delay periods and subjects then chose the cue presented for the longer duration. Durations of both cues, order of cue duration [long-short (LS) or short-long (SL)] and order of cue colour (blue-red or red-blue) were randomized on a trial-by-trial basis. We found that subjects responded differently between LS and SL trials and that most prefrontal neurones showed significantly different activity during either the first or the second delay period when comparing activity in LS and SL trials. The present result offers new insights into neural mechanisms of time perception. It appears that, during the delay periods, the PFC contributes to implement a strategic process in temporal processing associated with a trial type (LS or SL) such as representation of the trial type, retention of cue information and anticipation of the forthcoming cue.

Influence of auditory tempo on the endogenous rhythm of non-nutritive sucking

Abstract: The aim of this study was to examine the perception of time in the first months of life. Does the perception of contextual temporal information (an auditory tempo) induce modifications in spontaneous motor behavior (in the present case, non-nutritive sucking behavior) at birth and at 2 months? Two auditory tempos were successively tested. The first was the same as the previously recorded spontaneous motor tempo (SMT); the second was 15% faster or 15% slower than the infant's SMT according to the group. Results showed that modification of the sucking tempo depended on age and contextual temporal information. Two-month-old infants were able to adapt their endogenous sucking rhythm to an external tempo if it was faster than their spontaneous rhythm. Results also confirmed that slowing down the sucking rate was difficult for both groups of infants. In sum, the results suggest that, to a certain extent, very young infants are sensitive to contextual modifications (which indicates that they perceive them). This study has thus identified certain features of the internal time base rate from birth which could help define a developmental internal clock model of contextual temporal processing.

Age effects in time estimation: relationship to frontal brain morphometry.

Abstract: Compared with many other cognitive functions, relatively little is known about time representation in the brain. Recent work shows disrupted timing and time estimation in older adults, although it is unclear whether these effects are the result of normal aging or disease-related processes. The present study examined time estimation in persons across the adult lifespan who were free from significant medical or psychiatric history. Results showed older adults exhibited greater variability in time estimation, but no evidence for systematic acceleration or slowing emerged. This variability was correlated with performance on a variety of cognitive tests including attention, working memory and executive function. Although no relationship emerged between time estimation and EEG indices from central regions, multiple MRI indices were significantly correlated with time estimation. Stepwise regression showed volume of the supplementary motor area predicted variability in time estimation. These results indicate that healthy aging is associated with altered time estimation and suggest that changes in frontal brain regions mediate these effects.

Background music as a quasi clock in retrospective duration judgments

Abstract: The segmentation-change model of time perception proposes that individuals engaged in cognitive tasks during a given interval of time retrospectively estimate duration by recalling events that occurred during the interval and inferring each event's duration. Previous research suggests that individuals can recall the number of songs heard during an interval and infer the length of each song, exactly the conditions that foster estimates of duration based on the segmentation-change model. The results of a laboratory experiment indicated that subjects who solved word-search puzzles for 20 min. estimated the duration of the interval to be longer when 8 short songs (<3 min.) as opposed to 4 long songs (6+ min.) were played in the background, regardless of whether the musical format was Contemporary Dance or New Age. Assuming each song represented a distinct segment in memory, these results are consistent with the segmentation-change model. These results suggest that background music may not always reduce estimates of duration by drawing attention away from the passage of time. Instead, background music may actually expand the subjective length of an interval by creating accessible traces in memory, which are retrospectively used to infer duration.

Time, Place, and Content

Abstract: The goal of this article is to integrate information about basic mechanisms of time perception with research on time-place learning and research on the discrimination of what, when, and where (WWW). Several lines of evidence suggest that the psychological representation of time is nonlinearly related to physical estimates of time. These data prompt consideration of the proposal that interval timing is mediated by multiple, short-period oscillators. A multiple oscillator representation of time may be used to code the time of occurrence of events. These time-stamps for events, together with information about where the events occurred, may represent a promising direction for development of a quantitative, mechanistic theory of episodic-like memory in animals. The ability to track events that unfold in time is a central problem in the life of an animal. Research on timing focuses on the mechanisms by which animals accomplish this temporal tracking. At the most basic level, timing research seeks to identify the psychological representation of time. The focus of this research is primarily experiments that ex

Biases in the perceived timing of perisaccadic perceptual and motor events

Abstract: Subjects typically experience the temporal interval immediately following a saccade as longer than a comparable control interval. One explanation of this effect is that the brain antedates the perceptual onset of a saccade target to around the time of saccade initiation. This could explain the apparent continuity of visual perception across eye movements. This antedating account was tested in three experiments in which subjects made saccades of differing extents and then judged either the duration or the temporal order of key events. Postsaccadic stimuli underwent subjective temporal lengthening and had early perceived onsets. A temporally advanced awareness of saccade completion was also found, independently of antedating effects. These results provide convergent evidence supporting antedating and differentiating it from other temporal biases.

Pre-attentive representation of sound duration in the human brain

Abstract: Studies using a brain index for pre-attentive change detection, the mismatch negativity (MMN), suggested distinct neuronal populations for signaling changes in sound duration and frequency. However, these studies used only durations within the temporal window of loudness summation (ca. 200 ms) in which any duration change is accompanied by a loudness change. Hence, the present study employed stimulus durations both beyond and within this temporal window in order to examine the genuine duration representation in the brain. Magnetic mismatch responses (MMNm) for duration and frequency changes were compared with each other. The equivalent current dipole (ECD) of the duration MMNm was located in the auditory cortex slightly posterior to that for the frequency MMNm irrespective of stimulus duration. The results suggested separate memory representations for sound duration and frequency in the human brain.

La percepción del tiempo: una revisión desde la Neurociencia Cognitiva

Abstract: We present a review on the cognitive processes, structures and cerebral mechanisms underlying temporal processing, with special attention being paid to tasks involving temporal estimation of intervals of several hundreds of milliseconds. The main findings in Cognitive Neuroscience regarding time reveal the existence of brain systems specialized for timing tasks. Specifically, time perception involves subcortical structures such as the cerebellum and basal ganglia, which function is automatic timing. They are connected to cortical areas such as prefrontal and parietal cortex, thus carrying out controlled processes such as the accumulation and storage of temporal pulses generated by the internal clock. Finally, perception of time is related to another main cognitive process such as attention, emphasising the attentional mechanism of temporal orienting, which allows the anticipation and preparation to the future occurrence of relevant events.