Duration Discrimination Task Research Articles

HOW DOES MENTAL DISTRACTION INDUCED BY AN ADDITIONAL TASK AFFECT THE SEVERITY OF SIMULATOR SICKNESS SYMPTOMS IN PILOTS: A SPATIAL DISORIENTATION SIMULATOR STUDY

Introduction: To improve the effectiveness of spatial disorientation (SD) training in a flight simulator, pilots are recommended to perform an additional task that induces a mental distraction. The presented study explored how the inclusion of an additional task that may enhance the effectiveness of SD training changes the severity of simulator sickness symptoms reported after exposure in the Gyro-IPT simulator. Methods: We compared the incidence of simulator sickness symptoms in pilots across four setups of flight scenarios (varying according to cognitive load distraction) collected during our previous studies. A total of 77 male military pilots (age 28.3±6.2) with flight experience (810.72 ±969.43 hours) were randomly assigned to one of four groups and then exposed to a 60-min long flight session (12 flight profiles, six involved an SD-conflict) with active control in the Gyro IPT simulator. In addition to the primary flying task, in three flight scenarios, pilots were asked to perform an additional visual (a change detection flicker task [CDFT]), auditory (an auditory N-back task [NBT]), or duration-discrimination task (DDT)). To measure simulator sickness symptoms, the Simulator Sickness Questionnaire (SSQ) was administered pre- and post-simulator exposure. Results: The severity of simulator sickness symptoms due to visual and motion cues did not significantly change when the pilot performed a non-sickening cognitive task (additional visual or auditory task). The total SSQ score and scores for nausea, oculomotor disturbance, and disorientation in the CDFT and DDT were slightly higher than in the control condition (flight without additional task). Despite the observed differences, according to the SSQ scoring criteria, the simulator sickness symptoms reported by the pilots were negligible. Conclusions: The additional tasks (CDFT, auditory NBT, or DDT) applied to improve the effectiveness of SD training in the Gyro-IPT simulator do not significantly change unwanted effects, such as simulator sickness.

An Illusory Motion in Stationary Stimuli Alters Their Perceived Duration.

Despite having equal duration, stimuli in physical motion are perceived to last longer than static ones. Here, we investigate whether illusory motion stimuli produce a time-dilation effect similar to physical motion. Participants performed a duration discrimination task that compared the perceived duration of static stimuli with and without illusory motion to a reference stimulus. In the first experiment, we observed a 4% increase in the number of "longer" responses for the illusory motion images than static stimuli with equal duration. The time-dilation effect, quantified as a shift in the Point of Subjective Equality (PSE), was approximately 55 ms for a 2-second stimulus. Although small, the effect was replicated in a second experiment in which the total number of standard-duration repetitions was reduced from 73 to 19. In the third experiment, we found a positive linear trend between the strength of the illusory motion and the magnitude of the time-dilation effect. These results demonstrate that, similar to physical motion stimuli, illusory motion stimuli are perceived to last longer than static stimuli. Furthermore, the strength of the illusion influences the extent of the lengthening of perceived duration.

Lower loss rate of serotonergically modulated neuronal accumulator for time in patients with major depressive disorder

Major depressive disorder (MDD) is characterized by dramatic and persistent worsening of mood, as well as a subjective feeling of time slowing. However, experimental data on time perception are inconsistent. As serotonergic dysfunction implicated in MDD etiology, we aim to examine time perception in MDD through the framework of lossy temporal integration model, previously also related to serotonergic transmission. Thirty-one patients with recurrent depressive disorder in partial remission and thirty control participants, without a history of psychiatric and neurological disorders, performed duration discrimination of visual stimuli (duration ranges from 3.2 to 6.4 s) and subjective minute production tasks. To infer about central serotonergic transmission, an electroencephalogram in response to the 1000 Hz tone of different intensity (50, 60, 70 and 80 dB SPL) was recorded. Patients with MDD shorten the past durations in the duration discrimination task significantly less than controls, thus being more objective. No difference in the subjective minute production was recorded. Patients with MDD have also exhibited larger auditory evoked potentials in response to the tones of high intensity (70 and 80 dB SPL) when compared with the controls. This resulted in a steeper slope of auditory evoked potentials by intensity function. These converging findings suggest a lower loss rate of neuronal temporal accumulator modulated by serotonergic transmission in patients with MDD.

The role of cerebellum in timing processing: A contingent negative variation study

Time management is an important aspect of human behaviour and cognition. Several brain regions are thought to be involved in motor timing and time estimation tasks. However, subcortical regions such as the basal nuclei and cerebellum seem to play a role in timing control.The aim of this study was to investigate the role of the cerebellum in temporal processing. For this purpose, we transitorily inhibited cerebellar activity by means of cathodal transcranial direct current stimulation (tDCS) and studied the effects of this inhibition on contingent negative variation (CNV) parameters elicited during a S1-S2 motor task in healthy subjects.Sixteen healthy subjects underwent a S1-S2 motor task prior to and after cathodal and sham cerebellar tDCS in separate sessions. The CNV task consisted of a duration discrimination task in which subjects had to determine whether the duration of a probe interval trial was shorter (800 ms), longer (1600 ms), or equal to the target interval of 1200 ms.A reduction in total CNV amplitude emerged only after cathodal tDCS for short and target interval trials, while no differences were detected for the long interval trial. Errors were significantly higher after cathodal tDCS than at baseline evaluation of short and target intervals. No reaction time differences were found for any time interval after the cathodal and sham sessions.These results point to a role of the cerebellum in time perception. In particular, the cerebellum seems to regulate temporal interval discrimination for second and sub-second ranges.

Duration discrimination: A diffusion decision modeling approach

The human ability to discriminate the duration of two subsequently presented stimuli is often studied with tasks that involve a comparison between a standard stimulus (with fixed duration) and comparison stimuli (with varying durations). The performance in such tasks is influenced by the presentation order of these successively presented stimuli. The so-called Type A effect refers to the impact of presentation order on the point of subjective equality. The Type B effect describes effects of presentation order on the just-noticeable-difference. Cognitive models that account for these context effects assume that participants’ duration estimation is influenced by the history of previously encountered stimuli. For example, the internal reference model assumes that the magnitude of a “typical” stimulus is represented by an internal reference. This internal reference evolves throughout an experiment and is updated on every trial. Different recent models have in common that they describe how the internal reference is computed but are agnostic to the decision process itself. In this study, we develop a new model that incorporates the mechanisms of perceptual discrimination models into a diffusion model. The diffusion model focuses on the dynamics of the decision process itself and accounts for choice and response times based on a set of latent cognitive variables. We show that our model accurately predicts the accuracy and response time distribution in a classical duration discrimination task. Further, model parameters were sensitive to the Type A and B effect. The proposed model opens up new opportunities for studying human discrimination performance (e.g., individual differences).

The effect of red/blue color stimuli on temporal perception under different pupillary responses induced by different equiluminant methods.

As time plays a fundamental role in our social activities, scholars have studied temporal perception since the earliest days of experimental psychology. Since the 1960s, the ubiquity of color has been driving research on the potential effects of the colors red and blue on temporal perception and on its underlying mechanism. However, the results have been inconsistent, which could be attributed to the difficulty of controlling physical properties such as hue and luminance within and between studies. Therefore, we conducted a two-interval duration-discrimination task to evaluate the perceived duration of color stimuli under different equiluminant conditions: subjective or pupillary light reflex (PLR)-based equiluminance. The results, based on psychometric functional analyses and simultaneous pupillary recordings, showed that the perceived duration of red was overestimated compared with blue even when the intensity of the stimulus was controlled based on subjective equiluminance (Experiment 1). However, since blue is known to induce a larger PLR than red despite equiluminance, we conducted a controlled study to distinguish the indirect effect of pupillary response to temporal perception. Interestingly, the effect observed in Experiment 1 faded when the luminance levels of the two stimuli were matched based on PLR response (Experiment 2). These results indicate that duration judgement can be affected not only by the hue but also by different equiluminance methods. Furthermore, this causality between the equiluminance method and temporal perception can be explained by the fluctuations in incident light entering the pupil.

Reducing the tendency for chronometric counting in duration discrimination tasks

Chronometric counting is a prevalent issue in the study of human time perception as it reduces the construct validity of tasks and can conceal existing timing deficits. Several methods have been proposed to prevent counting strategies, but the factors promoting those strategies in specific tasks are largely uninvestigated. Here, we modified a classical two-interval duration discrimination task in two aspects that could affect the tendency to apply counting strategies. We removed the pause between the two intervals and changed the task instructions: Participants decided whether a short event occurred in the first or in the second half of a reference duration. In Experiment 1, both classical and modified task versions were performed under timing conditions, in which participants were asked not to count, and counting conditions, in which counting was explicitly instructed. The task modifications led to (i) a general decrease in judgment precision, (ii) a shift of the point of subjective equality, and (iii) a counting-related increase in reaction times, suggesting enhanced cognitive effort of counting during the modified task version. Precision in the two task versions was not differently affected by instructed counting. Experiment 2 demonstrates that—in the absence of any counting-related instructions—participants are less likely to engage in spontaneous counting in the modified task version. These results enhance our understanding of the two-interval duration discrimination task and demonstrate that the modifications tested here—although they do not significantly reduce the effectiveness of instructed counting—can diminish the spontaneous tendency to adopt counting strategies.

Preserved time but altered numerosity processing in epileptic patients with postoperative lesion in the inferior frontal gyrus

Previous researches have shown that the inferior frontal gyrus (IFG) is involved in time and numerosity processing. This study aimed at examining (i) interval timing and (ii) interaction between duration and numerosity processing in four drug-resistant epileptic patients with postoperative lesions in the IFG in comparison with thirteen healthy controls. The duration reproduction and discrimination tasks performed in the sub- and supra-second ranges did not reveal any significant differences between patients and controls. The duration discrimination task of stimuli varying in numerosity (DurN) and the numerosity discrimination task of stimuli varying in duration (NumD) revealed that only numerosity judgment was altered in IFG patients. A time-order effect was notably observed in the NumD task but in opposite directions for the two groups: The second patch was perceived as more numerous than the first patch in controls and conversely as less numerous in patients. Finally in the DurN task, we observed a congruency effect which was dependent on numerical distance in patients but not in controls. These converging results suggest that the IFG would be more specifically involved in numerosity than in duration processing, possibly playing a role in numerical decision.

The effect of background speech on attentive sound processing: A pupil dilation study

Listening to task-irrelevant speech while performing a cognitive task can involuntarily deviate our attention and lead to decreases in performance. One explanation for the impairing effect of irrelevant speech is that semantic processing can consume attentional resources. In the present study, we tested this assumption by measuring performance in a non-linguistic attentional task while participants were exposed to meaningful (native) and non-meaningful (foreign) speech. Moreover, based on the tight relation between pupillometry and attentional processes, we also registered changes in pupil diameter size to quantify the effect of meaningfulness upon attentional allocation. To these aims, we recruited 41 native German speakers who had neither received formal instruction in French nor had extensive informal contact with this language. The focal task consisted of an auditory oddball task. Participants performed a duration discrimination task containing frequently repeated standard sounds and rarely presented deviant sounds while a story was read in German or (non-meaningful) French in the background. Our results revealed that, whereas effects of language meaningfulness on attention were not detectable at the behavioural level, participants' pupil dilated more in response to the sounds of the auditory task when background speech was played in non-meaningful French compared to German, independent of sound type. In line with the initial hypothesis, this suggested that semantic processing of the native language required attentional resources, which lead to fewer resources devoted to the processing of the sounds of the focal task. Our results highlight the potential of the pupil dilation response for the investigation of subtle cognitive processes that might not surface when only behaviour is measured.

Using adaptive psychophysics to identify the neural network reset time in subsecond interval timing

State-dependent network models of sub-second interval timing propose that duration is encoded in states of neuronal populations that need to reset prior to a novel timing operation to maintain optimal timing performance. Previous research has shown that the approximate boundary of this reset interval can be inferred by varying the inter-stimulus interval between two to-be-timed intervals. However, the estimated boundary of this reset interval is broad (250–500 ms) and remains under-specified with implications for the characteristics of state-dependent network dynamics sub-serving interval timing. Here, we probed the interval specificity of this reset boundary by manipulating the inter-stimulus interval between standard and comparison intervals in two sub-second auditory duration discrimination tasks (100 and 200 ms) and a control (pitch) discrimination task using adaptive psychophysics. We found that discrimination thresholds improved with the introduction of a 333 ms inter-stimulus interval relative to a 250 ms inter-stimulus interval in both duration discrimination tasks, but not in the control task. This effect corroborates previous findings of a breakpoint in the discrimination performance for sub-second stimulus interval pairs as a function of an incremental inter-stimulus delay but more precisely localizes the minimal inter-stimulus delay range. These results suggest that state-dependent networks sub-serving sub-second timing require approximately 250–333 ms for the network to reset to maintain optimal interval timing.

Neuronal activity in the monkey prefrontal cortex during a duration discrimination task with visual and auditory cues

To investigate neuronal processing involved in the integration of auditory and visual signals for time perception, we examined neuronal activity in prefrontal cortex (PFC) of macaque monkeys during a duration discrimination task with auditory and visual cues. In the task, two cues were consecutively presented for different durations between 0.2 and 1.8 s. Each cue was either auditory or visual and was followed by a delay period. After the second delay, subjects indicated whether the first or the second cue was longer. Cue- and delay-responsive neurons were found in PFC. Cue-responsive neurons mostly responded to either the auditory or the visual cue, and to either the first or the second cue. The neurons responsive to the first delay showed activity that changed depending on the first cue duration and were mostly sensitive to cue modality. The neurons responsive to the second delay exhibited activity that represented which cue, the first or second cue, was presented longer. Nearly half of this activity representing order-based duration was sensitive to cue modality. These results suggest that temporal information with visual and auditory signals was separately processed in PFC in the early stage of duration discrimination and integrated for the final decision.

Medial entorhinal cortex lesions produce delay-dependent disruptions in memory for elapsed time

Our memory for time is a fundamental ability that we use to judge the duration of events, put our experiences into a temporal context, and decide when to initiate actions. The medial entorhinal cortex (MEC), with its direct projections to the hippocampus, has been proposed to be the key source of temporal information for hippocampal time cells. However, the behavioral relevance of such temporal firing patterns remains unclear, as most of the paradigms used for the study of temporal processing and time cells are either spatial tasks or tasks for which MEC function is not required. In this study, we asked whether the MEC is necessary for rats to perform a time duration discrimination task (TDD), in which rats were trained to discriminate between 10-s and 20-s delay intervals. After reaching a 90% performance criterion, the rats were assigned to receive an excitotoxic MEC-lesion or sham-lesion surgery. We found that after recovering from surgery, rats with MEC lesions were impaired on the TDD task in comparison to rats with sham lesions, failing to return to criterion performance. Their impairment, however, was specific to the longer, 20-s delay trials. These results indicate that time processing is dependent on MEC neural computations only for delays that exceed 10 s, perhaps because long-term memory resources are needed to keep track of longer time intervals.

Do Inattention/Hyperactivity and Motor Timing Predict Children’s Virtual Road-Crossing Performance?

The goal of this investigation was to examine how individual variation in inattention and hyperactivity is related to motor timing difficulties and whether children's performance on simple laboratory timing tasks is related to their performance on a virtual road-crossing task using a head-mounted virtual reality display system. Participants were a community sample of 92 9- to 11-year-old children. Parents completed questionnaires assessing their child's inattention and hyperactivity. Children completed two simple motor timing tasks (duration discrimination and synchronization-continuation) and crossed roads with continuous traffic in a head-mounted VR system. Higher parent-reported inattention and hyperactivity predicted poorer performance in the duration discrimination and synchronization-continuation tasks, but not the virtual pedestrian road-crossing task. Children with higher tap onset asynchrony in the synchronization-continuation task had poorer timing of entry into the gap in the virtual pedestrian road-crossing task. The findings provide further evidence that timing deficits are associated with individual differences in inattention and hyperactivity and that timing difficulties may be a risk factor for functional difficulties in everyday life.

Effect of glare illusion-induced perceptual brightness on temporal perception.

Temporal perception and the ability to precisely ascertain time duration are central to essentially all behaviors. Since stimulus magnitude is assumed to be positively related to the perceived duration from the early days of experimental psychology, most studies so far have assessed this effect by presenting stimuli with relatively different intensities in physical quantity. However, it remains unclear how perceptual magnitude itself directly affects temporal perception. In this study (n = 21, n = 20), we conducted a two‐interval duration‐discrimination task adapting a glare illusion (a visual illusion that enhances perceived brightness without changing physical luminance) to investigate whether the temporal perception is also influenced by perceptual magnitude. Based on the mean difference in the point of subjective equality derived from a psychometric function and pupil diameter, we found that temporal perception is influenced by the illusory brightness of glare stimuli. Interestingly, the perceived duration of the apparently brighter stimuli (glare stimuli; larger pupillary light reflex) was shorter than that of control stimuli (halo stimuli; smaller pupillary light reflex) despite the stimuli remaining physically equiluminant, in contrast with the well‐known "magnitude effect." Furthermore, this temporal modulation did not occur when the physical luminance of the stimuli was manipulated to match the illusory‐induced magnitude. These results indicate that temporal processing depends on the confluence of both external and perceived subjective magnitude and even illusory brightness is sufficient to affect the sense of duration; which may be explained by the internal magnitude decrease of the glare stimuli due to pupillary constriction decreasing the light entering the eye.

A common dynamic prior for time in duration discrimination

Estimation of time depends heavily on both global and local statistical context. Durations that are short relative to the global distribution are systematically overestimated; durations that are locally preceded by long durations are also overestimated. Context effects are prominent in duration discrimination tasks, where a standard duration and a comparison duration are presented on each trial. In this study, we compare and test two models that posit a dynamically updating internal reference that biases time estimation on global and local scales in duration discrimination tasks. The internal reference model suggests that the internal reference operates during postperceptual stages and only interacts with the first presented duration. In contrast, a Bayesian account of time estimation implies that any perceived duration updates the internal reference and therefore interacts with both the first and second presented duration. We implemented both models and tested their predictions in a duration discrimination task where the standard duration varied from trial to trial. Our results are in line with a Bayesian perspective on time estimation. First, the standard systematically biased estimation of the comparison, such that shorter standards increased the likelihood of reporting that the comparison was shorter. Second, both the previous standard and comparison systematically biased time estimation of subsequent trials in the same direction. Third, more precise observers showed smaller biases. In sum, our findings suggest a common dynamic prior for time that is updated by each perceived duration and where the relative weighting of old and new observations is determined by their relative precision.

A Time Duration Discrimination Task for the Study of Elapsed Time Processing in Rats.

Space and time are both essential features of episodic memory. However, while spatial tasks have been used effectively to study the behavioral relevance of place cells, the behavioral paradigms utilized for the study of time cells have not used time duration as a variable that animals need to be aware of to solve the task. In order to evaluate how time flow is coded into memory, time duration needs to be a variable that animals use to solve the behavioral task. This protocol describes a novel behavioral paradigm, the time duration discrimination (TDD) task, which is designed to directly investigate the neurological mechanisms that underlie temporal processing. During the TDD task, rats navigate around a Figure-8 Maze, which contains a rectangular track with a central arm and a delay box at the end of the central arm. While confined to the delay box, rats experience a 10- or 20-second time delay, during which a tone will play for the duration of the 10- or 20-second delay. When the delay box opens, the rat will choose whether to turn left or right out of the delay box and receive a reward for the correct choice (e.g., 10 seconds = left turn; 20 seconds = right turn). By directly manipulating elapsed time, we can better explore the behavioral relevance of hippocampal time cells and whether the time-dependent activity seen in physiological recordings of hippocampal neurons reflects a neuronal representation of time flow that can be used by the animal for learning and storing memories. Graphic abstract: Elapsed time duration discrimination in rats.

In the temporal organization of episodic memory, the hippocampus supports the experience of elapsed time.

Space and time are both essential features of episodic memory, for which the hippocampus is critical (Howard & Eichenbaum, 2015). Spatial tasks have been used effectively to study the behavioral relevance of place cells. However, the behavioral paradigms utilized for the study of time cells have not used time duration as a variable that animals need to be aware of to solve the task. Therefore, the behavioral relevance of this cell firing is unclear. In order to directly study the role of the hippocampus in processing elapsed time, we created a novel time duration discrimination task. Rats learned to make a decision to turn left or right depending on the preceding tone duration (10 s, left turn; 20 s, right turn). Once the rats reached criterion performance of 90% correct on two out of three consecutive days, they received either an excitotoxic hippocampal lesion or a sham-lesion surgery. After recovery, rats were tested to determine hippocampal involvement in discriminating time duration. Rats with hippocampal lesions performed at chance level on their first testing day postlesion, and they were impaired relative to the sham-lesioned rats. Although the hippocampal-lesioned rats began discriminating at above chance level, their performance never returned to criterion even with 50 days of postoperative testing. Furthermore, while sham rats showed no difference in the number of errors they made on 10- versus 20-s delay trials, hippocampal lesion rats similarly improved their performance under the 10-s delay condition, but not under the 20-s delay condition. Results indicate that hippocampal lesions resulted in a selective impairment in discriminating elapsed time only during the longer delay trials. The implications of these results are discussed in relation to the limits of working-memory capacity and to the role of sustained hippocampal time cell activity in memory performance depending on the perceived relevance of the delay period.

Effect of change saliency and neural entrainment on flicker-induced time dilation.

When a visual stimulus flickers periodically and rhythmically, the perceived duration tends to exceed its physical duration in the peri-second range. Although flicker-induced time dilation is a robust time illusion, its underlying neural mechanisms remain inconclusive. The neural entrainment account proposes that neural entrainment of the exogenous visual stimulus, marked by steady-state visual evoked potentials (SSVEPs) over the visual cortex, is the cause of time dilation. By contrast, the saliency account argues that the conscious perception of flicker changes is indispensable. In the current study, we examined these two accounts separately. The first two experiments manipulated the level of saliency around the critical fusion threshold (CFF) in a duration discrimination task to probe the effect of change saliency. The amount of dilation correlated with the level of change saliency. The next two experiments investigated whether neural entrainment alone could also induce perceived dilation. To preclude change saliency, we utilized a combination of two high-frequency flickers above the CFF, whereas their beat frequency still theoretically aroused neural entrainment at a low frequency. Results revealed a moderate time dilation induced by combinative high-frequency flickers. Although behavioral results suggested neural entrainment engagement, electroencephalography showed neither larger power nor inter-trial coherence (ITC) at the beat. In summary, change saliency was the most critical factor determining the perception and strength of time dilation, whereas neural entrainment had a moderate influence. These results highlight the influence of higher-level visual processing on time perception.

The Modulation of Stimulus Familiarity on the Repetition Effect in Duration Judgment.

The repetition of a stimulus often produces a shorter subjective duration than does the presentation of a novel item. To test whether familiarity mediates the repetition compression effect, the present study compared the influence of repeated words and pseudowords on apparent duration, using a duration discrimination task. We found a similar magnitude of temporal compression for the repeated-word and repeated-pseudoword conditions. When introducing a further experiment with two new conditions in which the standard–comparison pair shared a character at the first or second constituent position, we observed a shorter subjective duration for whole word (or whole pseudoword) repetition compared with the remaining conditions (i.e., first-character repetition, second-character repetition, and novel baseline). However, temporal compression for the first- and second-character repetitions was observed only for pseudowords but not for words. Our findings indicate that familiarity modulates the perception of duration in constituent character repetition. The results are discussed on the basis of the predictive coding theory.

Distraction at the cocktail party: Attenuation of the irrelevant speech effect after a training of auditory selective attention.

Task-irrelevant auditory stimuli such as speech are known to disrupt the retention of serial information held in verbal short-term memory (STM). Although such effects of irrelevant sound are typically very robust, there is evidence suggesting that some forms of auditory distraction are susceptible to cognitive control or auditory attention. In the present study, we tested whether an extensive training of auditory selective attention reduces the degree of interference produced by irrelevant speech in a serial STM task. Participants (n = 38) were trained on an adaptive dichotic-listening task requiring selective processing of a varying list of verbal items presented via headphones while ignoring auditory distractors presented simultaneously either by a different voice or in the irrelevant ear. The number of target items that could be memorized increased throughout 5 training sessions, suggesting improvement of auditory selective attention in a dichotic-listening situation. An active control group (n = 37) was trained on an auditory duration discrimination task for 5 sessions. Prior to the training, task-irrelevant speech was shown to interfere with serial recall in both groups. After the training, however, the irrelevant speech effect was attenuated in the group that was trained on the dichotic-listening task, whereas no reduction of auditory distraction was observed in the active control group. The results show that the interference produced by task-irrelevant speech can be reduced through an extensive dichotic-listening training, suggesting that the irrelevant speech effect is susceptible to auditory selective attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).