Timing accuracy in motion extrapolation: reverse effects of target size and visible extent of motion at low and high speeds

Atypical Time to Contact Estimation in Young Adults with Autism Spectrum Disorder

Individuals with Autism Spectrum Disorder (ASD) present atypical sensory processing in the perception of moving stimuli and biological motion. The present study aims to explore the performance of young adults with ASD in a time to contact (TTC) estimation task involving social and non-social stimuli. TTC estimation involves extrapolating the trajectory of a moving target concealed by an occluder, based on the visible portion of its path, to predict the target's arrival time at a specific position. Sixteen participants with a diagnosis of level-1 ASD (M = 19.2 years, SE = 0.54 years; 3 F, 13 M) and sixteen participants with TD (M = 22.3 years, SE = 0.44 years; 3 F, 13 M) took part in the study and underwent a TTC estimation task. The task presented two object types (a car and a point-light walker), different object speeds, occluder lengths, motion directions and motion congruency. For the car object, a larger overestimation of TTC emerged for ASDs than for TDs, whereas no difference between ASDs and TDs emerged for the point-light walker. ASDs exhibited a larger TTC overestimation for the car object than for the point-light walker, whereas no difference between object types emerged for TDs. Our results indicated an atypical TTC estimation process in young adults with ASD. Given its importance in daily life, future studies should further explore this skill. Significant effects that emerged from the analysis are discussed.

Effect of different time intervals on the judgment of hitting timing among tennis athletes

BACKGROUND

Accurate time estimation is crucial for performance in dynamic sports environments, yet its underlying mechanisms remain unclear. In particular, the effects of periodic moving stimuli and different time intervals on time-to-contact (TTC) estimation have been overlooked. This study examines these effects in tennis athletes, providing insights into the cognitive mechanisms of temporal processing in dynamic sports contexts.

METHODS

The cortical activity of 28 tennis athletes (17males; aged 23.11 ± 2.38 years) and 27 novices (20males; aged 22.19 ± 2.54 years) was measured using electroencephalography during a TTC task. Participants predicted when an invisible tennis ball would contact a target location under subsecond (0.667s) or suprasecond (1.333 s) intervals, following ball speed changes (0 %, +25 %, or -25 %).

RESULTS

All participants showed better time estimation precision in the suprasecond interval. Athletes exhibited significantly lower variable errors (p = 0.015) and marginally lower absolute errors (p = 0.065), indicating greater consistency in time estimation. Electroencephalography revealed significantly higher CNV amplitudes in athletes (p < 0.001) and lower CNV in the subsecond interval (p < 0.001). Alpha band power was reduced in the subsecond interval (p < 0.001). Higher CNV amplitudes correlated with lower ABS (r = -0.127, p = 0.021), and lower CE was linked to greater alpha band power (r = -0.117, p = 0.033).

CONCLUSION

These findings indicate that beat-based timing in complex motion relies on higher-level cognitive resources for effective anticipation. Suprasecond intervals enhance better time estimation precision due to cognitive control, whereas subsecond intervals reduce precision. This suggests the formation of an internal model for time estimation. Exploring various time intervals further could inform interventions to improve timing performance in sports training.

Prediction of time to contact under perceptual and contextual uncertainties

Accurately estimating time to contact (TTC) is crucial for successful interactions with moving objects, yet it is challenging under conditions of sensory and contextual uncertainty, such as occlusion. In this study, participants engaged in a prediction motion task, monitoring a target that moved rightward and an occluder. The participants' task was to press a key when they predicted the target would be aligned with the occluder's right edge. We manipulated sensory uncertainty by varying the visible and occluded periods of the target, thereby modulating the time available to integrate sensory information and the duration over which motion must be extrapolated. Additionally, contextual uncertainty was manipulated by having a predictable and unpredictable condition, meaning the occluder either reliably indicated where the moving target would disappear or provided no such indication. Results showed differences in accuracy between the predictable and unpredictable occluder conditions, with different eye movement patterns in each case. Importantly, the ratio of the time the target was visible, which allows for the integration of sensory information, to the occlusion time, which determines perceptual uncertainty, was a key factor in determining performance. This ratio is central to our proposed model, which provides a robust framework for understanding and predicting human performance in dynamic environments with varying degrees of uncertainty.

Neural mechanisms for integrating time and visual velocity cues in a prediction motion task: An fNIRS study

Human beings use accurate estimates of the time-to-collision of moving objects effortlessly in everyday life. In the laboratory, researchers typically apply prediction motion (PM) tasks to investigate motion processing. In the PM tasks, time structure refers to the ratio of travel time between the visible segment (first segment) and occluded segment (second segment). The condition of T = 1.0, which indicates that the time spent moving is the same across the two segments, is called equal time structure. The present study investigated the neural mechanisms of time and visual velocity information in prediction motion using functional near-infrared spectroscopy (fNIRS). Experiment 1 showed that when visual velocity was not available, participants performed better in equal time structure conditions than in unequal time structure conditions. Moreover, the left inferior parietal lobe (IPL) showed higher activation under equal time structure conditions. Experiment 2 showed that participants also performed better in equal time structure conditions when visual velocity was available. Both the left IPL and superior parietal lobe (SPL) exhibited stronger activation under equal time structure conditions in Experiment 2. A comparison between the two experiments showed that participants integrated time structure and visual velocity to estimate arrival time of the moving object. The fNIRS data indicated that the left SPL could be involved in information integration when judging arrival time.

Motion duration is overestimated behind an occluder in action and perception tasks

Motion estimation behind an occluder is a common task in situations like crossing the street or passing another car. People tend to overestimate the duration of an object's motion when it gets occluded for subsecond motion durations. Here, we explored (a) whether this bias depended on the type of interceptive action: discrete keypress versus continuous reach and (b) whether it was present in a perception task without an interceptive action. We used a prediction-motion task and presented a bar moving across the screen with a constant velocity that later became occluded. In the action task, participants stopped the occluded bar when they thought the bar reached the goal position via keypress or reach. They were more likely to stop the bar after it passed the goal position regardless of the action type, suggesting that the duration of occluded motion was overestimated (or its speed was underestimated). In the perception task, where participants judged whether a tone was presented before or after the bar reached the goal position, a similar bias was observed. In both tasks, the bias was near constant across motion durations and directions and grew over trials. We speculate that this robust bias may be due to a temporal illusion, Bayesian slow-motion prior, or the processing of the visible-occluded boundary crossing. Understanding its exact mechanism, the conditions on which it depends, and the relative roles of speed and time perception requires further research.

The effect of symbolic meaning of speed on time to contact

The effects of moving task-irrelevant objects on time-to-contact (TTC) judgments are examined in six experiments. In particular, we investigated the effects of the symbolic meaning of speed on TTC by presenting images of objects recalling the symbolic meaning of high speed (motorbike, rocket, formula one, rabbit, cheetah and flying Superman) and low speed (bicycle, hot-air balloon, tank, turtle, elephant and static Superman). In all experiments, participants judged the TTC of these moving objects with a black line, indicating the end of the occlusion. Experiment 7 was conducted to disambiguate whether the effects on TTC, found in the previous experiments, were either a by-product of a speed illusion or they were rather elicited by the implicit timing task. In a two-interval forced choice task, participants were instructed to judge if "high-speed objects" moved actually faster than "slow-speed objects". The results revealed no consistent speed illusion. Taken together the results showed shorter TTC estimated with stimuli recalling the meaning of high compared to low speed, but only with the long occlusion duration (3.14 s). At shorter occlusion durations, the pattern was reversed (participant tend to have shorter TTC with stimuli recalling the meaning of low speed). We suggest that the symbolic meaning of speed works mainly at low speed and long TTC, because the semantic elaboration of the stimulus needs a deeper cognitive elaboration. On the other hand, at higher speeds, a small erroneous perceptual judgment affects the TTC, perhaps due to a speed expectancy violation of the expected "slow object".

Timing in the absence of a clock reset

Prominent models of time perception assume a reset of the timing mechanism with an explicit onset of the interval to be timed. Here we investigated the accuracy and precision of temporal estimations when the duration does not have such an explicit onset. Participants were tracking a disc moving on a circular path with varying speeds, and estimated the duration of one full revolution before the stimulus stopped. The onset of that revolution was either cued (explicit), or undetermined until the stimulus stopped (implicit). Reproduced duration was overestimated for short and underestimated for long durations, and variability of the estimates scaled with the duration in both temporal conditions. However, the bias was more pronounced in the implicit condition. In addition, if the stimulus path was partially occluded, duration of the occluded motion was correctly estimated. In a second experiment, we compared the precision in the explicit and implicit conditions by asking participants to discriminate the duration of one revolution before the stimulus stopped to that of a static stimulus presentation in a forced-choice task. Sensitivity of discrimination was worse in the implicit onset condition, but surprisingly, still comparable to the explicit condition. In summary, the estimates follow principles described in prospective timing paradigms, although not knowing beforehand when to start timing decreases sensitivity of temporal estimations. Since in naturalistic contexts, we often do not know in advance which durations might be relevant to estimate, the simple task presented here could become a valuable tool for testing models of temporal estimation.

Neural Correlates of Speed-Tuned Motion Perception in Healthy Adults

It has been suggested that slow and medium-to-fast speeds of motion may be processed by at least partially separate mechanisms. The purpose of this study was to establish the cortical areas activated during motion-defined form and global motion tasks as a function of speed, using functional magnetic resonance imaging. Participants performed discrimination tasks with random dot stimuli at high coherence, at coherence near their own thresholds, and for random motion. Stimuli were moving at 0.1 or 5 deg/s. In the motion-defined form task, lateral occipital complex, V5/MT+ and intraparietal sulcus showed greater activation by high or near-threshold coherence than by random motion stimuli; V5/MT+ and intraparietal sulcus demonstrated greater activation for 5 than 0.1 deg/s dot motion. In the global motion task, only high coherence stimuli elicited significant activation over random motion; this activation was primarily in nonclassical motion areas. V5/MT+ was active for all motion conditions and showed similar activation for coherent and random motion. No regions demonstrated speed-tuning effects for global motion. These results suggest that similar cortical systems are activated by slow- and medium-speed stimuli during these tasks in healthy adults.

Fast moving texture has opposite effects on the perceived speed of visible and occluded object trajectories

In a series of psychophysical experiments, we altered the perceived speed of a spot (target) using a grayscale texture moving in the same (iso-motion) or opposite (anti-motion) direction of the target. In Experiment 1, using a velocity discrimination task (2IFC), the target moved in front of the texture and was perceived faster with anti-motion than iso-motion texture. The integration and segregation of motion signals in high-level motion areas may have accounted for the illusion. In Experiment 2, by asking observers to estimate the time-to-contact (TTC) with a bar indicating the end of the invisible trajectory, we showed that this illusory visible speed, due to anti- (iso-) texture, reduced (increased) the subsequent estimated duration of occluded target trajectory. However, in Experiment 3, when the target disappeared behind the iso-motion texture, the TTC was estimated shorter than anti- and static textures. In Experiment 4, using an interruption paradigm, we found negative Point of Subjective Equalities (PSEs) with iso-motion but not static texture, suggesting that iso-motion led to overestimation of the hidden speed. However, sensitivity to target speed differences, as assessed by JNDs and d'values was not affected. Results of Experiments 3 and 4 indicate that only the iso-texture affected the estimated target speed, but with opposite polarity compared to visible motion, suggesting a different origin of speed bias. Because our results show that visuospatial tracking was facilitated by the fast iso-motion, we conclude that motion of the occluded target was tracked by shifting visuospatial attention.

Probing the involvement of the earliest levels of cortical processing in motion extrapolation with rapid forms of visual motion priming and adaptation

In this study, we investigated the effect of brief motion priming and adaptation, occurring at the earliest levels of the cortical visual stream, on time-to-contact (TTC) estimation of a target passing behind an occluder. By using different exposure times of directional motion presented in the occluder area prior to the target's disappearance behind it, our aim was to modulate (prime or adapt) the extrapolated motion of the invisible target, thus producing different TTC estimates. Our results showed that longer (yet subsecond) exposures to motion in the same direction as the target produced late TTC estimates, whereas shorter exposures produced shorter TTC estimates, indicating that rapid forms of motion adaptation and motion priming affect extrapolated motion. Our findings suggest that motion extrapolation might occur at the earliest levels of cortical processing of motion, at which these rapid mechanisms of priming and adaptation take place.

Filling gaps in visual motion for target capture

A remarkable challenge our brain must face constantly when interacting with the environment is represented by ambiguous and, at times, even missing sensory information. This is particularly compelling for visual information, being the main sensory system we rely upon to gather cues about the external world. It is not uncommon, for example, that objects catching our attention may disappear temporarily from view, occluded by visual obstacles in the foreground. Nevertheless, we are often able to keep our gaze on them throughout the occlusion or even catch them on the fly in the face of the transient lack of visual motion information. This implies that the brain can fill the gaps of missing sensory information by extrapolating the object motion through the occlusion. In recent years, much experimental evidence has been accumulated that both perceptual and motor processes exploit visual motion extrapolation mechanisms. Moreover, neurophysiological and neuroimaging studies have identified brain regions potentially involved in the predictive representation of the occluded target motion. Within this framework, ocular pursuit and manual interceptive behavior have proven to be useful experimental models for investigating visual extrapolation mechanisms. Studies in these fields have pointed out that visual motion extrapolation processes depend on manifold information related to short-term memory representations of the target motion before the occlusion, as well as to longer term representations derived from previous experience with the environment. We will review recent oculomotor and manual interception literature to provide up-to-date views on the neurophysiological underpinnings of visual motion extrapolation.

Illusory speed is retained in memory during invisible motion

The brain can retain speed information in early visual short-term memory in an astonishingly precise manner. We investigated whether this (early) visual memory system is active during the extrapolation of occluded motion and whether it reflects speed misperception due to contrast and size. Experiments 1A and 2A showed that reducing target contrast or increasing its size led to an illusory speed underestimation. Experiments 1B, 2B, and 3 showed that this illusory phenomenon is reflected in the memory of speed during occluded motion, independent of the range of visible speeds, of the length of the visible trajectory or the invisible trajectory, and of the type of task. These results suggest that illusory speed is retained in memory during invisible motion.