Time perception in severe traumatic brain injury patients: A study comparing different methodologies

In this study, we investigated time perception in patients with traumatic brain injury (TBI). Fifteen TBI patients and 15 matched healthy controls participated in the study. Participants were tested with durations above and below 1 s on three different temporal tasks that involved time reproduction, production, and discrimination tasks. Data variables analyzed included amount of errors, relative errors, and coefficient of variation. Both groups completed a neuropsychological battery that included measures of attention, working memory, and executive functions. Results revealed significant differences between groups on the time reproduction and discrimination tasks, whereas groups showed similar performance on the time production task. Correlation analyses showed involvement of attention, working memory and executive functions on the time reproduction and time discrimination tasks, but there was no involvement on the time production task. These findings suggest that TBI does not impact specific temporal function. Rather, impairments in attention, working memory and executive function abilities may explain lower temporal performance in people with TBI.     

Observational drawing biases are predicted by biases in perception: Empirical support of the misperception hypothesis of drawing accuracy with respect to two angle illusions

We tested the misperception hypothesis of drawing errors, which states that drawing accuracy is strongly influenced by the perceptual encoding of a to-be-drawn stimulus. We used a highly controlled experimental paradigm in which nonartist participants made perceptual judgements and drawings of angles under identical stimulus exposure conditions. Experiment 1 examined the isosceles/scalene triangle angle illusion; congruent patterns of bias in the perception and drawing tasks were found for 40 and 60° angles, but not for 20 or 80° angles, providing mixed support for the misperception hypothesis. Experiment 2 examined shape constancy effects with respect to reproductions of single acute or obtuse angles; congruent patterns of bias in the perception and drawing tasks were found across a range of angles from 29 to 151°, providing strong support for the misperception hypothesis. In both experiments, perceptual and drawing biases were positively correlated. These results are largely consistent with the misperception hypothesis, suggesting that inaccurate perceptual encoding of angles is an important reason that nonartists err in drawing angles from observation.     

Analyzing a complex visuomotor tracking task with brain-electrical event related potentials

Non-invasive techniques such as neuroimaging and event-related potential (ERP) methods have dramatically enhanced our understanding of the human brain. According to the requirements of the applied method, it is useful to simplify tasks for methodological reasons. In the present study we tested whether ERP measures are also suitable for analyzing complex tasks. In order to do this, we developed an analysis strategy based on the post hoc analysis of the behavioural data. We applied this method to a pursuit-tracking task of 25 s trial duration, consisting of repeated and non-repeated waveforms, where subjects had to track a target cross with a mouse-controlled cursor cross. An EEG was recorded from 62 channels. Response-locked ERPs were computed for two types of error correction: the correction of errors induced externally by the change of target direction and of internal errors generated by the subject itself. We found several ERP components that could be assigned to different feedback and feedforward controlled processing steps in the frontoparietal circuitry underlying visuomotor control, such as movement planning, movement execution (motor potential), reafferent activity, visuospatial analysis, and attentional (P300) processes. Our results support newer models that propose a role for the posterior parietal cortex in integrating multimodal sensory information. In addition, fast (about 180 ms and probably facilitated by anticipation) and slow (about 230-260 ms) error corrections could be differentiated by the time course of ERP activity. Our results show that complex (motor) tasks can be investigated with ERPs. This opens fruitful perspectives for future research on motor control in an ecological setting.     

Spatial mislocalization as a consequence of sequential coding of stimuli

In three experiments, we tested whether sequentially coding two visual stimuli can create a spatial misperception of a visual moving stimulus. In Experiment 1, we showed that a spatial misperception, the flash-lag effect, is accompanied by a similar temporal misperception of first perceiving the flash and only then a change of the moving stimulus, when in fact the two events were exactly simultaneous. In Experiment 2, we demonstrated that when the spatial misperception of a flash-lag effect is absent, the temporal misperception is also absent. In Experiment 3, we extended these findings and showed that if the stimulus conditions require coding first a flash and subsequently a nearby moving stimulus, a spatial flash-lag effect is found, with the position of the moving stimulus being misperceived as shifted in the direction of its motion, whereas this spatial misperception is reversed so that the moving stimulus is misperceived as shifted in a direction opposite to its motion when the conditions require coding first the moving stimulus and then the flash. Together, the results demonstrate that sequential coding of two stimuli can lead to a spatial misperception whose direction can be predicted from the order of coding the moving object versus the flash. We propose an attentional sequential-coding explanation for the flash-lag effect and discuss its explanatory power with respect to related illusions (e.g., the Fr?hlich effect) and other explanations.     

Solving for two unknowns: an extension of vector-based models of landmark-based navigation

Vectors are mathematical representations of distance and direction information that take the form of line segments where length represents distance and orientation in space represents direction. Vector-based models have proven beneficial in understanding the spatial behavior of a variety of species in tasks that require landmark-based navigation via vector addition and vector averaging to determine a location. Extant research regarding vector-based representational and computational accounts of landmark-based navigation has involved tasks that required solving for one unknown (i.e., a location). Using a novel landmark-based navigation task, we provide evidence consistent with a form of vector algebra that involves solving two simultaneous equations with two unknowns in order to determine a location in space. Results extend vector-based accounts of landmark-based navigation and provide a novel methodological approach to the testing of mobile organisms.     

Delis-Kaplan Executive Function System

The purpose of the current study was to examine the performance of children with and without ADHD in time reproduction tasks involving varying durations and modalities. Twenty children with ADHD and 20 healthy controls completed time reproduction tasks in three modalities (auditory, visual, and a unique combined auditory/visual condition) and six durations (1 second, 4 seconds, 12 seconds, 24 seconds, 48 seconds, and 60 seconds). Consistent with our predictions, we found main effects of group (participants with ADHD were significantly less accurate than those without ADHD), duration (accuracy decreased as temporal duration increased), and modality (responses in the combined condition were more accurate than those in the auditory condition, which in turn were more accurate than those in the visual condition). Furthermore, predicted interactions between group and duration (the discrepancy in performance between the two groups grew as temporal duration increased), and group and modality (the modality effect was of greater for participants with ADHD) were supported. A marginal, nonsignificant interaction between group, modality, and duration was also found. These findings are discussed in relation to current theory on the nature of cognitive deficits evident in individuals with ADHD, and methodological limitations are noted.     

The coding of constrained and preselected movement distance: Same-limb versus switched-limb reproduction

Three experiments were conducted to investigate the codes subserving the retention of movement extent information. Each experiment compared preselected and constrained movements in two independent movement tasks: same-limb reproduction and switched-limb reproduction. When movement direction was the same for both criterion and reproduction movements (experiment 1), same-limb reproduction was more accurate than switched-limb performance. With movement direction altered, however, switched-limb reproduction was equal to same-limb reproduction (experiment 2). These results were confirmed in experiment 3 which manipulated both movement direction and reproduction limb in a within-subject design. Furthermore, while preselected reproduction was superior to constrained reproduction in all three experiments, the two groups were not differentially affected by either the movement task or direction variables. The overall findings were interpreted as providing support for a multiple-cue memorial representation of movement extent and the notion of coding flexibility.     

Investigating the contribution of metacontrast to the Fröhlich effect for size

According to the Fr?hlich effect, observers perceive the initial position of a fast moving stimulus displaced in the direction of motion. On the basis of Kirschfeld and Kammer's as well as Fr?hlich's original assumption that metacontrast plays an important role in the emergence of the phenomenon, we predicted different amounts of misperception for stimulus enlargement compared to stimulus reduction. These basic predictions were confirmed in Experiment 1. In Experiment 2, we investigated whether an overestimation-bias might account for these results. But the overestimation of non-changing stimuli was too small to adequately explain the dissociation. In Experiment 3, we predicted and found different effects of the factor stimulus lightness on misperception in the enlargement and reduction condition. In Experiment 4, we showed that misperception in the enlargement condition is reduced when frames are used instead of filled stimuli, as in the earlier experiments. Results are discussed with respect to the original Fr?hlich effect.     

第三方惩罚中的规范错觉：基于公正世界信念的解释

惩罚规范在一定程度上会影响个体的惩罚行为, 但个体对惩罚规范的感知与实际规范之间可能存在差异, 这被称为规范错觉。为了更好地从这一角度理解第三方惩罚, 我们需要回答的是：第三方惩罚中是否存在规范错觉?如果存在, 其方向如何?会对个体自身的惩罚行为产生何种影响?实验1 (N = 449)和实验2 (N = 134)的结果表明, 在违规情境中, 人们往往低估了他人的惩罚水平, 这导致自身较低的惩罚行为。实验3 (N = 164)和实验4 (N = 284)进一步发现, 较弱的公正世界信念导致人们对他人惩罚水平的低估, 从而影响了自身的惩罚行为, 而社会距离调节了公正世界信念对规范错觉的影响。上述结果表明, 规范错觉会受到内部(公正世界信念)和外部(社会距离)两个参照点的影响, 同时也在一定程度上说明第三方惩罚是一种注重维护规范的积极行为、而非注重个人收益的策略行为。     

Repetitive pointing to remembered proprioceptive targets improves 3D hand positioning accuracy

Repetitive pointing movements to remembered proprioceptive targets were investigated to determine whether dynamic proprioception could be used to modify the initial sensorimotor conditions associated with an active definition of the target position. Twelve blindfolded subjects used proprioception to reproduce a self-selected target position as accurately as possible. Ten repetitions for each limb were completed using overhead and scapular plane pointing tasks. A 3D optical tracking system determined hand trajectory start and endpoint positions for each repetition. These positions quantified three-dimensional pointing errors relative to the target position and the initial and preceding movement repetitions, as well as changes in movement direction and extent. Target position and cumulative start position errors were significantly greater than the corresponding preceding movement (inter-repetition) errors, and increased as the trial progressed. In contrast, hand trajectory start and endpoint inter-repetition errors decreased significantly with repeated task performance, as did movement extent, although it was consistently underestimated for each repetition. Pointing direction remained constant, except for the angle of elevation for scapular plane pointing, which consistently decreased throughout the trial. The results suggest that the initial conditions prescribed by actively defining a proprioceptive target were subsequently modified by dynamic proprioception, such that movement reproduction capability improved with repeated task performance.     

Constant errors occur in matched reproduction of angles even when likely biases are eliminated

The literature on the reproduction of visually perceived angles often seems to contain an explicit or implicit assumption that systematic errors are caused by misperception of the sizes of the angles. We argue that in the absence of procedural artifacts no consistent error should arise from purely perceptual causes. Accordingly, an experimental procedure was designed to eliminate or evaluate a number of artifacts that probably affected earlier experiments. A computer-controlled display generated both a standard angle and a variable one that could be adjusted by a subject to match the standard. The data analysis followed Cox’s (1970) procedure for the analysis of binary data to focus on the numbers of positive and negative errors rather than on their magnitudes and so eliminate the numerically distorting effects of asymmetrical error distributions. Nevertheless, the results showed what has usually been reported before: acute angles were matched with too large a comparison angle, and obtuse ones with too small an angle. Thus, there is a real effect to be explained, although the explanation must invoke response processes.     

Developmental changes in face processing skills

Expertise in processing differences among faces in the spacing among facial features (second-order relations) is slower to develop than expertise in processing the shape of individual features or the shape of the external contour. To determine the impact of the slow development of sensitivity to second-order relations on various face-processing skills, we developed five computerized tasks that require matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction, and sound being spoken. In Experiment 1, we evaluated the influence of second-order relations on performance on each task by presenting them to adults (N=48) who viewed the faces either upright or inverted. Previous studies have shown that inversion has a larger effect on tasks that require processing the spacing among features than it does on tasks that can be solved by processing the shape of individual features. Adults showed an inversion effect for only one task: matching facial identity when there was a change in head orientation. In Experiment 2, we administered the same tasks to children aged 6, 8, and 10 years (N=72). Compared to adults, 6-year-olds made more errors on every task and 8-year-olds made more errors on three of the five tasks: matching direction of gaze and the two facial identity tasks. Ten-year-olds made more errors than adults on only one task: matching facial identity when there was a change in head orientation (e.g., from frontal to tilted up). Together, the results indicate that the slow development of sensitivity to second-order relations causes children to be especially poor at recognizing the identity of a face when it is seen in a new orientation.     

Sense of Time and Executive Functioning in Children and Adults

A number of patient studies suggest that impairments in frontal lobe functions are associated with disorders in temporal information processing. One implication of these findings is that subjective experience of time should be related to executive functions regardless of etiology. In two experiments, we examined sense of time in relation to components of executive functioning in healthy children and adults. In Experiment 1, children between 8 to 12 years completed six experimental tasks that tapped three components of executive functioning: inhibition, updating, and mental shifting. Sense of time was examined in a duration judgment task in which participants reproduced stimulus durations between 4 to 32 s. In Experiment 2, adult participants completed the time reproduction task under varying concurrent task demands. Both experiments showed selective effects in that time reproduction errors were related to the inhibition and updating, but not to the shifting, components of executive functioning. However, the observed effects were modulated by task demands and age-related differences in cognitive competence. We conclude that individual differences in executive functioning are only weakly related to time reproduction performance in healthy children and adults.     

Early Impulse Control: Treatment of Potential Errors within Pre-Programming and Control

Abstract

Early aiming adjustments following an online perturbation are made possible by impulse control. This process may unfold even earlier when perturbations impose a greater risk of a costly overshoot error. Participants executed upward and downward aims to mediate the cost of potential errors—downward overshoots require more energy to correct against gravity. On 33% of the trials, texture elements on the aiming surface were shifted following onset to appear congruent or incongruent with the aiming direction, and consequently generate a misperception of the limb moving slower or faster, respectively. Thus, the risk of potential errors could be influenced by the online perturbation (e.g., increased perceived likelihood of overshooting following the incongruent background). Findings indicated greater undershooting for down compared to up, which reflects the principle of movement optimisation. There was also more undershooting for an incongruent compared to congruent background, which is consistent with early online adjustments counter-acting the misperceived limb velocity. However, there were no interactions throughout the movement trajectory. We suggest that while the initial pre-programme considers the cost of potential errors (target direction), early impulse control fails to discriminate the likelihood of these errors occurring following an online perturbation (moving background).     

“Flash” dance: How speed modulates perceived duration in dancers and non-dancers

Speed has been proposed as a modulating factor on duration estimation. However, the different measurement methodologies and experimental designs used have led to inconsistent results across studies, and, thus, the issue of how speed modulates time estimation remains unresolved. Additionally, no studies have looked into the role of expertise on spatiotemporal tasks (tasks requiring high temporal and spatial acuity; e.g., dancing) and susceptibility to modulations of speed in timing judgments. In the present study, therefore, using naturalistic, dynamic dance stimuli, we aimed at defining the role of speed and the interaction of speed and experience on time estimation. We presented videos of a dancer performing identical ballet steps in fast and slow versions, while controlling for the number of changes present. Professional dancers and non-dancers performed duration judgments through a production and a reproduction task. Analysis revealed a significantly larger underestimation of fast videos as compared to slow ones during reproduction. The exact opposite result was true for the production task. Dancers were significantly less variable in their time estimations as compared to non-dancers. Speed and experience, therefore, affect the participants' estimates of time. Results are discussed in association to the theoretical framework of current models by focusing on the role of attention.     

Remembered duration: working memory and the reproduction of intervals

On the basis of attention allocation models of time estimation, the role of working memory in prospective duration reproduction is explored. In four experiments, adult participants performed a counting task (duration, 400 sec) that allowed coordinative and sequential demands on working memory to be varied. After completing the counting task, the participants reproduced the time that they had worked on this task It emerged that (1) increased coordinative demands on working memory (but not increased sequential demands) reduced the accuracy of prospective duration reproduction (Experiments 1 and 2), (2) presenting context information during the reproduction phase enhanced the accuracy of the reproduced duration (Experiment 3), and (3) individual differences in coordinative working memory capacity affected duration reproduction in the same direction as the experimental manipulation of coordinative task demands (Experiment 4). The results suggest that attention allocation models of time estimation may benefit from taking a more differentiated view of the types of attentional demands that affect temporal cognition.     

Time perception in boys with attention-deficit/hyperactivity disorder according to time duration, distraction and mode of presentation.

In a recent theoretical model of attention-deficit/hyperactivity disorder (ADHD), Barkley (1997a) predicted that ADHD children experience impairments in their psychological sense of time. This was demonstrated in a series of experiments by Barkley, Koplowicz, Anderson, and McMurray (1997). The present study sought to investigate the effects of ADHD subtype, stimulus duration, mode of presentation (visual versus auditory) and distractors on the performance of a simple time reproduction task. Data were obtained from 44 ADHD children (14 predominantly inattentive and 30 combined type) and 44 age-matched Controls using the Time Perception Application version 1.0 (Barkley, University of Massachusetts Medical Center, 1998). Results revealed that the ADHD children made significantly larger errors on Visual time reproduction tasks than the Controls, regardless of ADHD subtype or the presence of distractors. Furthermore, ADHD children were more likely to overestimate the shorter time intervals (0.5 and 2 s) and underestimate the longer time intervals (3, 4 and 6 s) relative to Controls. No group differences were observed on the auditory time reproduction task, with both ADHD and Control groups consistently underestimating the durations to be reproduced. The results of this study provide further support for the prediction that children with ADHD have an impaired sense of time.     

Bigram Frequency,Number of Syllables and Morphemes and Their Effects on Lexical Decision and Word Naming

There has been an increasing volume of evidence supporting the role of the syllable in word processing tasks. Recently it has also been shown that orthographic redundancy, related to the pattern of bigram frequencies, could not explain the syllable number effect on lexical decision times. This was demonstrated on a large sample of words taken from the British Lexicon Project. In this study we extend this research by examining both lexical decision and word naming times taken from the English Lexicon Project . There was a syllable number effect for both tasks in the expected direction, and this effect was independent of the presence of a bigram trough. The research also examined the role of other bigram related variables and the number of morphemes on lexical decision and word naming times. The number of morphemes had a significant effect on both word processing tasks, with words with more morphemes producing faster reaction times and also fewer errors. This pattern was reversed for nonword lexical decision times. The results are discussed in the light of recent developments in models of reading.     

Computational Evidence That Frequency Trajectory Theory Does Not Oppose But Emerges From Age‐of‐Acquisition Theory

According to the age‐of‐acquisition hypothesis, words acquired early in life are processed faster and more accurately than words acquired later. Connectionist models have begun to explore the influence of the age/order of acquisition of items (and also their frequency of encounter). This study attempts to reconcile two different methodological and theoretical approaches (proposed by Lambon Ralph & Ehsan, 2006 and Zevin & Seidenberg, 2002 ) to age‐limited learning effects. The current simulations extend the findings reported by Zevin and Seidenberg (2002) that have shown that frequency trajectories (FTs) have limited and specific effects on word‐reading tasks. Using the methodological framework proposed by Lambon Ralph and Ehsan (2006) , which makes it possible to compare word‐reading and picture‐naming tasks in connectionist networks, we were able to show that FT has a considerable influence on age‐limited learning effects in a picture naming task. The findings show that when the input–output mappings are arbitrary (simulating picture naming tasks), the links formed by the network become entrenched as a result of early experience and that subsequent variations in frequency of exposure of the items have only a minor impact. In contrast, when the mappings between input‐output are quasi‐systematic or systematic (simulating word‐reading tasks), the training of new items was generalized and resulted in the suppression of age‐limited learning effects. At a theoretical level, we suggest that FT, which simultaneously takes account of time and the level of exposure across time, represents a more precise and modulated measure compared with the order of introduction of the items and may lead to innovative hypotheses in the field of age‐limited learning effects.