Perceived duration decreases with increasing eccentricity

Previous studies examining the influence of stimulus location on temporal perception yield inhomogeneous and contradicting results. Therefore, the aim of the present study is to soundly examine the effect of stimulus eccentricity. In a series of five experiments, subjects compared the duration of foveal disks to disks presented at different retinal eccentricities on the horizontal meridian. The results show that the perceived duration of a visual stimulus declines with increasing eccentricity. The effect was replicated with various stimulus orders (Experiments 1–3), as well as with cortically magnified stimuli (Experiments 4–5), ruling out that the effect was merely caused by different cortical representation sizes. The apparent decreasing duration of stimuli with increasing eccentricity is discussed with respect to current models of time perception, the possible influence of visual attention and respective underlying physiological characteristics of the visual system.     

Effect of short and long exposure duration and dual-tasking on a global-local task

Past research has demonstrated a global advantage in responses to visually presented hierarchical stimuli such that, on incongruent trials, the global form interferes with responses to the local level [Kimchi, R. (1992). Primacy of wholistic processing and global/local paradigm: A critical review. Psychological Bulletin, 112, 24-38]. In Experiment 1, 32 adults performed alternating blocks of global or local identification of hierarchical letter stimuli in which the global and local letters were congruent, incongruent, or neutral, and were presented at either a short (17 ms) or long (100 ms) exposure duration. A global advantage was demonstrated at both durations. In the local-directed task, interference on incongruent, relative to neutral, trials was observed at both exposure durations, but facilitation on congruent trials, relative to neutral trials, was present only when stimuli were presented at the long exposure duration. In Experiment 2, global or local identification was performed by another group of 24 adults at either a long or short exposure duration, and also under conditions of full attention (FA) or dual-task (DT) conditions with a digit-monitoring task. Under FA, we again found significant interference at both exposure durations, but facilitation only at the long exposure duration. Under DT conditions, the pattern of facilitation and interference at the short duration remained unchanged. At the long duration, however, dual-tasking eliminated interference in the RT but not error data, while facilitation was present in both sets of data. Results are in line with a perceptual account of the global advantage, and suggest that facilitation requires consciously-mediated processes, whereas interference does not.     

Effect of face familiarity on age decision

The present experiment was planned to check whether the extraction of apparent age is affected by face identity (familiarity) or not. According to the traditional view, age estimation should be carried out independently of face identity, because it is one of the visually derived semantic codes (like gender and ethnicity). However, little is known about its underlying mechanisms. Moreover, some recent studies have cast doubt on the parallel thesis regarding facial expression, facial speech, ethnicity, and gender. Given the promising results of a pilot experiment (n=24), 16 Caucasian participants were enrolled in an "age decision" task on morphed faces derived from one old and one young source-face, in the proportion 70:30. The respondents had previously been familiarised with half the source faces by a learning procedure (associating the face, surname, occupation and city of residence of the person displayed), while the remaining half were unfamiliar. The results showed that age decision was affected by face familiarity, at least when the task was perceptually difficult enough. This adds support to the thesis that the identification of identity and the extraction of visually derived semantic codes are not made independently from each other. The status of age, within the visually derived semantic codes, is also discussed.     

Introspective duration estimation of reactive and proactive motor responses

The metajudgment of motor responses refers to our ability to evaluate the accuracy of our own actions. Can humans metajudge the duration of their Reaction Times (RTs) to a light-flash and the accuracy of their reproduction of a reference time interval bounded by two light flashes (Anticipatory Response Time, ART)? A series of four distinct experiments shows that RT_Meta and ART_Metajudgments are possible but with accuracies about ×2.4 and ×3 poorer than the corresponding RT and ART ones. In order to reveal the origin of this drop in performance, we ask whether a visual feedback synchronous with subjects’ key-presses could improve performance. We show that overall the presence of a visual feedback does not significantly improve metajudgment accuracy although such a trend is noticeable in ART_Meta. We then compare these performances with the passive perceptual estimation of the played back (Pb) RT and ART time intervals when bounded by two (RT_Pb) and three (ART_Pb) light flashes. We show that RT_Meta and RT_Pb accuracies are close to equal, but that ART_Meta is about ×2 less accurate than ART_Pb which in turn is ×1.5 less accurate than ART. The latter observation fails however to reach statistical significance hence not sustaining proposals that active time estimation is more reliable than passive one. The whole dataset is accounted for by a clock-type model where duration estimation performance is limited by four noise sources (visual, clock-count, motor and proprioceptive + efference copy) plus one proper to ART_Meta task. It is proposed that the latter reflects the impossibility for the time-counting system to use the same time origin more than once.     

Matching perceived depth from disparity and from velocity: Modeling and psychophysics

We asked observers to match in depth a disparity-only stimulus with a velocity-only stimulus. The observers’ responses revealed systematic biases: the two stimuli appeared to be matched in depth when they were produced by the projection of different distal depth extents. We discuss two alternative models of depth recovery that could account for these results. (1) Depth matches could be obtained by scaling the image signals by constants not specified by optical information, and (2) depth matches could be obtained by equating the stimuli in terms of their signal-to-noise ratios (see Domini & Caudek, 2009). We show that the systematic failures of shape constancy revealed by observers’ judgments are well accounted for by the hypothesis that the apparent depth of a stimulus is determined by the magnitude of the retinal signals relative to the uncertainty (i.e., internal noise) arising from the measurement of those signals.     

Symmetry and repetition in perspective

Although ecologically relevant, perspective views of symmetries and repetitions have hardly been investigated. Any symmetry or repetition that is not oriented orthogonally to the line of sight yields perspective distortions on the retina. In this study, these distortions are analyzed in terms of first-order structures (i.e., virtual lines between corresponding points) and second-order structures (i.e., correlation quadrangles formed by two virtual lines). In the literature, these structures have been proposed to guide the detection of fron to parallel symmetry and repetition. But what about perspective views? First, the analysis in this study shows that perspective distorts the retinal first-order and second-order structures of symmetry and repetition differently. Second, the results of two experiments on this distortion difference suggest that, in perspective views, symmetry and repetition detection is not preceded by normalization but occurs directly on the basis of the retinal first-order and second-order structures.     

Stimulus spacing effects in duration perception are larger for auditory stimuli: Data and a model

Models of duration bisection have focused on the effects of stimulus spacing and stimulus modality. However, interactions between stimulus spacing and stimulus modality have not been examined systematically. Two duration bisection experiments that address this issue are reported. Experiment 1 showed that stimulus spacing influenced the classification of auditory, but not visual, stimuli. Experiment 2 used a wider stimulus range, and showed stimulus spacing effects for both visual and auditory stimuli, although the effects were larger for auditory stimuli. A version of Temporal Range Frequency Theory was applied to the data, and was used to demonstrate that the qualitative pattern of results can be captured with the single assumption that the durations of visual stimuli are less discriminable from one another than are the durations of auditory stimuli.     

The cycle of preference: Long-term dynamics of aesthetic appreciation

According to evolutionary psychology people prefer curved objects. We provide evidence that preferences for curved objects might be biologically motivated, but can also be, at least partly, modulated by fashion, trends or Zeitgeist effects. In four studies, participants (n1 = 38, n2 = 40, n3 = 38, n4 = 38) rated the curvature and appreciation of car models for ten 5-y periods (1950-1999). A parabolic function of curvature, with the lowest curvature for 1980s designs, was documented. Further, appreciation followed this parabolic trend. We revealed adaptation effects as plausible candidates for triggering such changes in preference. In sum, as appreciation of curvature changes dynamically over time, any study aiming to find static and general principles of liking regarding curvature is confounded with Zeitgeist effects.     

The force of symmetry revisited: symmetry-to-noise ratios regulate (a)symmetry effects

Freyd and Tversky's [Am. J. Psychol. 97 (1984) 109] data suggested that human observers tend to overestimate relatively high levels of symmetry (symmetry effect), and tend to underestimate relatively low levels of symmetry (asymmetry effect). However, on the basis of their holographic approach to visual regularity, van der Helm and Leeuwenberg [Psychol. Rev. 103(3) (1996) 429] predicted that, at any level of symmetry, both symmetry and asymmetry effects may occur as a consequence of correct estimates of symmetry-to-noise ratios. This prediction was tested in two experiments, with tasks and stimuli similar to those in Freyd and Tversky's study. First, subjects had to judge whether a noisy symmetry is more similar to a slightly more symmetrical variant or to a slightly less symmetrical variant. Second, for every pair of stimuli in such a triadic comparison, subjects had to judge which stimulus is the more symmetrical one. The results from both experiments show that the occurrence of (a)symmetry effects indeed depends on symmetry-to-noise ratios.     

From theory to implementation: Building a multidimensional space for face recognition

The purpose of the present study was to empirically construct a multidimensional model of face space based upon Valentine’s [Valentine, T. (1991). A unified account of the effects of distinctiveness, inversion, and race in face recognition. Quarterly Journal of Experimental Psychology, 43A, 161-204; Valentine, T. (2001). Face-space models of face recognition. In M. J. Wenger, & J. T. Townsend, (Eds.). Computational, geometric, and process perspectives on facial cognition: Contexts and challenges. Scientific psychology series (pp. 83-113). Mahwah, NJ: Erlbaum] metaphoric model. Two-hundred and ten participants ranked 200 faces on a 21-dimensional space composed of internal facial features. On the basis of these dimensions an index of distance from the center of the dimensional space was calculated. A factor analysis revealed six factors which highlighted the importance of both featural and holistic processes in face recognition. Testing the model in relation to facial distinctiveness and face recognition strengthened its validity by emphasizing the relevance of the constructed multidimensional space for face recognition. The data are discussed within the framework of theoretical models of face recognition.     

Representational economy, not processing speed, determines preferred processing strategy of visual patterns

According to Garner, visual patterns are mentally represented as categories rather than by their physical identity. On the other hand, physical and categorical identification tasks engender their own specific processing strategies. Nevertheless, categorical strategies should be more generic than physical ones. We tested this prediction using Garner patterns in a same-different task: one version involved categorical, the other physical identification. Both tasks showed effects of categorical representation but also contrasting categorical and physical processing strategies in their response time profiles. When trials from categorical and physical identification tasks were randomly intermixed, mixing costs were additive for categorical trials but not for physical trials, indicating a shift in processing strategy for the latter. For these trials, the physical response time profile was found to be displaced by a categorical profile. We concluded that the more generic processing strategy is the one that maximizes the role of categorical representation.     

Eye fixation behaviour in the number bisection task: Evidence for temporal specificity

Together with magnitude representations, knowledge about multiplicativity and parity contributes to numerical problem solving. In the present study, we used eye tracking to document how and when multiplicativity and parity are recruited in the number bisection task. Fourteen healthy adults evaluated whether the central number of a triplet (e.g., 21_24_27) corresponds to the arithmetic integer mean of the interval defined by the two outer numbers. We observed multiplicativity to specifically affect gaze duration on numbers, indicating that the information of multiplicative relatedness is activated at early processing stages. In contrast, parity only affected total reading time, suggesting involvement in later processing stages. We conclude that different representational features of numbers are available and integrated at different processing stages within the same task and outline a processing model for these temporal dynamics of numerical cognition.     

The effects of action video game experience on the time course of inhibition of return and the efficiency of visual search

The ability to efficiently search the visual environment is a critical function of the visual system, and recent research has shown that experience playing action video games can influence visual selective attention. The present research examined the similarities and differences between video game players (VGPs) and non-video game players (NVGPs) in terms of the ability to inhibit attention from returning to previously attended locations, and the efficiency of visual search in easy and more demanding search environments. Both groups were equally good at inhibiting the return of attention to previously cued locations, although VGPs displayed overall faster reaction times to detect targets. VGPs also showed overall faster response time for easy and difficult visual search tasks compared to NVGPs, largely attributed to faster stimulus-response mapping. The findings suggest that relative to NVGPs, VGPs rely on similar types of visual processing strategies but possess faster stimulus-response mappings in visual attention tasks.     

Unattended musical beats enhance visual processing

The present study investigated whether and how a musical rhythm entrains a listener's visual attention. To this end, participants were presented with pictures of faces and houses and indicated whether picture orientation was upright or inverted. Participants performed this task in silence or with a musical rhythm playing in the background. In the latter condition, pictures could occur off-beat or on a rhythmically implied, silent beat. Pictures presented without the musical rhythm and off-beat were responded to more slowly than pictures presented on-beat. This effect was comparable for faces and houses. Together these results indicate that musical rhythm both synchronizes and facilitates concurrent stimulus processing.     

Congruency-induced blindness: a cost-benefit analysis

Targets are identified more accurately when they are presented during an incongruent response (e.g., a left-pointing arrowhead presented during a right key press) than during a congruent response (e.g., a left-pointing arrowhead presented during a left key press). This effect, referred to here as congruency-induced blindness, has been hypothesised to result from the occupation of feature codes. According to the code occupation hypothesis (Behav. Brain Sci.; J. Experim. Psychol.: Human Percept. Perform.; Vis. Cogn., in press), only costs of congruency between features of a planned or executed action and a to-be-perceived target should be observed; neither costs nor benefits of incongruency are predicted by this account. In the present study, we investigated costs and benefits in identifying left and right targets directly by manipulating neutral response type and the symbols used to cue the neutral response, which produced four neutral conditions. Three important results emerged: (1). a significant main effect of RSI (suggesting that increasing temporal overlap between a planned action and target presentation interferes with perceptual reports of the target), (2). a significant main effect of congruency (showing that impairment is code-specific), and (3). clear-cut costs with little evidence for benefits. Other complex patterns of results provided additional information relevant for extant theories of perception-action interactions.     

Effects of feedback and calibration on the verbal estimation of the duration of tones

Two experiments investigated the effects of feedback (Experiment 1) and calibration (Experiment 2) on verbal estimation of the duration of tones ranging from 77 to 1183 ms in length. In Experiment 1, accurate feedback was provided after half the trials in the feedback condition, and this was contrasted with a no-feedback condition in which feedback was absent. In Experiment 2, in the calibration condition, participants estimated the duration of the second of two tones, after a first tone of a known duration (ranging from 50 to 1200 ms) had been presented. In the no calibration condition the value of the first tone was unknown. Compared with conditions without feedback or calibration, the feedback/calibration operation produced no significant change in group mean estimates, nor coefficients of variation of estimates, but the absolute deviation of estimates from the real stimulus duration, and the absolute deviation of individual estimates from the group mean, were both significantly reduced. The feedback/calibration thus made participants' mean estimates thus more accurate and more similar to one another, but the actual mechanism by which this was done was apparently a subtle process of adjustment, rather than a gross change in mean estimate or estimate variability.     

The influence of irrelevant stimulus changes on stimulus and response repetition effects

In this study the influence of irrelevant stimulus changes from one trial to another in a serial reaction time task was investigated. Two experiments were performed in which subjects were required to respond to stimulus colour. Four colours were mapped on two response keys, so that colour and response repetition effects could be dissociated. In Experiment 1, the irrelevant stimulus dimension was location and in Experiment 2 it was shape. Both experiments were performed with a short and a long response-stimulus interval (RSI)-condition. In both experiments, the irrelevant dimension influenced the response repetition effect but not the colour repetition effect. In the reaction times, a response alternation effect was observed only when the irrelevant location of the stimulus changed in the long RSI-condition. The error rates showed a response alternation benefit for both irrelevant dimensions, in the short and the long RSI-condition. The benefit for response alternations is explained in terms of a response bias towards change that is triggered by a changing stimulus feature. We assume that the response bias is stronger for location than for colour and that accuracy is more sensitive to this bias than response latencies.     

Kinematic property of target motion conditions gaze behavior and eye-hand synergy during manual tracking

This study investigated how frequency demand and motion feedback influenced composite ocular movements and eye-hand synergy during manual tracking. Fourteen volunteers conducted slow and fast force-tracking in which targets were displayed in either line-mode or wave-mode to guide manual tracking with target movement of direct position or velocity nature. The results showed that eye-hand synergy was a selective response of spatiotemporal coupling conditional on target rate and feedback mode. Slow and line-mode tracking exhibited stronger eye-hand coupling than fast and wave-mode tracking. Both eye movement and manual action led the target signal during fast-tracking, while the latency of ocular navigation during slow-tracking depended on the feedback mode. Slow-tracking resulted in more saccadic responses and larger pursuit gains than fast-tracking. Line-mode tracking led to larger pursuit gains but fewer and shorter gaze fixations than wave-mode tracking. During slow-tracking, incidences of saccade and gaze fixation fluctuated across a target cycle, peaking at velocity maximum and the maximal curvature of target displacement, respectively. For line-mode tracking, the incidence of smooth pursuit was phase-dependent, peaking at velocity maximum as well. Manual behavior of slow or line-mode tracking was better predicted by composite eye movements than that of fast or wave-mode tracking. In conclusion, manual tracking relied on versatile visual strategies to perceive target movements of different kinematic properties, which suggested a flexible coordinative control for the ocular and manual sensorimotor systems.     

Letter-specific processing in children and adults matched for reading level

Expert readers perform faster and more accurately during tasks that involve letters from the known language compared to tasks that involve unfamiliar letter-like forms (e.g., pseudoletters). Previous work with typically developing participants suggests that this letter-specific processing emerges as a consequence of increased reading ability, rather than increased age. In contrast, others have suggested that adults rely on visual information to a greater extent than children when reading, despite reading at similar less-than-expert levels, implying that adults may exhibit greater letter specificity than children. The present study aimed to discriminate between these possibilities by comparing the advantage for letters over pseudoletters in children and adults reading at the same less-than-expert (fourth grade) level. Results revealed greater letter specificity in adults than in children in both error rate and response time measures. Moreover, the magnitude of letter specificity did not vary with reading ability. Thus, results suggest that adults are more sensitive than children to the visual forms of letters, and that differences in letter specificity are not necessarily dependent on reading skill.