Journal of Vision最新文献

Presaccadic attention enhances visual perception at the upcoming saccade target location. While this enhancement is often described as obligatory and temporally stereotyped, recent studies indicate that its strength varies depending on saccade direction. Here, we investigated whether the time course of presaccadic attention also differs across saccade directions. Participants performed a two-alternative forced-choice orientation discrimination task during saccade preparation. Tilt angles were individually titrated in a fixation baseline condition to equate task difficulty across the upper and lower vertical meridians. Sensitivity was then assessed at different time points relative to saccade onset and cue onset, allowing us to characterize the temporal dynamics of attentional enhancement. We found that presaccadic attention built up faster and reached higher levels preceding downward than upward saccades. Linear model fits revealed significant slope differences but no differences in intercepts, suggesting that the observed asymmetries reflect differences in attentional deployment during saccade preparation rather than preexisting differences in sensitivity. Saccade parameters did not account for these asymmetries. Our findings demonstrate that the temporal dynamics of presaccadic attention vary with saccade direction, which may be a potential mechanism underlying previously observed differences in presaccadic benefit at the upper and lower vertical meridians. This temporal flexibility challenges the view of a uniform presaccadic attention mechanism and suggests that presaccadic attentional deployment is shaped by movement goals. Our results provide new insights into how the visual and oculomotor systems coordinate under direction-specific demands.

Lateral interactions are pervasive in early visual processing, contributing directly to processes such as object grouping and segregation. This study examines whether saccade preparation - known to affect visual perception - modulates lateral interactions. In a psychophysical task, participants were instructed to detect a Gabor target flanked by two adjacent Gabors, while they either prepared a saccade to the target or maintained central fixation. Flanker gratings could be iso- or orthogonally oriented to the target and were positioned at three different distances (4λ, 8λ, and 16λ). Contrast thresholds for target detection were estimated in each condition using a 3-down/1-up staircase procedure. The results showed that in both presaccadic and fixation conditions, the target was suppressed at the shortest flanker distance (4λ), revealed by markedly higher thresholds in iso-oriented compared to orthogonal flanker configurations. Lateral interaction effects were completely abolished at their largest separation (16λ). Interestingly, at the intermediate flanker distance (8λ), target suppression seemed to increase during the presaccadic period, whereas no such effect was observed during fixation. This result suggests that saccade preparation can modulate lateral interactions, promoting suppressive effects over larger distances. These findings are consistent with the visual remapping phenomenon observed before saccade execution, especially the convergent remapping of receptive fields in oculomotor and visual areas. Finally, this presaccadic expansion of inhibitory lateral interactions could assist target selection by suppressing homogeneous peripheral signals - such as iso-oriented collinear patterns - while prioritizing the processing of more salient visual information.

During self-movement, the visual system uses optic flow to identify scene-relative object motion and estimate the direction of self-movement (heading). Although both processes rely on optic flow, their relationship and the conditions under which independent object motion biases heading estimation remain unclear. The causal inference model predicts that misjudging object motion leads to its integration into heading estimation, causing errors in heading estimation, whereas correct judgments reduce these errors. However, most studies have examined these processes independently. Here we used a dual-task paradigm to investigate how visual cues affect the judgment of scene-relative object motion direction and concurrent heading estimation. Participants viewed a 90° × 90° display simulating self-movement through a three-dimensional cloud with a laterally moving object positioned at 8° or 16° from the simulated heading direction. They judged both the object's motion direction in the scene and their heading direction. Results show that increasing an object's speed and reducing its positional offset from the simulated heading direction improved the accuracy of scene-relative object motion direction judgment, but did not consistently improve the accuracy of heading estimation. Surprisingly, visual cues such as binocular disparity and object density improved scene-relative object motion direction judgment but reduced heading estimation accuracy. Furthermore, heading errors mostly peaked at object speeds where observers could reliably judge scene-relative object motion direction, challenging the predictions of the causal inference model. These findings provide strong evidence that scene-relative object motion judgment and heading estimation operate independently and question the generality of the causal inference model in explaining heading biases caused by independent object motion.

Continuous flash suppression (CFS) is a popular method for suppressing visual stimuli from awareness for extended periods. It involves a dynamic, high-contrast masking stimulus presented to one eye that suppresses a target stimulus presented to the other. The strength of suppression is usually inferred from how long it takes for the target to break through from suppression into awareness (the bCFS threshold). A new variant known as tracking CFS (tCFS) directly measures the strength of suppression by measuring both breakthrough and suppression thresholds. Here, we employed the tCFS paradigm while varying the temporal frequency of the masking stimulus. Our data revealed two clear results: (a) CFS exhibits a clear temporal frequency tuning, with bCFS thresholds peaking for masks modulating at ∼1 Hz; and (b) suppression depth (the difference between breakthrough and suppression thresholds) remains constant despite changes in bCFS. The first result confirms an earlier finding that peak bCFS occurs for very low temporal frequencies. The second result provides valuable insight in showing that bCFS changes occur completely independently of suppression strength, which remains constant. In this study, suppression averaged 13 dB, around two to three times stronger than suppression reported in binocular rivalry studies.

When visual input is uncertain, visual perception is biased toward the stimulation from the recent past. We can attend to stimuli either endogenously based on an internal decision or exogenously, triggered by an external event. Here, we wondered whether serial dependencies are selective for the attentional mode which we draw to stimuli. We studied overt attention shifts: saccades and recorded either motor error correction or visual orientation judgments. In Experiment 1, we assessed sensorimotor serial dependencies, focusing on how the postsaccadic error influences subsequent saccade amplitudes. In Experiment 2, we evaluated visual serial dependencies by measuring orientation judgments, contingent on the type of saccade performed. In separate sessions, participants performed either only voluntary saccades or only delayed saccades, or both saccade types alternated within a session. Our results revealed that sensorimotor serial dependencies were selective for the saccade type performed. When voluntary saccades had been performed in the preceding trial, serial dependencies were much stronger in the current trial if voluntary instead of delayed saccades were executed. In contrast, visual serial dependencies were not influenced by the type of saccade performed. Our findings reveal that shifts in exogenous and endogenous attention differentially impact sensorimotor serial dependencies, but visual serial dependencies remain unaffected.

Recent theories propose that, like endogenous and exogenous visual attention, voluntary and involuntary forms of phantom vision (e.g., mental imagery and dreams) are related and hence depend on overlapping mechanisms. However, the relationship between voluntary and involuntary phantom vision remains largely unknown. Here, we assess this relationship by examining how voluntary visual imagery relates to involuntary forms of phantom vision (specifically, visual illusions) in a unique population with no voluntary visual imagery (aphantasia). In our first study, we presented individuals with aphantasia with seven different visual illusions (Hermann grid, Ponzo illusion, Kanizsa triangles, Ebbinghaus illusion, watercolor effect, neon color-spreading, and rotating snakes). Compared to both a large group of undergraduates and an age-matched control sample, the only illusion in which individuals with aphantasia reported a significant reduction was the neon color illusion. In a large online follow-up study, we used the method of adjustment to obtain a more precise measure of the neon color-spreading illusion in individuals with aphantasia and those with visual imagery. We found that this measure of neon color was lower in those with aphantasia than in those with visual imagery, as were their subjective ratings of the illusion. Importantly, there were no differences between the groups for catch/mock neon color "illusion" trials or a separate color adjustment task. Together, these data provide evidence that individuals with aphantasia experience the neon color illusion at a lower intensity, supporting the hypothesis that some forms of voluntary and involuntary phantom vision depend on overlapping mechanisms.

When faces are blurred, presenting them at smaller sizes improves recognition. We term this unexpected advantage the blur paradox, which has been replicated in studies where face images are digitally blurred and scaled. To examine whether the blur paradox persists in physically realistic viewing conditions, we conducted two experiments using physical blur filters and varied viewing distances for size manipulation. First, we tested blurry celebrity face recognition at two viewing distances and found that recognition accuracy was significantly greater in the far condition than in the close condition. Second, we examined whether the blur paradox reflects gradual improvement across viewing distances or a sharp change in recognition performance at a particular distance. Across four viewing conditions, we found a significant main effect of viewing distance, with the highest recognition accuracy at the farthest viewing condition and lowest at the closest. Accuracy improved gradually, but nonlinearly, rather than showing an abrupt shift at a boundary. Exploration of participant demographics suggested a stronger effect among older participants (>50 years) and a weaker effect among left-handed participants. No significant sex differences were observed. These findings confirm the small-size advantage for recognition under blur and its persistence in physically realistic conditions, with accuracy improving gradually across a wide range of distances.

Perceptual reports can be attracted toward or repulsed from previous stimuli and responses. We investigated the conditions in which attractive and repulsive history effects occur with oriented Gabors by manipulating response type and frequency, as well as stimulus duration. When subjects adjusted a continuous response cue to match orientation, we observed repulsion from the previous stimulus when the stimulus was presented for 50 ms and attraction from the previous stimulus and response when it was presented for 500 ms, regardless of whether responses were given to every stimulus or every other stimulus. Both effects increased with relative orientation between events. With a categorical clockwise/counterclockwise response, there was attraction to the previous response and repulsion from the previous stimulus. Attraction to the previous response was stronger with sequential responses and short relative orientations. Repulsion was constant across all stimulus durations and response frequencies, and it increased with relative orientation. The overall history effect of the previous response and stimulus was repulsive with alternating categorical responses and attractive with sequential categorical responses. Our results replicate and synthesize seminal findings of the serial dependence and adaptation literature, as well as show independent history effects working with and against each other, determined by whether the response is categorical or continuous.

In visual search, our gaze is guided by mental representations of stimulus features, known as attentional templates. These templates are thought to be probabilistic, shaped by environmental regularities. For example, participants can learn to distinguish between the shapes of different distractor color distributions in visual search. The present study assessed whether such subtle differences in distractor color distributions (Gaussian vs. uniform) are reflected in saccade endpoints. We conducted two experiments, each consisting of learning trials, designed to prime a specific distractor color distribution, and test trials, where target color varied in its distance from the mean of previously presented distractor distributions. Saccade endpoint deviations were observed through the global effect, where the saccades tended to land between two nearby stimuli. The experiments differed in difficulty, with test trials in Experiment 2 involving more distractors and colors. During test trials, reaction times and saccade endpoints were affected by target distance from the mean of the preceding distractor distribution. The farther the target color was from this mean, the less the saccade deviated from the target and the lower the reaction times. However, saccade endpoints did not reflect the shape of distractor color distributions, an effect that was observed only on reaction times in Experiment 2. Overall, color priming affects both reaction times and saccade deviations, but distractor feature distribution learning depends on search difficulty and response measures, with saccade endpoints less sensitive to subtle differences in the shape of color distributions.

Saccadic choice studies have shown that humans initiate faster saccades toward faces than other visual categories. Here, we tested whether the saccadic advantage for faces observed in past studies is partly due to stimuli being typically presented along the horizontal meridian (HM). Our previous work suggests that the radial bias along the HM facilitates access to the horizontal structure of faces, which optimally drives human face-specialized processing. We expected to corroborate the saccadic advantage for faces along the HM, where the radial bias facilitates access to horizontal content, and to observe a reduction of this advantage along the vertical meridian (VM), especially in participants showing a strong horizontal tuning for face recognition. Fifty participants performed a saccadic choice task targeting faces or vehicles presented at 15° eccentricity along the HM and VM. We also assessed the strength of the radial bias and the horizontal tuning for face identity recognition in each individual. As expected, saccades were faster and more accurate toward faces than vehicles; they were also faster along the HM than the VM. Contrary to our hypothesis, the saccadic face advantage did not differ between meridians, suggesting the robustness of face saccadic advantage. However, the saccadic face advantage along the VM correlated with the strength of the horizontal tuning of face identity recognition. Additionally, the radial bias predicted saccade latency toward faces along the HM. These findings indicate that low-level radial biases and high-level face-specialized mechanisms independently contribute to distinct functional aspects of the ultra-fast saccadic responses toward faces.