Attention Perception & Psychophysics最新文献

The connectedness effect is the tendency to perceive connected items as fewer units, such as two connected dots seen as one. It commonly occurs with intermediate numerosity perception alongside the activity of the approximate number system (ANS), indicating that intermediate quantities are perceived as discrete units rather than continuous magnitudes. The present study explored how this effect influences the enumeration of small numerosities (fewer than 5), which are accurately assessed through a mechanism known as subitizing under normal conditions. In the single enumeration task, where participants enumerated 2–4 dots solely from the indicated target patch prior to stimulus presentation, connectivity did not induce underestimation, indicating that subitizing is impervious to the connectedness effect. Conversely, connectivity led to significant underestimation in the dual enumeration task, where participants had to simultaneously estimate dots in both patches and respond upon cueing of the target patch. Furthermore, the connectedness effect is more pronounced in the simultaneous comparison task compared with the sequential task. Weber fractions for small numerosities correlate with those for intermediate numerosities in the simultaneous comparison task, whereas no such correlation is observed in the sequential task. This suggests that subitizing prevails in single/sequential tasks, while estimation takes precedence in dual/simultaneous tasks under attentional load. The connectedness effect does not impact the subitizing mechanism in single tasks, but it occurs alongside estimation regardless of the number regime, leading to significant underestimation in dual tasks. Approximate estimation relies on segmented objects, rather than continuous magnitude, even for very small numerosities.

This study investigated patch-leaving strategies in mixed hybrid visual foraging scenarios, focusing on how target specificity and the number of target sets influence overall outcomes. In mixed hybrid foraging, participants collect targets from patches with varying types (specific and categorical) and numbers (three or six) of targets. Despite the complexity introduced by having multiple target types, participants’ patch-leaving behavior remained broadly consistent with the predictions of the marginal value theorem (MVT), suggesting that quitting strategies are based on similar rules across different conditions. While overall foraging performance varied with target specificity and the number of sets, patch-leaving decisions consistently adhered to a simple, rule-based approach. This study highlights the robustness of visual foraging strategies and suggests that effective patch-leaving behavior is maintained even in complex visual environments.

Inferences on semantic scene content enable the visual system to efficiently parse complex naturalistic scenes. In the early stages of scene perception, conceptual scene gist activates semantic expectations and relevant scene-object associations that bias the viewer to affirm the presence of semantically consistent objects and to reject the presence of semantically inconsistent objects within the overall scene context. This contextual scene-object bias is crucial to various visual cognitive functions, from object recognition to attentional guidance. Despite its top-down influence, however, few studies have directly investigated the factors that drive the activation of scene-object bias. Here, we tested the role of global scene semantics in the activation of scene-object bias by comparing response bias on briefly presented upright versus inverted scenes. We found that scene inversion not only significantly delayed overall bias activation, but also differentially impacted superordinate-level versus basic-level bias. Hierarchical differences were also highlighted by earlier and more robust activation of superordinate-level bias than basic-level bias. Taken together, the present work provides important characterization to gist-activated scene-object bias, which is an essential and influential top-down mechanism in scene perception and visual cognition.

Motion perception relies on at least two distinct systems: a velocity-based motion system driven by early direction-selective cells and a position-based motion system that tracks objects over space and time. However, how these systems interact when operating in parallel remains unclear. We explored their respective contributions to the perceptual organization of motion using a bistable stimulus of eight moving dots, perceived either as rotating in local pairs (local motion percept) or as forming two illusory squares translating around fixation (global motion percept). To disrupt the velocity-based motion system, we varied interstimulus intervals (ISIs) stroboscopically from 0 to 116.6 ms – selectively impairing early direction-selective cells with short temporal integration windows ((<100) ms). Additionally, we manipulated contrast polarity to bias perceptual grouping (local-group, global-group, or no-group). We found that the pattern of perceptual bistability shifted markedly at ISIs of 33 ms. For ISIs (ge )33 ms, contrast- and proximity-based grouping strongly influenced perception. For ISIs (<33) ms, the global motion percept dominated even in the presence of strong static grouping cues (i.e., contrast and proximity), suggesting that the velocity-based motion system introduces a perceptual bias that can override or counteract static grouping cues. These findings reveal distinct, and at times opposing, contributions of velocity- and position-based motion systems to the perceptual organization of motion.

Our spotlight of attention allows selecting and filtering relevant information from the world around us, and thereby influences how we perceive the world. However, it remains poorly understood whether there are, next to state influences, also stable differences in the sharpness of the spotlight between individuals: trait differences. Therefore, our aim was to investigate the validity of a cueing paradigm to assess group and individual differences. In an online experiment, we presented a cue to covertly direct attention to one side of the screen. This was followed by a target (gapped circle) appearing at varying distances from the cue, in either the valid or the invalid hemifield. The accuracy of reporting the gap direction was used to map the size of the attentional spotlight. First, results indicated that our task elicited the standard exogeneous cueing effects. Then, we fitted linear slopes to index the spatial gradient of the spotlight and demonstrated performance decline as a function of increasing target distance, showing that attention modulates the sharpness of the spotlight. Test-retest analyses revealed that while the patterns observed at the group level are robust, performance on the individual level was not reliably stable over a 2-week period, limiting the validity of the cueing paradigm for individual differences research. Whereas not suitable to detect variance in the homogeneous neurotypical population, we discuss potential use of the task for future research in clinical populations where altered attentional functioning are hallmarks in the clinical diagnosis (e.g., autism spectrum conditions), and in reassessing previously reported group level differences.

The present study investigated the previous claim that auditory stimuli appear to last longer than visual ones, but that the modality has no influence on the experience of the passage of time (POT). Participants judged the duration, the POT, and the phenomenal quality of the two temporal experiences after hearing a tone or viewing a blue square with a duration between 200 ms and 5 s. The results showed modality effects on both duration and POT judgements, with longer duration and slower POT judgements for auditory than for visual stimuli. Judgements of phenomenal quality showed large interindividual differences, with most participants showing positive but some also negative relationships with target duration for both qualities. Importantly, duration and POT judgements were largely unaffected by these interindividual differences. The present results clearly contradict the previous assumption that the experienced POT is not influenced by sensory modality.

Younger adults can, in certain conditions, select two responses in parallel, thereby bypassing the central attentional bottleneck that constrains their dual-task performance. Older adults, meanwhile, have never been found to attain such parallel central processing (i.e., dual-task automaticity), even with highly practiced or extremely easy tasks. Here we asked whether older adults do not bypass the central bottleneck because they apply extra attention to one or both tasks as a strategy to compensate for cognitive deficits. In Experiment 1, we used the traditional psychological refractory period (PRP) procedure and replicated the typical finding: even though Task 2 was extremely easy, it suffered from large dual-task interference (353 ms) due to a central bottleneck. Because the PRP paradigm prioritizes Task 1, we hypothesized that this central bottleneck is strategic: older adults strategically over-prepare Task 1 at the expense of Task 2. So, in Experiment 2, we induced older adults to more evenly balance preparation between the two tasks. We did so by randomly intermixing single-task trials of each task amongst the dual-task PRP trials. This rebalancing of preparation allowed most older adults (20 out of 24) to consistently select the two responses in parallel, as evidenced by a close match between the observed distribution of inter-response intervals and that predicted by bottleneck bypassing, as well as by surprisingly little dual-task interference on Task 2 (85 ms). We conclude that older adults’ processing mode is governed by the preparatory state, which can be modified to enable dual-task automaticity.

Contextual cueing describes the phenomenon where repeated associations between stimuli facilitate visual search performance. For example, previous research has demonstrated that when 12 repeated stimuli are organized into four color-based clusters, probing only the repeated cluster containing the target alongside nine randomly generated stimuli can elicit similar contextual cueing as probing all the stimuli. This suggests that feature-based attention, when directed by color, strengthens the associations between the target and distractors within the same cluster, making it the primary contributor to contextual cueing. However, the influence of location-based organization on contextual cueing is less clear. We hypothesized that when 12 repeated stimuli are evenly divided into four quadrants, location-based attention similarly strengthens the associations between the target and distractors within the same quadrant. Consequently, probing only the target-containing quadrant may produce similar contextual cueing to probing the entire configuration, whereas probing only three repeated stimuli without quadrant organization would not. Experiments 1 and 2 confirmed this hypothesis. To further investigate the effect of location-based attention, Experiment 3 manipulated the number of stimuli attended to simultaneously (i.e., the attentional scope). We hypothesized that a larger attentional scope enhances the associations between stimuli, thereby facilitating contextual cueing. The results support this hypothesis, indicating that a broader attentional scope led to more pronounced contextual cueing. In summary, the present study demonstrates that the extent of contextual cueing depends on location-based organization.