Testing the role of response repetition in spatial priming in visual search

In common “attention” tasks, which require stimulus-identity processing prior to the formation of a speeded key-press response, spatial priming effects depend on response repetition. Typically, the repetition of a stimulus location is advantageous when the prior response repeats, but disadvantageous or inconsequential when the prior response changes. This link between responding and space makes it difficult to draw inferences about attentional bias from two-choice key-press tasks. Instead, the findings are accounted for by episodic retrieval theories, which argue that the response associated with a prior stimulus location is retrieved when a later stimulus occupies its space. This retrieval operation is advantageous if the prior response is needed but not otherwise, which explains typical patterns. This perspective motivated us to evaluate whether spatial priming effects in the visual-search literature depend critically on response repetition. To assess this, we reevaluated a series of experiments recently published by Tower-Richardi, Leber, and Golomb (Attention, Perception, & Psychophysics, 78(1), 114–132, 2016). Their goal was to determine the reference frame of spatial priming across visual search displays. Reassessment reveals that spatial priming was strongly dependent on response repetition when spatiotopic, retinotopic, and object-centered reference frames were perfectly confounded. However, when eye movements were made to dissociate the spatiotopic and object-centered reference frame from the retinotopic reference frame, spatial priming was positive and unaffected by response repetition. The findings demonstrate that at least two distinct processes factor into spatial priming across visual searches, which occur at different levels of representation.     

The roles of order,distance, and interstitial items in temporal visual statistical learning

Humans are adept at learning regularities in a visual environment, even without explicit cues to structure and in the absence of instruction—this has been termed “visual statistical learning” (VSL). The nature of the representations resulting from VSL are still poorly understood. In five experiments, we examined the specificity of temporal VSL representations. In Experiments 1A, 1B, and 2, we compared recognition rates of triplets and all embedded pairs to chance. Robust learning of all structures was evident, and even pairs of non-adjacent items in a sequentially presented triplet (AC extracted from a triplet composed of ABC) were recognized at above-chance levels. In Experiment 3, we asked whether people could recognize rearranged pairs to examine the flexibility of learned representations. Recognition of all possible orders of target triplets and pairs was significantly higher than chance, and there were no differences between canonical orderings and their corresponding randomized orderings, suggesting that learners were not dependent upon originally experienced stimulus orderings to recognize co-occurrence. Experiment 4 demonstrates the essential role of an interstitial item in VSL representations. By comparing the learning of quadruplet sets (e.g., ABCD) and triplet sets (e.g., ABC), we found learning of AC and BD in ABCD (quadruplet) sets were better than the learning of AC in ABC (triplet) sets. This pattern of results might result from the critical role of interstitial items in statistical learning. In short, our work supports the idea of generalized representation in VSL and provides evidence about how this representation is structured.     

Predictive visual search: Role of environmental regularities in the learning of context cues

Repeatedly searching through invariant spatial arrangements in visual search displays leads to the buildup of memory about these displays (contextual-cueing effect). In the present study, we investigate (1) whether contextual cueing is influenced by global statistical properties of the task and, if so, (2) whether these properties increase the overall strength (asymptotic level) or the temporal development (speed) of learning. Experiment 1a served as baseline against which we tested the effects of increased or decreased proportions of repeated relative to nonrepeated displays (Experiments 1b and 1c, respectively), thus manipulating the global statistical properties of search environments. Importantly, probability variations were achieved by manipulating the number of nonrepeated (baseline) displays so as to equate the total number of repeated displays across experiments. In Experiment 1d, repeated and nonrepeated displays were presented in longer streaks of trials, thus establishing a stable environment of sequences of repeated displays. Our results showed that the buildup of contextual cueing was expedited in the statistically rich Experiments 1b and 1d, relative to the baseline Experiment 1a. Further, contextual cueing was entirely absent when repeated displays occurred in the minority of trials (Experiment 1c). Together, these findings suggest that contextual cueing is modulated by observers’ assumptions about the reliability of search environments.     

Analysis of Creative and Identity Processes among Mapuche Women Weavers in the Araucanía Region

The Mapuche practice of weaving has occupied a transcendental role for this community in its system of symbolic representation. These textiles involve different elements of cultural identity for the community, for the wearers of the garments and, most of all, for their creators. This article analyzes the creation context in which the Mapuche textile tradition brings into tension different aspects of cultural identity and innovation within the construction of cultural memory. It examines two principal scenarios that arose from ethnographic work: 1) selection of materials; 2) preparation and fabrication. The findings show that, in both scenarios, the new rules emerging from religious and commercial concerns in the present-day context of these weavers are linked with the diverse positions taken by each woman. We discuss how these new rules are associated with different processes of cultural identity in this group of Mapuche women.     

Critical Places Beyond the Psychology of Well-Being and Competitiveness

The purpose of the present contribution is to look beyond the limits evident in dualistic discourses in educational practices. Torn between the promises of well-being or the hard facts of competitiveness, educational institutions at all levels of instruction might miss the point of a more holistic approach to learning and creativity. Looking beyond dichotomous discourses in educational practices is harder than ever, in a world where globalisation demands high standards of competitiveness and neoliberalism denies all but economic growth targets. Approaches that envision different solutions are necessarily imaginative, critical and alternative to rigid discourses. In order to find foundational evidence for alternative ways of thinking and talking about learning, I will look at how Dewian and Vygotskyan conceptualisations walk the same paths and go towards holistic suggestions. Concluding remarks will address the disruptive potential of critical thinking in schools for the future.     

Continuous flash suppression and monocular pattern masking impact subjective awareness similarly

Peters and Lau (eLife, 4, e09651, 2015) found that when criterion bias is controlled for, there is no evidence for unconscious visual perception in normal observers, in the sense that they cannot directly discriminate a target above chance without knowing it. One criticism of that study is that the visual suppression method used, forward and backward masking (FBM), may be too blunt in the way it interferes with visual processing to allow for unconscious forced-choice discrimination. To investigate this question, we compared FBM directly to continuous flash suppression (CFS) in a two-interval forced-choice task. Although CFS is popular, and may be thought of as a more powerful visual suppression technique, we found no difference in the degree of perceptual impairment between the two suppression types. To the extent that CFS impairs perception, both objective discrimination and subjective awareness are impaired to similar degrees under FBM. This pattern was consistently observed across three experiments in which various experimental parameters were varied. These findings provide evidence for an ongoing debate about unconscious perception: normal observers cannot perform forced-choice discrimination tasks unconsciously.     

Perception of objects oriented downward from a vertical position

In the present work we investigated people’s perceptions of orientation for surfaces that are conceived of as being sloped downward from vertical against a vertical reference frame. In the three conditions of Experiment 1, participants either (1) placed a ladder against a wall at what they thought was the most stable position, and then estimated its orientation; (2) gave a verbal (conceptual) estimate of what the most stable position of a ladder leaned against a wall would be; or (3) drew a line representing the most stable position of a ladder to be placed against a wall, and then gave a verbal estimate of the ladder’s orientation. Ladder placement was shallower than the most stable position, as were the verbal estimations of both the positioned and drawn orientations and the verbal (conceptual) estimates of the most stable position for a ladder to be leaned against a wall, relative to the actual orientations. In Experiment 2, participants verbally estimated various ladder orientations. The estimates were again shallower than the actual orientations. For orientations between 60° and 90°, the estimates showed a scale compression effect from horizontal. This perceived exaggeration of the orientation of an object typically oriented down from vertical is similar to the perceived exaggeration of the orientation of hills and ramps, typically thought of as oriented up from horizontal. This may point to a generic perceived exaggeration of slant whose direction depends on the conceptual or actual reference frame being used.     

The influence of relevant and irrelevant stereoscopic depth cues: Depth information does not always capture attention

Previous research reported ambiguous findings regarding the relationship of visuospatial attention and (stereoscopic) depth information. Some studies indicate that attention can be focused on a distinct depth plane, while other investigations revealed attentional capture from irrelevant items located in other, unattended depth planes. To evaluate whether task relevance of depth information modulates the deployment of attentional resources across depth planes, the additional singleton paradigm was adapted: Singletons defined by depth (i.e., displayed behind or in front of a central depth plane) or color (green against gray) were presented among neutral items and served as targets or (irrelevant) distractors. When participants were instructed to search for a color target, no attentional capture from irrelevant depth distractors was observed. In contrast, it took substantially longer to search for depth targets when an irrelevant distractor was presented simultaneously. Color distractors as well as depth distractors caused attentional capture, independent of the distractors’ relative depth position (i.e., in front of or behind the target). However, slight differences in task performance were obtained depending on whether or not participants fixated within the target depth plane. Thus, the current findings indicate that attentional resources in general are uniformly distributed across different depth planes. Although task relevant depth singletons clearly affect the attentional system, this information might be processed subsequent to other stimulus features.