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An important but often neglected aspect of attention is how changes in the attentional spotlight size impact perception. The zoom-lens model predicts that a small ("focal") attentional spotlight enhances all aspects of perception relative to a larger ("diffuse" spotlight). However, based on the physiological properties of the two major classes of visual cells (magnocellular and parvocellular neurons) we predicted trade-offs in spatial and temporal acuity as a function of spotlight size. Contrary to both of these accounts, however, across two experiments we found that attentional spotlight size affected spatial acuity, such that spatial acuity was enhanced for a focal relative to a diffuse spotlight, whereas the same modulations in spotlight size had no impact on temporal acuity. This likely reflects the function of attention: to induce the high spatial resolution of the fovea in periphery, where spatial resolution is poor but temporal resolution is good. It is adaptive, therefore, for the attentional spotlight to enhance spatial acuity, whereas enhancing temporal acuity does not confer the same benefit.

There are volumes of information available to process in visual scenes. Visual spatial attention is a critically important selection mechanism that prevents these volumes from overwhelming our visual system's limited-capacity processing resources. We were interested in understanding the effect of the size of the attended area on visual perception. The prevailing model of attended-region size across cognition, perception, and neuroscience is the zoom-lens model. This model stipulates that the magnitude of perceptual processing enhancement is inversely related to the size of the attended region, such that a narrow attended-region facilitates greater perceptual enhancement than a wider region. Yet visual processing is subserved by two major visual pathways (magnocellular and parvocellular) that operate with a degree of independence in early visual processing and encode contrasting visual information. Historically, testing of the zoomlens has used measures of spatial acuity ideally suited to parvocellular processing. This, therefore, raises questions about the generality of the zoom-lens model to different aspects of visual perception. We found that while a narrow attended-region facilitated spatial acuity and the perception of high spatial frequency targets, it had no impact on either temporal acuity or the perception of low spatial frequency targets. This pattern also held up when targets were not presented centrally. This supports the notion that visual attendedregion size has dissociable effects on magnocellular versus parvocellular mediated visual processing.

The motivational intensity model proposes that the strength of one’s urge to approach or avoid a stimulus is the primary driver of cognitive broadening/narrowing (Gable & Harmon-Jones, 2010d; Harmon-Jones et al., 2012). However, it is unclear whether motivational intensity is truly distinct from well-established dimensions of valence and arousal. Here we found an overwhelmingly strong relationship between motivational intensity and valence across all studies. In Study 1, we operationalized motivational intensity on 2 response rating scales and had multiple groups of participants (total 150) rate their response of motivational intensity, valence, and arousal to 300 pictures. There was a very strong relationship between motivational intensity and valence (rs in excess of .9, in studies 1a and 1b), which challenges the idea that these 2 constructs are distinct. In contrast, motivational intensity ratings were not consistently positively related to arousal ratings, with only a moderate relationship found with avoidance motivation. In Study 2 we used an implicit measure of motivational intensity and valence and asked participants to classify their motivational intensity and valence in response to 100 pictures from Study 1. A high degree of correspondence was found between motivational intensity and valence on this measure. Overall, our findings are at odds with proposals in the literature that arousal can be used as a proxy for motivational intensity across the full approach-avoidance spectrum. Furthermore, these studies suggest that the cognitive effects attributed to motivational intensity in previous literature are best explained by valence.

Object substitution masking (OSM) occurs when a sparse (e.g., four-dot), temporally trailing mask obscures the visibility of a briefly presented target. Here, we review theories of OSM: those that propose that OSM reflects the interplay between feedforward and feedback/reentrant neural processes, those that predict that feedforward processing alone gives rise to the phenomenon, and theories that focus on cognitive explanations, such as object updating. We discuss how each of these theories accommodates key findings from the OSM literature. In addition, we examine the relationship between OSM and other visual-cognitive phenomena, including object correspondence through occlusion, change blindness, metacontrast masking, backward masking, and visual short-term memory. Finally, we examine the level of processing at which OSM impairs target perception. Collectively, OSM appears to reflect the conditions under which the brain confuses two visual events for one when they are encoded with low spatiotemporal resolution, due to processing resources being otherwise occupied.Keywords Object substitution masking . Attention . Reentrant processing . Consciousness When observing a visual scene, at any point in time, we are conscious of only a small fraction of the available information. Given this limitation, it is important to understand the mechanisms that determine what stimuli we become conscious of, when we become conscious of them, and the nature of processing that occurs in the absence of explicit awareness. There exists a long and rich history in experimental psychology of using visual masking to explore such issues. Visual masking refers to conditions where the visibility of one to-be-reported visual stimulus (the target) is obscured by the presentation of another stimulus (the mask) that appears in close spatiotemporal proximity and does not require report. Object substitution masking (OSM) is a recent discovery in the field of visual masking and is an ideal tool for exploring questions about visual awareness because it selectively impairs the extent to which an individual becomes conscious of a visual stimulus without the extent of image-level degradation that other forms of visual masking induce. This review, therefore, focuses on the determinants and consequences of visual awareness in OSM.Here, we integrate a diverse range of literature to discern what OSM can tell us about perceptual consciousness and visual cognition in general. Specifically, we discuss the role of feedforward versus feedback processing in giving rise to OSM, whether the phenomenon is better characterized as reflecting object updating or object substitution, the similarities and differences between OSM and other forms of masking, and OSM's relationship to other visual-cognitive phenomena. In addition, we review evidence regarding the role of attention in masking. Our aim is to address controversies in the OSM literature in depth and offer insights into how some of them may already be resolved and how the field might go about resolving ...