The Identity‐Location Binding Problem

The binding problem is fundamental to visual perception. It is the problem of associating an object's visual properties with itself and not with some other object. The problem is made particular difficult because different properties of an object, such as its color, shape, size, and motion, are often processed independently, sometimes in different cortical areas. The results of these separate analyses have to be combined before the object can be seen as a single coherent entity as opposed to a collection of unconnected features. Visual bindings are typically initiated and updated in a serial fashion, one object at a time. Here, we show that one type of binding, location‐identity bindings, can be updated in parallel. We do this by using two complementary techniques, the simultaneous‐sequential paradigm and systems factorial technology. These techniques make different assumptions and rely on different behavioral measures, yet both came to the same conclusion.     

Metacognitive sensitivity of subjective reports of decisional confidence and visual experience

Previous studies provided contradicting results regarding metacognitive sensitivity estimated from subjective reports of confidence in comparison to subjective reports of visual experience. We investigated whether this effect of content of subjective reports is influenced by the statistical method to quantify metacognitive sensitivity. Comparing logistic regression and meta-d in a masked orientation task, a masked shape task, and a random-dot motion task, we observed metacognitive sensitivity of reports regarding decisional confidence was greater than of reports about visual experience irrespective of mathematical procedures. However, the relationship between subjective reports and the logistic transform of accuracy was often not linear, implying that logistic regression is not a consistent measure of metacognitive sensitivity. We argue that a science of consciousness would benefit from the assessment of both visual experience and decisional confidence, and recommend meta-d as measure of metacognitive sensitivity for future studies.     

Ignition’s glow: Ultra-fast spread of global cortical activity accompanying local “ignitions” in visual cortex during conscious visual perception

Despite extensive research, the spatiotemporal span of neuronal activations associated with the emergence of a conscious percept is still debated. The debate can be formulated in the context of local vs. global models, emphasizing local activity in visual cortex vs. a global fronto-parietal “workspace” as the key mechanisms of conscious visual perception. These alternative models lead to differential predictions with regard to the precise magnitude, timing and anatomical spread of neuronal activity during conscious perception. Here we aimed to test a specific aspect of these predictions in which local and global models appear to differ – namely the extent to which fronto-parietal regions modulate their activity during task performance under similar perceptual states. So far the main experimental results relevant to this debate have been obtained from non-invasive methods and led to conflicting interpretations. Here we examined these alternative predictions through large-scale intracranial measurements (Electrocorticogram – ECoG) in 43 patients and 4445 recording sites. Both ERP and broadband high frequency (50–150 Hz – BHF) responses were examined through the entire cortex during a simple 1-back visual recognition memory task. Our results reveal short latency intense visual responses, localized first in early visual cortex followed (at ∼200 ms) by higher order visual areas, but failed to show significant delayed (300 ms) visual activations. By contrast, oddball image repeat events, linked to overt motor responses, were associated with a significant increase in a delayed (300 ms) peak of BHF power in fronto-parietal cortex. Comparing BHF responses with ERP revealed an additional peak in the ERP response – having a similar latency to the well-studied P3 scalp EEG response. Posterior and temporal regions demonstrated robust visual category selectivity. An unexpected observation was that high-order visual cortex responses were essentially concurrent (at ∼200 ms) with an ultra-fast spread of signals of lower magnitude that invaded selected sites throughout fronto-parietal cortical areas. Our results are compatible with local models in demonstrating a clear task-dependence of the 300 ms fronto-parietal activation. However, they also reveal a more global component of low-magnitude and poor content selectivity that rapidly spreads into fronto-parietal sites. The precise functional role of this global “glow” remains to be elucidated.     

The role of agency for perceived ownership in the virtual hand illusion

The rubber hand illusion shows that people can perceive artificial effectors as part of their own body under suitable conditions, and the virtual hand illusion shows the same for virtual effectors. In this study, we compared a virtual version of the rubber-hand setup with a virtual-hand setup, and manipulated the synchrony between stimulation or movement of a virtual “effector” and stimulation or movement of people’s own hand, the similarity between virtual effector and people’s own hand, and the degree of agency (the degree to which the virtual effector could be controlled by people’s own movements). Synchrony-induced ownership illusion was strongly affected by agency but not similarity, which is inconsistent with top-down modulation approaches but consistent with bottom-up approaches to ownership. However, both agency and similarity induce a general bias towards perceiving an object as part of one’s body, suggesting that ownership judgments integrate various sources of information.     

Acting knowingly: effects of the agent's awareness of an opportunity on causal attributions

According to difference-based (e.g. counterfactual/covariational) models of causal judgement, the epistemic state of the agent should not affect judgements of cause. Four experiments examined opportunity chains in which a physical event (distal cause) enabled a subsequent proximal cause to produce an outcome. All four experiments showed that when the proximal cause was a human action, it was judged as more causal if the agent was aware of his opportunity than if he was not or if the proximal cause was a physical event. The first two experiments showed that these preferences could not be explained in terms of differences in perceived conditional probability (whether from the observer's or the agent's point of view), social controllability or perceptions of the causal sequence as forming a single unit. The third experiment showed that awareness affected the perceived deliberateness with which the action brought the outcome about but not its perceived voluntariness. The fourth experiment showed that when the outcome was intended, the perceived deliberateness of the agent's action was a plausible mediator of the effect of awareness of opportunity on causal preference. We conclude that awareness of the opportunity allows inferences about the deliberate production of the outcome when the action is voluntary, which in turn influence causal judgements.     

How retaining objects containing multiple features in visual working memory regulates the priority for access to visual awareness

The content of visual working memory influences the access to visual awareness. Thus far, research has focused on retention of a single feature, whereas memoranda in real life typically contain multiple features. Here, we intermixed a delayed match-to-sample task to manipulate VWM content, and a breaking Continuous Flash Suppression (b-CFS) task to measure prioritization for visual awareness. Observers memorized either the color (Exp. 1), the shape (Exp. 2) or both the features (Exp. 3) of an item and indicated the location of a suppressed target. We observed that color-matching targets broke suppression faster than color-mismatching targets both when color was memory relevant or irrelevant. Shape only impacted priority for visual awareness through an interaction with color. We conclude that: (1) VWM can regulate the priority of visual information to access visual awareness along a single feature dimension; (2) different features of a memorandum vary in their potency to impact access to visual awareness, and the more dominant feature may even suppress the effect of the less dominant feature; (3) even stimuli that match an irrelevant feature dimension of the memorandum can be prioritized for visual awareness.     

A brief and unsupervised online intervention improves performance on a validated test of hazard perception skill used for driver licensing

Drivers who have higher levels of hazard perception skill also tend to have fewer crashes. Training designed to improve this skill has therefore been proposed as a strategy for reducing crash risk. To date, however, hazard perception training has only been evaluated in supervised settings. This means that improvements in hazard perception skill resulting from such training may not generalize to unsupervised situations, which may limit opportunities for large scale roll-out via automated delivery methods. In the present study, we investigated whether a brief video-based training intervention could improve hazard perception skill when drivers completed it online without supervision. The training involved drivers watching videos of traffic scenes, while generating a commentary of what they were searching for, monitoring, and anticipating in each scene. Drivers then compared their own commentary to a pre-recorded commentary generated by an expert driver, hence allowing for performance feedback without an instructor present. A convenience sample of 93 drivers (who did not receive any performance-related incentives) participated in a randomized control study. The training was found to significantly improve response times to hazards in stimuli from the official hazard perception test used for driver licensing in Queensland, Australia, which is known to predict crash involvement. That is, the training was effective in improving hazard perception skill (Cohen’s d = 0.50), even though participants were aware that no one was monitoring the extent to which they engaged in the intervention. Given that the training could, in principle, be deployed at scale with minimal resources (e.g. via any online platform that allows video streaming), the intervention may represent a practical and effective opportunity to improve road safety.     

From anticipation to behavioral intention: Insights into human processing of multiple retrieval cues in road traffic

Anticipation in road traffic enables safer and more comfortable driving. Anticipatory driving is achieved through effective retrieval of prior driving-relevant knowledge using mental models and appropriate cues. Knowing when and which retrieval cues have a critical impact on the anticipation process and how information compatibility affects anticipation can be the basis for supporting people in anticipating and appropriate behavior in road traffic.For generating in-depth insights into the processing of retrieval cues, a video-based experimental study was conducted combining specific compatible and incompatible retrieval cues in urban driving scenarios. From a driver's perspective, participants were asked to anticipate in a two-step approach (measuring low and high certainty anticipation) whether a vehicle ahead would enter their lane or turn onto another street due to a lane blockage ahead. Further, they choose their preferred behavioral intention (accelerate, decelerate or maintain speed). In general, drivers strived for coherent situation representation, and in this process, multiple retrieval cues influenced anticipation in different ways. Participants were more likely to be consistent in their anticipation response. That is, they tend to follow their first intention (equivalent low and high certainty anticipation for either lane change or turn) even in the presence of incompatible stimuli. Inconsistent compared to consistent anticipation responses, however, led to reduced subjective confidence, and in part to increased criticality. Not only anticipation but also intended behavior was influenced by retrieval cues. In accordance, the anticipation of others' behaviors can be considered a predictor of specific intended behavior in road traffic.     

Interoceptive Abnormalities and Suicidality: A Systematic Review

Dysfunction of interoception (i.e., difficulties sensing the physiological state of one's own body) is increasingly linked to different mental health disorders and suicidal outcomes. The aim of this study was to systematically review the literature on the association between suicidality and interoception, as well as identify potential confounders and mediators of the relationship. We conducted a systematic review of four databases, allowing for critical examination of the role of different measures of interoception (accuracy, sensibility, awareness, cognitive/emotional evaluation) across the suicide continuum (ideation, plans, attempts, deaths). The search strategy identified 22 studies (14,988 participants). Preliminary but limited evidence was found for impaired interoceptive accuracy among those reporting suicide attempt histories. We found evidence of interoceptive sensibility disturbances across the suicide continuum, including experiences of not trusting one’s own body sensations and impaired abilities to sustain and control attention to such sensations. Consistent evidence was also reported for disturbances related to cognitive and emotional evaluations of interoceptive sensations. The latter was particularly pronounced for those reporting suicide attempts, relative to those reporting suicidal thinking or planning alone. Overall, this review’s results suggest that interoceptive abnormalities are potentially important indicators of risk for suicidal thinking, intentions, and behaviors. However, due to the inconsistent adjustment for variables of interest, and cross-sectional designs, it is unclear whether interoceptive changes and disturbances have a direct role, or whether the association is explained and mediated by key third variables (e.g. depression, disordered eating, emotional dysregulation). We discuss the implications with respect to suicidal risk and therapeutic interventions.     

Reconnecting to Internal Sensation and Experiences: A Pilot Feasibility Study of an Online Intervention to Improve Interoception and Reduce Suicidal Ideation

Risk factors that are strongly associated with suicide and are amenable to intervention are in need of discovery. This three-study investigation demonstrates that an intervention designed to improve interoception—one potential suicide risk factor—may reduce suicide-related outcomes. Study 1 included 136 undergraduate participants and found that relative to a control condition, participating in a progressive muscle relaxation exercise was associated with reduced implicit identification with suicide through greater body trust, which is one domain of interoception that is consistently linked to suicide-related outcomes. Study 2 included 97 MTurk participants and found that relative to a control condition, participating in a body functionality writing exercise was associated with greater awareness of the body as a whole. Study 3 was a pilot study of a four-session online intervention designed to increase interoception. Study 3 included a sample of 22 clinical participants who completed pre- and postintervention assessments. Participants rated the intervention as highly acceptable and moderately effective. Moreover, the intervention was associated with improvements in interoception and reductions in suicidal ideation, general psychological symptoms, and disordered-eating symptoms. Overall, these findings indicate that our online interoceptive awareness training is acceptable and may be associated with improvements in clinical outcomes. Randomized controlled trials are needed to explore whether the intervention’s purported mechanism—improved interoception—leads to changes in clinical outcomes.