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Biology subjects

Solovey, G.

Publications and source records attributed to Solovey, G..

3 recordsLinked to original sources

Uncertainty during visual search: Insights from a computational model and behavioral experiment in natural stimuli

Visual search, driven by bottom-up and top-down processes, offers a unique framework for investigating decision-making. This study examines individuals awareness of their own visual search by combining computational modeling with behavioral experiments. Fifty-seven participants performed a classical visual search task in which the goal was to find an object in a natural scene. Crucially, in some trials, the search was interrupted by clearing the screen before the gaze reached the target object. Participants had to report their best guess of the targets location and the uncertainty on their response. We show that a modified version of the Entropy-Limit Minimization (ELM) model captures scanpaths and perceived target locations, while also revealing that uncertainty is influenced by scanpath length, the distance between the perceived and true target location, and the entropy of decision maps. These findings highlight the models capacity to reflect cognitive processes underlying response selection and uncertainty judgment.

neuroscience↗

Learning to read the imprints of consciousness on global brain dynamics: an application to intra-operative monitoring of anesthesia

In daily life, in the operating room and in the laboratory, the operational way to assess wakefulness and consciousness is through responsiveness. A number of studies suggest that the awake, conscious state is not the default behavior of an assembly of neurons, but rather a very special state of activity that has to be actively maintained and curated to support its functional properties. Thus responsiveness is a feature that requires active maintenance, such as a homeostatic mechanism to balance excitation and inhibition. In this work we developed a method for monitoring such maintenance processes, focusing on a specific signature of their behavior derived from the theory of dynamical systems: stability analysis of dynamical modes. When such mechanisms are at work, their modes of activity are at marginal stability, neither damped (stable) nor exponentially growing (unstable) but rather hovering in between. We have previously shown that, conversely, under induction of anesthesia those modes become more stable and thus less responsive, then reversed upon emergence to wakefulness. We take advantage of this effect to build a single-trial classifier which detects whether a subject is awake or unconscious achieving high performance. We show that our approach can be developed into a mean for intra-operative monitoring of the depth of anesthesia, an application of fundamental importance to modern clinical practice.

neuroscience↗

Behavioural, modeling, and electrophysiological evidence for domain-generality in human metacognition

Metacognition, or the capacity to introspect on ones own mental states, has been mostly characterized through confidence reports in visual tasks. A pressing question is to what extent the results from visual studies generalize to other domains. Answering this question allows determining whether metacognition operates through shared, domain-general mechanisms, or through idiosyncratic, domain-specific mechanisms. Here, we report three new lines of evidence for decisional and post-decisional mechanisms arguing for the domain-generality of metacognition. First, metacognitive efficiency correlated between auditory, tactile, visual, and audiovisual tasks. Second, confidence in an audiovisual task was best modeled using supramodal formats based on integrated representations of auditory and visual signals. Third, confidence in correct responses involved similar electrophysiological markers for visual and audiovisual tasks that are associated with motor preparation preceding the perceptual judgment. We conclude that the domain-generality of metacognition relies on supramodal confidence estimates and decisional signals that are shared across sensory modalities.

neuroscience↗