Ricardo Martins
University of Coimbra
Human–computer interactionHaptic technologyArtificial intelligenceNeuroscienceGRASPVisual perceptionPattern recognitionObject modelPerceptionBipolar disorderGrey matterVisual cortexPerceptComputer visionComputer scienceProbabilistic logicMethodObject-oriented designSchizophreniaBistability
22Publications
5H-index
104Citations
Publications 21
Newest
#1Lília JorgeH-Index: 3
#2Nádia CanárioH-Index: 4
Last. Miguel Castelo-BrancoH-Index: 32
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#1Alexandre Sayal (UC: University of Coimbra)H-Index: 2
#2Teresa Sousa (UC: University of Coimbra)H-Index: 7
Last. Miguel Castelo-BrancoH-Index: 32
view all 6 authors...
Abstract Hysteresis is a well-known phenomenon in physics that relates changes in a system with its prior history. It is also part of human visual experience (perceptual hysteresis), and two different neural mechanisms might explain it: persistence (a cause of positive hysteresis), which forces to keep a current percept for longer, and adaptation (a cause of negative hysteresis), which in turn favors the switch to a competing percept early on. In this study, we explore the neural correlates unde...
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#1Nuno Madeira (UC: University of Coimbra)H-Index: 6
#2João V. Duarte (UC: University of Coimbra)H-Index: 6
Last. Miguel Castelo-Branco (UC: University of Coimbra)H-Index: 32
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Abstract Schizophrenia is believed to be a neurodevelopmental disease with high heritability. Differential diagnosis is often challenging, especially in early phases, namely with other psychotic disorders or even mood disorders. such as bipolar disorder with psychotic symptoms. Key pathophysiological changes separating these two classical psychoses remain poorly understood, and current evidence favors a more dimensional than categorical differentiation between schizophrenia and bipolar disorder....
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#1Teresa SousaH-Index: 7
#2João V. Duarte (UC: University of Coimbra)H-Index: 6
Last. Miguel Castelo-Branco (UC: University of Coimbra)H-Index: 32
view all 7 authors...
The role of long-range integration mechanisms underlying visual perceptual binding and their link to interhemispheric functional connectivity, as measured by fMRI, remains elusive. Only inferences on anatomical organization from resting state data paradigms not requiring coherent binding have been achieved. Here, we used a paradigm that allowed us to study such relation between perceptual interpretation and functional connectivity under bistable interhemispheric binding vs. non-binding of visual...
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#1Teresa Sousa (UC: University of Coimbra)H-Index: 7
#2Alexandre Sayal (UC: University of Coimbra)H-Index: 2
Last. Miguel Castelo-BrancoH-Index: 32
view all 6 authors...
Abstract Visual adaptation describes the processes by which the visual system alters its operating properties in response to changes in the environment. It is one of the mechanisms controlling visual perceptual bistability – when two perceptual solutions are available – by controlling the duration of each percept. Moving plaids are an example of such ambiguity. They can be perceived as two surfaces sliding incoherently over each other or as a single coherent surface. Here, we investigated, using...
1 CitationsSource
#1Gabriel Nascimento Costa (UC: University of Coimbra)H-Index: 6
#2João V. Duarte (UC: University of Coimbra)H-Index: 6
Last. Miguel Castelo-Branco (UC: University of Coimbra)H-Index: 32
view all 5 authors...
In vision, perceptual features are processed in several regions distributed across the brain. Yet, the brain achieves a coherent perception of visual scenes and objects through integration of these features, which are encoded in spatially segregated brain areas. How the brain seamlessly achieves this accurate integration is currently unknown and is referred to as the “binding problem.” Among the proposed mechanisms meant to resolve the binding problem, the binding-by-synchrony hypothesis propose...
3 CitationsSource
#1João V. Duarte (UC: University of Coimbra)H-Index: 6
#2Gabriel Nascimento Costa (UC: University of Coimbra)H-Index: 6
Last. Miguel Castelo-Branco (UC: University of Coimbra)H-Index: 32
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It remains an open question whether long-range disambiguation of ambiguous surface motion can be achieved in early visual cortex or instead in higher level regions, which concerns object/surface segmentation/integration mechanisms. We used a bistable moving stimulus that can be perceived as a pattern comprehending both visual hemi-fields moving coherently downward or as two widely segregated nonoverlapping component objects (in each visual hemi-field) moving separately inward. This paradigm requ...
5 CitationsSource
#1Ricardo Martins (UC: University of Coimbra)H-Index: 5
#1Rodrigo Martins (UC: University of Coimbra)H-Index: 65
Last. Jorge Dias (Khalifa University)H-Index: 29
view all 4 authors...
This text presents the integration of touch attention mechanisms to improve the efficiency of the action-perception loop, typically involved in active haptic exploration tasks of surfaces by robotic hands. The progressive inference of regions of the workspace that should be probed by the robotic system uses information related with haptic saliency extracted from the perceived haptic stimulus map (exploitation) and a "curiosity"-inducing prioritisation based on the reconstruction's inherent uncer...
3 CitationsSource
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