Biology subjects

Ramirez-Haro, A.

Publications and source records attributed to Ramirez-Haro, A..

3 recordsLinked to original sources

bioRxiv2025

A comprehensive EEG dataset for investigating visual touch perception

Visual touch perception is fundamental to body awareness and social bonding, helping us perceive ourselves and connect with others. However, understanding its neural basis has been limited by a lack of comprehensive public datasets. To address this, we present an electroencephalography (EEG) and self-report dataset from 80 participants. It includes neural responses from 2,880 trials per participant, during which participants viewed touch interactions between two hands involving either direct skin contact or object-mediated touch. Complementing the EEG data are self-report measures on empathy, perspective-taking, vicarious touch, and mirror-touch synaesthesia, providing a robust resource for exploring individual differences in visual touch perception. Ninety unique videos were presented in four orientations, with trials evenly split between self- and other-perspectives, and showing touch to either the left or right hand. This design supports investigation into how viewing perspective and hand laterality influence touch processing. Technical validation reveals distinct neural patterns associated with visual, sensory, and emotional touch dimensions, highlighting the datasets potential to advance research into diverse aspects of visual touch perception.

neuroscience↗

bioRxiv2025

The neural processes of illusory occlusion in object recognition

Fast and accurate object recognition is crucial for effective behaviour in dynamic visual environments. In some cases, the visual system must overcome ambiguity in visual input during object recognition, such as when an object is partially hidden behind another. Recurrent processing between higher- and lower-order areas is thought to play a role in resolving such ambiguity, enabling the filling in of missing visual information. Here we examined this claim using a novel paradigm in which partial object images appear occluded by an illusory Kanizsa figure, perception of which also depends on recurrent processing by the grouping of Pacmen inducers. If both recognising the partial object and perceiving the illusory shape depend on recurrent processing, object recognition should vary as a function of the presence of illusory shape. Across two behavioural experiments and a separate EEG decoding study, we found no evidence for an interaction between illusion perception and object recognition, and different neural time courses for the illusory figures alone compared to those of the partial objects, which were decoded earlier. Ultimately, our study highlights the robustness of the visual system to solve the identity of the ambiguous object, independently from the processing of different ambiguities occurring at the same time, providing new insights into the mechanisms of recurrence in the early and late stages of information processing and its application to ambiguous object recognition.

neuroscience↗

bioRxiv2024

Rapid visual engagement in neural processing of detailed touch interactions

Touch perception is an inherently multisensory process in which vision plays an essential role. However, our understanding of how vision encodes sensory and emotional-affective aspects of observed touch, and the timing of these processes, is still limited. Here we address this gap by investigating the neural dynamics of visual touch observation by analysing electroencephalographic (EEG) data from participants viewing detailed hand interactions from the Validated Touch-Video Database. We examined how the brain encodes basic body cues such as hand orientation and viewing perspective, in addition to sensory aspects, including the type of touch (e.g., stroking vs. pressing; hand vs. object touch) and the object involved (e.g., knife, brush), as well as emotional-affective dimensions. Using multivariate decoding, information about body cues was present within 60 ms, with sensory and emotional details, including valence, arousal, and pain present around 130 ms, demonstrating efficient early visual processing. Threat was most clearly identified by approximately 265 ms, similarly involving visual regions, suggesting that such evaluations require slightly extended neural engagement. Our findings reveal that bottom-up, automatic visual processing is integral to complex tactile assessments, important for rapidly extracting both the personal relevance and the sensory and emotional dimensions of touch.

neuroscience↗