Biology subjects

Cracco, E.

Publications and source records attributed to Cracco, E..

11 recordsLinked to original sources

bioRxiv2025

Using time-resolved auditory frequency tagging to capture self-preferential processing of the own (vs other) name

The own name is an important, salient self-related stimulus and ostensive cue. Prioritized processing of ones own name plays a key role in attention, self-awareness, and social and cognitive development. Previous studies using event-related potentials (ERPs) have reported a self-preferential effect for the own name, characterized by enhanced neural responses compared to the names of (close) others. In this study, we aimed to develop and validate an EEG auditory frequency-tagging task to measure self-preferential processing of the own name, leveraging the superior signal-to-noise ratio of this technique, which is highly relevant for future studies on infants and clinical populations. To this end, we ran two separate studies (dichotic: n1 = 31, non-dichotic: n2 = 32). In contrast to previous ERP research, we did not find evidence of a self-preferential effect. We reasoned that collapsing temporal information may have led to the failure to capture the effect, which ERP research has shown to emerge at a late stage of processing, and that this effect may have been overshadowed by early brain responses. To address this issue, we applied a novel approach that we refer to as the time-resolved frequency tagging approach, which incorporates knowledge of the effect in the temporal domain. This did result in a clear self-preferential effect of the own name. Hence, we were able to develop and validate an EEG frequency-tagging task to measure the self-preferential effect of the own name. Our approach can also be used in future EEG frequency-tagging studies investigating other complex cognitive processes.

neuroscience↗

bioRxiv2024

EEG frequency tagging reveals the integration of dissimilar observed actions

Extensive research has demonstrated that visual and motor cortices can simultaneously represent multiple observed actions. This ability undoubtedly constitutes a crucial ingredient for the understanding of complex visual scenes involving different agents. However, it is still unclear how these distinct representations are integrated into coherent and meaningful percepts. In line with studies of perceptual binding, we hypothesized that similar movements would be more easily integrated. To test this hypothesis, we developed an EEG frequency tagging experiment in which two hand movements were displayed simultaneously at two different presentation rates. Crucially, the degree of similarity between the two movements varied along two dimensions, namely action identity (i.e., same or different performed movement), and agent identity (i.e., one agent performing a bimanual movement, or two agents moving each one hand). Contrary to our predictions, we found a larger intermodulation oscillatory component, indexing the integrated processing of the two individual movements, when they were less similar. We propose that integration-by-dissimilarity might serve as a top-down process to solve conflict caused by incongruent movements in a complex social scene.

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bioRxiv2023

Evidence for a role of synchrony but not common fate in the perception of biological group movements

Extensive research has shown that observers are able to efficiently extract summary information from groups of people. However, little is known about the cues that determine whether multiple people are represented as a social group or as independent individuals. Initial research on this topic has primarily focused on the role of static cues. Here, we instead investigate the role of dynamic cues. In two experiments with male and female human participants, we use EEG frequency tagging to investigate the influence of two fundamental Gestalt principles - synchrony and common fate - on the grouping of biological movements. In Experiment 1, we find that brain responses coupled to four point-light figures walking together are enhanced when they move in sync vs. out of sync, but only when they are presented upright. In contrast, we found no effect of movement direction (i.e., common fate). In Experiment 2, we rule out that synchrony takes precedence over common fate by replicating the null effect of movement direction while keeping synchrony. These results put forward synchrony as an important driver of social grouping, consistent with the fact that it is an important feature of social interaction and an indicator of social cohesion. In contrast, the influence of common fate on social grouping is less clear and will require further research.

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bioRxiv2023

Top-down biological motion perception does not differ between adults scoring high versus low on autism traits

The perception of biological motion is an important social cognitive ability. Models of biological motion perception recognize two processes that contribute to the perception of biological motion: a bottom-up process that binds optic-flow patterns into a coherent percept of biological motion and a top-down process that binds sequences of body-posture snapshots over time into a fluent percept of biological motion. The vast majority of studies on autism and biological motion perception have used point-light figure stimuli, which elicit biological motion perception predominantly via bottom-up processes. Here, we investigated whether autism is associated with deviances in the top-down processing of biological motion. For this, we tested a sample of adults scoring low vs high on autism traits on a recently validated EEG paradigm in which apparent biological motion is combined with frequency tagging (Cracco et al., 2022) to dissociate between two percepts: 1) the representation of individual body postures, and 2) their temporal integration into movements. In contrast to our hypothesis, we found no evidence for a diminished temporal body posture integration in the high-scoring group. We did, however, find a group difference that suggests that adults scoring high on autism traits have a visual processing style that focuses more on a single percept (i.e. either body postures or movements, contingent on saliency) compared to adults scoring low on autism traits who instead seemed to represent the two percepts included in the paradigm in a more balanced manner. Although unexpected, this finding aligns well with the autism literature on perceptual stability(/rigidity).

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bioRxiv2023

Hebbian learning of stimulus-response associations using transcranial magnetic stimulation

Classical conditioning states that the systematic co-occurrence of a neutral stimulus with an unconditioned stimulus can cause the neutral stimulus to, over time, evoke the same response as the unconditioned stimulus. On a neural level, Hebbian learning suggests that this type of learning occurs through changes in synaptic plasticity when two neurons are simultaneously active, resulting in increased connectivity between them. Inspired by learning theories, we here investigated whether the mere co-activation of visual stimuli and stimulation of the primary motor cortex using transcranial magnetic stimulation (TMS) would result in stimulus-response associations that can impact future behaviour. During a learning phase, we repeatedly paired the presentation of a specific colour (but not other colours) with a TMS pulse over the motor cortex. Next, participants performed a two-alternative forced choice task where they had to categorize simple shapes and we studied whether the shapes task-irrelevant colour (and its potentially associated involuntary motor activity) affected the required motor response. Participants showed more errors on incongruent trials for stimuli that were previously paired with high intensity TMS pulses, but only when tested on the same day. Using a drift diffusion model for conflict tasks, we further demonstrate that this interference occurred early, and gradually increased as a function of associated TMS intensity. Taken together, our findings show that the human brain can learn stimulus-response associations using externally induced motor cortex stimulation.

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bioRxiv2022

The Role of Objecthood and Animacy in Apparent Movement Processing

Movement perception involves both motion and form processing. Previous research has shown that processing along the motion pathway requires a familiar but not necessarily a human shape. However, the role of objecthood and animacy in the form pathway is less clear. Here, we used EEG frequency tagging to study how objecthood and animacy influence both posture processing and the integration of postures into movements. Specifically, we measured brain responses to repeating sequences of well-defined or pixelated images (objecthood) of human or corkscrew agents (animacy) performing fluent or non-fluent movements (movement fluency). The results revealed that movement processing was sensitive to objecthood but not to animacy, whereas posture processing was sensitive to both. Thus, our results indicate that movement processing in the form pathway requires a familiar shape, but not necessarily a human shape. Instead, stimulus animacy appears to be relevant only for posture processing.

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bioRxiv2022

EEG frequency tagging evidence of intact social interaction recognition in adults with autism

To explain the social difficulties in autism, a large amount of research has been conducted on the neural correlates of social perception. However, this research has mostly used basic social stimuli (e.g. eyes, faces, hands, single agent), not resembling the complexity of what we encounter in our daily social lives, and as such, the situations people with autism experience difficulties in. A more complex stimulus that we do come across often and is also highly relevant for social functioning is that of third-party social interactions. Here, we investigated if individuals with and without autism process third-party social interactions differently. More specifically, we measured neural responses to social scenes depicting either social interaction or not with an electroencephalogram (EEG) frequency tagging task and compared these responses between adults with and without autism (N = 61). The results revealed an enhanced response to social scenes with interaction, replicating previous findings in a neurotypical sample (Oomen et al., 2022). Crucially, this effect was found in both groups with no difference between them. This suggest that social interaction recognition is not anomalous in adults with autism and cannot explain the social difficulties adults with autism experience. Lay abstractPeople with autism have social difficulties and are thought to experience the world differently. To better understand these differences, research has studied how the brain of people with and without autism processes social stimuli. However, this research has mostly used basic social stimuli (e.g. eyes, faces, hands, and single agents). Such stimuli do not resemble the complexity of daily life, where we typically do not come across isolated body parts, but instead have to make sense of complex social scenes with multiple people. To do so, it is imperative that we are able to recognize social interaction. Hence, if social interaction processing is anomalous, this could have pervasive consequences for social functioning more generally. Here, we used brain imaging to test if adults with autism process social interaction scenes differently than adults without autism. In line with previous findings from a neurotypical sample (Oomen et al. (2022), we found that social scenes depicting interaction elicited stronger brain responses than social scenes not depicting interaction. Crucially, this effect was found in both groups with no difference between them. These findings suggest that the fundamental process of social interaction recognition is not anomalous in adults with autism.

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bioRxiv2022

EEG Frequency Tagging Objectively Measures Biological Motion Perception

Detecting biological motion is essential for adaptive social behavior. Previous research has revealed the brain processes underlying this ability. However, brain activity during biological motion perception captures a multitude of components. As a result, it is often unclear which components reflect movement processing and which components reflect secondary processes building on movement processing. To address this issue, we developed a new approach that objectively defines the brain response associated with biological motion perception. Specifically, we showed 30 male and female adults a point-light walker moving at a pace of 2.4 Hz and used EEG frequency tagging to measure the brain response coupled to that pace ( movement tagging). The results revealed a reliable response at the walking frequency that was reduced by two manipulations known to disrupt biological motion perception: phase scrambling and inversion. Interestingly, we also identified a brain response at half the walking frequency (i.e., 1.2 Hz), corresponding to the rate at which the individual dots completed a cycle. In contrast to the 2.4 Hz response, the response at 1.2 Hz was increased for scrambled walkers. These results show how frequency tagging can be used to objectively measure the visual processing of biological movements and can dissociate between global (2.4 Hz) and local (1.2 Hz) processes involved in biological motion perception, at different frequencies of the brain signal.

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bioRxiv2020

EEG frequency tagging reveals neural entrainment to people moving in synchrony

Humans and other animals have evolved to act in groups, but how does the brain distinguish multiple people moving in group from multiple people moving independently? Across three experiments, we test whether biological motion perception depends on the spatiotemporal relationships among people moving together. In Experiment 1, we apply EEG frequency tagging to apparent biological motion and show that fluently ordered sequences of body postures drive brain activity at three hierarchical levels of biological motion processing: image, body sequence, and movement. We then show that movement-, but not body- or image-related brain responses are enhanced when observing four agents moving in synchrony. Neural entrainment was strongest for fluently moving synchronous groups (Experiment 2), displayed in upright orientation (Experiment 3). Our findings show that the brain preferentially entrains to the collective movement of human agents, deploying perceptual organization principles of synchrony and common fate for the purpose of social perception.

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bioRxiv2019

Defining the neural correlates of spontaneous theory of mind (ToM): An fMRI mega-analytic investigation

There is a major debate in the theory of mind (ToM) field, concerning whether spontaneous and explicit ToM are based on the same or two distinct cognitive systems. While there is extensive research on the neural correlates of explicit ToM, revealing consistent activation of the temporo-parietal junction (TPJ) and medial prefrontal cortex (mPFC), few studies investigated spontaneous ToM, with conflicting results, probably due to having small samples of participants. Here, we implemented a mega-analytic approach by pooling data from three fMRI studies, to achieve enough statistical power to better define the neurocognitive mechanisms underlying spontaneous ToM. Participants watched videos in which an agent acquires a true or false belief about the location of a ball. By analysing the blood-oxygen level dependent signal during the belief formation phase for false versus true beliefs, we found a cluster of activation in the right, and to a lesser extent, left posterior parietal cortex spanning the TPJ, but no mPFC activation. Region of interest (ROI) analysis on bilateral TPJ and mPFC confirmed these results and added evidence to the content-selectivity for false beliefs with positive content and asymmetry in laterality of the spontaneous ToM system. Interestingly, the whole brain analysis, supported by an overlap with brain maps, revealed maximum activation in areas involved in visuospatial working memory and attention switching functions, such as the supramarginal gyrus, the middle temporal gyrus, and the inferior frontal gyrus. Taken together, these findings suggest that spontaneous and explicit ToM rely on partially overlapping brain systems. However, spontaneous ToM tasks also show clear differences with explicit ToM tasks.

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bioRxiv2018

Representing Multiple Observed Actions in the Motor System

There is now converging evidence that others actions are represented in the motor system. However, social cognition requires us to represent not only the actions but also the interactions of others. To do so, it is imperative that the motor system can represent multiple observed actions. The current fMRI study investigated whether this is possible by measuring brain activity from 29 participants while they observed two right hands performing sign language gestures. Three key results were obtained. First, brain activity in the premotor and parietal motor cortex was stronger when two hands performed two different gestures than when one hand performed a single gesture. Second, both individual observed gestures could be decoded from brain activity in the same two regions. Third, observing two different gestures compared with two identical gestures activated brain areas related to motor conflict, and this activity was correlated with parietal motor activity. Together, these results show that the motor system is able to represent multiple observed actions, and as such reveal a potential mechanism by which third-party social encounters could be processed in the brain.

neuroscience↗