Biology subjects

Chica, A. B.

Publications and source records attributed to Chica, A. B..

4 recordsLinked to original sources

bioRxiv2026

When the heart and the brain meet: Cardiac-neural coupling in feature integration

In contemporary Cognitive Neuroscience, increasing attention is devoted to brain-body interactions, as an expanding body of literature suggests that processing the external world may not emerge from the brain in isolation but rather from the coordinated contribution of multiple bodily systems. These interactions have been extensively studied in the context of interoception. However, evidence linking them to visual perception remains scarce. To address this gap, the present study examines heart-brain interactions during a visual feature integration task. The task of the participants required shape and color integration of features to identify a target while inhibiting distractor-related information. Cardiac and neural activity were simultaneously recorded, enabling the assessment of the heart rate (HR), heart-evoked potentials (HEP), and, albeit seldom reported previously, heart-evoked oscillations (HEO). Pre-stimulus cardiac-related neural activity differed between correctly and incorrectly integrated features. HEO analysis revealed alpha and low beta band modulations before target onset, which vanished when cardiac time-locking was removed, indicating that they were specifically driven by brain-heart coupling rather than by ongoing brain activity alone. These findings provide the first evidence that HEO dynamics contribute to successful perceptual integration and extend previous work on HEPs from stimulus detection to higher-level perceptual processes. More broadly, they suggest that cardiac signals shape early brain states that bias perception, supporting theoretical frameworks proposing an active role for bodily signals in perceptual processing. HighlightsO_LIPre-stimulus heart-evoked potentials differ between correct and incorrect feature integration. C_LIO_LIHeartbeat-locked alpha and low beta activity increase before correct feature integration C_LIO_LIPre-stimulus oscillatory effects vanish without cardiac activity, revealing HEO contribution. C_LIO_LIBrain-heart coupling biases perceptual outcomes. C_LI

neuroscience↗

bioRxiv2026

Within-Trial Noise Accounts for Inhibition of Return

Inhibition of return (IOR) refers to the slowing of response times (RTs) for stimuli presented at previously inspected locations relative to novel locations. However, the exact processing stage(s) at which IOR occurs, and its nature across different response modalities, remain debated. By reanalyzing RT data from a target-target IOR paradigm with a single noisy accumulator model, we tested whether IOR could occur at sensory or attentional stages of processing, or at later stages of decision and action selection. We considered IOR under two conditions: manual and saccadic responses. The within-trial Gaussian noise parameter best explained both manual and saccadic IOR, suggesting that in both modalities, IOR may result from a more fluctuating accumulation of evidence for repeated locations. These results support the hypothesis that target-target IOR may primarily involve attentional-level mechanisms. Significance statementWe respond more slowly to a stimulus that is presented within a short interval in the same location ("inhibition of return"), a bias thought to promote efficient visual exploration. Using evidence-accumulation modeling of manual and eye-movement reaction times from two previous studies, we found that the key change linked to inhibition of return is greater within-trial variability (noise) in evidence accumulation, not a higher decision threshold. Understanding which processing stage is affected can help connect behavioral effects to the brain networks that support attention and orienting.

neuroscience↗

bioRxiv2026

Rescuing unseen stimuli through alerting retro-cues

AO_SCPLOWBSTRACTC_SCPLOWCan alerting retro-cues improve the conscious perception of stimuli that would otherwise remain unseen? While pre-stimulus alerting is known to facilitate conscious access, the effects of retro-cues remain ambiguous due to methodological confounds in existing literature. Specifically, most studies finding retro-cue benefits have relied on spatial features (such as lateralized targets or cues), which confound alerting with spatial selection. Our design addresses this gap by employing central visual targets and non-lateralized auditory cues, thereby isolating the temporal boost of phasic alerting from spatial orienting. Across four experiments, participants reported the presence and orientation of a central Gabor patch presented at near-threshold ([~]50% detection)) or higher visibility ([~]75% detection) levels. An auditory alerting tone was presented prior to, simultaneously with, or after the Gabor, at various short and long stimulus onset asynchronies, with both short and long temporal ranges. Results consistently showed that pre-stimulus and simultaneous cues significantly enhanced conscious perception, increasing both seen rates and (in some experiments) perceptual sensitivity. Crucially, the presence of retro-cue benefits was observed at higher stimulus visibility, but not at near-threshold, suggesting a potential influence of target visibility on retro-cue efficacy. When targets were near-threshold, retro-cues did not reliably improve conscious perception, whereas tones presented 200 ms after target offset significantly increased the proportion of seen reports when target visibility was increased . These findings indicate that nonspatial auditory retrocues can modulate conscious report when the underlying sensory trace is sufficiently robust. More broadly, they show that the timing of conscious access can be influenced by late alerting signals even in the absence of spatial information, providing a behavioural platform to refine models of how alerting and evidence strength interact in conscious perception.

neuroscience↗

bioRxiv2020

Distinct Contributions of Nonpredictive and Predictive Peripheral Cues to Visual Conscious Perception: an MEG study

How do attentional networks influence conscious perception? To answer this question, we used magnetoencephalography (MEG) in human participants, and assessed the effects of spatially nonpredictive or predictive supra-threshold peripheral cues on the conscious perception of near-threshold Gabors. Three main results emerged. (1) As compared with invalid cues, both nonpredictive and predictive valid cues increased conscious detection. Yet, only predictive cues shifted the response criterion towards a more liberal decision (i.e., willingness to report the presence of a target under conditions of greater perceptual uncertainty) and affected target contrast leading to 50% detections. (2) Conscious perception following valid predictive cues was associated to enhanced activity in frontoparietal networks. These responses were lateralized to the left hemisphere during attentional orienting, and to the right hemisphere during target processing. The involvement of frontoparietal networks occurred earlier in valid than in invalid trials, a possible neural marker of the cost of re-orienting attention. (3) When detected targets were preceded by invalid predictive cues, and thus reorienting to the target was required, neural responses occurred in left hemisphere temporo-occipital regions during attentional orienting, and in right hemisphere anterior insular and temporo-occipital regions during target processing. These results confirm and specify the role of frontoparietal networks in modulating conscious processing, and detail how invalid orienting of spatial attention disrupts conscious processing. Significance StatementDo we need to pay attention to external objects in order to become aware of them? Characterizing the spatiotemporal dynamics of attentional effects on visual perception is critical to understand how humans process and select relevant information. Participants detected near-threshold visual targets preceded by supra-threshold spatial cues with varying degrees of predictivity, while their brain activity was recorded using magnetoencephalography. Results demonstrated that valid predictive cues biased participants conscious perception through an early recruitment of frontoparietal regions, and that attentional costs associated to invalid predictive cues were related to activation of the right hemisphere ventral network. This work characterizes the neural dynamics associated with the cost of attentional reorienting on conscious processing.

neuroscience↗