Browsing by Author "Morales, Juan-Pablo"

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    Cocaine polydrug use and its impact on intentional harm recognition: a high-density EEG study
    (2025) Morales, Juan-Pablo; Van Dam, Nicholas T.; Huepe-Artigas, Daniela; Rivera-Rei, Álvaro; San-Martin, Consuelo; Rojas-Thomas, Felipe; Valdés Bize, Joaquín; Ibáñez, Agustín; Huepe, David
    Background Cocaine and stimulant consumption constitute a significant global issue and are associated with impaired social skills. However, the relationship between substance abuse and intentional harm recognition remains unclear. Intentional harm recognition is a crucial social cognitive ability that allows individuals to determine whether a harmful action performed by another person is deliberate or accidental. Methods The present study examined self-reported, behavioural, and neural responses associated with intentional harm recognition in n = 19 cocaine polydrug users (COC) and n = 19 healthy controls (HC). High-density electroencephalography (hdEEG) was used to measure brain activity during an Intentional Inference Task (IIT), which assesses fast intention recognition in scenarios involving deliberate or unintentional harm to people and objects. This study took place between 2014 and 2015 in Santiago, Chile. Results Behaviorally, COC exhibited slower reaction times (RT) than HC. Event-related potential (ERP) analysis revealed late frontal differences in HC when attributing intentional harm, while these differences were absent in COC. Conclusions These findings suggest a potential shift in COC towards emotional over-involvement and away from rational cognitive assessment of social information. The present results provide new insights into the recognition of intentional harm processing in cocaine polydrug users and highlight the potential clinical benefits of interventions focused on socio-emotional regulation training.
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    Impact of acute psychosocial stress on attentional control in humans. A study of evoked potentials and pupillary response
    (2023) Rojas Thomas, Felipe Eduardo; Artigas, C.; Wainstein, G.; Morales, Juan-Pablo; Arriagada, M.; Soto, D.; Dagnino-Subiabre, A.; Silva, J.; López, V.Rojas Thomas, Felipe Eduardo; Artigas, C.; Wainstein, G.; Morales, Juan-Pablo; Arriagada, M.; Soto, D.; Dagnino-Subiabre, A.; Silva, J.; López, V.
    Psychosocial stress has increased considerably in our modern lifestyle, affecting global mental health. Deficits in attentional control are cardinal features of stress disorders and pathological anxiety. Studies suggest that changes in the locus coeruleus-norepinephrine system could underlie the effects of stress on top-down attentional control. However, the impact of psychosocial stress on attentional processes and its underlying neural mechanisms are poorly understood. This study aims to investigate the effect of psychosocial stress on attentional processing and brain signatures. Evoked potentials and pupillary activity related to the oddball auditory paradigm were recorded before and after applying the Montreal Imaging Stress Task (MIST). Electrocardiogram (ECG), salivary cortisol, and subjective anxiety/stress levels were measured at different experimental periods. The control group experienced the same physical and cognitive effort but without the psychosocial stress component. The results showed that stressed subjects exhibited decreased P3a and P3b amplitude, pupil phasic response, and correct responses. On the other hand, they displayed an increase in Mismatch Negativity (MMN). N1 amplitude after MIST only decreased in the control group. We found that differences in P3b amplitude between the first and second oddball were significantly correlated with pupillary dilation and salivary cortisol levels. Our results suggest that under social-evaluative threat, basal activity of the coeruleus-norepinephrine system increases, enhancing alertness and decreasing voluntary attentional resources for the cognitive task. These findings contribute to understanding the neurobiological basis of attentional changes in pathologies associated with chronic psychosocial stress.