Biology subjects

Chivukula, U.

Publications and source records attributed to Chivukula, U..

4 recordsLinked to original sources

bioRxiv2026

Causal Dissociation of Frontoparietal Control Mechanisms in Automatic Alcohol Approach Tendencies Using Continuous Theta Burst Stimulation

Compulsive alcohol intake is often sustained by approach tendencies that automatically orient individuals toward alcohol-related cues, even when they intend to avoid them. Converging evidence implicates the frontoparietal regions in regulating such automatic behavior; however, the specific contributions of the right dorsolateral prefrontal cortex (rDLPFC) and right posterior parietal cortex (rPPC), and the underlying neurocognitive mechanisms, remain unclear. To determine the specific contributions of these regions, we applied continuous theta burst stimulation (cTBS) to the rDLPFC or rPPC in separate groups of non-clinical alcohol users (rDLPFC: n = 29; rPPC: n = 28) using a within-subject, active-sham counterbalanced design. Alcohol approach tendencies were assessed using the Alcohol Approach-Avoidance Task at baseline and following active and sham stimulation. Active rDLPFC cTBS selectively slowed alcohol push responses without affecting pull responses, whereas rPPC cTBS produced a bidirectional, alcohol-specific shift in which push responses slowed and pull responses simultaneously accelerated. Although stimulation at either site shifted automatic tendencies toward greater alcohol approach, the behavioral profiles were dissociable. The findings suggest that rDLPFC contributes to sustaining the regulatory signal that drives avoidance over prepotent alcohol approach responses, whereas rPPC determines whether that signal is successfully expressed in behavior when competing cue-driven influences are present. These findings provide node-specific evidence for functional specialization within the frontoparietal network and identify a potential parietal mechanism linking cue salience to overt alcohol approach behavior.

neuroscience↗

bioRxiv2026

Modulation of Automatic Alcohol Approach Tendencies using Single-Session 10 Hz rTMS over the Right dLPFC

BackgroundMaladaptive drinking is often sustained by automatic approach tendencies toward alcohol cues that override conscious self-control. While cognitive and behavioral modification techniques show some promise, their effects remain limited, highlighting the need for alternative neuromodulatory strategies. The current study examined the feasibility of a single session of 10 Hz repetitive transcranial magnetic stimulation (rTMS) to the right dorsolateral prefrontal cortex (dLPFC) as a targeted approach to reduce automatic alcohol approach tendencies. MethodForty-five healthy alcohol-using participants completed an alcohol approach- avoidance task (A-AAT) with concurrent electroencephalographic recording before and after active or sham stimulation. Primary analyses focused on participants with baseline alcohol approach tendencies (n = 35). ResultsAt baseline, individuals with approach tendencies exhibited attenuated N2 and P3b amplitudes to alcohol relative to non-alcohol cues, indicating reduced cognitive control and attentional mechanisms irrespective of group. Following stimulation, active rTMS selectively facilitated alcohol avoidance responses and enhanced prefrontal N2 amplitudes, suggesting strengthened top-down control and protection against repetition-induced automaticity, which was evident in the sham group. ConclusionThese findings suggest that high-frequency rTMS over the right dLPFC can modulate automatic alcohol-related action tendencies by strengthening neural control mechanisms, supporting its further evaluation as a neuromodulatory adjunct for maladaptive drinking. Baseline motivational profiles may additionally influence rTMS response and warrant consideration when tailoring such approaches.

neuroscience↗

bioRxiv2025

Counterconditioning Alcohol Cues: Neural and Behavioral Modulation of Automatic Tendencies and Pavlovian-to-Instrumental Transfer in Male Alcohol Users

ObjectiveRepeated alcohol-cue pairings with rewarding experiences establish automatic response tendencies that bias instrumental behavior through Pavlovian-to-instrumental transfer (PIT). How individual differences in approach and avoidance tendencies shape PIT and intervention responsiveness remains poorly understood. This study examined whether automatic tendencies differentially modulate PIT, and whether counterconditioning (CC) combined with retrieval cues can attenuate approach biases and cue-driven instrumental interference. MethodThirty-nine male alcohol users completed an Alcohol Approach-Avoidance Task and PIT task before and after CC, classified into approach or avoidance groups based on their baseline Alcohol Approach Index. Alcohol cues were paired with monetary loss during CC, with retrieval cues introduced to facilitate reactivation of newly formed aversive associations. Right frontal N2 and centroparietal P3 were examined as indices of early evaluative and attentional processing. ResultsDespite comparable behavioral PIT performance, approach-oriented individuals showed attenuated right frontal N2 during push actions at baseline, reflecting reduced frontal regulatory engagement during cue-incongruent responding. CC selectively reduced approach biases in the approach group, with retrieval cues producing additional reductions, accompanied by N2 and P3 restoration. CC recalibrated PIT interference by reducing push and increasing pull interference, particularly with retrieval cues. CC-induced changes in approach bias did not predict PIT interference, suggesting modulation through partially dissociable pathways. ConclusionsCC with retrieval cues selectively reduced approach biases and recalibrated cue-driven instrumental interference in approach-oriented individuals, providing proof-of-concept for retrieval cue-integrated CC as a targeted associative intervention and highlighting the importance of individual tendency profiles in intervention responsiveness.

neuroscience↗

bioRxiv2025

Neural Mechanisms Underlying Approach and Avoidance Tendencies in Alcohol Use: An Electrophysiological Investigation

Background: A growing body of research highlights the differential role of approach and avoidance tendencies toward alcohol cues in the development and maintenance of harmful drinking behavior. Some individuals involved in alcohol consumption show an automatic approach towards alcohol-related stimuli, whereas others demonstrate avoidance, suggesting the need to understand the neurocognitive mechanisms underlying these automatic tendencies. Methods: The current study employed an Alcohol Approach-Avoidance Task (A-AAT) with electroencephalography (EEG) to investigate neural responses among individuals with alcohol approach and avoidance tendencies. Alcohol group participants were categorized into approach and avoidance subgroups based on their behavioral tendencies following A-AAT administration. Findings: Results revealed significant attenuation in P3 and FN400 amplitudes at frontal and parietal sites, respectively, in the alcohol-approach participants compared to both the alcohol-avoidance and non-alcohol participants. These findings suggest weakened controlled cue processing and impaired stimulus-response conflict resolution in individuals with stronger approach tendencies. Notably, right prefrontal activity exhibited prominent differences between the approach and avoidance groups, highlighting its potential role in regulating automatic alcohol-related responses. Implications: The identified ERP markers provide clinical utility for assessing alcohol approach tendencies and monitoring the progress of intervention. Findings further emphasize the importance of individually tailored targeted interventions aimed at reducing harmful alcohol consumption behavior by altering alcohol approach tendencies.

neuroscience↗