id_730. REDUCED AROUSAL FOLLOWING SLEEP DEPRIVATION DOES NOT DIMINISH PSEUDONEGLECT IN FREE VISUAL EXPLORATION
Aleksandra Smus1, Wiktor Więcławski1,2, Wojciech Żukowski1, Marek Binder1
1 Institute of Psychology, Jagiellonian University, Romana Ingardena 6, Kraków, Poland
2 Doctoral School of Social Sciences, Jagiellonian University, prof. St. Łojasiewicza 4, Kraków, Poland
INTRODUCTION: When freely exploring naturalistic scenes, healthy individuals typically exhibit an initial attentional bias toward the left visual field. Although this phenomenon—known as pseudoneglect—is robust and easily replicable, its underlying mechanisms remain unclear. Beyond explanations invoking hemispheric asymmetries in attentional control, it has been proposed that arousal plays a key role in modulating the magnitude and direction of this bias. Several studies have suggested that reduced arousal may attenuate leftward bias or even lead to a reversal toward the right visual field.
AIM(S): Given the lack of a clear mechanistic account and mixed empirical evidence, replication of these findings is warranted. We also aimed to disentangle the effects of two main drivers of low arousal: circadian rhythms and sleep deprivation.
METHOD(S): We therefore conducted an experiment in 42 right-handed young adults to examine whether reductions in arousal influence pseudoneglect during free visual exploration. Participants performed a free-viewing task under three conditions: normal arousal in the evening (20:00), reduced arousal at the circadian trough (05:00), and following a full night of sleep deprivation (09:00). Arousal and vigilance were carefully monitored using behavioral measures.
RESULTS: As expected, arousal levels were lowest at 05:00. Despite this reduction, visual exploration patterns did not differ across conditions, with all sessions showing a robust and comparable leftward bias.
CONCLUSIONS: These findings suggest that transient reductions in arousal, including those induced by circadian phase and sleep deprivation, do not diminish pseudoneglect. Our results contribute to the ongoing debate on the mechanisms underlying pseudoneglect and indicate that factors other than global arousal may play a more critical role in shaping spatial attentional biases.
FINANCIAL SUPPORT: The study was supported by the grant awarded by Rada Kół Naukowych Uniwersytetu Jagiellońskiego to Aleksandra Smus (RKN/2025/2A/020)