Target Distance from the Visual Field and Increased Age Affect Visual Search Efficiency: Behavioral and Modeling Evidence

Recent findings suggest that conjunction visual search can be explained through the serial processing of features. However, the roles of several critical factors, including target distance from the visual field and age, have yet to be explored. Given their significance in visual search, we aim to investigate their impact on search time and accuracy in a conjunction visual search task. Participants engaged in target-present and target-absent trials, revealing distinct patterns in search times. Behavioral results and drift-diffusion modeling (DDM) indicated that target-present trials exhibited efficient processing with faster search times, while target-absent trials showed longer search times, reflecting an increased cognitive load. Participants exhibited prolonged search times in target-absent trials, correlating with set size, while accuracy remained consistent. Conversely, target-present trials showed decreasing accuracy with larger set sizes, indicating increased cognitive load. The study further explores the impact of target distance from the central visual field on conjunction visual processing, revealing increased search times with greater distances and set sizes, emphasizing the intricate interplay between spatial factors and set size in target localization. Age-related dynamics were observed, with increasing age correlating with elevated search times in target-absent trials, suggesting challenges in declaring non-existence. However, accuracy in declaring absence improved with age, demonstrating nuanced interactions with set size. This comprehensive examination contributes to understanding cognitive mechanisms in visual processing. Significance Statement Our study delves into the intricacies of conjunction visual search, offering a comprehensive analysis of psychophysical functions, including search time and accuracy, across varied conditions. The observed patterns in search times between target-present and target-absent trials provide valuable insights into the cognitive mechanisms involved in visual search tasks. Notably, participants exhibited efficient processing in identifying target, while target-absent trials revealed prolonged search times indicative of heightened cognitive load. The nuanced examination of search time dynamics, accuracy metrics, and the interplay with set size contributes to a deeper understanding of conjunction visual search processes. Additionally, our exploration of target distance, set size, and search time unravels the intricate relationship governing target localization, shedding light on spatial and cognitive factors influencing efficiency. Furthermore, our investigation into age-related dynamics in conjunction search task uncovers a significant association between age and task performance, offering valuable insights into the challenges and compensatory mechanisms associated with aging.