In this study we examined attention-related reaction time (RT†) and intra-individual variability (IIV) in

younger and older adults using an iPad-based visual search test, in which, for each trial, participants

were required to sequentially press a series of on-screen stimuli numbered from 1 to 8. Although overall

performance RT was significantly slower, with greater IIV for the older compared to the younger adult

group, there was also a disproportionately slowed RT and greater IIV for the first item in the series compared

to all other responses within the trial. When the response to the first stimulus was removed from statistical

analysis, the significant age-related RT slowing effect remained, but IIV was no longer significantly greater

for the older compared to the younger adults. This pattern of results reveals a dichotomy between the

preservation of RT and IIV in aging, and one that is strongly related to research methodology. A finding

that may account, at least in part, for the outcome heterogeneity in the study of IIV in aging

Dr. Nasreen Basoudan is a distinguished academic and researcher, widely recognized for her contributions to her field. She holds advanced degrees and has an extensive background in research and teaching. Dr. Basoudan's work is particularly noted for its innovation and impact, helping to shape contemporary understanding in her area of expertise. She is also actively engaged in professional collaborations, contributing to a variety of academic publications, conferences, and seminars. Dr. Basoudan remains committed to furthering education and research, consistently seeking new opportunities to advance her field