Temporal Stability of Neural Markers of Motivated and Voluntary Attention: Case-by-Case and Group Analyses

There is growing evidence that electrophysiological markers of selective attention can be reliably assessed at the level of the individual case. The present study extends this work by examining their temporal stability across a one-week retest interval, with a focus on motivated and voluntary attention. Seventeen healthy young adults were tested twice, 1 week apart, using a dense sensor EEG setup. Each session included blocks featuring either highly arousing erotic or mutilation images alongside low-arousing control stimuli. To simultaneously assess voluntary attention, participants performed an emotion categorization task in which high or low arousal images served as targets in separate blocks. Across both emotion categories, the majority of participants showed significant emotional modulation of the EPN (88%) and LPP (100%) components, as well as target P3 effects (76%) in both sessions. Complementary classification approaches based on different significance thresholds further supported the consistency of these effects. Subsampling analyses revealed that although reducing trial numbers diminished reliability, robust effects, particularly for the EPN and LPP in response to erotic stimuli, remained detectable at moderate trial counts. Analyses at the group level revealed excellent test-retest reliabilities for the EPN (ICC > 0.91) and target P3 (ICC > 0.86). While reliability was good for the LPP (ICC > 0.60), the confidence intervals indicated substantial variability. Together, these findings demonstrate that neural correlates of both motivated and voluntary attention exhibit high test-retest reliability at the individual level, reinforcing their utility as biomarkers and highlighting the value of single-case analyses in electrophysiological research.