Individual differences in the temporal dynamics of attentional selection

Abstract

Attention can be focused on specific locations in our visual field (space-based attention), but also spreads along objects (object-based attention). However, object-based effects are prone to large individual differences and seem not as prevalent as previously assumed. Here we investigated whether the low prevalence of object-based effects is related to individual differences in temporal dynamics of attentional selection. We measured space- and object-based effects on reaction times for individual participants in a two-rectangle discrimination task. Cue-to-target intervals were varied between 50 and 600 ms. We used bootstrapping to investigate in which cue-to-target intervals object-based effects were maximal, and fast Fourier transform (FFT) to investigate rhythmic samplings of visual space within and between objects. Whereas overall, space-based effects were robust and stable across all cue-to-target intervals for most participants, object-based effects were small and were only found for a small subset of participants. In the frequency domain, our results confirm rhythmic patterns of visual-target detection within (8 Hz) and between objects (4 and 8 Hz). However, we found large inter-individual variability for the phase of the sampling rhythms and no consistent phase relationship. Our results show that the low-prevalence of object-based effects cannot be explained by inter-individual variability in the temporal dynamics of attentional selection, and provide further evidence for considering individual variations in developing theories of visual attention.

Effects of cue validity on attentional selection

“…As participants respond more quickly or more accurately to spatial cues than to object-based cues ( Egly et al, 1994 ; Hein, Blaschke, & Rolke, 2017 ; Moore et al, 1998 ; Pilz et al, 2012 ), spatial representations seem to play a more important role in guiding attention than object representations. This effect may account for the small or nonsignificant object-based effects observed in studies using the two-rectangle paradigm ( Macquistan, 1997 ; Moore et al, 1998 ; Nah et al, 2018 ; Pilz et al, 2012 ; Lou et al, 2020 ).…”

“…Space- and object-based attentional effects have been extensively investigated and demonstrated in previous studies ( Al-Janabi & Greenberg, 2016 ; Duncan, 1984 ; Egly, Driver, & Rafal, 1994 ; Eriksen & Eriksen, 1974 ; Moore, Yantis, & Vaughan, 1998 ; Nah & Shomstein, 2020 ; Pilz, Roggeveen, Creighton, Bennett, & Sekuler, 2012 ; Posner, 1980 ; Posner, Snyder, & Davidson, 1980 ; Shomstein & Behrmann, 2008 ). Whereas space-based effects are strong and robust, object-based effects have been found to be smaller ( Egly et al, 1994 ; Hecht & Vecera, 2007 ; Moore et al, 1998 ; Pilz et al, 2012 ) and prone to large individual differences ( Pilz et al, 2012 ; Lou et al, 2020 ). Some studies even failed to find significant object-based effects (e.g., Macquistan, 1997 ; Shomstein & Behrmann, 2008 ).…”

“…It was also found that the temporal occurrence of object-based effects varied between individuals. Lou et al (2020) recently found that object-based effects were observed at different cue-to-target intervals for different individuals. The large individual differences in the temporal occurrence of object-based effects might explain why object-based effects were small and even absent in previous studies with a fixed cue-to-target interval.…”

“…In the current study, we further investigate whether and how probability of target appearance affects the temporal occurrence of attentional selection, and whether it affects the prevalence and magnitude of object-based effects, in particular. In three experiments, we employed a visual discrimination task combined with the two-rectangle paradigm ( Moore et al, 1998 ; Pilz et al, 2012 ; Lou et al, 2020 ). We systematically changed the interval between the cue and target from 50 to 600 ms to measure temporal occurrence of space- and object-based attention, as in Lou et al (2020) .…”

“…In three experiments, we employed a visual discrimination task combined with the two-rectangle paradigm ( Moore et al, 1998 ; Pilz et al, 2012 ; Lou et al, 2020 ). We systematically changed the interval between the cue and target from 50 to 600 ms to measure temporal occurrence of space- and object-based attention, as in Lou et al (2020) . We manipulated cue validity among three experiments to further investigate the effects of probability of target appearance on attentional selection.…”