Is search priming reflected in BOLD repetition suppression?

Le résumé fourni par la source

In priming of visual search, response times decrease when the target defining feature or target location repeat across two consecutive search trials. These examples of lag-one priming have been linked to suppression in the fMRI BOLD-response in the frontoparietal attention network, and in regions within visual cortex (Kristjansson et al., 2007). However, similar results have also been interpreted as response enhancement associated with reversals of target and distractor properties, rather than as suppression associated with search priming (Rorden et al. 2011). Another typical aspect of search priming is that response-time effects from a single trial decay exponentially across 5 to 8 trials (Martini, 2010). If BOLD repetition suppression does represent a physiological correlate of search priming, then it should follow a similar decay. Here we test this prediction. First we aimed to replicate the findings of decaying behavioral priming (Martini) and lag-one BOLD repetition suppression (Kristjansson et al). By independently varying target color, location and response defining feature in a priming-of-pop-out task we assessed the individual effects of these factors on subsequent trials. We confirmed Martini's exponential signature of search priming for all three target properties, and our fMRI findings are in correspondence with those of Kristjansson et al. for repetition of color and location. Moreover, BOLD repetition suppression was found for the response-defining feature. Next, we assessed the time course of BOLD repetition suppression across trials, hypothesizing that the priming decay seen behaviorally will be reflected in the BOLD-response in brain areas involved in this priming. Indeed, we find BOLD repetition suppression that changes in magnitude across trials in intraparietal sulcus and frontal eye fields among other areas. We suggest that this time course of repetition suppression reflects the neural basis of search priming. Meeting abstract presented at VSS 2016

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