Poster C117, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
Are unattended memory items under cognitive control?
Jacqueline Fulvio1, Bradley Postle1; 1University of Wisconsin - Madison
In two-item visual working memory, when memory is probed twice, both times preceded by a 100% predictive retrocue, a single pulse of transcranial magnetic stimulation (spTMS) influences the processing of the unattended memory item (UMI) in two ways: 1) it transiently reinstates the decodability of the UMI from the concurrently measured electroencephalogram (EEG); and 2) it increases false-alarm responses when the UMI is presented as the recognition memory probe (i.e., as a lure). We have interpreted the fact that these two effects are only observed during the first delay, and therefore only when the UMI remains potentially relevant for the trial, as evidence that the putatively activity-silent state of the UMI is under strategic control (Rose et al., 2016). However, it remains possible that the specificity of these “reactivation” effects to the first delay period is due to the fact that time-since-sample-presentation is necessarily different for the two delay periods. To address this, in the current study spTMS was delivered unpredictably to right-hemisphere intraparietal sulcus (IPS2) while subjects performed trials replicating Rose et al. (2016), plus single-delay trials (with a retrocue) that created the priority status for the UMI of second delay from Rose et al. (2016), but within the time frame of the first delay. Behavioral results revealed an elevated spTMS-related false-alarm rate only for UMI-lure probes occurring during the first delay period of two-probe trials. These results confirm that the ability to activate the UMI with spTMS depends on its priority status, not the latency from sample presentation.
Topic Area: EXECUTIVE PROCESSES: Working memory