Sequential effects in continued visual search: Using fixation‐related potentials to compare distractor processing before and after target detection

Abstract

To search for a target in a complex environment is an everyday behavior that ends with finding the target. When we search for two identical targets, however, we must continue the search after finding the first target and memorize its location. We used fixation-related potentials to investigate the neural correlates of different stages of the search, that is, before and after finding the first target. Having found the first target influenced subsequent distractor processing. Compared to distractor fixations before the first target fixation, a negative shift was observed for three subsequent distractor fixations. These results suggest that processing a target in continued search modulates the brain's response, either transiently by reflecting temporary working memory processes or permanently by reflecting working memory retention.

Combining EEG and eye movement recording in free viewing: Pitfalls and possibilities

“…In a multiple target search task, the presaccadic amplitude is more negative for distractors following than preceding the fixation on a target. These results suggest that presaccadic activity reflects memory uptake of target information (Körner et al, 2014). Moreover, presaccadic activity predicts the success of visual short-term memory encoding.…”

“…This type of baseline is selected from one saccade-related epoch within a limited number of sequential epochs of interest and applied to all these epochs. For example, a local baseline can be selected at the fixation on a target and can be applied to the fixations on several previous and following distractors (Körner et al, 2014). This method provides a common reference point for several sequential processes of interest.…”

“…Most co-registration studies of free viewing behavior use either a mastoid reference (Devillez et al, 2015;Fischer et al, 2013;Graupner et al, 2007;Körner et al, 2014;Ossandón et al, 2010;Rama & Baccino, 2010;Simola et al, 2015) or an average reference Dimigen et al, 2009;Kamienkowski et al, 2012). We used a mastoid reference in the analysis of CB dataset because the limited number of electrodes did not allow us to convert the data to average reference reliably (Dien, 1998) and an average reference in the analysis of VS dataset, which was recorded from 256 electrodes.…”

“…2 Thus, EFRP is a hybrid construct, combining an exploration-driven, eye movement induced signal with a stimulus-driven one, the potential evoked by the visual features at fixation. EFRPs during both controlled and free eye movement behavior have been studied for several decades (Billings, 1989b;Devillez, Guyader, & Guerin-Dugue, 2015;Dimigen et al, 2011;Fudali-Czyz, Francuz, & Augustynowicz, 2014;Kazai & Yagi, 1999;Körner et al, 2014;Nikolaev et al, 2011;Rama & Baccino, 2010;Thickbroom et al, 1991;Yagi, 1979).…”

“…In particular, co-registration is increasingly becoming popular in conditions involving continued exploration, i.e., free viewing. 1 Because it can be used in naturalistic conditions, co-registration provides an exciting new paradigm for studying attention (Fischer, Graupner, Velichkovsky, & Pannasch, 2013), memory encoding (Nikolaev, Jurica, Nakatani, Plomp, & van Leeuwen, 2013;Nikolaev, Nakatani, Plomp, Jurica, & van Leeuwen, 2011), visual search (Dias, Sajda, Dmochowski, & Parra, 2013;Kamienkowski, Ison, Quiroga, & Sigman, 2012;Kaunitz et al, 2014;Körner et al, 2014), reading (Dimigen, Sommer, Hohlfeld, Jacobs, & Kliegl, 2011;Hutzler et al, 2007), and responses to emotionally charged visual information (Simola, Le Fevre, Torniainen, & Baccino, 2015;Simola, Torniainen, Moisala, Kivikangas, & Krause, 2013), just to mention some domains http://dx.doi.org/10.1016/j.bandc.2016.06.004 0278-2626/Ó 2016 Elsevier Inc. All rights reserved. of basic research in which this technique is successfully being used.…”