„Looking at Nothing“ (LaN) - gazes to locations that do no longer contain information - occurs both when location-associated information is retrieved from long-term memory (LTM) or accessed and consequently further activated in working memory (WM). WM activation can result from information integration when deciding between alternatives: LaN increases to the (empty) location of the alternative about to be chosen. The goal of the reported experiment was to demonstrate LaN driven by WM of to-be-compared alternatives even without LTM retrieval and to explore changes in LaN across trials when LTM develops for repeated alternatives.
Participants repeatedly performed binary decisions. The six alternatives (cars) were characterized by four textual attributes presented in distinct geometrical frames. In each trial, two alternatives with their respective attributes were visible next to each other for 4 or 5 s (full interval). Then the attribute information disappeared (empty interval) and participants indicated their preferred alternative by response keys. In addition, participants rated the single alternatives as well as the subjective importance of the individual attributes.
Higher rated alternatives were chosen more frequently with increasing number of decisions and difficult decisions (between similarly rated alternatives) took longer. During the empty interval, the relative dwell time on the chosen (vs. the other) alternative, as well as the best-rated attribute (vs. other attributes) was higher, showing that LaN occured even when no LTM representation existed yet. As participants memorized the alternatives, LaN more clearly reflected attribute relevance while response time decreased.