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Theoretical considerations and results from individual differences studies suggest that working memory and conflict resolution are interrelated functions. Yet, there is little direct evidence suggesting that they actually share common cognitive resources. To study how overcoming conflict influences the maintenance of working memory representations and vice versa, we conducted 4 experiments using a dual-task paradigm in which both working memory load and level of conflict were independently manipulated. Participants performed an auditory Stroop task ("high" or "low" spoken in high/low pitch), which was presented during the retention period of a visual change detection task (Experiments 1-4) or simultaneously with the working memory encoding phase (Experiment 2-4). Across the 4 experiments, we found no consistent interaction between level of conflict and working memory load on working memory performance, although there was evidence in 2 of the 4 experiments for a small effect on auditory Stroop accuracy (but not on response times). These findings present at best weak evidence for the hypothesis that the maintenance of task goals in working memory is critical for successful conflict resolution.

Conflict-adaptation effects (i.e., reduced response-time costs on high-conflict trials following high-conflict trials) supposedly represent our cognitive system's ability to regulate itself according to current processing demands. However, currently it is not clear whether these effects reflect conflict-triggered, active regulation, or passive carry-over of previous-trial control settings. We used eye movements to examine whether the degree of "experienced" conflict modulates conflict-adaptation effects, as the conflict-triggered regulation view predicts. Across 2 experiments in which participants had to identify a target stimulus based on an endogenous cue while--on conflict trials--having to resist a sudden-onset distractor, we found a clear indication of conflict adaptation. This adaptation effect disappeared however, when participants inadvertently fixated the sudden-onset distractor on the previous trial--that is, when they experienced a high degree of conflict. This pattern of results suggests that conflict adaptation can be explained parsimoniously in terms of a broader memory process that retains recently adopted control settings across trials.

It is almost a truism that language aids serial-order control through self-cuing of upcoming sequential elements. We measured speech onset latencies as subjects performed hierarchically organized task sequences while "thinking aloud" each task label. Surprisingly, speech onset latencies and response times (RTs) were highly synchronized, a pattern that is not consistent with the hypothesis that speaking aids proactive retrieval of upcoming sequential elements during serial-order control. We also found that when instructed to do so, subjects were able to speak task labels prior to presentation of response-relevant stimuli and that this substantially reduced RT signatures of retrieval--however, at the cost of more sequencing errors. Thus, while proactive retrieval is possible in principle, in natural situations it seems to be prevented through a strong "gestalt-like" tendency to synchronize speech and action. We suggest that this tendency may support context updating rather than proactive control.

With the goal to determine the cognitive architecture that underlies flexible changes of control settings, we assessed within-trial and across-trial dynamics of attentional selection by tracking of eye movements in the context of a cued task-switching paradigm. Within-trial dynamics revealed a switch-induced, discrete delay in onset of task-congruent fixations, a result that is consistent with a higher level configuration process. Next, we derived predictions about the trial-to-trial dynamic coupling of control settings from competing models, assuming that control is achieved either through task-level competition or through higher level configuration processes. Empirical coupling dynamics between trial n-1 eye movements and trial n response times--estimated through mixed linear modeling--revealed a pattern that was consistent with the higher level configuration model. The results indicate that a combination of eye movement data and mixed modeling methods can yield new constraints on models of flexible control. This general approach can be useful in any domain in which theoretical progress depends on high-resolution information about dynamic relationships within individuals. (Contains 2 tables, 7 figures, and 6 footnotes.)