The dual-mechanisms framework of cognitive control posits mechanistic and neural differences between proactive and reactive control (Braver, 2012). In the laboratory, the two are often manipulated across different timescales, with demands on proactive control varied from block to block (e.g., by varying the proportion of incongruent trials within each block to create “high-” versus “low-” incongruity blocks), whereas reactive control, by definition, is engaged each time that conflict is detected (e.g., for every incongruent Stroop stimulus (e.g., Bugg, McDaniel, Scullin, & Braver, 2011), or for every “recent negative” probe in a test of working memory (e.g., D'Esposito, Postle, Jonides, & Smith, 1999). Nonetheless, it’s surely the case that, in everyday life, proactive control can be adjusted at a rate higher than, for example, the .0017 Hz that might be inferred from the roughly10 min-long blocks of Mostly Congruent vs. Mostly Incongruent vs. Mostly Neutral trials used by Bugg et al. (2011). Somewhat surprisingly to us, however, this may not be a universally accepted proposition.

Consider the scenario of quietly reading a book when suddenly, unexpectedly, a mosquito buzzes in your ear. Your immediate, reflexive response is to slap your ear, and this behavior is unambiguously an instance of reactive control. But what if your slap isn’t successful? One ensuing behavioral strategy might be to set the book in your lap and sit completely still, vigilantly waiting to hear (and perhaps also see) the mosquito again, with the plan to, this time, “slap” with both hands (i.e., to execute a “clap,” with the intention of executing your antagonizer). Some would also classify this as “reactive control,” but it’s our contention that this would be incorrect. We assert, instead, that after assessing the outcome of the first slap, what one is doing is volitionally increasing the level of proactive control and sustaining this elevated level until the target is detected again and the clap achieves its goal. After that, as one returns to the book, the level of vigilance and attention to the external world (and, therefore, the level of proactive control) return to the baseline state that is characteristic of being engrossed in a book. Note that this entire scenario, which involved an unexpected event, followed by an increase in the level of proactive control, followed by briefly sustaining this increased level, followed by a return to baseline, can have played out over the course of just a few seconds, and certainly over a span of time considerably shorter than 10 minutes. (“Actual duration will vary, depending on your mosquito.”)

Could one use the word “reactive” to describe the evaluation of the failed slap, then the creation of the plan to clap and the concurrent increase of attention to peri-personal space? Well yes, one could, but only if intending “reaction” in a non-technical sense, as in “she reacted to the bad news by changing the plans that she had previously made.” But to refer to these steps as an implementation of reactive control in the context of the dual-mechanisms framework would be incorrect. That is because the act of changing one or more control variables in response to a change of conditions in the environment, thereby optimizing the likelihood that a newly appropriate action will be successful when triggered, is a prototypical example of engaging proactive control. Furthermore, if our book reader were fitted with an EEG cap, we wager that one would see an increase of power in the theta band at frontal midline electrodes during the gap between slap and clap (as we do during the ITI following incongruent events, in Teng et al. (in press)—an electrophysiological hallmark of the recruitment of proactive control in anticipation of a heightened level of conflict (e.g., Cavanagh & Frank, 2014).

And so, if you come across a paper from us that contrasts “preparatory” control with “reflexive” control, you can safely infer that it was reviewed by individuals whose reviews suggest that they think that proactive control cannot be adjusted on a trial-by-trial basis. Do we really think that this is what they truly believe? Probably not. But this strikes us as a situation in which, perversely, the constraints imposed by a frequently used task paradigm are now shaping theoretical views of the cognitive constructs that the task paradigm was originally designed to study.

References

Braver, T. S. (2012). The variable nature of cognitive control: a dual mechanisms framework. Trends in Cognitive Sciences, 16, 106-113. https://doi.org/10.1016/j.tics.2011.12.010

Bugg, J. M., McDaniel, M. A., Scullin, M. K., & Braver, T. S. (2011). Revealing List-Level Control in the Stroop Task by Uncovering Its Benefits and a Cost. Journal of Experimental Psychology-Human Perception and Performance, 37(5), 1595-1606. https://doi.org/10.1037/a0024670

Cavanagh, J. F., & Frank, M. J. (2014). Frontal theta as a mechanism for cognitive control. Trends Cogn Sci, 18(8), 414-421. https://doi.org/10.1016/j.tics.2014.04.012

D'Esposito, M., Postle, B. R., Jonides, J., & Smith, E. E. (1999). The neural substrate and temporal dynamics of interference effects in working memory as revealed by event-related functional MRI. Proceedings of the National Academy of Sciences, USA, 96, 7514-7519. https://doi.org/10.1073/pnas.96.13.7514

Teng, C., Fulvio , J. M., Pietrelli, M., Jiang , J., & Postle, B. R. (in press). Temporal dynamics and representational consequences of the control of processing conflict between visual working memory and visual perception. Journal of Cognitive Neuroscience. https://doi.org/10.1162/jocn_a_02310