Although it is well accepted that working memory (WM) is intimately related to consciousness, little research has illuminated the liaison between the two phenomena. To investigate this under-explored nexus, we used an imagery monitoring task to investigate the subjective aspects of WM performance. Specifically, in two experiments, we examined the effects on consciousness of (a) holding in mind information having a low versus high memory load, and (b) holding memoranda in mind during the presentation of distractors (e.g., visual stimuli associated with a response incompatible with that of the memoranda). Higher rates of rehearsal (conscious imagery) occurred in the high load and distractor conditions than in comparable control conditions. Examination of the temporal properties of the rehearsal-based imagery revealed that, across subjects, imagery events occurred evenly throughout the delay. We hope that future variants of this new imagery monitoring task will reveal additional insights about WM, consciousness, and action control.
Perhaps no mental operation is as consistently coupled with conscious processing as is working memory (WM; Baddeley, 2007 and LeDoux, 2008). (WM has been defined as a temporary, capacity-limited storage system under attentional control that is used to intentionally hold, and manipulate, information in mind; Baddeley, 1986 and Baddeley, 2007.) It is obvious to the scientist and nonscientist alike that when one tries to hold or manipulate information that is not furnished by the external world, one’s conscious mind seems to be occupied almost entirely with the task at hand (James, 1890). For instance, when holding a to-be-dialed telephone number in mind (or gargling with mouthwash for 30 s), action-related mental imagery occupies one’s conscious mind till the number is dialed (Paivio, 1979). While many sophisticated processes can be carried out unconsciously (see review of unconscious processing in Morsella & Bargh, 2011), WM performance tends to be a conscious phenomenon (but see Hassin, 2005).
Apart from these quotidian observations, and despite that theorists have long noted that WM is intimately related to conscious processing (Baddeley, 2007, Gray, 2004, LeDoux, 2008 and Oberauer and Hein, 2012), little empirical research has illuminated the nexus between the two phenomena. To address this gap in the literature, our experimental project—involving novel paradigms, predictions, and dependent measures—serves as a first step to investigate the interrelations between these two multifaceted phenomena. Before describing our synthesis of the two areas of research and delineating our experimental project, it is helpful to first survey the challenges and advances associated with the study of the most complicated of the two phenomena: conscious processing.
Despite these limitations, we believe that these experiments reveal that the subjective effects associated with WM-based control (including memoranda-related imagery) are systematic, measurable, and arise from processing in a principled fashion. We hope that these initial data and novel paradigms will serve as a foundation for further explorations on the liaison between WM and consciousness, an under-explored nexus whose investigation is likely to reveal many insights about WM, action control, consciousness, and executive processing.
