Research

The balance of external and internal attention

In daily life, people often have to switch attention between external and internal sources of information. For example, when grocery shopping, you might direct your attention (externally) toward scanning the shelves for the product you are looking for, after which you need to switch your attention (internally) to the next item of your memorized grocery list (Verschooren, Schindler, et al., 2019). In my PhD research, I have found that switching attention between these two sources is asymmetrical, in the sense that there is a larger cost for switching to internal than to external attention (Verschooren, Liefooghe, et al., 2019). In a series of experiments, we then compared different theoretical explanations and found that an internal shielding benefit best explains this cost asymmetry (Verschooren, Pourtois, & Egner, 2020). In my later theoretical work, I have linked this internal shielding benefit to a wide range of literatures speaking to the balancing of external versus internal attention, including research on working memory, attention switching, visual search, mind wandering, sustained attention, mental effort, and meditation (Verschooren & Egner, 2023). I argue that major findings in these disparate research lines can be coherently understood under this principle, which I termed the Internal Dominance over External Attention (IDEA) hypothesis. This research has been funded by personal grants from FWO and BAEF.

The next step in this research line is to investigate this balance of external and internal attention when taking mind wandering and external distraction into account. People often choose to distract themselves, either externally (e.g., looking at their phone) or internally (e.g., thinking about weekend plans). It is currently not clear how, when, or why people (choose to) become distracted, but this is a pressing issue, as distraction is omnipresent in our society, obstructing our capacity to focus both on personal goals and the many challenges humanity faces. To advance our understanding on how distraction occurs, I propose to capture the different research fields on attention in a single space defined by the dimensions “direction” (external vs. internal) and “locus” (on-task vs. distracted), distinguishing four attentional states (i.e., On-Task-External, On-Task-Internal, External Distraction, and Mind Wandering). I will map the dynamical transitions between these states and develop manipulations to causally influence the amount of time people spend in each of them. Inspired by recent empirical work on attention switching and neurobiological models of mind wandering, I hypothesize (i) the existence of an Off-Focus state through which these dynamical transitions occur, (ii) that internal bias and goal value determine which areas are visited most, and (iii) that contextual manipulations can alter the relative times spent in each area. I have been awarded a Marie Skłodowska-Curie Action grant to carry out this research at the Arctic University of Tromso (starting summer of 2025).

Voluntary control over the internal body

When it comes to body movements in space (i.e., “exteroaction”), people can easily learn fine-grained voluntary control, for example when manipulating tiny objects. Ideomotor theory states that people control these movements by anticipating – or attempting to bring about – their sensory consequences (e.g., visual feedback of an arm movement). Compared to somatomotor actions, voluntarily controlling visceromotor actions inside the body (“interoactions”), such as decreasing heart rate or increaing skin temperature, is much more difficult and requires dedicated training (e.g., practicing yoga or mediation). It is currently not clear how such control is acquired or why it is more difficult. To address this question, I proposed the ideomotor hypothesis of voluntary interoaction (Verschooren, Gaebler, & Brass, 2023), which asserts that voluntary control of extero- and interoactions are governed by the same general principle, namely the anticipation of sensory feedback. This hypothesis explains why learning to control visceromotor responses is more difficult, as its feedback (i.e., interoceptive signals from the internal body) is of lower sensory quality than the afferent signal we receive from exteroaction (i.e., exteroceptive signals from the environment). I will test this hypothesis using autogenic and biofeedback training, which are two techniques aimed at acquiring voluntary control over visceromotor responses. While autogenic training uses the natural interoceptive consequences, biofeedback training objectively maps the interoceptive signal onto an exteroceptive stimulus. This research is being funded by a personal grant from the Humboldt Foundation