The Role of Verbalization in Hierarchical Control

Presenter: Emily Stutz – Psychology

Faculty Mentor(s): Melissa Moss, Ulrich Mayr

Session: (In-Person) Poster Presentation

 Performing complex tasks usually requires the cognitive system to handle rules at multiple levels of abstraction, where lower-level rules depend on the status of higher-level rules (e.g., a child may be allowed to eat with her fingers at home, but use silverware in a restaurant). Previous work has identified verbalization (“inner speech”) as critical for such hierarchical control in the context of situations that require following a sequential plan. However, this work did not assess the need for inner speech in the context of non-serial, or cue-based tasks. Further, only relatively simple, two-level hierarchical control sequences were used. The current study used articulatory suppression to assess whether verbalization is important when handling complex serial-order and cue-based hierarchical tasks. Participants executed tasks with one, two, or three levels of either cue-based rule complexity or sequence complexity, while performing a secondary task that manipulated verbalization demands (articulatory suppression versus foot-tapping). Surprisingly and contrary to previous findings, we did not find a decrease in performance in either the cue-based or the sequential tasks with articulatory suppression. These results seem to indicate that hierarchical control does not require inner speech. Potential reasons for the discrepancy with the previous literature results are discussed.

The Role of Abstract Chunk Patterns in the Organization of Complex Sequences

Presenter(s): Min Zhang

Faculty Mentor(s): Ulrich Mayr & Melissa Moss

Poster 111

 Session: Social Sciences & Humanities

In order to execute complex sequences, such as playing a piece of music, people group sequential elements (e.g., individual notes) into “chunks”. The dominant theory assumes that chunks are merely independent bundles of elements (Lashley, 1951), though little is known about the organization of chunked information. Applying the efficient coding principle, chunks may be coded in a relational manner, based on structural similarities, to allow people to smoothly execute complex tasks (Botvinick et al., 2015). In two experiments, we assessed how performance is affected by whether chunks contain similar, abstract patterns of elements (“matching” chunks, e.g., ABA pattern of elements in both chunks). Participants completed a task in which they needed to remember and execute sequences of rules. The rule sequences contained two 3-element chunks with various patterns of rule elements. Some sequences contained matching chunks, while others contained non-matching chunks. In Experiment 1, participants executed sequences in which both chunks contained the same types of rules arranged in matching or non-matching patterns. In Experiment 2, the two chunks contained different sets of rules, thus requiring a greater degree of abstraction across chunks. Results showed better performance for sequences containing matching chunks. The effect of pattern similarity on sequential performance was much weaker in Experiment 2 than in Experiment 1. Generally, these findings indicate that our cognitive system makes use of abstract patterns to efficiently code sequential information.

Is Inhibition Dependent on Working Memory Capacity?

Presenter(s): Jena Kunimune

Faculty Mentor(s): Ulrich Mayr & Melissa Moss

Poster 93

Session: Social Sciences & Humanities

The ability to stop initiated actions is a critical component of effective self-regulation, such as resisting the urge for ‘sex, drugs, and rock and roll.’ The current dominant theory in cognitive control assumes that maintaining task-relevant information in working memory is necessary for the effective implementation of inhibitory control. In this study, we addressed the interplay of inhibitory control and working memory maintenance processes using a dual-task paradigm in which both inhibitory control demands and working memory load were manipulated. Because the standard theory predicts mutual interference between the two processes, we hypothesized that if inhibition interferes with working memory maintenance, working memory performance will be lower when participants successfully employ inhibitory control in response to a stop signal, versus when they fail to inhibit their action. Further, this interference in performance should be greatest when working memory load is high. Participants completed a combined working memory and stopping task in which stopping behavior occurred during the working memory maintenance interval. Our results showed no evidence of mutual interference between working memory load and stopping behavior on working memory performance. This result is inconsistent with the dominant view of working memory capacity as the primary constraining factor in inhibitory control. Rather, distinct processing resources may underlie these two different aspects of self-regulation.