Item-specific adaptation and the conflict-monitoring hypothesis: A computational model.

Abstract

M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, and J. D. Cohen (2001) implemented their conflict-monitoring hypothesis of cognitive control in a series of computational models. The authors of the current article first demonstrate that M. M. Botvinick et al.'s (2001) conflict-monitoring Stroop model fails to simulate L. L. Jacoby, D. S. Lindsay, and S. Hessels's (2003) report of an item-specific proportion-congruent (ISPC) effect in the Stroop task. The authors then implement a variant of M. M. Botvinick et al.'s model based on the assumption that control must be able to operate at the item level. This model successfully simulates the ISPC effect. In addition, the model provides an alternative to M. M. Botvinick et al.'s explanation of the list-level proportion-congruent effect in terms of an ISPC effect. Implications of the present modeling effort are discussed.

The Parallel Episodic Processing (PEP) model: Dissociating contingency and conflict adaptation in the item-specific proportion congruent paradigm

“…First, memory encoding and retrieval processes are sufficient to produce an ISPC effect. Like conflict monitoring models (e.g., Blais et al, 2007;Verguts & Notebaert, 2008), the PEP successfully simulated the ISPC effect in both cycle times and error percentages. Thus, conflict monitoring and adaptation do not need to be assumed to simulate the ISPC effect.…”

“…Of course, sufficiency does not prove that contingencies are the whole story. Conflict monitoring models can also produce the ISPC effect (Blais et al, 2007;Verguts & Notebaert, 2008) and the current simulation does not preclude the possibility that both contingency and conflict monitoring biases are present in the task. Experiment 1, however, has more to say on that point.…”

“…If participants are detecting how much conflict they encounter in the task, then it is not clear how they would be able to adapt to conflict differently for high versus low PC items, which are intermixed in the task. Although claims have been forwarded that participants can learn the conflict associated with individual items and rapidly adjust attention accordingly (e.g., Blais, Robidoux, Risko, & Besner, 2007;Verguts & Notebaert, 2008), there is another potential explanation that does not rely on conflict adaptation at all.…”

Trial-by-trial adjustments in control triggered by incidentally encoded semantic cues

“…Traditional accounts focus on rule-based topdown components of control, while recent accounts suggest that control can be rapid, effortless, and implicit (Blais et al, 2007;Botvinick et al, 2001;Jacoby et al, 2003;Verguts & Notebaert, 2008) and focus on more bottom-up components of control (e.g., slowing down after an incongruent trial; see De Pisapia & Braver, 2006, for a computational model of this principle).…”

“…Computational models of these effects (e.g., Blais, Robidoux, Risko, & Besner, 2007;Verguts & Notebaert, 2008) rely on a conflict-mediated association mechanism. Response conflict is used to mediate the strength of connection weights between any active features by increasing the strength for relevant features and decreasing it for features that are detrimental to performance (such as an irrelevant dimension).…”