The role of conjunctive representations in cognitive control, learning, and aging - Project Summary/Abstract Goal-directed thinking and acting relies on a cognitive system that maintains stable thoughts and action plans in the face of interference but can also flexibly change course when necessary. These opposing qualities are attributed to cognitive control functions, and combined, are key to almost every complex, human behavior. Further, greater distractibility and/or loss of cognitive flexibility are key manifestations of a wide range of mental health and neurological disorders. Specific aspects of cognitive control, such to utilize control in a proactive manner, are also negatively affected through aging. There is thus, a fundamental need to understand how both stability and flexibility can be achieved in a context-adequate manner, or how these aspects relate to life-span changes in cognitive functioning. Both human-level, cognitive theories and recent evidence from animal models point to the importance of conjunctive representations for successful thinking and acting. Conjunctive representations integrate the various aspects of an action episode (rules, stimulus, or response features) in a manner that is “more than the sum of its parts”. This in turn, makes these representations resistant to interfering information, but also more difficult to change or use across different contexts. At the same time, a reliance on basic-level representations, should allow for greater flexibility and generalization, at the cost of susceptibility to interference. Therefore, the balance between conjunctive and basic-level representations and the ability to shift this balance in a context- adequate manner should be key to successful cognitive control and provide a mechanistic explanation for age or individual differences in mental functioning. The project uses novel methods based on electroencephalographic (EEG) recordings from the human scalp to track the cognitive system’s reliance on either basic-level or conjunctive representations with high temporal resolution. These analytic techniques allow examining how the balance between the different levels of representations responds to the control context, such as the degree of conflict or the demands on flexibility. Further, these methods can link the strength of conjunctive versus basic-level representations to key behavioral outcomes (e.g., performance efficiency, flexibility, or learning). This in turn, provides the basis for testing theoretical predictions about how aging-related changes in proactive control affect the representational balance, with potentially important consequences for higher-level cognitive functions. The proposed research represents a strong synthesis of psychology and neuroscience approaches to provide new answers to fundamental questions about how cognitive control is achieved and why it differs across the life span or across individuals.
