Switching between certainty and uncertainty: General and age-related dynamics of seeking environmental support

Older adults tend to rely on environmental information more than necessary (Lindenberger & Mayr, 2014). Yet, little is known about how our cognitive system calibrates between internal and external representations, or what drives the age differences. These may reflect either a strategic bias or a difficulty distinguishing contexts in which environmental signals are useful from those in which they are not. We introduced a new Certainty/Uncertainty Switching Paradigm, in which participants were free to consult sudden-onset peripheral cues indicating which of two S-R rules was valid on a given trial. In maximum-certainty trials, S-R rules were fully predictable, rendering cues unnecessary; in maximum-uncertainty trials, S-R rules changed randomly (p = .5), requiring cue inspection. Across two experiments, young adults showed adaptive cue-checking with both short- and longer term adjustments, as well as modulation by trial-level uncertainty (i.e., conflict and errors), but not by broader task control demands. In Experiment 2, older adults exhibited slower adaptation, reduced sensitivity to trial-to-trial uncertainty, and weaker differentiation between certainty and uncertainty contexts. Beyond identifying uncertainty as a key driver of the internal-external control balance, our findings indicate that age-related increases in environmental reliance reflect a deficit in context differentiation, not a strategic bias. (PsycInfo Database Record (c) 2026 APA, all rights reserved).