Domain general processes moderate age-related performance differences on the mnemonic similarity task

ABSTRACT

Several prominent domain general theories (e.g., processing speed and inhibitory function) have been developed to explain cognitive changes associated with aging. A bias to “pattern complete” in aging has also been suggested to account for some of the age-related changes in episodic memory. The current experiments test whether domain-general processes of cognitive aging moderate age-related performance decrements on the mnemonic similarity task, a task thought to rely on hippocampal pattern separation and completion. The study phase of the mnemonic similarity task, a memory task with old, new, and similar trials at recognition, was manipulated to assess the contribution of processing speed (Experiment 1 – different encoding times) and inhibitory function (Experiment 2 – item-level directed forgetting) to age-related performance differences in a sample of 100 healthy younger and older adults. Both experiments exhibited significant interactions between age group and encoding manipulation, replicating a decrement in performance in older adults, and indicating that processing speed and inhibitory function moderate this effect. Results suggest that age-related differences in performance on the mnemonic similarity task can at least partially be accounted for by experimental manipulations of domain general processes that also decline with age.

KEYWORDS:

• Mnemonic similarity task
• memory
• processing speed
• inhibition

Acknowledgements

We thank Megan Wright, Kalin Williams, and Trevor McPherson for their assistance with data collection. We are also grateful for the Chase-Dashiell-Crane Dissertation Start-Up Award for funding.

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Chris M. Foster http://orcid.org/0000-0001-5049-6049