Inhibitory Control and Source Monitoring: A Developmental Investigation into Memory for Recently Witnessed Events

Research has demonstrated that younger children experience difficulty monitoring the source of information and, accordingly, have disproportionately more difficulty accurately recalling details of witnessed events. Within age variability in memory performance, however, suggests that chronological age may not be the only nor the best predictor of source monitoring ability. The present study examined whether inhibitory control (IC) better accounts for variations in the ability to monitor the source of retrieved information than chronological age. Ninety-five children aged 4 to 10 years engaged in a source monitoring task designed to evaluate their ability to accurately identify what information they had witnessed the prior week. Participants further completed measures of IC and other cognitive tasks (receptive vocabulary, memory span, verbal fluency). Exploratory factor analyses revealed three distinct types of IC processes (distractor interference, resistance to PI, prepotent inhibition), indicating that the IC measures administered did not all tap the same unified construct. Participants across ages and IC ability successfully identified witnessed events, and experienced difficulty rejecting the items they previously confabulated. Multiple regression analyses further indicated that IC predicted substantial variance in the ability to reject events that were not witnessed or discussed, while age and the cognitive variables only added a small non-statistically- significant amount of variance above this. IC further predicted variance in the ability to reject events that were not witnessed or discussed once controlling for age and the cognitive variables. The current findings provide evidence suggesting that: 1) measures of IC should not be assumed to assess the same underlying processes; and 2) distractor interference and prepotent inhibition abilities specifically contribute to the ability to reject information that was not witnessed or discussed during source monitoring tasks. This provides further evidence that the development of IC is an important aspect of source monitoring ability in children.