While the knowledge on age-related differences in susceptibility to episodic false
memories is extensive, little is known about this phenomenon in visual short-term
memory (STM). Our previous behavioural research indicated that older adults are more
confident of their erroneous STM recognitions than young adults. However, unlike in
episodic memory, we did not find support for older adults' higher rate of false alarms.
To further understand this specific age-difference, here we investigated its neural
correlates. First, the pattern of behavioural results replicated the one from our
previous experiment. Second, younger adults, when compared to older adults, exhibited
higher false recognition-related activity of the visual cortex, the anterior cingulate
cortex, the frontal operculum/insular cortex as well as regions within the anterior
and dorsolateral prefrontal cortex. No agedifferences were observed in hippocampal
activity. Third, younger but not older adults presented higher activity in the anterior
cingulate cortex and the frontal operculum/insular cortex for false recognitions when
compared to highly confident correct rejections. Finally, frontal activity was influenced
by both the individuals' performance and their metacognitive abilities. The results
suggest that age-related differences in confidence of STM false recognitions may arise
from age-differences in performance monitoring and uncertainty processing rather than
in hippocampal-mediated binding.
