Older Adults Encode Task-Irrelevant Stimuli, but Can This Side-Effect be Useful to Them?

Abstract

We studied whether, due to deteriorating inhibitory functions, older people are more likely to process irrelevant stimuli; and if so, could they later use this information better than young adults. In the study phase of our experiment, a Posner-type gaze-cued version of a Simon task was performed in which we presented task-irrelevant cues, where faces or patches with either left- or right-looking dots for the pupil of the eye preceded the task to press a button congruent or incongruent with the presentation side of the target stimulus. In the follow-up test phase, participants completed an unexpected facial recognition test. In the study phase not only a decreased P1, but also an increased N170 amplitude of the event-related potentials (ERPs) were found in older, compared to younger adults, and also for faces compared to patches. Even though in the test phase both age-groups could recognize the faces better than statistically by chance, neither the older nor the younger participants could discriminate them effectively. The late positive component (LPC)—the ERP correlates of the old/new effect, being the higher amplitude for the earlier presented stimuli when compared with the unseen stimuli during the recognition test—was not evolved in the older group, while a reversed old/new effect was seen in younger participants: higher amplitude was found in New-Right and Old-Wrong conditions (for faces they did not recognize independent of seeing them before) compared to Old-Right and New-Wrong conditions (for faces they thought they recognized from the study phase). In conclusion, although older adults showed enhanced processing of task-irrelevant stimuli compared to younger adults, as indicated by the N170 amplitude, however, they were not able to utilize this information in a later task, as was suggested by the recognition rate and LPC amplitude results.

Predictability-Based Source Segregation and Sensory Deviance Detection in Auditory Aging

“…It may be the case that their negativity in the MMN latency range is counter-intuitively larger than those of many others because they fail to ignore the sound stream. This would be consistent with findings from cognitive aging in a wider sense, showing that the ability to inhibit task-irrelevant stimuli decreases with age across modalities and task types (e.g., Weeks and Hasher, 2018;Gaál et al, 2020). Interindividual differences in the ability to ignore task-irrelevant information ("resist interference") would be one explanation why no consistent relation between MMN amplitude and benefit was found at group level.…”

Mechanisms of spatial contextual cueing in younger and older adults

“…According to that assumption, N2pc to repeated configurations increases as a result of participants being better at using contextual information either to suppress irrelevant information (Luck & Hillyard, 1994) or to enhance processing of the target (Eimer, 1996). Because inhibiting irrelevant stimuli is more challenging for older adults (Gaál et al, 2020;Kojouharova et al, 2020), our results could be interpreted as attentional selection contributing to the contextual cueing effect in younger but not in older adults. Nevertheless, there is some indication that an additional attentional process might be taking place in the older group.…”

“…It is a central issue in cognitive aging that older adults generally have difficulties with inhibiting irrelevant stimuli and therefore show poorer performance (Gaál et al, 2020). The contextual cueing effect is a form of implicit learning which improved performance for repeated configurations in this paradigm, and the increased N2 amplitude suggests that repeated spatial context may improve the inhibition of irrelevant stimuli and consequently, performance.…”

“…Besides our main aim of determining whether early or late processes contribute to the contextual cueing effect in different age groups, some additional tentative predictions could be made regarding the two accounts for N2pc. For older adults, inhibiting visual distractors is more difficult compared with younger adults (Gaál et al, 2020; Kojouharova et al, 2020). Because of that, in the spatial contextual cueing paradigm, they may process more information about the spatial configurations, and then use this additional information to improve performance on the task for the repeated configurations resulting in a larger contextual cueing effect.…”

Age-related differences in working memory subprocesses decomposed by the reference-back paradigm

“…Firstly, the involvement of frontal areas suggests that gate closing may be an active process, consistent with Nir-Cohen et al's [7] conception. Secondly, a common issue among older adults is their decreased ability to protect the contents of their working memory; so, they are very sensitive to the interference of task-irrelevant stimuli [e.g., 61,62]. We might assume that this phenomenon is connected to the gate closing process as irrelevant information can intrude if the gate closing is not effective enough.…”