Testing the Over-Reliance on Central Attention (ORCA) Hypothesis: Do Older Adults Have Difficulty Automatizing Especially Easy Tasks?

Does aging increase the reliance on central attention to carry out tasks, even when those tasks do not need it? To test the hypothesis of over-reliance on central attention (ORCA), we examined the ability of older adults to entirely bypass ideomotor-compatible (IM) tasks. IM tasks operate automatically for younger adults: The perception of an IM stimulus (e.g., a left-pointing arrow) directly activates the associated response code (e.g., pressing the left key). In a psychological refractory period (PRP) procedure, younger and older adults performed a slow auditory-vocal Task 1 paired with a fast visual-manual Task 2 that was either IM or non-IM. Task-2 compatibility (IM vs. non-IM) was manipulated as a between-subjects factor (Experiment 1) and as a within-subjects factor (Experiment 2). Both experiments yielded the counterintuitive finding of larger age differences in dual-task performance when Task 2 was easy (i.e., IM) than when it was difficult (i.e., non-IM), as evidenced by old/young ratio analyses and Brinley plots. Relatedly, whereas younger adults routinely bypassed the bottleneck with an IM Task 2 (as evidenced by a small PRP effect and a high rate of response reversals), older adults did not. The present findings cannot easily be explained by the hypotheses of generalized cognitive slowing and of specific processing deficits but support the ORCA hypothesis. As cognitive decline sets in, older adults begin to try harder: This extra application of central attention compensates for cognitive decline but can result in applying attention when it is not needed.

Automated summary

The study found that as individuals age, they tend to rely more on central attention to carry out tasks, even when those tasks do not require it. Older adults showed larger age differences in dual-task performance in IM tasks compared to younger adults.