When and how did you go wrong? Characterizing mild functional difficulties in older adults during an everyday task

Abstract

Mild functional difficulties associated with cognitive aging may be reliably measured by coding "micro-errors" during everyday tasks, like meal preparation. Micro-errors made by 25 older adult and 48 younger adults were coded on four dimensions to evaluate the influence of: 1) poor error monitoring; 2) goal decay; 3) competition for response selection when switching to a new subtask; and 4) interference from distractor objects. Micro-errors made by young adults under a dual task load also were analyzed to determine the influence of overall performance level. Older adults' micro-errors were observed when switching to a new subtask and to unrelated distractors. Slowed error monitoring and goal decay also influenced micro-errors in older adults, but not significantly more so than younger adults under the dual task. Interventions to reduce interference from distractors and to increase attention at critical choice points during tasks may optimize everyday functioning and preclude decline in older adults.

Keywords: Aging; activities of daily living; cognitive interference; error monitoring; everyday function; object use.

Figure 1:

The hierarchical subtask structure of the Lunch task that was used in the present study. The three major subtasks (e.g., sandwich, drink, snack) are depicted as well as subordinate task steps (e.g., spreading peanut butter on the bread, pouring the beverage in the thermos, etc.). Transitions within subtasks are depicted by solid lines; transitions between subtasks are depicted by dotted lines. Steps within a subtask (pour lemonade then cap thermos) are more strongly associated. By contrast, the last step in a subtask (cap thermos) is not as strongly associated with the next step (take cookies); consequently, greater deliberation is required to select the next step, making between task transitions choice-points that are prone to error.

Figure 2:

Objects used for the Lunch task shown from the point of view of the participant. This set up was used for all older adults and the majority of the younger adults.

Figure 3.

Panel A- Mean ranks of proportions of reach, touch, and extra action micro-errors in older adults and younger adults (Standard Condition). Panel B- Mean ranks of proportions of errors made in the beginning, middle, and ending segment of the task in older adults and younger adults (Standard Condition). Panel C - Mean ranks of proportions of errors made within and between subtasks in older adults and younger adults (Standard Condition). Panel D - Mean ranks of proportions of errors made to target, related, and unrelated distractor objects in older adults and younger adults (Standard Condition). *= p <.05; **p <.01.