Our past studies focused on 1) understanding the breakdown of everyday action performance, including the mechanisms involved in everyday error detection and correction populations with moderate-level cognitive impairment and 2) developing strategies to improve everyday action in these populations (i.e., everyday action interventions).
Goal 1: UNDERSTANDING The Breakdown of Everyday Action
Everyday Action in Dementia Project: Our work supported a new conceptualization of everyday action impairment, called the Omission-Commission Model. In contest to previous models, the Omission-Commission Model conceptualizes two general types of errors when performing everyday tasks. Omission errors (i.e., failure to complete task steps) are associated with declarative memory deficits (i.e., episodic memory encoding and task knowledge) and the volume of the medial temporal lobe and hippocampus. By contrast, commission errors (i.e., performing task steps inaccurately; e.g., incorrect sequence or with wrong objects, etc.) are associated with executive functioning and the integrity of the deep white matter in the brain. Our work has shown that people with different dementia syndromes, which are associated with different cognitive profiles, show different patterns of errors when performing everyday tasks.
Everyday Action Measurement Project: Our laboratory has relied heavily on the Naturalistic Action Test (NAT), a performance-based test of everyday action with an elaborate error coding taxonomy to characterize performance. We have developed variants of the NAT items and elaborated the error coding methods to test specific hypotheses and to evaluate error detection and everyday task knowledge.
Everyday Action in Schizophrenia Project: We characterized everyday action errors and error detection in people diagnosed with chronic schizophrenia and found the large majority of errors were commissions. People with schizophrenia were typically capable of completing everyday task goals (i.e., few omissions) but were highly disorganized, repetitive and inefficient when doing so. Everyday action impairment in people with schizophrenia is best explained by executive dysfunction.
Goal 2: EVERYDAY Action INTERVENTION
Task Training: While a graduate student in the Temple Cognitive Neuropsychology Laboratory, Dr. Brianne Bettcher developed and tested a method for enhancing knowledge of everyday tasks in people with dementia, called “Task Training.” Task Training was designed to be delivered immediately preceding task performance and targeted problems with everyday error monitoring by boosting task knowledge. Results with the intervention showed significantly lower error rates and significantly higher error detection following a brief Task Training interval. Training stimuli are available here for download:
- General Task Training Instructions
- Task1 (Task1 part1; Task1 part2)
- Task2 (Task2 part1)
- Task3 (Task3 part1; Task3 part2; Task3 part3)
- Script Content Quiz
Personal Object Project: We identified an advantage for personal objects on tasks of semantic knowledge and use in people with Alzheimer’s disease. People with Alzheimer’s disease demonstrated richer semantic associations and more accurate use gestures when presented with their own, personally familiar objects relative to exemplars of the same object provided by the examiner (i.e., their comb vs. a comb provided by the examiner). This effect was observed even when people were not able to reliably distinguish their own personal object from the examiner’s object. This finding suggests that to optimize everyday function in people with dementia we must ensure that they use objects that are highly familiar to them or provide opportunities for object training.
Strategic Object Placement Project: We have demonstrated the placement of objects in the workspace significantly influences everyday action performance in people with dementia and people with schizophrenia. Most people benefit greatly from the strategic placement of objects in the workspace (i.e., placing objects in the order in which they should be used in a task and removing distractor objects from view).
The Effect of Goal Cues on Everyday Action in Dementia: Goal cues may be used to remind people of a task goal to prevent decay of task schema and keep individuals on track. We have shown that reminders about task goals greatly reduces the number of omission errors but does little to change the number of commission errors. In fact, goal cues were only effective at significantly improving performance for individuals with a large number of omission errors. This finding underscores the importance of careful characterization of everyday action impairment and indicates that in order to maximize the benefit of behavioral interventions, we must match intervention strategies to peoples’ specific functional deficit profiles.