Our ongoing studies address the following specific aims: 1) to understand the breakdown of everyday action performance following brain damage, 2) to understand the mechanisms involved in everyday error detection and correction, and 3) to develop strategies to improve everyday action in individuals with cognitive impairment (i.e., action rehabilitation).
Goal 1: The Breakdown of Everyday Action
Everyday Action in Dementia Project: Our earlier work in dementia included individuals diagnosed with a wide range of dementia syndromes. These studies showed that everyday action error rate was best explained by the degree of global cognitive dysfunction, and specific error patterns were influenced by the environmental context or task demands. For example, patients with severe dementia made more errors than those with mild dementia. However, all patients, regardless of their level of severity, demonstrated a tendency for object selection errors when distractor objects were present and sequence errors when tasks had multiple complex steps. Our more recent work compares everyday action performance across individuals with distinct dementia syndromes/neurocognitive profiles (e.g., Alzheimer’s disease vs. vascular dementia vs. frontotemporal dementia). Distinct performance patterns are emerging among these dementia syndromes.
Action Measurement Project: We are currently developing novel measures to assess error detection and everyday task knowledge.
Everyday Action in Schizophrenia Project: We have been exploring the nature of everyday action errors and error detection in patients diagnosed with schizophrenia. Thus far, we have observed that these individuals show error patterns that are quite distinct from dementia patients. Everyday action impairment in this population may be best explained by executive dysfunction.
Goal 2: Error Detection in Everyday Action
Error Detection in Dementia Project: It is impossible to eliminate all errors in everyday tasks. Error detection/correction is a critical aspect of successful action performance that is often impaired in individuals with dementia. This project examines whether or not individuals with dementia differ in their ability to detect and correct errors. We are currently characterizing patterns of error detection and correction in dementia patients with distinct clinical syndromes and neuroimaging profiles.
Error Detection in Schizophrenia Project: Most theories of error awareness in schizophrenia predict deficient error detection and correct. We plan to examine error detection in everyday tasks to assess this prediction.
Goal 3: Action Rehabilitation
Task Training: Dr. Brianne Bettcher has recently developed and tested a method for enhancing knowledge of everyday tasks in people with dementia. This intervention strategy was specifically developed for improving everyday error monitoring. Results have shown significantly lower error rates and significantly higher error detection following a brief task training interval. Training stimuli are available here for download:
Personal Object Project: We are currently exploring the relation between personal object familiarity and object use in dementia. Researchers have shown that dementia patients with semantic knowledge degradation (i.e., semantic dementia) show an advantage in object naming and use 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). However, the mechanism for this advantage is not well understood. The results of this study will suggest strategies for facilitating naturalistic action independence for patients with dementia.
Strategic Object Placement Project: We have demonstrated the placement of objects in the workspace significantly influences everyday action performance in dementia. We are examining this effect for schizophrenia patients and we are also exploring the patient characteristics that predict the greatest improvement from strategic object placement.
The Effect of Donepezil (Aricept) on Everyday Action in Dementia: We are currently examining whether Aricept has effects on everyday action performance in VaD. Normally, drug efficacy studies examine performance on only paper and pencil cognitive tests or caregiver reports of everyday action. Thus, this study is unique in its inclusion of performance-based naturalistic action as an outcome variable.