Is a Perseveration a Perseveration? An Evaluation of Cognitive Error Types in Patients with Subcortical Pathology

Abstract

This study investigated several constructs of executive functioning in a group of 77 patients with subcortical pathology. Specifically, we examined the validity of categorizing perseverative errors as “recurrent,” “stuck-in-set,” or “continuous,” as proposed by Sandson and Albert (1984). A principal components analysis of 2 measures of recurrent perseveration, 2 measures of stuck-in-set perseveration, and 2 measures of intrusive errors yielded a 2 component solution with stuck-in-set perseverations and intrusive errors loading on Component 1, and recurrent perseverations loading on Component 2. Presence of a continuous perseveration on a graphomotor test was significantly associated with higher factor scores on Component 1, but not Component 2. The stuck-in-set perseveration and intrusion component was associated with the majority of the other neuropsychological tests administered, including tests of executive function and memory. The recurrent perseveration component was not associated with the other measures of cognitive functioning. Presence of a continuous perseveration was associated with executive function but not memory measures. This study provides evidence that recurrent perseverations are distinct from the other types of perseverative and intrusive errors, and that stuck-in-set and intrusive errors are good indicators of general cognitive functioning in patients with subcortical pathology.

This research was supported in part by National Institute of Neurological Disorders and Stroke Grant R01 41372 to J.V.F.

Notes

This research was supported in part by National Institute of Neurological Disorders and Stroke Grant R01 41372 to J.V.F.

We also examined stuck-in-set perseverations on the Letter and Category Fluency tests and found that only 13 participants committed these types of errors. Because of this low occurrence, stuck-in-set errors from the fluency tests were not included in the analyses described below.

Continuous perseverations were also examined on the CVLT, Letter Fluency, and Category Fluency tests and were found to occur in only 7 participants. This low number did not allow us to include these errors from these tests in the analyses described below.

Principal components extraction with direct oblimin rotation was also performed to determine if the solution would change if the components were allowed to correlate. The measures loading on each component did not change from those determined by varimax rotation and the correlation between the components was negligible at -.05, so varimax rotation was chosen.

⁴Clearly, there are many mechanisms other than inhibition that could account for the pattern of correlations observed in this present study. We are simply suggesting that a deficit in inhibition is one possible account of why these error types are related.