The role of learned irrelevance in attentional set-shifting impairments in Parkinson's disease.

Abstract

In this study, the cognitive and neurochemical factors underlying learned irrelevance, one of the mechanisms thought to be responsible for attentional set-shifting deficits in Parkinson's disease (PD), were investigated. In a visual discrimination learning task, the extent to which a target dimension was irrelevant prior to an extra-dimensional shift was varied. Twenty patients with PD and 22 healthy participants performed the task twice, with patients tested on and off L-dopa. The patients made more errors than control participants in the condition in which the target dimension was completely irrelevant prior to the extradimensional shift, but not when it was partially reinforced. Moreover, L-dopa had no effect on the patients' task performance, despite improving their working memory. These results confirm that learned irrelevance is a significant factor in accounting for attentional set-shifting deficits in patients with PD, although unlike other executive impairments in this group, the phenomenon appears to be unrelated to their central dopaminergic deficit.

Distinct Hippocampal and Basal Ganglia Contributions to Probabilistic Learning and Reversal

“…Parkinson subjects are impaired at shifting attention from one stimulus to another (Slabosz et al, 2006;Lewis, Slabosz, Robbins, Barker, & Owen, 2005;Cools et al, 2001;Owen, Beksinska, et al, 1993;Owen, Roberts, et al, 1993). Here, we found that Parkinson subjects respond to the reversal by shifting to a new stimulus more so than healthy controls.…”

“…Although this finding on the surface may appear to be contradictory, there are several important differences between the cognitive demands in the present task compared with prior studies that explicitly examined attentional shift. Prior studies focused on the ability to shift to a previously irrelevant stimulus, an ability impaired in Parkinson subjects (Slabosz et al, 2006;Lewis et al, 2005;Cools et al, 2001;Owen, Beksinska, et al, 1993;Owen, Roberts, et al, 1993). By contrast, in the present study, all stimuli are equally relevant during acquisition and during reversal.…”

NAS-50 and NAS-40: New scales for the assessment of self-control

“…Dysfunctions of task switching cause perseveration, i.e., persistent carrying out of activities which previously were proper, but are currently inadequate because of significant changes of circumstances. A manifestation of rigidity, complementary to perseveration, is learned irrelevance (see, e.g., Słabosz et al, 2006), consisting in the lack of ability to reuse a rule that previously turned out to be useless, but now again requires applying. Perseveration and learned inadequacy can be observed in intensified form in patients with disorders of control functions (e.g., Sandson & Albert, 1984), although in lesser intensity they can also be seen in healthy and able individuals.…”

Self-Control Scale AS-36: Construction and validation study

“…Dysfunctions of task switching cause perseveration, i.e., persistent carrying out of activities which previously were proper, but are currently inadequate because of a significant change of circumstances. A manifestation of rigidity, complementary to perseveration, is learned irrelevance (see, e.g., Słabosz et al, 2006), consisting in the inability to reuse a rule which previously turned out to be useless, but now again requires applying. Perseveration and learned irrelevance can be observed in intensified form in patients with disorders of control functions (e.g., Sandson & Albert, 1984), although in lesser intensity they can also be seen in healthy and able individuals.…”