Process dissociation using a guided procedure

Cardiovascular risk factors are associated with cognitive trajectory in the first year after stroke

Introduction

Stroke often leads to cognitive impairment, but its progression and influencing factors over time remain poorly understood. This study evaluates immediate post-stroke cognitive impacts and investigates the influence of concurrent factors on cognitive evolution over the first year.

Patients and methods

In the STRATEGIC study, 179 patients with first symptomatic ischemic stroke underwent neuropsychological assessments within three months post-stroke, and 141 were re-evaluated at 12 months. Risk factors tested for associations with cognitive outcome included demographic variables, cardiovascular and other medical factors, and lesion characteristics. Cognitive performance was primarily measured via the Montreal Cognitive Assessment (MoCA), with domain-specific assessments for episodic memory (Free and Cued Selective Reminding Task), short-term memory (Digit Span forward), and working memory (Digit Span backward).

Results

At the time of stroke, participants ranged in age from 46 to 89 years (M = 70, SD = 9.5) and 36.9% were female. Ischemic heart disease predicted cognitive non-improvement between 3 and 12 months. Atrial fibrillation and carotid stenosis were linked to changes in episodic and working memory, respectively. Moreover, female sex and lower education correlated with stagnant global cognition and episodic memory.

Discussion and conclusion

Our findings underscore the important influence of cardiovascular risk factors on cognitive functional recovery after stroke. Interventions targeting these risk factors may improve cognitive prognosis and affect traditional outcome measures such as recurrent vascular events. Future trials should include cognitive measures to fully capture the potential benefits of intensive risk factor intervention.

Controlled recall of verbal material in temporal lobe epilepsy

This study used a guided process-dissociation procedure to examine the contribution of controlled and automatic uses of memory to a cued-recall task in 24 patients with unilateral temporal lobe epilepsy (TLE: 12 left-sided; 12 right-sided), and 12 neurotypical controls. In an inclusion task, participants attempted to complete three-letter word stems using previously studied words, in an exclusion task they aimed to avoid using studied words to complete stems. Patients with left TLE produced fewer target completions under inclusion conditions. Completion rates were not significantly different under exclusion conditions. Estimates derived from process dissociation calculations, confirmed that the cued-recall deficit in left TLE patients arose entirely from impairment in controlled memory processes. There were no group differences in the estimates of automatic processes. Recognition judgements of stems corresponding to studied words did not differ between the groups. Overall the results support the view that controlled and automatic memory processes are mediated by separable neural systems. Hippocampal and related structures within the left MTL are more important than corresponding right hemisphere structures for the controlled retrieval of verbal material. In contrast, the findings from this study do not suggest that the left and right temporal lobes make a differential contribution to automatic memory processing. The theoretical and clinical relevance of these findings are discussed.