Declarative Learning, Priming, and Procedural Learning Performances comparing Individuals with Amnestic Mild Cognitive Impairment, and Cognitively Unimpaired Older Adults

Abstract

Objective: While declarative learning is dependent on the hippocampus, procedural learning and repetition priming can operate independently from the hippocampus, making them potential targets for behavioral interventions that utilize non-declarative memory systems to compensate for the declarative learning deficits associated with hippocampal insult. Few studies have assessed procedural learning and repetition priming in individuals with amnestic mild cognitive impairment (aMCI). Method: This study offers an overview across declarative, conceptual repetition priming, and procedural learning tasks by providing between-group effect sizes and Bayes Factors (BFs) comparing individuals with aMCI and controls. Seventy-six individuals with aMCI and 83 cognitively unimpaired controls were assessed. We hypothesized to see the largest differences between individuals with aMCI and controls on declarative learning, followed by conceptual repetition priming, with the smallest differences on procedural learning. Results: Consistent with our hypotheses, we found large differences between groups with supporting BFs on declarative learning. For conceptual repetition priming, we found a small-to-moderate between-group effect size and a non-conclusive BF somewhat in favor of a difference between groups. We found more variable but overall trivial differences on procedural learning tasks, with inconclusive BFs, in line with expectations. Conclusions: The current results suggest that conceptual repetition priming does not remain intact in individuals with aMCI while procedural learning may remain intact. While additional studies are needed, our results contribute to the evidence-base that suggests that procedural learning may remain spared in aMCI and helps inform behavioral interventions that aim to utilize procedural learning in this population.

Early-Stage Alzheimer's Disease Affects Fast But Not Slow Adaptive Processes in Motor Learning

“…From a clinical perspective, it is commonly thought that patients with declarative memory deficits can learn some motor tasks, such as rotary pursuit, serial reaction time tasks, and mirror-tracking ( Ferraro et al, 1993 ; Willingham et al, 1997 ; Dick et al, 2001 ; Rouleau et al, 2002 ; Hong et al, 2020 ; De Wit et al, 2022 ), because such tasks rely on implicit ways of learning. For example, Shadmehr et al (1998) showed that an amnesic patient (H.M.), due to a resection of the medial–temporal lobe, was still able to adapt his reaches to a perturbing force field but was unaware that he learned the task.…”

“…While patient brains show widespread neurodegeneration, this progressive memory loss is strongly related to bilateral atrophy of the medial temporal lobe, including the entorhinal cortex and the hippocampus proper, as well as atrophy in parietal areas ( Hyman et al, 1984 ; Braak and Braak, 1991 , 1996 ; Van Hoesen et al, 1991 ; Foundas et al, 1997 ). Despite this loss, there is evidence that aspects of learning and memory that rely more on automatic and unconscious processing, referred to as nondeclarative or procedural memory, are relatively intact ( Shadmehr et al, 1998 ; Zanetti et al, 2001 ; van Halteren-van Tilborg et al, 2007 ; Kessels et al, 2011 ; De Wit et al, 2021 , 2022 ).…”

Practice effects in cognitive assessments three years later in non-carriers but not in symptom-free mutation carriers of autosomal-dominant Alzheimer's disease: Exemplifying procedural learning and memory?

“…The distinction of performance in declarative and procedural memory in AD was supported in a large study on MMSE in patients with AD with reduced episodic memory by a PE at retest 4 months later (Gross et al, 2018 ). Recently, it was demonstrated that patients with MCI and cognitively unimpaired adults did not differ in performance of the classical procedural learning task (mirror tracking), while groups differed in typical episodic memory (the RAVL test) (De Wit et al, 2022 ).…”

Behavioral, neurological, and psychiatric frailty of autobiographical memory

“…Priming has been divided into “perceptual priming” and “conceptual priming.” Under “perceptual priming,” the re‐identification of previously perceived items or information is understood, while “conceptual priming” refers to category verification, that is, to the identification of items or information related to the originally perceived one (= belonging to the same category). This division has frequently been used in order to demonstrate that perceptual priming is still possible in individuals with reduced memory abilities, while conceptual priming is impaired, and that patients with mild cognitive impairment profit to a higher degree than nonimpaired individuals from priming effects (De Wit et al, 2022; Rowe et al, 2021; Ward, 2022).…”