Effects of musical mnemonics on working memory performance in cognitively unimpaired older adults and persons with amnestic mild cognitive impairment.

Episodic memory (EM) and working memory (WM) are negatively affected by healthy ageing, and additional memory impairment typically occurs in clinical ageing-related conditions such as amnestic mild cognitive impairment (aMCI). Recent studies on musical mnemonics in Alzheimer's dementia (AD) showed promising results on EM performance. However, the effects of musical mnemonics on WM performance have not yet been studied in (a)MCI or AD. Particularly in (a)MCI the use of musical mnemonics may benefit the optimisation of (working) memory performance. Therefore, in the present study, we examined the effects of musical presentation of digits consisting of pre-recorded rhythms, sung unfamiliar pitch sequences, and their combinations, as compared to spoken presentation. Furthermore, musical expertise was assessed with two perceptual tests and the Self-Report Inventory of the Goldsmiths Musical Sophistication Index. Thirty-two persons with aMCI and 32 cognitively unimpaired older adults (OA) participated in this study. Confirming and extending previous findings in research on ageing, our results show a facilitating effect of rhythm in both cognitively unimpaired OA and persons with aMCI (p = .001, ηp 2 = .158). Furthermore, pitch (p = .048, ηp 2 = .062) and melody (p = .012, ηp 2 = .098) negatively affected performance in both groups. Musical expertise increased this beneficial effect of musical mnemonics (p = .021, ηp 2 = .090). Implications for the future design of music-based memorisation strategies in (a)MCI are discussed.

Associative working memory and subsequent episodic memory in Alzheimer's disease.

Recent studies indicate deficits in associative working memory in patients with medial-temporal lobe amnesia. However, it is unclear whether these deficits reflect working memory processing or are due to hippocampally mediated long-term memory impairment. We investigated associative working memory in relation to subsequent episodic memory formation in patients with early Alzheimer's disease to examine whether these findings reflect deficits in long-term encoding rather than 'pure' working memory processing. Nineteen patients with Alzheimer's disease and 21 controls performed a working memory task in which objects had to be searched at different locations. The subsequent episodic memory test required participants to reposition objects to their original locations. Patients with Alzheimer's disease were impaired on associative working memory and subsequent episodic memory, but they performed above chance at high-load episodic memory trials. This suggests that when working memory capacity is exceeded, long-term memory compensates.

Learning by observation and guidance in patients with Alzheimer's dementia.

How people suffering from dementia can be taught new motor skills for everyday household activities is an important but relatively unexplored area of research. Previous studies have demonstrated intact implicit learning abilities in patients with Alzheimer dementia (AD) on computerized motor-learning tasks and everyday activities, but explicit training strategies have been found to be beneficial in AD as well. The aim of the present study was to compare two explicit training methods, i.e. observational learning and learning by guidance, and an implicit training method in patients with AD and healthy controls. All three types of training methods resulted in statistically significant learning. However, while improvement from baseline was similar in both groups, the absolute performance of the patients in the explicit training methods was well below that of the controls. The modest success of the explicit training methods and the slightly better results achieved with the observation method should be investigated further in studies of the acquisition of everyday activities.

Spatial and nonspatial implicit motor learning in Korsakoff's amnesia: evidence for selective deficits.

Patients with amnesia have deficits in declarative memory but intact memory for motor and perceptual skills, which suggests that explicit memory and implicit memory are distinct. However, the evidence that implicit motor learning is intact in amnesic patients is contradictory. This study investigated implicit sequence learning in amnesic patients with Korsakoff's syndrome (N = 20) and matched controls (N = 14), using the classical Serial Reaction Time Task and a newly developed Pattern Learning Task in which the planning and execution of the responses are more spatially demanding. Results showed that implicit motor learning occurred in both groups of participants; however, on the Pattern Learning Task, the percentage of errors did not increase in the Korsakoff group in the random test phase, which is indicative of less implicit learning. Thus, our findings show that the performance of patients with Korsakoff's syndrome is compromised on an implicit learning task with a strong spatial response component.

Motor-skill learning in Alzheimer's disease: a review with an eye to the clinical practice.

Since elderly people suffering from dementia want to go on living independently for as long as possible, they need to be able to maintain familiar and learn new practical skills. Although explicit or declarative learning methods are mostly used to train new skills, it is hypothesized that implicit or procedural techniques may be more effective in this population. The present review discusses 23 experimental studies on implicit motor-skill learning in patients with Alzheimer's disease (AD). All studies found intact implicit motor-learning capacities. Subsequently, it is elaborated how these intact learning abilities can be exploited in the patients' rehabilitation with respect to the variables 'practice' and 'feedback.' Recommendations for future research are provided, and it is concluded that if training programs are adjusted to specific needs and abilities, older people with AD are well able to (re)learn practical motor skills, which may enhance their autonomy.