Clinical Manifestations

This study aimed to evaluate the impact of image-based unimodal cognitive training (CT) on cognitive function in Aβ+ and Aβ- MCI patients compared to healthy controls (HC).

Fifty-five older adults participated: 19 Aβ+ MCI, 16 Aβ- MCI, and 8 HC. All underwent neuropsychological assessment before and after CT. The assessment included a Memory Complaints and Strategy Use Questionnaire, which evaluated subjective memory difficulties and the spontaneous use of mnemonic strategies before and after training; performance in a memory task (Generalization Tasks) with and without images (Baseline, Post-Training, and 9-month Follow-up); Logical Memory (LM 1 - Immediate Recall, LM 2 - Delayed Recall); Rey Auditory Verbal Learning Test (RAVLT A1-A5 - Immediate Recall, RAVLT A7 - Delayed Recall). Statistical analyses included ANOVA or Kruskal-Wallis, depending on normality (Shapiro-Wilk) and homogeneity of variances (Levene). For group comparisons, Dunn's post hoc test was applied following Kruskal-Wallis, while Tukey's test was used for ANOVA.

Memory Complaints: Before training, 94.74% of Aβ+ and 85% of Aβ- reported memory complaints, compared to 6.5% in HC. After training, complaints reduced to 15%, 20%, and 0%, respectively. Use of Strategies: Initially, only 5.26% of Aβ+ and 10% of Aβ- used memory strategies, compared to 31.25% in HC. After training, strategy use increased in the MCI groups. Memory Performance: Immediate Recall (LM 1 and RAVLT A1-A5): Pre-training, HC performed significantly better than Aβ+ (p < 0.05). After training, all three groups improved, reducing the gap between Aβ+ and Aβ- in relation to HC; Delayed Recall (LM 2 and RAVLT A7): HC performed significantly better than Aβ+ and Aβ- (p < 0.01 pre and post-training). Both MCI groups improved, but differences remained; and Generalization Tasks: At baseline, HC had significantly better scores (p < 0.0061). Post-training, HC continued to outperform Aβ+ and Aβ- (p < 0.01).

CT improved memory, strategy use, and generalization in the Aβ+, Aβ-, and HC groups. Regarding immediate and delayed memory, statistical analysis showed that all groups improved post-training, with the Aβ- group benefiting the most.