Mnemonic Strategy Training Research Articles

Toward rational use of cognitive training in those with mild cognitive impairment.

The term cognitive training includes a range of techniques that hold potential for treating cognitive impairment caused by neurologic injury and disease. Our central premise is that these techniques differ in their mechanisms of action and therefore engage distinct brain regions (or neural networks). We support this premise using data from a single-blind randomized-controlled trial in which patients with mild cognitive impairment were randomized to either mnemonic strategy training (MST) or spaced retrieval training (SRT) as they learned ecologically relevant object-location associations. Both training approaches were highly effective in the short term, but MST demonstrated a clear advantage after days to weeks. MST also increased activation in and functional connectivity between frontal, temporal, and parietal regions as well as the hippocampus. In contrast, patterns of reduced activation and functional connectivity were evident following SRT. These findings support the rational development of cognitive training techniques.

Preserving prospective memory in daily life: A systematic review and meta-analysis of mnemonic strategy, cognitive training, external memory aid, and combination interventions.

To preserve or improve independent functioning in older adults and those with neurocognitive impairments, researchers and clinicians need to address prospective memory deficits. To be effective, prospective memory interventions must restore (or circumvent) the underlying attention and memory mechanisms that are impaired by aging, brain injury, and neurodegeneration. We evaluated two decades of prospective memory interventions for efficacy, time/resource costs, and ecological validity. We systematically reviewed 73 prospective memory intervention studies of middle- to older-aged healthy adults and clinical groups (N = 3,749). We also rated the ecological validity of each study's prospective memory assessment/task using a newly developed scale. When possible (72% of studies), we estimated effect sizes using random-effects models and Hedges' g. We identified four categories of prospective memory interventions, including mnemonic strategy, cognitive training, external memory aid, and combination interventions. Mnemonic strategy (g = .450) and cognitive training (g = .538) interventions demonstrated efficacy. Combination interventions showed mixed results (g = .254), underscoring that "more is not always better." External memory aids demonstrated very positive outcomes (g = .805), though often with small-sample, case-series designs. Prospective memory assessments had high ecological validity in external memory aid studies (84%), but not in mnemonic strategy (14%), cognitive training (20%), or combination intervention (50%) studies, p < .001, ηp2 = .33. Everyday prospective memory can be meaningfully improved, perhaps particularly with external memory aids, but larger trials are required to optimize treatments, increase adherence, and broaden implementation in daily life. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Mnemonic strategy training modulates functional connectivity at rest in mild cognitive impairment: Results from a randomized controlled trial.

IntroductionMnemonic strategy training (MST) has been shown to improve cognitive performance and increase brain activation in those with mild cognitive impairment (MCI). However, little is known regarding the effects of MST on functional connectivity (FC) at rest. The aim of the present study was to investigate the MST focused on face‐name associations effect on resting‐state FC in those with MCIMethodsTwenty‐six amnestic MCI participants were randomized in MST (N = 14) and Education Program (active control; N = 12). Interventions occurred twice a week over two consecutive weeks (ie, four sessions). Resting‐state functional magnetic resonance imaging was collected at pre‐ and post‐intervention. Regions of interest (ROIs) were selected based on areas that previously showed task‐related activation changes after MST. Changes were examined through ROI‐to‐ROI analysis and significant results were corrected for multiple comparisons.ResultsAt post‐intervention, only the MST group showed increased FC, whereas the control group showed decreased or no change in FC. After MST, there was an increased FC between the left middle temporal gyrus and right orbitofrontal cortex. In addition, a time‐by‐group interaction indicated that the MST group showed greater increased FC between the right inferior frontal gyrus and left brain regions, such as fusiform gyrus, temporal pole, and orbitofrontal cortex relative to controls.DiscussionMST enhanced FC in regions that are functionally relevant for the training; however, not in all ROIs investigated. Our findings suggest that MST‐induced changes are reflected in task‐specific conditions, as previously reported, but also in general innate connectivity. Our results both enhance knowledge about the mechanisms underlying MST effects and may provide neurophysiological evidence of training transfer.

Effects of Mnemonic Strategy Training on Brain Activity and Cognitive Functioning of Left-Hemisphere Ischemic Stroke Patients.

Memory dysfunction is one of the main cognitive impairments caused by stroke, especially associative memory. Therefore, cognitive training, such as face-name mnemonic strategy training, could be an important intervention for this group of patients. The goal of this study was to evaluate the behavioral effects of face-name mnemonic strategy training, along with the neural substrate behind these effects, in the left frontoparietal lobe stroke patients. Volunteers underwent 2 sessions of functional magnetic resonance imaging (fMRI) during face-name association task: one prior and the other after the cognitive training. The fMRI followed a block design task with three active conditions: trained face-name pairs, untrained face-name pairs, and a couple of repeated face-name pairs. Prior to each fMRI session, volunteers underwent neuropsychological assessment. Training resulted in better performance on delayed memory scores of HVLT-R, and on recognition on a generalization strategy task, as well as better performance in the fMRI task. Also, trained face-name pairs presented higher activation after training in default-mode network regions, such as the posterior cingulate cortex, precuneus, and angular gyrus, as well as in lateral occipital and temporal regions. Similarly, untrained face-name pairs also showed a nonspecific training effect in the right superior parietal cortex, right supramarginal gyrus, anterior intraparietal sulcus, and lateral occipital cortex. A correlation between brain activation and task performance was also found in the angular gyrus, superior parietal cortex, anterior intraparietal sulcus, and lateral occipital cortex. In conclusion, these results suggest that face-name mnemonic strategy training has the potential to improve memory performance and to foster brain activation changes, by the recruitment of contralesional areas from default-mode, frontoparietal, and dorsal attention networks as a possible compensation mechanism.

Mnemonic strategy training increases neocortical activation in healthy older adults and patients with mild cognitive impairment

Learning and memory deficits characterize the diagnosis of amnestic mild cognitive impairment (aMCI), which is widely viewed as a clinical precursor to Alzheimer's type dementia. There is a growing interest in non-pharmacologic interventions, such as mnemonic strategies, for improving learning and memory in patients with aMCI as well as for maintaining functioning in healthy older adults. Using an ecologically relevant object-location association paradigm, we conducted a randomized, controlled, single-blind study in which healthy older adults and patients with aMCI were randomized to either mnemonic strategy training or a control group that was matched for stimulus exposure. We previously reported that mnemonic strategy training resulted in significantly greater learning and memory improvements compared to the matched exposure condition, in both aMCI patients and healthy controls. The current study examined changes in neocortical activation during encoding in a subset of participants who underwent functional magnetic resonance imaging (fMRI) scanning both before and after training. To minimize potential confounds in between-group comparisons, we employed non-linear cortex based alignment and included only correctly encoded stimuli in our analyses. When re-encoding stimuli learned during training (i.e., trained stimuli), we found a general enhancement of activation in right prefrontal and parietal regions, possibly reflecting practice-related improvement in coordinate spatial processing in all but the aMCI exposure group. Left hemisphere activation was typically only evident in the mnemonic strategy trained participants, regardless of diagnostic status, with the ventrolateral prefrontal cortex appearing especially important for strategy use. While encoding relatively novel stimuli, both mnemonic strategy groups (aMCI patients and healthy controls) demonstrated increased activation in a subset of regions showing change for the trained stimuli, indicating a mnemonic strategy-induced change in the processing of new information. These findings could not be explained by repeated exposure since there was little to no activation overlap in the respective exposure control groups. The current results reinforce the potential benefits of cognitive interventions in these growing populations and indicate that neuroplastic change in key rostral and lateral prefrontal regions mediate this behavioral change.

Training gains and transfer effects after mnemonic strategy training in mild cognitive impairment: A fMRI study

Prior work has revealed that mnemonic strategy training (MST) can enhance memory for specific content and engages regions in the frontoparietal cognitive control network. Evidence of transfer to novel content is less clear. Here, we provide secondary analysis of functional magnetic resonance imaging (fMRI) data acquired during a randomized controlled trial that compared MST to an active education control condition in patients with amnestic mild cognitive impairment (a-MCI). In the trial, thirty participants with a-MCI were randomized to the education program (EP) or MST, where they learned to apply the technique to face-name associations during four intervening hour long training sessions. Participants underwent pre- and post-training fMRI scans, during which they encoded both the trained (i.e., those used during the four training sessions) and untrained (‘novel’) face-name associations. The primary cognitive outcome measures revealed significantly improved memory for both trained and novel stimuli – effects supporting near transfer of MST. Relative to pre-training, there were significant and highly similar increases in activation for both trained and novel stimuli, especially in regions associated with the frontoparietal cognitive control network bilaterally, but also in temporal areas related to social cognition and emotional processing. Critically, this pattern of activation was notably different from the EP group. Thus, the changes in activation were consistent with the strategies trained and, combined with the cognitively-based near transfer effects, suggest that MST focused on face-name association enhances performance by engaging cognitive control and social/emotional processing. Finally, our data indicated that our MST is a relevant and efficient intervention to a-MCI.

Cognitive and Brain Activity Changes After Mnemonic Strategy Training in Amnestic Mild Cognitive Impairment: Evidence From a Randomized Controlled Trial.

Background: Mnemonic strategy training (MST) has been shown to improve cognitive performance in amnestic mild cognitive impairment (a-MCI), however, several questions remain unresolved. The goal of the present study was to replicate earlier pilot study findings using a randomized controlled design and to evaluate transfer effects and changes in brain activation.Methods: Thirty patients with a-MCI were randomized into MST or education program. At baseline, participants completed clinical and neuropsychological assessments as well as structural and functional magnetic resonance imaging (fMRI). Interventions were administered individually and comprised four sessions, over 2 weeks. MST taught patients to use a three-step process to learn and recall face-name associations. Post-treatment assessment included fMRI, a separate face-name association task, neuropsychological tests, and measures of metamemory. Behavioral (i.e., non-fMRI) measures were repeated after one and 3-months.Results: Participants in the MST condition showed greater improvement on measures of face-name memory, and increased associative strategy use; effects that were accompanied by increased fMRI activation in the left anterior temporal lobe. While all participants reported greater contentment with their everyday memory following intervention, only the MST group reported significant improvements in their memory abilities. There was no clear indication of far-transfer effects to other neuropsychological tests.Conclusion: Results demonstrate that patients with a-MCI not only show stimulus specific benefits of MST, but that they appear capable of transferring training to at least some other cognitive tasks. MST also facilitated the use of brain regions that are involved in face processing, episodic and semantic memory, and social cognition, which are consonant with the cognitive processes engaged by training.

Combined mnemonic strategy training and high-definition transcranial direct current stimulation for memory deficits in mild cognitive impairment

IntroductionMemory deficits characterize Alzheimer's dementia and the clinical precursor stage known as mild cognitive impairment. Nonpharmacologic interventions hold promise for enhancing functioning in these patients, potentially delaying functional impairment that denotes transition to dementia. Previous findings revealed that mnemonic strategy training (MST) enhances long-term retention of trained stimuli and is accompanied by increased blood oxygen level–dependent signal in the lateral frontal and parietal cortices as well as in the hippocampus. The present study was designed to enhance MST generalization, and the range of patients who benefit, via concurrent delivery of transcranial direct current stimulation (tDCS). MethodsThis protocol describes a prospective, randomized controlled, four-arm, double-blind study targeting memory deficits in those with mild cognitive impairment. Once randomized, participants complete five consecutive daily sessions in which they receive either active or sham high definition tDCS over the left lateral prefrontal cortex, a region known to be important for successful memory encoding and that has been engaged by MST. High definition tDCS (active or sham) will be combined with either MST or autobiographical memory recall (comparable to reminiscence therapy). Participants undergo memory testing using ecologically relevant measures and functional magnetic resonance imaging before and after these treatment sessions as well as at a 3-month follow-up. Primary outcome measures include face-name and object-location association tasks. Secondary outcome measures include self-report of memory abilities as well as a spatial navigation task (near transfer) and prose memory (medication instructions; far transfer). Changes in functional magnetic resonance imaging will be evaluated during both task performance and the resting-state using activation and connectivity analyses. DiscussionThe results will provide important information about the efficacy of cognitive and neuromodulatory techniques as well as the synergistic interaction between these promising approaches. Exploratory results will examine patient characteristics that affect treatment efficacy, thereby identifying those most appropriate for intervention.

Mnemonic strategy training of the elderly at risk for dementia enhances integration of information processing via cross-frequency coupling

IntroductionWe sought to identify whether intensive 10-week mobile health mnemonic strategy training (MST) could shift the resting-state brain network more toward cortical-level integration, which has recently been proven to reflect the reorganization of the brain networks compensating the cognitive decline. MethodsOne hundred fifty-eight patients with mild cognitive impairment (MCI) were selected and participated in 10-week training lasting 90 min/d of memory training. They benefited from an initial and a follow-up neuropsychological evaluation and resting-state electroencephalography (EEG). ResultsAt follow-up, MST revealed an extensive significant training effect that changed the network with an increase of synchronization between parietotemporal and frontal areas; frontalθ-parietalα2 causal strengthening as part of top-down inhibitory control; enhancement of sensorimotor connections in β band; and a general increase of cortical-level integration. More precisely, MST induced gain as an increase of the global cost efficiency (GCE) of the whole cortical network and a neuropsychological performance improvement, which was correlated with it (r = 0.32, P = .0001). The present study unfolded intervention changes based on EEG source activity via novel neuroinformatic tools for revealing intrinsic coupling modes in both amplitude-phase representations and in the mixed spectrospatiotemporal domain. DiscussionFurther work should identify whether the GCE enhancement of the functional cortical brain networks is a compensation mechanism to the brain network dysfunction or a more permanent neuroplasticity effect.

Mnemonic strategy training improves memory for object location associations in both healthy elderly and patients with amnestic mild cognitive impairment: a randomized, single-blind study.

To evaluate the efficacy of mnemonic strategy training versus a matched-exposure control condition and to examine the relationship between training-related gains, neuropsychological abilities, and medial temporal lobe volumetrics in patients with amnestic mild cognitive impairment (aMCI) and age-matched healthy controls. Twenty-three of 45 screened healthy controls and 29 of 42 screened patients with aMCI were randomized to mnemonic strategy or matched-exposure groups. Groups were run in parallel, with participants blind to the other intervention. All participants completed five sessions within 2 weeks. Memory testing for object-location associations (OLAs) was performed during sessions one and five and at a 1-month follow-up. During Sessions 2-4, participants received either mnemonic strategy training or a matched number of exposures with corrective feedback for a total of 45 OLAs. Structural magnetic resonance imaging was performed in most participants, and medial temporal lobe volumetrics were acquired. Twenty-one healthy controls and 28 patients with aMCI were included in data analysis. Mnemonic strategy training was significantly more beneficial than matched exposure immediately after training, p = .006, partial η2 = .16, and at 1 month, p < .001, partial η2 = .35, regardless of diagnostic group (healthy group or aMCI group). Although patients with aMCI demonstrated gains comparable to the healthy control groups, their overall performance generally remained reduced. Mnemonic strategy-related improvement was correlated positively with baseline memory and executive functioning and negatively with inferior lateral ventricle volume in patients with aMCI; no significant relationships were evident in matched-exposure patients. Mnemonic strategies effectively improve memory for specific content for at least 1 month in patients with aMCI.

Mnemonic strategy training partially restores hippocampal activity in patients with mild cognitive impairment

Learning and memory deficits typify patients with mild cognitive impairment (MCI) and are generally attributed to medial temporal lobe dysfunction. Although the hippocampus is perhaps the most commonly studied neuroanatomical structure in these patients, there have been few attempts to identify rehabilitative interventions that facilitate its functioning. Here, we present results from a randomized, controlled, single-blind study in which patients with MCI and healthy elderly controls (HEC) were randomized to either three sessions of mnemonic strategy training (MS) or a matched-exposure control group (XP). All participants underwent pre- and posttraining fMRI scanning as they encoded and retrieved object-location associations. For the current report, fMRI analyses were restricted to the hippocampus, as defined anatomically. Before training, MCI patients showed reduced hippocampal activity during both encoding and retrieval, relative to HEC. Following training, the MCI MS group demonstrated increased activity during both encoding and retrieval. There were significant differences between the MCI MS and MCI XP groups during retrieval, especially within the right hippocampus. Thus, MS facilitated hippocampal functioning in a partially restorative manner. We conclude that cognitive rehabilitation techniques may help mitigate hippocampal dysfunction in MCI patients.

Memory Performance as a Function of Age, Reattribution Training and Type of Mnemonic Strategy Training

This experiment investigated whether mnemonic strategy training, occurring over a two-month period, would result in improved memory performance when combined with reattribution training. It was also hypothesized that the old and young may differ in their ability to perform nonverbal and verbal mnemonics. Therefore, age-related differences in memory performance were investigated as a function of whether the mnemonic was verbal (Alphabet Search Method) or non-verbal (Method of Loci), and whether or not reattribution training was combined with mnemonic training. Subjects were 34 old (Mean age = 69.5) and 34 young (Mean age = 22.8) adults. Memory performance was measured on the California Verbal Learning Test, the Nelson-Denny Vocabulary Test, the Beck Depression Inventory and four memory span tasks, prior and following a two-month period of weekly mnemonic strategy training sessions. A third of the subjects were trained with the Method of Loci, a third with Alphabet Search, and the remaining third served as the waitlist control group. In addition, half the young and old subjects from each mnemonic group did, and half did not, participate in a reattribution training workshop. Results clearly showed that mnemonic strategy training was useful for the old and young. However, the combination of reattribution and mnemonic strategy training only enhanced old, not young, memory scores when the type of strategy required verbal skills (Alphabet Search). The implication was that mnemonic strategy training may be more effective for the old if combined with reattribution training, and, if the mnemonic requires verbal rather than non-verbal skills.

Knowledge and processing speed as determinants of associative learning.

Abstract : In five experiments with over 2,500 subjects, we examined the hypothesis that cognitive processing variables measuring breadth of declarative knowledge and information processing speed were related to learning outcomes on a paired-associates task. Experiments 1 and 2 compared recall with recognition tests, Experiment 3 assessed the effect of study-block size, Experiment 4 examined the effect of mnemonic strategy, and Experiment 5 tested the effect of mixing study times and presenting words versus nonsense syllable stimuli. Across all experiments, breadth of verbal knowledge was found to be a strong predictor of retention overall, and a strong predictor in increment in retention benefit due to increases in study time. Mnemonic strategy training improved retention but also served to enhance the relationship between knowledge and retention. Memory search speed also predicted retention, but primarily under conditions of high information flow, either as a result of short (5 seconds per pair) study or time-sharing pressure (mixed study-time blocks). High-knowledge subjects and Fast Memory-Search subjects were also quicker at retrieving the answer, when they knew the answer; but High-Knowledge subjects took longer in retrieving an answer under conditions of uncertainty. Results are discussed in terms of a general model of associative learning in which encoding is viewed as a process of generating links by constructing elaborations of the terms studied. Keywords: Cognition, Cognitive ability, Computerized testing, Individual differences, Learning, Learning ability.

TRANSIENT IMPROVEMENT OF MEMORY IN SENILE DEMENTIA FOLLOWING MNEMONIC TRAINING

ABSTRACTThe effect of Levodopa administration and mnemonic strategy training in the treatment of memory deficits associated with denile dementia of the Alzheimer type was investigated in a short‐term longitudinal study. Levodopa administration exerted no significant effect upon memory functioning whereas training in the chunking of information and in visual association led to a significant, but temporary, improvement in memory functioning. Training raised performance of demented subjects to about 58% of that of non‐demented controls, compared to the 38% observed at baseline. No significant interactions between the drug and training manipulation were indicated.