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Noninvasive stimulation of prefrontal cortex strengthens existing episodic memories and reduces forgetting in the elderly.

Sandrini M, Brambilla M, Manenti R, Rosini S, Cohen LG, Cotelli M - Front Aging Neurosci (2014)

Bottom Line: On Day 2 (24 h later), they received a reminder or not, and after 10 min tDCS was applied over the left DLPFC.Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later).These results provide a framework for testing the hypothesis that facilitatory tDCS of left DLPFC might strengthen existing episodic memories and reduce memory loss in older adults with amnestic mild cognitive impairment.

View Article: PubMed Central - PubMed

Affiliation: Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA ; Center for Neuroscience and Regenerative Medicine, Uniformed Services University of Health Sciences Bethesda, MD, USA.

ABSTRACT
Memory consolidation is a dynamic process. Reactivation of consolidated memories by a reminder triggers reconsolidation, a time-limited period during which existing memories can be modified (i.e., weakened or strengthened). Episodic memory refers to our ability to recall specific past events about what happened, including where and when. Difficulties in this form of long-term memory commonly occur in healthy aging. Because episodic memory is critical for daily life functioning, the development of effective interventions to reduce memory loss in elderly individuals is of great importance. Previous studies in young adults showed that the dorsolateral prefrontal cortex (DLPFC) plays a causal role in strengthening of verbal episodic memories through reconsolidation. The aim of the present study was to explore the extent to which facilitatory transcranial direct current stimulation (anodal tDCS) over the left DLPFC would strengthen existing episodic memories through reconsolidation in elderly individuals. On Day 1, older adults learned a list of 20 words. On Day 2 (24 h later), they received a reminder or not, and after 10 min tDCS was applied over the left DLPFC. Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later). Surprisingly, anodal tDCS over the left DLPFC (i.e., with or without the reminder) strengthened existing verbal episodic memories and reduced forgetting compared to sham stimulation. These results provide a framework for testing the hypothesis that facilitatory tDCS of left DLPFC might strengthen existing episodic memories and reduce memory loss in older adults with amnestic mild cognitive impairment.

No MeSH data available.


Related in: MedlinePlus

The plot shows the mean percentage of words correctly recalled in each group (Anodal-R, Anodal-NR and Sham-R) at Day 1, Day 3, and Day 30. There was significant memory decay (i.e., forgetting) from Day 1 to Day 3 in all groups. Forgetting was reduced up to 1 month in the anodal tDCS groups (Anodal-R and Anodal-NR) compared to the sham group (Sham-R). Error bars represent standard errors of the means (s.e.m.). *p < 0.05.
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Figure 2: The plot shows the mean percentage of words correctly recalled in each group (Anodal-R, Anodal-NR and Sham-R) at Day 1, Day 3, and Day 30. There was significant memory decay (i.e., forgetting) from Day 1 to Day 3 in all groups. Forgetting was reduced up to 1 month in the anodal tDCS groups (Anodal-R and Anodal-NR) compared to the sham group (Sham-R). Error bars represent standard errors of the means (s.e.m.). *p < 0.05.

Mentions: Considering the group effect, the post-hoc comparisons showed significant differences between Anodal-NR (mean 49.9; SD 21.6) and Sham-R (mean 31.9; SD 17.1) (p = 0.04) and between Anodal-R (mean 49.9; SD 24.6) and Sham-R (p < 0.01). No difference was found between Anodal-NR and Anodal-R (p = 0.47) (see Figure 2).


Noninvasive stimulation of prefrontal cortex strengthens existing episodic memories and reduces forgetting in the elderly.

Sandrini M, Brambilla M, Manenti R, Rosini S, Cohen LG, Cotelli M - Front Aging Neurosci (2014)

The plot shows the mean percentage of words correctly recalled in each group (Anodal-R, Anodal-NR and Sham-R) at Day 1, Day 3, and Day 30. There was significant memory decay (i.e., forgetting) from Day 1 to Day 3 in all groups. Forgetting was reduced up to 1 month in the anodal tDCS groups (Anodal-R and Anodal-NR) compared to the sham group (Sham-R). Error bars represent standard errors of the means (s.e.m.). *p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202785&req=5

Figure 2: The plot shows the mean percentage of words correctly recalled in each group (Anodal-R, Anodal-NR and Sham-R) at Day 1, Day 3, and Day 30. There was significant memory decay (i.e., forgetting) from Day 1 to Day 3 in all groups. Forgetting was reduced up to 1 month in the anodal tDCS groups (Anodal-R and Anodal-NR) compared to the sham group (Sham-R). Error bars represent standard errors of the means (s.e.m.). *p < 0.05.
Mentions: Considering the group effect, the post-hoc comparisons showed significant differences between Anodal-NR (mean 49.9; SD 21.6) and Sham-R (mean 31.9; SD 17.1) (p = 0.04) and between Anodal-R (mean 49.9; SD 24.6) and Sham-R (p < 0.01). No difference was found between Anodal-NR and Anodal-R (p = 0.47) (see Figure 2).

Bottom Line: On Day 2 (24 h later), they received a reminder or not, and after 10 min tDCS was applied over the left DLPFC.Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later).These results provide a framework for testing the hypothesis that facilitatory tDCS of left DLPFC might strengthen existing episodic memories and reduce memory loss in older adults with amnestic mild cognitive impairment.

View Article: PubMed Central - PubMed

Affiliation: Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA ; Center for Neuroscience and Regenerative Medicine, Uniformed Services University of Health Sciences Bethesda, MD, USA.

ABSTRACT
Memory consolidation is a dynamic process. Reactivation of consolidated memories by a reminder triggers reconsolidation, a time-limited period during which existing memories can be modified (i.e., weakened or strengthened). Episodic memory refers to our ability to recall specific past events about what happened, including where and when. Difficulties in this form of long-term memory commonly occur in healthy aging. Because episodic memory is critical for daily life functioning, the development of effective interventions to reduce memory loss in elderly individuals is of great importance. Previous studies in young adults showed that the dorsolateral prefrontal cortex (DLPFC) plays a causal role in strengthening of verbal episodic memories through reconsolidation. The aim of the present study was to explore the extent to which facilitatory transcranial direct current stimulation (anodal tDCS) over the left DLPFC would strengthen existing episodic memories through reconsolidation in elderly individuals. On Day 1, older adults learned a list of 20 words. On Day 2 (24 h later), they received a reminder or not, and after 10 min tDCS was applied over the left DLPFC. Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later). Surprisingly, anodal tDCS over the left DLPFC (i.e., with or without the reminder) strengthened existing verbal episodic memories and reduced forgetting compared to sham stimulation. These results provide a framework for testing the hypothesis that facilitatory tDCS of left DLPFC might strengthen existing episodic memories and reduce memory loss in older adults with amnestic mild cognitive impairment.

No MeSH data available.


Related in: MedlinePlus