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Updated: Dec 22, 2025
Transcranial Direct Current Stimulation tDCS for Memory Enhancement
Published on: September 18, 2021
Encoding strategy mediates the effect of electrical stimulation over posterior parietal cortex on visual short-term
Sisi Wang1, Sirawaj Itthipuripat2, Yixuan Ku3
1Guangdong Provincial Key Laboratory of Social Cognitive Neuroscience and Mental Health, Department of Psychology, Sun Yat-Sen University, Guangzhou, China; Peng Cheng Laboratory, Shenzhen, China; Shanghai Key Laboratory of Brain Functional Genomics, Shanghai Changning-ECNU Mental Health Center, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China; Department of Psychology, Vanderbilt University, Nashville, TN, USA.
Encoding strategy influences visual short-term memory (VSTM) capacity. Electrical stimulation of the posterior parietal cortex (PPC) enhanced VSTM capacity only when participants used a specific strategy, suggesting strategy mediates stimulation effects.
Area of Science:
- Cognitive Neuroscience
- Neuroscience
- Psychology
Background:
- Converging evidence implicates the posterior parietal cortex (PPC) in visual short-term memory (VSTM) storage capacity.
- Electrical stimulation of PPC has shown potential for enhancing VSTM, but findings are inconsistent.
- Variability in results may stem from differing participant encoding strategies.
Purpose of the Study:
- To investigate the role of encoding strategy in VSTM capacity.
- To determine if encoding strategy mediates the effects of transcranial direct-current stimulation (tDCS) over PPC on VSTM.
- To explore the interaction between PPC stimulation and encoding strategy.
Main Methods:
- Human subjects (male and female) performed a VSTM recall task.
- Participants were instructed to use either a 'remember-all' or 'remember-subset' encoding strategy.
- Transcranial direct-current stimulation (tDCS) was applied over the PPC.
Main Results:
- VSTM capacity was higher in the 'remember-all' group compared to the 'remember-subset' group.
- Anodal tDCS over PPC significantly enhanced VSTM capacity exclusively in the 'remember-subset' group.
- No significant effects of encoding strategy or its interaction with tDCS were observed on VSTM precision.
Conclusions:
- Encoding strategy selectively influences VSTM capacity.
- The effect of PPC stimulation on VSTM capacity is mediated by the participant's encoding strategy.
- Understanding encoding strategies is crucial for optimizing VSTM enhancement techniques.
