Enhancing Memory for Relationship Actions by Transcranial Direct Current Stimulation of the Superior Temporal Sulcus

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuromodulation

Background:

• The right superior temporal sulcus (rSTS) is implicated in processing social cognition and action understanding.
• Memorizing relationship-action sentences involves encoding social intentions and actions.
• Individual differences in personality traits may influence cognitive functions and responses to neuromodulation.

Purpose of the Study:

• To investigate the effect of transcranial direct current stimulation (tDCS) on the memorization of approach/avoidance relationship-action sentences.
• To explore whether tDCS of the rSTS modulates memory performance for these specific sentence types.
• To examine the role of individual differences in behavioral approach system (BAS) and behavioral inhibition system (BIS) in modulating the tDCS effects.

Main Methods:

• A between-subjects design was used with 65 university students.
• Participants received 20 minutes of anodal, cathodal, or sham tDCS targeting the rSTS.
• Memory for approach/avoidance sentences was assessed using a changed/same task, with comparisons to a no-stimulation condition and to BAS/BIS scale scores.

Main Results:

• Anodal tDCS significantly improved the discriminability index (d') compared to sham and cathodal conditions for both approach and avoidance sentences.
• Anodal stimulation showed a greater improvement in d' for approach sentences compared to a no-stimulation condition.
• The memory benefits of anodal tDCS were primarily observed in participants with low BAS and low BIS scores.

Conclusions:

• tDCS of the rSTS can enhance the memorization of verbally described intentional relationship-actions.
• The findings highlight the rSTS's role in encoding and memory for social-relational information.
• Individual differences in BAS and BIS traits modulate the effectiveness of tDCS for memory enhancement.