Tuning out emotional distractors by tuning in theta rhythm: improving visual working memory using transcranial...

Area of Science:

• Cognitive Neuroscience
• Neuroscience
• Psychology

Background:

• Attentional control and visual working memory (vWM) are linked, with transcranial magnetic stimulation (TMS) previously shown to enhance vWM by boosting prefrontal theta rhythm.
• The efficacy of TMS protocols for attentional control against emotional distractors, compared to neutral ones, remains under investigation.
• Attentional control mechanisms may involve amplifying relevant stimuli or inhibiting distractors.

Purpose of the Study:

• To investigate if rhythmic TMS (rhTMS) targeting prefrontal theta rhythm can improve attentional control for emotional auditory distractors in a vWM task.
• To determine whether attentional control operates via amplification of relevant stimuli or inhibition of distractors in the context of emotional auditory interference.

Main Methods:

• Utilized rhTMS to increase theta power over the left dorsolateral prefrontal cortex in 19 healthy participants.
• Participants performed a visual change-detection task while auditory distractors (neutral and angry prosodies) were presented.
• Measured electroencephalography (EEG) signals including theta power, contralateral delay activity (for vWM maintenance), and auditory P2 (for distractor processing).

Main Results:

• rhTMS successfully boosted theta power and improved vWM accuracy compared to a sham condition.
• The observed theta power boost correlated with reduced processing of emotional auditory distractors.
• No significant improvement in visual item maintenance (contralateral delay activity) was found, suggesting inhibition over amplification.

Conclusions:

• The findings suggest that rhTMS-induced attentional control in vWM, when facing emotional auditory distractors, primarily functions through inhibiting distractor processing.
• This study elucidates the inhibitory mechanism underlying attentional control for emotional distractors within the visual working memory system.