The effects of tDCS on object perception: A systematic review and meta-analysis

• Published in: Behavioural brain research Vol. 430; p. 113927
• Main Authors: Lavezzi, Gabriel Damon, Sanz Galan, Sofia, Andersen, Hallie, Tomer, Daniel, Cacciamani, Laura
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 26.07.2022
• Subjects: Electrical stimulation; Object perception; Object recognition; Systematic review; Transcranial direct current stimulation; Electrical stimulation; Systematic review; Object recognition; Transcranial direct current stimulation; Object perception; object recognition; electrical stimulation; systematic review; object perception; transcranial direct current stimulation
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2022.113927

Transcranial direct current stimulation (tDCS) is a novel, non-invasive method of modulating brain activity by applying electrical current directly to the scalp. While the effects of tDCS are more established in the clinical setting, its influence on cognition, specifically object perception, is less clear. The goal of this systematic review was to investigate whether object perception can be improved by tDCS, and if so, under what conditions. A literature search was conducted on the following databases: PubMed, ScienceDirect, Google Scholar and PsycInfo. To be included, studies must have employed tDCS on healthy adult populations and included a measure of object perception. A total of 18 articles met inclusion criteria. The results showed that 58% of studies that applied anodal tDCS to the target region observed enhanced object perception. This was particularly the case with frontal stimulation for object detection tasks. A quantitative meta-analysis further confirmed that anodal tDCS improved object perception overall, and specifically, tDCS to frontal sites increased accuracy scores by an average of 8.8%. Although the qualitative synthesis suggested that anodal tDCS to occipital sites, such as the lateral occipital complex, may enhance object recognition, the meta-analysis showed that this effect was not significant within the occipital subgroup. This is the first systematic review and meta-analysis investigating the effects of tDCS on object perception. Although there are inconsistencies in the behavioral and tDCS methodologies employed by these studies, our analysis revealed that tDCS can enhance object perception when targeting frontal brain regions involved in top-down attention. •Review summarizes 18 studies investigating the effects of tDCS on object perception.•Anodal tDCS led to improved object perception in the majority of studies.•Frontal stimulation enhanced performance on tasks involving attentional search.•Occipital stimulation enhanced performance on object recognition tasks.•TDCS can improve object perception depending on the task and brain area targeted.