Sad expressions during encoding attenuate recognition of facial identity in visual working memory: behavioural and electrophysiological evidence

ABSTRACT

The current study investigated how sad expressions during encoding affected recognition of facial identity in visual working memory (WM) and its electrophysiological correlates. Event-related potentials were obtained from 36 individuals during a delayed face discrimination task. The hit (correctly recognising studied faces) rates, correct rejection (CR: correctly rejecting unstudied faces) rates, sensitivity d’ (discrimination power of face identity recognition), and N170 (150–200 ms), the vertex positive potential (VPP; 150–200 ms), N250 (250–300 ms), P3b (350–450 ms), and late positive potential (LPP; 550–800 ms) amplitudes elicited by the neutral probe faces (previously encoded with sad and happy expressions) during hits and CR conditions were analysed. The participants showed lower hits and CRs and therefore had a lower discrimination power for facial identity preceded by sad expressions compared to happy expressions. For hits, neutral probe faces previously encoded with sad expressions exhibited increased N170, VPP, N250, P3b and LPP amplitudes compared to amplitudes following encoding with happy expressions. For correct rejections, the ERP effect of sad/happy expressions was absent. These results indicate that sad expressions during encoding attenuated the recognition of facial identity in visual WM. The reduced facial identity recognition for previously encoded sad expressions may be associated with increased early structural encoding, more late attention and perceptual resource engagement.

KEYWORDS:

• Sad expression
• N170/VPP
• P3b
• LPP
• encoding
• working memory

Acknowledgements

The authors highly appreciate the helpful comments of the reviewers, including Holger Wiese.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was sponsored by the MOE (Ministry of Education in China) Project of Humanities and Social Sciences [grant number 18YJA190010]; the Key Research Base Project of Humanities and Social Sciences in Jiangxi Provincial Universities [grant number JD17079]; and the Graduate Innovation Fund Project of Education Department of Jiangxi Province [grant number YC2019-B053].