Irrelevant emotional expressions interfered with response inhibition: the role of contrast emotions

ABSTRACTIrrelevant emotional faces would facilitate or inhibit response inhibition, depending on how these faces are paired with different emotional faces. In previous studies, angry faces were either paired with neutral, happy, or fearful faces in the response inhibition task, potentially leading to mixed results. This is the first study where all four irrelevant emotional faces (happy, angry, fearful, and neutral) were used simultaneously and presented in the same block as a stop-signal in the stop-signal paradigm. Participants were required to respond to the go signals. Occasionally, a stop-signal with irrelevant facial expressions was presented, where participants were required to withhold their motor response. All stop signals with irrelevant emotional facial expressions in comparison to neutral facial expressions interfered with the response inhibition process. Our results extend previous findings by suggesting that approach and avoidance reactions to facial expressions depend on the contrasting emotions presented in the task.KEYWORDS: Emotionsattentionresponse inhibitionhappy faceangry face Data availability statementThe authors confirm that the data supporting the findings of this study can be downloaded from the following link. https://drive.google.com/file/d/1jiGUmQT0cyW2GRbMKZ9-oOPawxGa6yPk/view?usp=sharing.Disclosure statementNo potential conflict of interest was reported by the author(s).Ethical approvalAll procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The ethics committee of the Indian Institute of Technology Bombay approved the study.Informed consentInformed consent was obtained from all individual participants included in the study.Notes1 In Verbruggen and De Houwer's (Citation2007) study, irrelevant emotional stimuli were not part of the stop signals; instead, they were presented as primes before the go and stop trials. Also, in this study, IAPS pictures were used as stop signals, whereas in the other two studies (Gupta & Singh, Citation2021; Pessoa et al., Citation2012), faces were used as stop-signals. In both studies (Gupta & Singh, Citation2021; Pessoa et al., Citation2012), faces with irrelevant positive (happy faces) and negative emotions (fearful faces in Pessoa et al. (Citation2012) and angry in Gupta & Singh, Citation2021) were used as stop signals. Also, non-emotional and non-face stimuli were used as go-signals in both studies ("circle" or "square" in Pessoa et al., Citation2012; "X" or "O" in Gupta & Singh, Citation2021). However, in the study by Pessoa et al. (Citation2012), both the go and stop signals were presented in the foveal vision (centre). In contrast, in Gupta and Singh (Citation2021), go signals were presented at the centre, and stop signals were presented at the top of the go signals (see also Gupta et al., Citation2011). The arousal level of positive and negative emotional stimuli used in the study by Pessoa et al. (Citation2012) was neither measured nor controlled, which is the main drawback of their study. However, in Gupta and Singh (Citation2021), the arousal level of positive (happy faces) and negative (angry faces) emotions was measured and controlled.2 In Verbruggen and De Houwer's (Citation2007) study, irrelevant emotional stimuli were not part of the stop signals; instead, they were presented as primes before the go and stop trials. Also, in this study, IAPS pictures were used as stop signals, whereas in the other two studies (Gupta & Singh, Citation2021; Pessoa et al., Citation2012), faces were used as stop-signals. In both studies (Gupta & Singh, Citation2021; Pessoa et al., Citation2012), faces with irrelevant positive (happy faces) and negative emotions (fearful faces in Pessoa et al. (Citation2012) and angry in Gupta & Singh, Citation2021) were used as stop signals. Also, non-emotional and non-face stimuli were used as go-signals in both studies ("circle" or "square" in Pessoa et al., Citation2012; "X" or "O" in Gupta & Singh, Citation2021). However, in the study by Pessoa et al. (Citation2012), both the go and stop signals were presented in the foveal vision (centre). In contrast, in Gupta and Singh (Citation2021), go signals were presented at the centre, and stop signals were presented at the top of the go signals (see also Gupta et al., Citation2011). The arousal level of positive and negative emotional stimuli used in the study by Pessoa et al. (Citation2012) was neither measured nor controlled, which is the main drawback of their study. However, in Gupta and Singh (Citation2021), the arousal level of positive (happy faces) and negative (angry faces) emotions was measured and controlled.3 The difference between angry and neutral SSRT scores was marginally significant in a previous study (Gupta & Singh, Citation2021), but in the present study, this difference reached statistical significance. In this respect, the results are replicated. However, in the study by Gupta and Singh (Citation2021), angry faces facilitated response inhibition; but interfered with response inhibition in the present study.Additional informationFundingThis research was supported by the IRCC, IITB seed [grant number RD/0518-IRCCSH0-013] to Prof. Gupta.