The direction of the eye gaze conveys valuable information and is crucial in social interactions. Observing one’s gaze direction provides inferences about their current attentive focus, emotional state and behavioural intentions (Bayliss et al., 2006), while following individuals’ gaze shifts contributes to social learning (Michel et al., 2021) and to the detection of rewarding stimuli in social settings (Ohlsen et al., 2013). Investigations of the effects of variations in gaze direction on attentional shifts have often adopted the typical Posner’s gaze-cueing paradigm (Friesen & Kingstone, 1998), in which a direct gaze face is presented and subsequently the gaze turns to the left or right. After a variable delay (called stimulus onset asynchrony [SOA]), a peripheral target appears at the gazed-at or non-gazed-at locations, and the participants are required to detect the target’s whereabouts. These studies have reliably demonstrated the gaze-cueing effect (GCE; Jones et al., 2010), that is, an attentional shift towards the cueing location revealed by faster responses when the target appears to the side of the space previously cued by the gaze.
A range of social factors have been identified to modulate the GCE. Collectively, the factors that impact the GCE have been categorised into three major types: the observer, the cueing face and the relationship between the two (Dalmaso et al., 2020). Specifically, the observer refers to the effect of individual differences, such as gender (Bayliss et al., 2005), age (Slessor et al., 2008), personal traits (Park & Lee, 2016) and internal states (Wilkowski et al., 2009), on the GCE. The cueing face refers to how facial features, such as facial expressions (McCrackin et al., 2019), face dominance (Jones et al., 2011) and facial attractiveness (Roth et al., 2021), affect individuals’ GCEs. Finally, researches on the relationship between the two have mainly focused on internal and external groups (Chen et al., 2017), ethnic members (Pavan et al., 2011), familiarity (Deaner et al., 2007), cooperation (Ciardo et al., 2015) and so forth.
Social ostracism is a type of social relation that might occur during human interaction and cause the excluded individual to feel intense negative feelings, such as exclusion, sorrow and rage (Buckley et al., 2004; Riva et al., 2017; Williams & Jarvis, 2006). In studies of this, those who have experienced social exclusion have reported lower levels of belonging, self-esteem, control and meaningful existence, creating psychological misery comparable to physiological pain (Williams et al., 2000). Therefore, in the aftermath of an exclusion experience, individuals tend to pursue a sense of belonging so that they may gain acceptance (Dewall et al., 2007). It is common knowledge that following others’ gaze shifting is an indication of social connectedness (Brooks & Meltzoff, 2014). An example of this is the study carried out by Wilkowski et al. (2009), in which individuals recalled exclusion and inclusion events to induce the relevant emotional experience using virtual faces as cues. The authors discovered that social exclusion produced a greater GCE than social inclusion. Contrary to the above research, Capellini et al. (2019) employed an online ball-tossing game (Cyberball) to induce participants’ social exclusion and inclusion experiences, and they reported that social exclusion could reduce the GCE with real faces as cues. The authors explained that this may be because the participants interpreted an averted gaze as a signal of social avoidance and were unwilling to follow the gaze shifting. In general, the inquiry into the impact of social exclusion on the modulation of others’ gaze direction towards an individual’s attention orientation continues to be a topic that warrants further exploration.
Notably, previous studies have focused on whether individuals’ processing of an unfamiliar face’s gaze cues alters after experiencing social exclusion or inclusion, which explored the general impact of social exclusion on social attention. However, because we live in complex social environments populated by other individuals and because our attentional resources are limited, our social attention system has likely developed to enable us to react more promptly to certain cueing faces than others. In this sense, the emotional experience of social exclusion is typically associated with one or more excluders in real-world social interactions. Thus, we ask: Is the influence of the emotional experience regarding social attention orientation triggered by gaze direction related to the specific cueing face (exclusion face vs control face)? To date, this issue has not been addressed.
In summary, the present study combined the Cyberball and gaze-cueing tasks to investigate whether social exclusion impacts the processing of the excluder’s gaze cues. The participants were randomly divided into two groups: the exclusion group and the inclusion group. In the first phase, participants completed the Cyberball manipulation, in which the number of times they caught the ball was predetermined to induce emotional experiences of social exclusion (exclusion group) and inclusion (inclusion group), with fewer balls caught representing social exclusion and more balls caught representing social inclusion. In the second phase, participants performed the standard gaze-cueing task, in which a face with the eyes gazing left or right served as the cue and the task was to detect where the target appeared following the cueing face. The cueing faces in the gaze-cueing task were represented by two virtual avatars (experimental faces) who cooperated with the participant to complete the Cyberball game and then two new faces (control faces). The GCE reflects the spatial attention allocation of a target (Lassalle, 2013), while SOA has been thought to refer to whether this attention allocation occurs automatically or volitionally (McKay et al., 2021). To be specific, under short SOA, an attention shift primarily indicates a reflective orientation, whereas, under long SOA, it reflects both the reflective orientation and attention maintenance (Driver et al., 1999; Friesen et al., 2004). Previous research has revealed that the impact of high-level social factors on the GCE varies depending on SOA (Dodd et al., 2011; Takao et al., 2018). Consequently, this investigation employed two SOA conditions—200 ms and 700 ms—to explore the potential regulation of SOA during the process of social exclusion on the GCE. Based on previous studies (Capellini et al., 2019; Wilkowski et al., 2009), we anticipated that social exclusion would modulate the GCE, namely, that exclusion and inclusion faces would exhibit significant differences in the GCE. Furthermore, since human emotions, cognition and behaviour are highly adaptive (Martin et al., 2013; Stockinger et al., 2021) and the nature of human learning is to produce specific responses to specific stimuli because this is more conducive to survival and socialisation, we would expect the effect of social exclusion on social attention to be limited to exclusion faces and not be generalisable to control faces; that is, we might observe that exclusion faces and control faces have different GCEs. In parallel, since guilt is a complex emotion that impacts an individual’s thinking and actions in a top–down manner, we anticipated that the effect of social exclusion on the GCE would be observed with long SOA only.