Self-Prioritization Reconsidered: Scrutinizing Three Claims

Control over self and others' face: exploitation and exploration

The face serves as a crucial cue for self-identification, while the sense of agency plays a significant role in determining our influence through actions in the environment. The current study investigates how self-identification through facial recognition may influence the perception of control via motion. We propose that self-identification might engender a belief in having control over one's own face, leading to a more acute detection and greater emphasis on discrepancies between their actions and the sensory feedback in control judgments. We refer to the condition governed by the belief in having control as the exploitation mode. Conversely, when manipulating another individual's face, the belief in personal control is absent. In such cases, individuals are likely to rely on the regularity between actions and sensory input for control judgments, exhibiting behaviors that are exploratory in nature to glean such information. This condition is termed the explorative mode. The study utilized a face-motion mixing paradigm, employing a deep generative model to enable participants to interact with either their own or another person's face through facial and head movements. During the experiment, participants observed either their own face or someone else's face (self-face vs. other-face) on the screen. The motion of the face was driven either purely by their own facial and head motion or by an average of the participant's and the experimenter's motion (full control vs. partial control). The results showed that participants reported a higher sense of agency over the other-face than the self-face, while their self-identification rating was significantly higher for the self-face. More importantly, controlling someone else's face resulted in more movement diversity than controlling one's own face. These findings support our exploration-exploitation theory: When participants had a strong belief in control triggered by the self-face, they became highly sensitive to any sensorimotor prediction errors, leading to a lower sense of agency. In contrast, when the belief of control was absent, the exploration mode triggered more explorative behaviors, allowing participants to efficiently gather information to establish a sense of agency.

An identity-irrelevant discrimination task reveals familiarity-advantage in face perception and no self-advantage in voice perception

Whether or not self-face and self-voice are processed more accurately than others' remains inconclusive. Most previous studies asked participants to judge the presented stimulus as their own or as others', and compared response accuracy to discuss self-advantage. However, it is possible that participants responded correctly in the "other" trials not by identifying "other" but rather by rejecting "self." The present study employed an identity-irrelevant discrimination task, in which participants detected the odd stimulus among the three sequentially presented stimuli. We measured the discrimination thresholds for the self, friend, and stranger conditions. In Experiment 1 (face), the discrimination thresholds for self and friends' faces were lower than those for strangers' faces. This suggests that self-face may not be perceived as special or unique, and facial representation may become more accurate due to increased familiarity through repetitive exposure. Whereas, in Experiment 2 (voice), the discrimination thresholds did not differ between the three conditions, suggesting that the sensitivity to changes is the same regardless of identity. Overall, we found no evidence for self-advantage in identification accuracy, as we observed a familiarity-advantage rather than self-advantage in face processing and a null difference in voice processing.

Self as a prior: The malleability of Bayesian multisensory integration to social salience

Our everyday perceptual experiences are grounded in the integration of information within and across our senses. Due to this direct behavioural relevance, cross-modal integration retains a certain degree of contextual flexibility, even to social relevance. However, how social relevance modulates cross-modal integration remains unclear. To investigate possible mechanisms, Experiment 1 tested the principles of audio-visual integration for numerosity estimation by deriving a Bayesian optimal observer model with perceptual prior from empirical data to explain perceptual biases. Such perceptual priors may shift towards locations of high salience in the stimulus space. Our results showed that the tendency to over- or underestimate numerosity, expressed in the frequency and strength of fission and fusion illusions, depended on the actual event numerosity. Experiment 2 replicated the effects of social relevance on multisensory integration from Scheller & Sui, 2022 JEP:HPP, using a lower number of events, thereby favouring the opposite illusion through enhanced influences of the prior. In line with the idea that the self acts like a prior, the more frequently observed illusion (more malleable to prior influences) was modulated by self-relevance. Our findings suggest that the self can influence perception by acting like a prior in cue integration, biasing perceptual estimates towards areas of high self-relevance.

The self-bias in working memory: the favorability of self-referential stimuli in resource allocation

Self-representations guide and shape our thoughts and behaviour. People usually exhibit inherent biases in perception, attention, and memory to favour the information associated with themselves over that associated with others. The present study explored the phenomenon of self-bias in working memory (WM), specifically how self-referential processing impacts WM precision. Four precision-based experiments were conducted to assess the recall precision of self-referential items and items associated with other social agents. The findings revealed a robust self-prioritisation effect in WM precision, wherein self-referential items were recalled with greater precision than items associated with other social agents. Additionally, increased precision for self-referential items did not decrease the precision for simultaneously remembered items. This effect was limited by the total amount of WM resources and not influenced by a perceptual distractor. The inherent self-bias in WM can serve as a proxy to access the role self-representation in goal-oriented cognitive processing, providing a means of exploring the interaction between self-reference and high-level cognitive function.

Stimulus valence moderates self-learning

Self-relevance has been demonstrated to impair instrumental learning. Compared to unfamiliar symbols associated with a friend, analogous stimuli linked with the self are learned more slowly. What is not yet understood, however, is whether this effect extends beyond arbitrary stimuli to material with intrinsically meaningful properties. Take, for example, stimulus valence an established moderator of self-bias. Does the desirability of to-be-learned material influence self-learning? Here, in conjunction with computational modelling (i.e. Reinforcement Learning Drift Diffusion Model analysis), a probabilistic selection task was used to establish if and how stimulus valence (i.e. desirable/undesirable posters) impacts the acquisition of knowledge relating to object-ownership (i.e. owned-by-self vs. owned-by-friend). Several interesting results were observed. First, undesirable posters were learned more rapidly for self compared to friend, an effect that was reversed for desirable posters. Second, learning rates were accompanied by associated differences in reward sensitivity toward desirable and undesirable choice selections as a function of ownership. Third, decisional caution was greater for self-relevant (vs. friend relevant) responses. Collectively, these findings inform understanding of self-function and how valence and stimulus relevance mutually influence probabilistic learning.

Electrical stimulation induced self-related auditory hallucinations correlate with oscillatory power change in the default mode network

Self-related information is crucial in our daily lives, which has led to the proposal that there is a specific brain mechanism for processing it. Neuroimaging studies have consistently demonstrated that the default mode network (DMN) is strongly associated with the representation and processing of self-related information. However, the precise relationship between DMN activity and self-related information, particularly in terms of neural oscillations, remains largely unknown. We electrically stimulated the superior temporal and fusiform areas, using stereo-electroencephalography to investigate neural oscillations associated with elicited self-related auditory hallucinations. Twenty-two instances of auditory hallucinations were recorded and categorized into self-related and other-related conditions. Comparing oscillatory power changes within the DMN between self-related and other-related auditory hallucinations, we discovered that self-related hallucinations are associated with significantly stronger positive power changes in both alpha and gamma bands compared to other-related hallucinations. To ensure the validity of our findings, we conducted controlled analyses for factors of familiarity and clarity, which revealed that the observed effects within the DMN remain independent of these factors. These results underscore the significance of the functional role of the DMN during the processing of self-related auditory hallucinations and shed light on the relationship between self-related perception and neural oscillatory activity.

How far can the self be extended? Automatic attention capture is triggered not only by the self-face

The preferential processing of self-related information is thought to be driven by its high level of familiarity. However, some behavioral studies have shown that people may exhibit a preference for initially unfamiliar stimuli that have been associated with themselves arbitrarily. One of the key questions that needs to be addressed concerns the role of early attention in the prioritization of newly acquired information associated with the self. Another question is whether both highly familiar as well as new information referring to a subjectively significant person (i.e. close-other) benefits from preferential attentional processing. We aimed to tackle both questions by investigating the neural mechanisms involved in processing extremely familiar stimuli, like one's own face or the face of a close-other, as well as stimuli (abstract shapes) that were newly linked to each person. We used a dot-probe paradigm that allowed us to investigate the early stages of attentional prioritization. Our analysis of the N2pc component unveiled that attention was automatically captured by the self-face, a shape associated with oneself, and the face of the close person. However, a shape associated with the close-other did not elicit the same attentional response, as the N2pc was absent. Thus, both the self-face and information referring to the extended self (self-assigned shape, close-other's face) benefit from preferential early and automatic attentional processing.