Research hypotheses
The nature of self is one of the most enduring questions in science. Recently, cognitive neuroscientists and neuropsychologists have undertaken the ambitious task of linking the self to its neural substrates. Specifically, the neural basis of self-referential processing (SRP) is investigated. SRP includes not only self-mentalizing and self-reflection, but also processing of stimuli experienced as strongly related to one's own person, such as self-name and self-face.
Two neuroimaging methods are used to address this issue: functional magnetic resonance imaging (fMRI) and event-related potentials (ERP). Findings of numerous fMRI and ERP studies in this field consistently show enhanced brain activity associated with processing of self-related information in comparison to processing of information referring to other people.
There is an ongoing debate regarding causes of a ‘privileged’ status of SRP. The prioritized SRP may be driven by both the high familiarity of self-related information and its emotional significance. In previous studies of my group, an innovative control condition to the self – ‘the close-other’ – was introduced (operationalized as a freely chosen person who was the most important person at the time of experimentation) . Thus, selected by participants ‘the close-others’ presented a mixture of the familiarity and emotional load factors, exactly as it is the case for the self. It worth noting, however, that there was no possibility to separate the two factors.
The current project aims at assessing the plausible role of familiarity and emotional-load factors in isolation. In order to achieve this goal, novel experimental procedures will be elaborated that will enable investigation of the role of one factor while minimizing or even eliminating the involvement of the other one.
Two alternative research hypotheses will be tested: (i) The role of the emotional relevance of any self-related information is crucial in the emergence of the prioritized SRP. Therefore, a newly acquired information referring to the self and a newly acquired information referring to another person (i.e. the familiarity factors are equalized for the self and another person conditions but the emotional significance differs) will be associated with different brain responses, with higher brain activity in ‘the self’ condition. (ii) The familiarity is the main factor driving the preferential processing of self-related information. Thus, unknown emotional stimuli and the self-related stimuli (i.e. both types of stimuli are emotional but their levels of familiarity differ) will be associated with different brain responses, with higher responses in ‘the self’ condition.
Research project methodology
Analyses of recorded EEG data will be mainly focused on ERPs. In addition, EEG data will be used to analyze task-related functional connectivity. Patterns of functional connectivity may provide insights on how some specific brain regions communicate while processing incoming information and whether such connectivity patterns differ in the self vs. control conditions.
The impact of the emotional aspects on the SRP will be investigated by comparing ‘new names’ (arbitrary chosen just before the experimental session and subsequently linked to the self and another person) associated with the self and with a personally-known-but-not-significant person. Thus, ‘the self’ and ‘the other person’ conditions will differ only in respect of their emotional relevance. The impact of familiarity on the SRP will be addressed by a direct comparison of the self-face vs. emotional faces, with the self-face being highly familiar and emotional faces (taken from the Karolinska Directed Emotional Faces database) being unfamiliar. Statistical analyses of experimental data will be done using the traditional statistics (e.g. ANOVA). This approach will be complemented by the Bayesian statistics.
Expected impact on the development of science
The design of our studies will enable us to shed further light on the neural basis underpinning the self-related information processing and – specifically – to disentangle the familiarity and emotional significance in the SRP by orthogonally manipulating these two factors. All in all, the current project will substantially extend our knowledge on the brain activity and connectivity patterns associated with the modulatory impact of the familiarity and the emotional relevance on the preferential processing of information related to the self.
PRACOWNIA NEUROBIOLOGII PROCESÓW JĘZYKOWYCH
Instytut Biologii Doświadczalnej im. Marcelego Nenckiego
Polska Akademia Nauk
ul. Pasteura 3, 02-093 Warszawa, Polska