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Processing of self-related information in the human brain

Defining the concept of self and understanding the cortical underpinnings of such concept is a challenge for neuroscience. Many recent studies in cognitive neuroscience that have focused on the issue of how the brain gives rise to the sense of ‘self’, concentrated on self-recognition as an ability necessary for developing more complex forms of self-awareness. Self-recognition may be based on different kinds of self-related cues, such as images of one’s face or name. In our ERP and fMRI studies we have focused on the following issues related to self-recognition processes:

ATTENTION AND SELF-RELATED CUES

Self-related information seems to have a preferential access to our attentional resources (cf. the cocktail party effect). However, it remains uncertain whether this attention preference is the same for different kinds of self-related cues. In the ERP study we showed that self-name and self-face when compared with other names and faces, produced very similar patterns of behavioral and neural responses, i.e., shorter reaction times (RTs) and enhanced P300. The processing of the two self-related cues did not differ between each other, neither in RTs nor in P300 responses. In fact, the amplitudes of P300 to self-name and self-face were correlated. These results suggest that the adaptive value of different kinds of self-related cues tends to be equal and they engage attention resources to a similar extent.

MULTIPLE REPETITIONS AND SELF-NAME

The aim of this study was to investigate the effect of multiple repetitions on the processing of names and faces varying in terms of pre-experimental familiarity. We measured both behavioral and electrophysiological responses to self-, famous and unknown names and faces in three phases of the experiment. The subsequent presentations of famous and unknown names and faces were associated with increasing amplitudes of P300. In contrast, P300 remained unchanged after the subsequent presentations of self-name and self-face. Moreover, the P300 for unknown faces grew more quickly than for unknown names. The latter suggests that the process of learning faces is more effective than learning names, possibly because faces carry more semantic information.

PROCESSING OF SELF-NAME vs. OTHER NAME: ARE THE DIFFERENCES QUALITIVE OR QUANTITIVE IN NATURE?

Our own name, due to its high social relevance, is supposed to have a unique status in our information processing. However, demonstrating this phenomenon empirically proves difficult as famous and unknown names, to which self-name is often compared in the studies, may differ from self-name not only in terms of the ‘me vs. not-me’ distinction, but also as regards their emotional content and frequency of occurrence in everyday life. In the fMRI study, apart from famous and unknown names we used the names of the most important persons in our subjects’ lives. All names were presented as auditory stimuli. When compared to famous or unknown names recognition, self-name recognition was associated with robust activations in widely distributed bilateral network including fronto-temporal, limbic and subcortical structures, however, when compared to significant other’s name, the activations were present specifically in the right inferior frontal gyrus. In addition, the significant other’s name produced a similar pattern of activations to the one activated by self-name. These results suggest that the differences between own and other’s name processing may rather be quantitative than qualitative in nature.

CROSS-MODAL PATTERN OF BRAIN ACTIVATIONS ASSOCIATED WITH THE PROCESSING OF SELF- AND SIGNIFICANT OTHER’S NAME

Previous neuroimaging studies have shown that the patterns of brain activity during
the processing of personally-relevant names (e.g. own name, friend’s name, partner’s name etc.) and the names of famous people (e.g. celebrities) are different. However, it is not known how the activity in this network is influenced by the modality of the presented stimuli. In this fMRI study, we investigated the pattern of brain activations during the recognition of aurally and visually presented full names of the subject, a significant other, a famous person and unknown individuals. In both modalities, we found that the processing of self-name and the significant other’s name was associated with increased activation in the medial prefrontal cortex (MPFC). Acoustic presentations of these names also activated bilateral inferior frontal gyri (IFG). This pattern of results supports the role of MPFC in the processing of personallyrelevant information, irrespective of their modality.

Tacikowski P., Brechmann A., Nowicka A. Cross-modal pattern of brain activations associated with the processing of self- and significant other’s name. Human Brain Mapping, 34: 2069-2077, 2013 

Tacikowski P, Brechmann A, Marchewka A, Jednoróg K, Dobrowolny M, Nowicka A. Is it about self or teh significance|? An fMRI study of self-name recognition. Social Neuroscience,  6 (1): 98-107, 2011

Tacikowski, P., Jednoróg, K., Marchewka, A., Nowicka, A. How multiple repetitions influence the processing of own, famous and unknown names and faces: An ERP study. International Journal of Psychophysiology, 79: 219-230, 2011

Tacikowski P, Nowicka A. Allocation of attention to self-name and self-face: An ERP study. Biological Psychology, 84: 318-324, 2010 

 

 

Nencki Institute of Experimental Biology (c) 2015