Friday, June 22, 2012

Research - Neural activity associated with self-reflection


This article details a research project that sought to identify the specificity of brain regions involved in self-reflection vs. other reflection (thinking about a known person). They were able to identify the cingulate, medial and lateral prefrontal, insular and inferior parietal regions as relevant for self-related cognition. One possible application of this information, suggested by the authors, is with the investigation of pathological self-related processing in individuals. 

The question for me, as always, is if we scan the brain of a person with dysfunctional self-related processing (for example, someone experiencing depersonalization) and we find organic dysfunction in these brain regions, was the person born with an organic abnormality, did they suffer some form on insult (TBI) that created the problem, or is there a link between subjective experience and dysfunctional changes in brain architecture?

It's good to identify the brain regions involved in dysfunction, but if we cannot also identify the cause of the abnormality, we are left with no real understanding of the etiology.


Neural activity associated with self-reflection

Uwe Herwig, Tina Kaffenberger, Caroline Schell, Lutz Jäncke, Annette B Bruehl
BMC Neuroscience 2012, 13:52. doi:10.1186/1471-2202-13-52

Abstract

Background
Self-referential cognitions are important for self-monitoring and self-regulation. Previous studies have addressed the neural correlates of self-referential processes in response to or related to external stimuli. We here investigated brain activity associated with a short, exclusively mental process of self-reflection in the absence of external stimuli or behavioural requirements. Healthy subjects reflected either on themselves, a personally known or an unknown person during functional magnetic resonance imaging (fMRI). The reflection period was initialized by a cue and followed by photographs of the respective persons (perception of pictures of oneself or the other person).

Results
Self-reflection, compared with reflecting on the other persons and to a major part also compared with perceiving photographs of one-self, was associated with more prominent dorsomedial and lateral prefrontal, insular, anterior and posterior cingulate activations. Whereas some of these areas showed activity in the “other”-conditions as well, self-selective characteristics were revealed in right dorsolateral prefrontal and posterior cingulate cortex for self-reflection; in anterior cingulate cortex for self-perception and in the left inferior parietal lobe for self-reflection and -perception.

Conclusions
Altogether, cingulate, medial and lateral prefrontal, insular and inferior parietal regions show relevance for self-related cognitions, with in part self-specificity in terms of comparison with the known-, unknown- and perception-conditions. Notably, the results are obtained here without behavioural response supporting the reliability of this methodological approach of applying a solely mental intervention. We suggest considering the reported structures when investigating psychopathologically affected self-related processing.

Background

Humans not only have a neural representation of the external and social world, they also have the ability to represent themselves as coherent human beings and as a self. They can reflect on themselves as a person and they have a neural representation of their own body. Understanding the basis of neural self-representation is not only interesting from a philosophical or scientific point of view but may also have practical implications in psychiatry, for example, in understanding disturbed self-related functions occurring during depression [1].

In the last decade, a growing number of studies has assessed the neural bases of self-related processes using functional neuroimaging methods [2-11] and electrical tomographic techniques [12]. In these studies, brain activity was examined, for example, while viewing photographs of oneself compared to that obtained while viewing photographs of other persons, or while recognizing one’s own face, names, voices or morphed photographs [3,4,13-19]. Other approaches have addressed the relevance of trait adjectives with reference to oneself and compared brain activity to that occurring under control conditions, for example reference of trait adjectives to close friends or others, or have applied more complex self-referential tasks which required responses to external stimuli [2,3,12,20-25]. Self-referential memory [26-28], emotional domains [29,30] and cognitive aspects in the spatial domain such as navigational tasks or perspective-taking tasks [31,32] have also been examined. Self-reference has been further studied in relation to the external world or from the perspective of the self as an object, i.e. from the perspective of a third-person [9,33,34] or relative to certain features of the self, for example individual goals [35], psychological aspects [36] and social issues [20].

Recent meta-analyses of functional neuroimaging studies have confirmed the involvement of certain brain regions in self-referential processes [6,10,37]: medial prefrontal cortex (MPFC), anterior and posterior cingulate cortices (ACC, PCC) and (pre)cuneus, which also reflect the concept of cortical midline areas and self-reference [38]. Further, the lateral and ventromedial prefrontal, medial temporal, and parieto-temporal regions, the insular cortex and other regions were found to be active during self-referential processes [6,9,10,25,37].

From a methodological perspective, all these studies have in common that they examine the neural bases of self-reference in response to external stimuli or in comparison to behavioural tasks potentially involving other cognitive domains. This could make it difficult to assess self-referential activity possible interferences from neural activity related to external cognitions or actions. Certainly, these studies acknowledged the methodological issue of implementing behavioural controls. However, it may be of value to assess whether or not the brain areas reported are also active during a restrictively mental and not behavioural self-referential condition, and whether these areas show more or less specific activity for self-reference than other areas in terms of activation during self-reflection but not during reflection about others or during self-photo perception. In this study, we investigated the neural processes underlying self-reference in the sense of self-reflection, however, compared to other studies without possibly interfering for instance visual or verbal stimuli. The term “self-reflection” comprises at very least processes such as becoming aware of and reflecting on one’s current and past experiences and one’s self-concept, including the self-relevance of trait words [39]. The division between self-reflection, and self-recognition or self-awareness and even self-consciousness is not clear-cut [38,40,41]. Some authors have defined self-reflection as cognitively reflecting on one’s sense of self, i.e. on a collection of schema regarding one’s abilities and traits [42]. Accordingly, we here aimed to direct the subjects to reflect on themselves as a person and on their identity. This was realized by issuing a concrete instruction to the subject for self-reflection (e.g. “who am I?”), whereby the subjects could select their own content. As control condition, we instructed subjects to reflect on a personal acquaintance of the same gender. This was to control for the process of reflecting on a personally known person and the related knowledge and memory. Subjects were further requested to reflect on an unknown person who was introduced to them by photograph prior to the functional magnetic resonance imaging (fMRI) session. This controlled for general reflection on a person. In order to intensify reflection, we also presented photographs of the respective persons after the reflection period. Considering the unconventional methodological approach with respect to non-implementation of a behavioural control, we applied very conservative statistics.

Our hypothesis was that the solely mental task of self-reflection would still be associated with brain activity particularly in cortical midline regions such as the medial prefrontal (MPFC) and cingulate cortices, but also in ventrolateral and dorsolateral prefrontal and insular regions and in lateral parietal cortex areas [2,9,25,43]. We predicted different activities for mental self-reflection than for perception of self-related stimuli, thus insinuating self-reflection specific activation. In addition, we were interested in whether or not certain brain regions are specifically associated with self-reflection (refl-self) and self-perception (perc-self) when compared to those areas associated with reflections on other persons (refl-known, reflunknown) or the perception of photographs of other persons (perc-known, perc-unknown).

Read the rest of the study.

Full citation:
Herwig, U., Kaffenberger, T., Schell, C., Jäncke, L. and Bruehl, A.B. (2012, May 24). Neural activity associated with self-reflection. BMC Neuroscience, 13:52. doi:10.1186/1471-2202-13-52
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