Elsevier

Brain Research Bulletin

Volume 74, Issue 6, 1 November 2007, Pages 387-396
Brain Research Bulletin

Review
Self-awareness and the left inferior frontal gyrus: Inner speech use during self-related processing

https://doi.org/10.1016/j.brainresbull.2007.06.013Get rights and content

Abstract

To test the hypothesis of a participation of inner speech in self-referential activity we reviewed 59 studies measuring brain activity during processing of self-information in the following self-domains: agency, self-recognition, emotions, personality traits, autobiographical memory, preference judgments, and REST. The left inferior frontal gyrus (LIFG) has been shown to sustain inner speech use. We calculated the percentage of studies reporting LIFG activity for each self-dimension. 55.9% of all studies reviewed identified LIFG (and presumably inner speech) activity during self-awareness tasks. Furthermore, the LIFG was more frequently recruited during conceptual tasks (e.g., emotions, traits) than during perceptual tasks (e.g., agency, self-recognition). This supports the view of a relative involvement of inner speech in self-reflective processes.

Section snippets

Methods

English-language articles published prior to September 2006 were identified from searches using PubMed, Scirus, Cogprints, and PsycINFO.1

Overview

Fig. 1 presents the percentage of studies in which LIFG activity for each self-domain examined here was observed. Overall, 33 of the 59 studies (55.9%) reported LIFG activity during self-awareness tasks. This activity most likely reflects inner speech use, as opposed to other potential LIFG functions, namely, cognitive control (the ability to orchestrate thoughts and actions in accordance with internal goals), working memory (temporarily storing and manipulating information), selection among

Conclusion

The notion that language, and more specifically inner speech, are an integral part of self-referential activities is both intuitively appealing and largely accepted in the literature (but see [51], p. xxiii). Empirical evidence nonetheless is sparse, and the present review provides additional (albeit indirect) support to this hypothesis. 55.9% of the 59 studies we examined found LIFG activity during various self-awareness tasks. We suggest that this activity most likely consists in the use of

Conflicts of Interest

None.

Acknowledgements

We would like to thank Petra Kamstra, James Taylor, and Gen Thurlow for their constructive comments on earlier versions of this paper.

References (135)

  • C. Farrer et al.

    Experiencing oneself vs. another person as being the cause of an action: the neural correlates of the experience of agency

    NeuroImage

    (2002)
  • P. Fossati et al.

    Distributed self in episodic memory: neural correlates of successful retrieval of self-encoded positive and negative personality traits

    NeuroImage

    (2004)
  • I.I. Goldberg et al.

    When the brain loses its self: Prefrontal inactivation during sensorimotor processing

    Neuron

    (2006)
  • D.L. Greenberg et al.

    The neuropsychology of autobiographical memory

    Cortex

    (2003)
  • P.L. Jackson et al.

    Empathy examined through the neural mechanisms involved in imagining how I feel versus how you feel pain

    Neuropsychologia

    (2006)
  • J.P. Keenan et al.

    The right hemisphere and the dark side of consciousness

    Cortex

    (2005)
  • T.T.J. Kircher et al.

    Towards a functional neuroanatomy of self-processing: effects of faces and words

    Cogn. Brain Res.

    (2000)
  • T.T.J. Kircher et al.

    Recognising one's own face

    Cognition

    (2001)
  • T.W. Kjaer et al.

    Reflective self-awareness and conscious states: PET evidence for a common midline parietofrontal core

    NeuroImage

    (2002)
  • D.T. Leube et al.

    The neural correlates of perceiving one's own movements

    NeuroImage

    (2003)
  • B. Mazoyer et al.

    Cortical networks for working memory and executive functions sustain the conscious resting state in man

    Brain Res. Bull.

    (2001)
  • A. Miyake et al.

    Inner speech as a retrieval aid for task goals: the effects of cue type and articulatory suppression in the random task cuing paradigm

    Acta Psychol.

    (2004)
  • G. Northoff et al.

    Cortical midline structures and the self

    Trends Cogn. Sci.

    (2004)
  • G. Northoff et al.

    Self-referential processing in our brain: a meta-analysis of imaging studies on the self

    Neuroimage

    (2006)
  • K.N. Ochsner et al.

    The neural correlates of direct and reflected self-knowledge

    Neuroimage

    (2005)
  • M. Overgaard et al.

    The electrophysiology of introspection

    Conscious Cogn.

    (2006)
  • F. Perrin et al.

    Neural mechanisms involved in the detection of our first name: a combined ERPs and PET study

    Neuropsychologia

    (2005)
  • K.L. Phan et al.

    Neural correlates of individual ratings of emotional salience: a trial-related fMRI study

    NeuroImage

    (2004)
  • P. Piolino et al.

    Re-experiencing old memories via hippocampus: a PET study of autobiographical memory

    NeuroImage

    (2004)
  • S.M. Platek et al.

    Where am I? The neurological correlates of self and other

    Cogn. Brain Res.

    (2004)
  • R.A. Poldrack

    Can cognitive processes be inferred from neuroimaging data?

    Trends Cogn. Sci.

    (2006)
  • D.M. Amodio et al.

    Meeting of minds: the medial frontal cortex and social cognition

    Nat. Rev. Neurosci.

    (2006)
  • M.V. Baciu et al.

    fMRI assessment of hemispheric language dominance using a simple inner speech paradigm

    NMR Biomed.

    (1999)
  • J.R. Binder et al.

    Conceptual processing during the conscious resting state: A functional MRI study

    J. Cogn. Neurosci.

    (1999)
  • N.J. Blackwood et al.

    Persecutory delusions and the determination of self-relevance: an fMRI investigation

    Psychol. Med.

    (2004)
  • G. Briscoe

    Language, inner speech, and consciousness

  • N. Budwig

    Language and the construction of self: developmental reflections

  • T. Burns et al.

    The social construction of consciousness Part 1: collective consciousness and its socio-cultural foundations

    J. Cons. Stud.

    (1998)
  • R. Cabeza et al.

    Lateralization of prefrontal activity during episodic memory retrieval: evidence for the production-monitoring hypothesis

    J. Cogn. Neurosci.

    (2003)
  • R. Cabeza et al.

    Imaging cognition II: an empirical review of 275 PET and fMRI studies

    J. Cogn. Neurosci.

    (2000)
  • R. Cabeza et al.

    Brain activity during episodic retrieval of autobiographical and laboratory events: An fMRI study using a novel photo paradigm

    J. Cogn. Neurosci.

    (2004)
  • P. Carruthers

    The cognitive functions of language

    Behav. Brain Sci.

    (2002)
  • M.A. Conway et al.

    A positron emission tomography (PET) study of autobiographical memory retrieval

    Memory

    (1999)
  • F. Craik et al.

    In search of the self: a positron emission tomography study

    Psychol. Sci.

    (1999)
  • H.D. Critchley et al.

    Neural systems supporting interoceptive awareness

    Nat. Neuroci.

    (2004)
  • S.M. Daselaar et al.

    Neuroanatomical correlates of episodic encoding and retrieval in young and elderly subjects

    Brain

    (2003)
  • D.C. Dennett

    Consciousness Explained

    (1991)
  • L. Fadiga et al.

    Language in shadow

    Soc Neuro.

    (2006)
  • G.R. Fink et al.

    Cerebral representation of one's own past: Neural networks involved in autobiographical memory

    J. Neurosci.

    (1996)
  • P. Fossati et al.

    In search of the emotional self: an fMRI study using positive and negative emotional words

    Am. J. Psychiatry

    (2003)

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