Elsevier

Brain Research Bulletin

Volume 81, Issue 6, 5 April 2010, Pages 565-573
Brain Research Bulletin

Research report
The resting state questionnaire: An introspective questionnaire for evaluation of inner experience during the conscious resting state

https://doi.org/10.1016/j.brainresbull.2009.11.014Get rights and content

Abstract

We designed a semi-structured questionnaire for the introspective evaluation of inner experience of participants undergoing functional magnetic resonance imaging (fMRI) in the resting state. This resting state questionnaire (ReSQ) consists of 62 items organized by five main types of mental activity: visual mental imagery (IMAG); inner language (LANG), split into two subtypes, inner speech (SPEE) and auditory mental imagery (AUDI); somatosensory awareness (SOMA); inner musical experience (MUSI); and mental manipulation of numbers (NUMB). For IMAG and LANG, additional questions estimated association of such activities with ongoing learning, retrospective memories, or prospective thoughts. Using a 0–100% scale, the participant quantitatively rated the proportion of time spent in each mental activity during the resting state fMRI acquisition. A total of 180 healthy volunteers completed the ReSQ immediately after being scanned with fMRI while at rest. Of these, 66% exhibited dominance of a type of mental activity at rest (IMAG: 35%; LANG: 17%; SOMA: 7%; MUSI: 6%; NUMB: 1%). A majority of participants reported either retrospective memories (82%) or prospective thoughts (78%), with 58% of participants reporting both in at least one type of mental activity. Thoughts related to ongoing learning were low (37% of participants). The present results are consistent with those of previous studies investigating inner experience in a natural environment. In conclusion, we provide a robust and easy-to-implement tool for the exploration of mental activities during rest of healthy participants undergoing fMRI. This tool relies on normative data acquired from a 180-participant sample balanced for sex and handedness.

Introduction

A significant part of our wakeful brain activity is self-directed rather than goal-directed, consisting of periods of uncontrolled stream of thoughts, recollection of past episodes of our life, analysis of current inner sensations, thinking about problems, or planning for the future. This particular mind state, also referred to as “random episodic silent thinking” (REST) [1], “default mode” [34], or “conscious rest” [4], [28], has received increased attention in recent years because the corresponding brain state is both a physiological baseline [34] and a state of high neural activity and energy metabolism [38].

Several investigators have identified a large-scale cortical network with activity that appears to be maximal during REST and reduced during goal-directed cognitive tasks [4], [28], [30], [31], [37]. This network seems to support, at least in part, self-oriented activities [1], [4], [7], [12], [19], [28]. Modulation in brain default mode network activity due to life events, such as development [15], [16], learning [27], aging [2], [13], and neuropsychiatric diseases [36], [39], [43], has also been studied with the underlying hypothesis that the associated behavioral/cognitive changes or deficits may be related to such modulation.

A major concern in all neuroimaging experiments addressing the resting state is the assessment of the participant's mental content while being imaged. First, the researcher must ensure that the participant has adequately followed instructions. Second, although some investigators have made efforts to perform online evaluation of the participant's mental content while in the resting state [8], [31], avoiding interaction with the participant being scanned is recommended to prevent switching between a free mode and a goal-directed mode. As a consequence, assessment of participant mental content during a functional magnetic resonance imaging (fMRI) study must rely on a posteriori introspective evaluation.

We previously attempted to complete such an introspective post-fMRI evaluation in a group of participants who were scanned at rest with positron emission tomography (PET) [28]. This evaluation was qualitative, however, and restricted to having the participants indicate whether their mental content during the resting state consisted mainly of mental imagery or inner language. However, the conscious resting state is a mind state during which various types of thought, not necessarily limited to language and imagery, alternate. Here we report on a new questionnaire, the resting state questionnaire (ReSQ) that we designed to obtain a quantitative and detailed evaluation of the mental content during the resting state. A total of 180 healthy adults, including women and men and right- and left-handers, completed this questionnaire, and English and French versions are available upon request.

Section snippets

Participants and experimental context

The present study included 180 young (26.0 ± 6.6 years, mean ± SD), healthy volunteers. The participants had no history of any psychiatric, neurological or medical conditions. The sample was balanced for sex (91 women) and handedness (90 left-handers). All participants gave their informed written consent, and the local ethical committee (CPP de Basse-Normandie, France) approved the study. Participant handedness was assessed using the Edinburgh Handedness Inventory [33], and educational level was

Participants

Table 2 shows handedness, age, and educational level for the sample. The sample average handedness scores were 88.6 ± 18.0 (N = 90, mean ± SD) for the right-handers and −61.4 ± 38.6 (N = 90) for the left-handers. The sample mean age was 26.0 ± 6.6 years (N = 180, range = [18.1–51.3] years) without sex or handedness effect (ANOVA). The mean educational level of the participants was 15 ± 3 years (mean ± SD, range = [11–20] years), indicating an average of 3 years at a university, with left-handers having a

Discussion

The development of neuroimaging techniques that allow correlation of subjective experience with a neuroanatomical substrate has triggered a new interest in the study of the neural bases of inner experience, a phenomenon long considered to be beyond the reach of scientific investigations [20]. Consciousness access is the phenomenon by which information is accessible to the mind for report. We can therefore access our thinking (we can introspect) and we can report accurately about our

Conclusions and perspectives

We conclude that ReSQ is a robust and easy tool for exploration of the mental activities of healthy participants during the resting state of an fMRI experiment. The results are consistent with those from studies investigating inner experience under natural conditions. These behavioral data add some evidence to the self-referential memory and planning activity nature of the resting state. The paper also provides a normative set of data, built on sex and handedness equilibrated in a participant

References (43)

  • R.C. Oldfield

    The assessment and analysis of handedness: the edinburgh inventory

    Neuropsychologia

    (1971)
  • R.G. Shulman et al.

    Energetic basis of brain activity: implications for neuroimaging

    Trends Neurosci.

    (2004)
  • N.C. Andreasen et al.

    Remembering the past: two facets of episodic memory explored with positron emission tomography

    Am. J. Psychiatry

    (1995)
  • B.J. Baars

    How brain reveals mind: neural studies support the fundamental role of conscious experience

    J. Conscious. Stud.

    (2003)
  • J.R. Binder et al.

    Conceptual processing during the conscious resting state

    A Funct. MRI study. J. Cogn. Neurosci.

    (1999)
  • W. Brodsky et al.

    The mental representation of music notation: notational audiation

    J. Exp. Psychol. Hum. Percept. Perform.

    (2008)
  • K. Christoff et al.

    Experience sampling during fMRI reveals default network and executive system contributions to mind wandering

    Proc. Natl. Acad. Sci. U.S.A.

    (2009)
  • M.A. Conway

    Sensory-perceptual episodic memory and its context: autobiographical memory

    Philos. Trans. R. Soc. Lond.

    (2001)
  • M.A. Conway et al.

    Images and goals

    Memory

    (2004)
  • M.A. Conway et al.

    The construction of autobiographical memories in the self-memory system

    Psychol. Rev.

    (2000)
  • J.S. Damoiseaux et al.

    Reduced resting-state brain activity in the “default network” in normal aging

    Cereb. Cortex

    (2008)
  • Cited by (0)

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