Within and between session changes in subjective and neuroendocrine stress parameters during magnetic resonance imaging: A controlled scanner training study

Abstract

Accumulating evidence suggests that the magnetic resonance imaging (MRI) scanner can act as a stressor, eliciting subjective and neuroendocrine stress responses. Approaches to familiarize subjects with the scanner could help minimizing unintended effects on neural activation patterns of interest. Controlled studies on the effects of a scanner training are however missing. Using a comparative design, we analyzed within- and between session changes in subjective and neuroendocrine stress parameters in 63 healthy, scanner-naïve adults who participated in a two-day training protocol in an MRI, mock, or lab environment. A habituation task was used to assess within-session changes in subjective and neuroendocrine (cortisol) stress parameters; between-session changes were indicated by differences between days. MRI and mock, but not lab training were successful in reducing subjective distress towards the scanner. In contrast, cortisol reactivity towards the training environment generally increased during day 2, and the percentage of cortisol responders particularly rose in the mock and MRI groups. Within-session habituation of subjective arousal and anxiety was observed during both days and irrespective of training condition. Present findings demonstrate that training in a scanner environment successfully reduces subjective distress, but may also induce sensitization of endocrine stress levels during repeated scanning. Subjective distress can further be stabilized by acclimating subjects to the environment prior to the MRI assessment, including a short habituation phase into the assessment protocol. If replicated, present findings should be considered by researchers employing repeated measurement designs where subjects are exposed to a scanner more than once.

Stress Response to the Functional Magnetic Resonance Imaging Environment in Healthy Adults Relates to the Degree of Limbic Reactivity during Emotion Processing

“…Individual differences in pre-fMRI cortisol may be capturing anticipatory reactivity [47], suggesting that anticipation of the fMRI environment may act as a mild stressor, regardless of scan time, even among adults with no personal or family history of mental illness. Although this effect could reflect individual differences, independent of the experience of the fMRI environment, this finding is consistent with previous research [27,28,31,33,34] and highlights the importance of considering how stress responses may change over the course of an fMRI experiment and/or impact the task performance. Capitalizing on these individual differences in elevation and temporal pattern of cortisol activity may help to reduce heterogeneity in studies of those with active illness (i.e.…”

“…However, it is unclear whether the fMRI scanner environment itself may elicit HPA activation or may be affected by individual differences in stress responses. The anticipation and experience of fMRI procedures can potentially evoke distress, anxiety, claustrophobia, and arousal of the sympathetic nervous system [27,28,29,30]. Low to moderate levels of stress from fMRI exposure may increase cortisol levels, thereby affecting neural functioning and task performance, even among healthy control subjects [31].…”

“…Low to moderate levels of stress from fMRI exposure may increase cortisol levels, thereby affecting neural functioning and task performance, even among healthy control subjects [31]. A few investigations have demonstrated that anticipation of and first-time exposure to fMRI procedures increases cortisol and heart rate [28,31,32,33], whereas others have found that fMRI produces a more nuanced stress effect, impacting only some individuals or dissipating over the course of an fMRI scan [27,34]. The lack of clarity on this important topic is notable given the substantial amount of research conducted using emotion regulation paradigms that operate on existing assumptions about cortisol reactivity for ‘baseline' conditions.…”

Visceral pain perception in patients with irritable bowel syndrome and healthy volunteers is affected by the MRI scanner environment

“…Interaction and order effects have been previously described between imaging and nonimaging environments and consequently a standardized test session sequence was chosen for the current study to reduce variability. 68 The significant changes in sensory findings despite the limited sample size attest to the robustness of the effects of the scanner environment. Future studies must integrate more specific psychological assessment tools used at repeated time-points.…”

Using Edge Voxel Information to Improve Motion Regression for rs-fMRI Connectivity Studies

“…While it is possible to prevent some in-scanner motion through the use of new MRI pulse sequences (Bright and Murphy, 2013;Brown et al, 2010;Kundu et al, 2013;Kuperman et al, 2011;Maclaren et al, 2013;Ooi et al, 2011;White et al, 2010), training on MRI simulators before scanning (Lueken et al, 2012;Raschle et al, 2009), or even the use of head restraints and other bite bars, most data collection either do not or cannot make use of these techniques and motion artifacts are still detectable in these rs-fMRI data.…”