Amygdala Regulation Following fMRI-Neurofeedback without Instructed Strategies

Abstract

Within the field of functional magnetic resonance imaging (fMRI) neurofeedback, most studies provide subjects with instructions or suggest strategies to regulate a particular brain area, while other neuro-/biofeedback approaches often do not. This study is the first to investigate the hypothesis that subjects are able to utilize fMRI neurofeedback to learn to differentially modulate the fMRI signal from the bilateral amygdala congruent with the prescribed regulation direction without an instructed or suggested strategy and apply what they learned even when feedback is no longer available. Thirty-two subjects were included in the analysis. Data were collected at 3 Tesla using blood oxygenation level dependent (BOLD)-sensitivity optimized multi-echo EPI. Based on the mean contrast between up- and down-regulation in the amygdala in a post-training scan without feedback following three neurofeedback sessions, subjects were able to regulate their amygdala congruent with the prescribed directions with a moderate effect size of Cohen’s d = 0.43 (95% conf. int. 0.23–0.64). This effect size would be reduced, however, through stricter exclusion criteria for subjects that show alterations in respiration. Regulation capacity was positively correlated with subjective arousal ratings and negatively correlated with agreeableness and susceptibility to anger. A learning effect over the training sessions was only observed with end-of-block feedback (EoBF) but not with continuous feedback (trend). The results confirm the above hypothesis. Further studies are needed to compare effect sizes of regulation capacity for approaches with and without instructed strategies.

Monitoring and control of amygdala neurofeedback involves distributed information processing in the human brain

“…To fill this knowledge gap, we adapted an rtfMRI amygdala neurofeedback protocol established by our group (Paret et al, 2014). Previous research has shown that amygdala regulation with neurofeedback is feasible (Br€ uhl et al, 2014;Marxen et al, 2016;Paret et al, 2014;Zotev et al, 2011) and can improve the regulation of emotions in patients suffering from affective dysregulation (Gerin et al, 2016;Keynan et al, 2016;Nicholson et al, 2016;Paret et al, 2016a;Young et al, 2014Young et al, , 2017aYoung et al, , 2017bYuan et al, 2014). Emotion regulation is associated with specific control of amygdala activation (Buhle et al, 2013) and involves the dlPFC (Kalisch, 2009), whereas the monitoring of affect involves the ACC and medial PFC (Etkin et al, 2011).…”

A network engineering perspective on probing and perturbing cognition with neurofeedback

“…To test whether a subject's ability to directly modulate target brain regions improves task performance, investigators can present sensory feedback that scales with the amplitude of brain activity. The use of this technique has revealed that subjects can learn to regulate the activity of subcortical areas, including the amygdala and basal ganglia, and extended areas of the limbic system, including the insula and parahippocampus . Interestingly, participants can also learn to modulate the primary sensory motor cortex (primary motor area, premotor cortex, and supplementary motor area) as well as higher‐order areas, including the anterior cingulate cortex, ventral tegmental area, frontal and parietal cognitive control areas, anterior midcingulate cortex, and frontal cortex .…”

“…Studies demonstrate that, even when explicit instructions or strategies are not provided, subjects can search for an effective strategy to self‐regulate functional brain dynamics . Such open‐ended experimentation is especially powerful for investigating how subjects employ unique strategies to modulate brain dynamics . Indeed, it is of interest to explicitly map individual variability in the chosen control strategy to the subjects' ability to modulate target brain areas.…”

“…By engineering the feedback signal, neurofeedback investigators can flexibly design novel experimental paradigms to study the role of cognition in single brain areas or across multiple brain areas in tandem. This practice has already demonstrated the ability to direct neurofeedback to more focal targets or to perturb dynamics across more distributed targets . In addition, the difficulty of the neurofeedback training can be titrated to affect a specific change on both attentional circuits and regions devoted to internally directed cognition .…”

“…26,38,47,57 Such open-ended experimentation is especially powerful for investigating how subjects employ unique strategies to modulate brain dynamics. 38,40,57 Indeed, it is of interest to explicitly map individual variability in the chosen control strategy to the subjects' ability to modulate target brain areas. Understanding the relationship between cognitive strategy and effective modulation could inform experimental approaches to fine-tune the mapping between cognitive processes and functional brain regions ( Fig.…”