Neurofeedback - learning to modulate brain function through real-time monitoring of current brain state - is both a powerful method to perturb and probe brain function and an exciting potential clinical tool. For neurofeedback effects to be useful clinically, they must persist. Here we examine the time course of symptom change following neurofeedback in two clinical populations, combining data from two ongoing neurofeedback studies. This analysis reveals a shared pattern of symptom change, in which symptoms continue to improve for weeks after neurofeedback. This time course has several implications for future neurofeedback studies. Most neurofeedback studies are not designed to test an intervention with this temporal pattern of response. We recommend that new studies incorporate regular follow-up of subjects for weeks or months after the intervention to ensure that the time point of greatest effect is sampled. Furthermore, this time course of continuing clinical change has implications for crossover designs, which may attribute long-term, ongoing effects of real neurofeedback to the control intervention that follows. Finally, interleaving neurofeedback sessions with assessments and examining when clinical improvement peaks may not be an appropriate approach to determine the optimal number of sessions for an application.

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Hyperactivation of amygdala is a neural marker for post-traumatic stress disorder (PTSD) and improvement in control over amygdala activity has been associated with treatment success in PTSD. In this randomized, double-blind clinical trial we evaluated the efficacy of a real-time fMRI neurofeedback intervention designed to train control over amygdala activity following trauma recall. Twenty-five patients with PTSD completed three sessions of neurofeedback training in which they attempted to downregulate the feedback signal after exposure to personalized trauma scripts. For subjects in the active experimental group (N = 14), the feedback signal was from a functionally localized region of their amygdala associated with trauma recall. For subjects in the control group (N = 11), yoked-sham feedback was provided. Changes in control over the amygdala and PTSD symptoms served as the primary and secondary outcome measurements, respectively. We found significantly greater improvements in control over amygdala activity in the active group than in the control group 30-days following the intervention. Both groups showed improvements in symptom scores, however the symptom reduction in the active group was not significantly greater than in the control group. Our finding of greater improvement in amygdala control suggests potential clinical application of neurofeedback in PTSD treatment. Thus, further development of amygdala neurofeedback training in PTSD treatment, including evaluation in larger samples, is warranted.

False recognition, or the mis-categorization of a “new” stimulus as “old,” might support fixed false beliefs by blocking new learning or otherwise contributing to internal representations of the world that are at odds with reality. However, the mechanisms through which false recognition is facilitated among paranoid individuals remain unclear. We examined 2 phenomena that may contribute to this effect: an overreliance on fluency-based processes during recognition, manifesting as a lower threshold for judging items as recently studied, and a propensity to require less information to come to a highly confident judgment. The former would be expected to be particularly pronounced among items that are generally familiar, as opposed to completely novel. Here, we manipulated familiarity in a recognition memory paradigm by using stimuli that varied in their rate of extraexperimental exposure (i.e., real words vs. pseudowords). Further, to determine whether paranoia was associated with a tendency to differentially misallocate confidence to errors, we calculated a hierarchical Bayesian estimate of metacognitive sensitivity (meta-d′) in addition to the more classic d′. In line with our hypotheses, paranoia was associated with an increased rate of false alarm errors, differentially so for familiar versus unfamiliar stimuli, suggesting that a context-agnostic, familiarity-based memory system might underlie observed memory distortions. What’s more, paranoia was associated with heightened confidence on error trials and reduced metacognitive sensitivity. These findings highlight 2 distinct deficits—in both novelty detection and metacognitive monitoring—that contribute to false recognition judgments, offering targets for cognitive interventions to reduce memory distortion among paranoid individuals.

Visual stimuli are often used for obsessive-compulsive (OC) symptom provocation in research studies. We tested the induction of anxiety and OC checking symptoms across different types of checking provocation stimuli in three populations: individuals with obsessive compulsive disorder (OCD), individuals with checking symptoms but without a diagnosis of OCD, and control individuals with neither checking symptoms nor a clinical diagnosis. One set of provocative images depicted objects that are commonly associated with checking anxiety. Another set ('enhanced provocative images') depicted similar objects but also included contextual cues suggesting a specific harmful scenario that could occur. As expected, the enhanced provocative images were more effective at inducing anxiety and OC symptoms than the standard provocative images. Future studies requiring checking symptom provocation should therefore consider incorporating similarly suggestive images. Individuals with clinical OCD reported the greatest provocation in response to these images, followed by those with nonclinical checking, followed by control individuals. Thus, these stimuli are able to provoke OC checking symptoms and anxiety differentially across groups, with the intensity of provocation reflecting diagnostic status. All groups demonstrated a similar qualitative pattern of provocation across images. Finally, in all groups, reported anxiety closely tracked intrusive thoughts and checking urges.