John JB Allen

PMID: 19428431;PMCID: PMC2680784;Abstract:

Hyperactive cortico-striatal circuits including the anterior cingulate cortex (ACC) have been implicated to underlie obtrusive thoughts and repetitive behaviors in obsessive-compulsive disorder (OCD). Larger error-related negativities (ERNs) in OCD patients during simple flanker tasks have been proposed to reflect an amplified error signal in these hyperactive circuits. Such amplified error signals typically are associated with an adaptive change in response, yet in OCD these same repetitive responses persist to the point of distress and impairment. In contrast to this repetitive character of OC behavior, larger ERN amplitudes have been linked to better avoidance learning in reinforcement learning tasks. Study I thus investigated if OC symptomatology in non-patients predicted an enhanced ERN after suboptimal choices in a probabilistic learning task. Absent any behavioral differences, higher OC symptoms predicted smaller ERNs. Study II replicated this effect in an independent sample while also replicating findings of a larger ERN in a flanker task. There were no relevant behavioral differences in reinforcement learning or error monitoring as a function of symptom score. These findings implicate different, yet overlapping neural mechanisms underlying the negative deflection in the ERP following the execution of an erroneous motor response and the one following a suboptimal choice in a reinforcement learning paradigm. OC symptomatology may be dissociated in these neural systems, with hypoactivity in a system that enables learning to avoid maladaptive choices, and hyperactivity in another system that enables the same behavior to be repeated when it was assessed as not quite good enough the first time. © 2009 Elsevier Ltd. All rights reserved.

PMID: 12470444;Abstract:

Introduction: An important methodological challenge encountered in acupuncture clinical research involves the design of treatment protocols that help ensure standardization and replicability while allowing for the necessary flexibility to tailor treatments to each individual. Manualization of protocols used in clinical trials of acupuncture and other traditionally-based complementary and alternative medicine (CAM) systems facilitates the systematic delivery of replicable and standardized, yet individually-tailored treatments. Objectives: To facilitate high-quality CAM acupuncture research by outlining a method for the systematic design and implementation of protocols used in CAM clinical trials based on the concept of treatment manualization. Methods: A series of treatment manuals was developed to systematically articulate the Chinese medical theoretical and clinical framework for a given Western-defined illness, to increase the quality and consistency of treatment, and to standardize the technical aspects of the protocol. In all, three manuals were developed for National Institutes of Health (NIH)-funded clinical trials of acupuncture for depression, spasticity in cerebral palsy, and repetitive stress injury. In Part I, the rationale underlying these manuals and the challenges encountered in creating them are discussed, and qualitative assessments of their utility are provided. In Part II, a methodology to develop treatment manuals for use in clinical trials is detailed, and examples are given. Conclusions: A treatment manual provides a precise way to train and supervise practitioners, enable evaluation of conformity and competence, facilitate the training process, and increase the ability to identify the active therapeutic ingredients in clinical trials of acupuncture.

The error-related negativity (ERN) is a response-locked brain potential (ERP) occurring 80-100ms following response errors. This report contrasts three views of the genesis of the ERN, testing the classic view that time-locked phasic bursts give rise to the ERN against the view that the ERN arises from a pure phase-resetting of ongoing theta (4-7Hz) EEG activity and the view that the ERN is generated - at least in part - by a phase-resetting and amplitude enhancement of ongoing theta EEG activity.

PMID: 22084638;PMCID: PMC3210982;Abstract:

The medial prefrontal cortex (mPFC) is particularly reactive to signals of error, punishment, and conflict in the service of behavioral adaptation and it is consistently implicated in the etiology of major depressive disorder (MDD). This association makes conceptual sense, given that MDD has been associated with hyper-reactivity in neural systems associated with punishment processing. Yet in practice, depression-related variance in measures of mPFC functioning often fails to relate to performance. For example, neuroelectric reflections of mediofrontal error signals are often found to be larger in MDD, but a deficit in post-error performance suggests that these error signals are not being used to rapidly adapt behavior. Thus, it remains unknown if depression-related variance in error signals reflects a meaningful alteration in the use of error or punishment information. However, larger mediofrontal error signals have also been related to another behavioral tendency: increased accuracy in avoidance learning. The integrity of this error-avoidance system remains untested in MDD. In this study, EEG was recorded as 21 symptomatic, drug-free participants with current or past MDD and 24 control participants performed a probabilistic reinforcement learning task. Depressed participants had larger mid-frontal EEG responses to error feedback than controls. The direct relationship between error signal amplitudes and avoidance learning accuracy was replicated. Crucially, this relationship was stronger in depressed participants for high conflict "lose-lose" situations, demonstrating a selective alteration of avoidance learning. This investigation provided evidence that larger error signal amplitudes in depression are associated with increased avoidance learning, identifying a candidate mechanistic model for hypersensitivity to negative outcomes in depression. © 2011 Cavanagh, Bismark, Frank and Allen.

PMID: 12184348;Abstract:

Conventional treatments for Major Depression, although reasonably effective, leave many without lasting relief. Alternative approaches would therefore be welcome for both short- and long-term treatment of depression. Thirty-eight women were randomized to one of three treatment conditions in a double-blind randomized controlled trial of acupuncture in depression. All participants eventually received eight weeks of acupuncture treatment specifically for depression. From among the 33 women who completed treatment, 26 (79%) were interviewed at six-month follow-up. Relapse rates were comparable to those of established treatments, with four of the 17 women (24%) who achieved full remission at the conclusion of treatment experiencing a relapse six months later. Compared to other empirically validated treatments, acupuncture designed specifically to treat major depression produces results that are comparable in terms of rates of response and of relapse or recurrence. These results suggest a larger trial of acupuncture in the acute- and maintenance-phase treatment of depression is warranted. © 2002 Elsevier Science Ltd. All rights reserved.