Paul Fitzgerald

Monash University (Australia) · Monash Alfred Psychiatry Research Centre

Mindfulness meditation involves training attention, commonly towards the current sensory experience, with an attitude of non-judgemental awareness. Theoretical perspectives suggest meditation alters the brain's predictive processing mechanisms, increasing the synaptic gain and precision with which sensory information is processed, and reducing the...

Electroencephalography (EEG) is a useful tool to measure neural activity. However, EEG data are usually contaminated with non-neural artifacts, including voltage shifts generated by eye movements and muscle activity, and other artifacts that are less easily characterizable. The confounding influence of artifacts is often addressed by decomposing da...

Background: Applying deep brain stimulation (DBS) to several brain regions has been investigated in attempts to treat highly treatment-resistant depression, with variable results. Our initial pilot data suggested that the bed nucleus of the stria terminalis (BNST) could be a promising therapeutic target. Objective: The aim of this study was to gath...

Objectives: To provide guidance for the optimal administration of repetitive transcranial magnetic stimulation, based on scientific evidence and supplemented by expert clinical consensus. Methods: Articles and information were sourced from existing guidelines and published literature. The findings were then formulated into consensus-based recomm...

Automated EEG pre-processing pipelines provide several key advantages over traditional manual data cleaning approaches; primarily, they are less time-intensive and remove potential experimenter error/bias. Automated pipelines also require fewer technical expertise as they remove the need for manual artifact identification. We recently developed the...

Repetitive transcranial magnetic stimulation (rTMS) is a promising technology to reduce chronic pain. Investigating the mechanisms of rTMS analgesia holds the potential to improve treatment efficacy. Using a double-blind and placebo-controlled design at both stimulation and pharmacologic ends, this study investigated the opioidergic mechanisms of r...

This study is a post-hoc examination of baseline MRI data from a clinical trial investigating the efficacy of repetitive transcranial magnetic stimulation (rTMS) as a treatment for patients with mild–moderate Alzheimer’s disease (AD). Herein, we investigated whether the analysis of baseline MRI data could predict the response of patients to rTMS tr...

Background: Repetitive transcranial magnetic stimulation (rTMS) has been increasingly used worldwide in the treatment of depression, however, we currently lack the means to reliably predict whether patients will respond to the treatment. Recent research suggests that the neurophysiological measures of beta power and correlation dimension may have p...

Objectives: Previous research has demonstrated that mindfulness meditation is associated with a variety of benefits, including improved mental health. Researchers have suggested these benefits may be underpinned by differences in neural oscillations. However, previous studies measuring neural oscillations have not controlled for non-oscillatory neu...

Objective Mindfulness meditation is associated with functional brain changes in regions subserving higher order cognitive processes such as attention. However, no research to date has causally probed these areas in meditators using combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG). This study aimed to investigate whe...

Objectives Regulation of the heart by the brain is a vital function of the autonomic nervous system (ANS), and healthy ANS function has been linked to a wide range of well-being measures. Although there is evidence of mindfulness-meditation related changes to brain functioning and heart functioning independently, few studies have examined the inter...

Objectives Mindfulness meditation (MM) is suggested to improve attention. Research has explored this using the “attentional-blink” (AB) task, where stimuli are rapidly presented, and a second target stimulus (T2) is often missed if presented ~300 ms after an initial target stimulus (T1). Previous research has shown improved task accuracy during the...

Obsessive-compulsive disorder (OCD) is a debilitating mental health condition that is largely resistant to conventional treatments, such as pharmacotherapy and behavioural interventions. Individualized noninvasive brain stimulation techniques such as transcranial alternating current stimulation (tACS) might be capable of successfully treating OCD t...

[This corrects the article DOI: 10.1371/journal.pone.0094788.].

Electroconvulsive therapy (ECT) is a complex medical procedure, the delivery of which requires specialist knowledge and skills. We reviewed the standards required for ECT credentialing in different jurisdictions in Australia. We reviewed the Chief Psychiatrist guidelines and statewide policy standards on ECT and focused on standards required for in...

Background- We report results of a large multisite double-blind randomized trial investigating the short and long-term efficacy of repetitive transcranial magnetic stimulation (rTMS) applied to patients with Alzheimer’s disease (AD) at mild to moderate stages, in doses of either 2 or 4 weeks of treatment (5 days/week), whilst compared with 4 weeks...

We report results of a large multisite double-blind randomized trial investigating the short and long-term efficacy of repetitive transcranial magnetic stimulation (rTMS) applied to patients with Alzheimer’s disease (AD) at mild to moderate stages, in doses of either 2 or 4 weeks of treatment (5 days/week), whilst compared with 4 weeks of sham TMS....

Objective: To find sensitive neurophysiological correlates of non-motor symptoms in Huntington's disease (HD), which are essential for the development and assessment of novel treatments. Methods: We used resting state EEG to examine differences in oscillatory activity (analysing the isolated periodic as well as the complete EEG signal) and funct...

Previous research has examined resting electroencephalographic (EEG) data to explore brain activity related to meditation. However, this research has mostly examined power in different frequency bands. Here we compared >7000 time-series features of the EEG signal to comprehensively characterize brain activity differences between meditators and non-...

In the last century, prescribing electroconvulsive therapy usually involved considering the relative merits of unilateral versus bilateral electroconvulsive therapy, with most other parameters fixed. However, research over the last 30 years has discovered that several parameters of the electroconvulsive therapy stimulus can have a significant impac...

Repetitive transcranial magnetic stimulation (rTMS) is an effective and evidence-based therapy for treatment-resistant major depressive disorder. A conventional course of rTMS applies 20-30 daily sessions over 4-6 weeks. The schedule of rTMS delivery can be accelerated by applying multiple stimulation sessions per day, which reduces the duration of...

Obsessive-Compulsive Disorder (OCD) is a mental health condition causing significant decline in the quality of life of sufferers and the limited knowledge on the pathophysiology hinders successful treatment. The aim of the current study was to examine electroencephalographic (EEG) findings of OCD to broaden our understanding of the disease. Resting...

Background: Obsessive-compulsive disorder (OCD) is a psychiatric condition leading to significant distress and poor quality of life. Successful treatment of OCD is restricted by the limited knowledge about its pathophysiology. This study aimed to investigate the pathophysiology of OCD using electroencephalographic (EEG) event-related potentials (E...

Objective Deep brain stimulation (DBS) and whether it alters patient personality is a much-debated topic within academic literature, yet rarely explored with those directly involved. This study qualitatively examined how DBS for treatment-resistant depression impacts patient personality, self-concept, and relationships from the perspectives of both...

We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the bilateral medial prefrontal cortex (mPFC) and administered at either delta or alpha frequencies, on brain activity and apathy in people with Huntington's disease (HD) (n = 17). Given the novelty of the protocol, neurotypical controls (n = 20) were als...

We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the medial prefrontal cortex (mPFC) on resting electroencephalographic (EEG) indices of oscillatory power, aperiodic exponent and offset, and functional connectivity in 22 late premanifest and early manifest stage individuals with HD and 20 neurotypical c...

Objective: Repetitive transcranial magnetic stimulation (rTMS) may be a relevant method to assist postoperative pain. However, studies to date have only used conventional 10 Hz rTMS and targeted the DLPFC for postoperative pain. A more recent form of rTMS, termed intermittent Theta Burst Stimulation (iTBS), enables to increase cortical excitabilit...

Background Response rates to repetitive transcranial magnetic stimulation (rTMS) for depression are 25-45%. Biomarkers predicting response to rTMS may reduce treatment burden. TMS-evoked neural activity recorded via electroencephalography (EEG) has potential as a biomarker of treatment response. We examined whether these measures could differentiat...

Objectives Mindfulness meditation (MM) is suggested to improve attention. Research has explored this using the ‘attentional-blink’ (AB) task, where stimuli are rapidly presented, and a second target stimulus (T2) is often missed if presented ∼300ms after an initial target stimulus (T1). This research showed improved task-accuracy and altered neural...

Objective: Electroencephalography (EEG) is often used to examine neural activity time-locked to stimuli presentation, referred to as Event-Related Potentials (ERP). However, EEG is influenced by non-neural artifacts, which can confound ERP comparisons. Artifact cleaning reduces artifacts, but often requires time-consuming manual decisions. Most au...

Objective: Electroencephalographic (EEG) data are often contaminated with non-neural artifacts which can confound experimental results. Current artifact cleaning approaches often require costly manual input. Our aim was to provide a fully automated EEG cleaning pipeline that addresses all artifact types and improves measurement of EEG outcomes MET...

Background: Despite efforts to improve targeting accuracy of the dorsolateral prefrontal cortex (DLPFC) as a repetitive transcranial magnetic stimulation (rTMS) target for Major Depressive Disorder (MDD), the heterogeneity in clinical response remains unexplained. Objective: We sought to compare the patterns of functional connectivity from the D...

Objectives Mindfulness meditation is associated with better attention function. Performance monitoring and error-processing are important aspects of attention. We investigated whether experienced meditators showed different neural activity related to performance monitoring and error-processing. Previous research has produced inconsistent results. T...

Background: Obsessive-Compulsive Disorder (OCD) is a psychiatric condition leading to significant distress and poor quality of life. Successful treatment of OCD is restricted by the limited knowledge about its pathophysiology. This study aimed to investigate the pathophysiology of OCD using electroencephalographic (EEG) event related potentials (ER...

Objectives Research into the effects of mindfulness meditation indicates improvements in mental health and cognitive function. Mechanisms underpinning these improvements include increased attentional function and decreased emotional reactivity. These functions are engaged when an individual reacts to an error. As such, researchers have examined dif...

Background: Obsessive-Compulsive Disorder (OCD) is a mental health condition causing significant decline in the quality of life of sufferers and the limited knowledge on the pathophysiology hinders successful treatment. The aim of the current study was to examine electroencephalographic (EEG) findings of OCD to broaden our understanding of the dise...

We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the bilateral medial prefrontal cortex (mPFC) and administered at either delta or alpha frequencies, on brain activity and apathy in people with Huntingtons disease (HD) (n = 17). Neurotypical controls (n = 20) were also recruited for comparison. All part...

Objective To find sensitive biological markers of non-motor symptoms in Huntington’s disease (HD), which are essential for the development and assessment of novel treatments. Methods We used resting state EEG to examine differences in oscillatory activity (analysing the isolated periodic as well as the complete EEG signal) and functional connectiv...

Objectives Mindfulness meditation is associated with better attention function. Performance monitoring and error-processing are important aspects of attention. We investigated whether experienced meditators showed different neural activity related to performance monitoring and error-processing. Previous research has produced inconsistent results. T...

Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and withou...

Electroencephalography (EEG) is commonly used to examine neural activity time-locked to the presentation of a stimulus, referred to as an Event-Related Potential (ERP). However, EEG is also influenced by non-neural artifacts, which can confound ERP comparisons. Artifact cleaning can reduce artifacts, but often requires time-consuming manual decisio...

Electroencephalographic (EEG) data is typically contaminated with non-neural artifacts which can confound the results of experiments. Artifact cleaning approaches are available, but often require time-consuming manual input and significant expertise. Advancements in artifact cleaning often only address a single artifact, are only compared against a...

Background Cognitive impairment is highly prevalent in schizophrenia and treatment options are severely limited. Development of effective treatments will rely on successful engagement of biological targets. There is growing evidence that the cognitive impairments in schizophrenia are related to impairments in prefrontal cortical inhibition and dysf...

Although previous research in alcohol dependent populations identified alterations within local structures of the addiction 'reward' circuitry, there is limited research into global features of this network, especially in early recovery. Transcranial magnetic stimulation (TMS) is capable of non-invasively perturbing the brain network while electroe...

Alzheimers disease is characterised by progressive cognitive decline for which there are currently no effective treatments. There is growing evidence that neural network dysfunction is a likely proximate cause of cognitive impairment in Alzheimers and, as such, may represent a promising therapeutic target. Here we investigated whether a course of i...

Objectives: Up to 40% of adolescents with Major Depressive Disorder (MDD) do not respond to treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective treatment in adults for MDD which shows promising efficacy in adolescents, however additional controlled investigations are needed. This pilot study compared rTMS applied to the l...

Following on from the publication of the Royal Australian and New Zealand Journal of Psychiatry Mood Disorder Clinical Practice Guidelines (2020) and criticisms of how these aberrantly addressed repetitive transcranial magnetic stimulation treatment of depression, questions have continued to be raised in the journal about this treatment by a small...

Damage to specific brain circuits can cause specific neuropsychiatric symptoms. Therapeutic stimulation to these same circuits may modulate these symptoms. To determine whether these circuits converge, we studied depression severity after brain lesions (n = 461, five datasets), transcranial magnetic stimulation (n = 151, four datasets) and deep bra...

Continuous theta burst stimulation (cTBS) is thought to reduce cortical excitability and modulate functional connectivity, possibly by altering cortical inhibition at the site of stimulation. However, most evidence comes from the motor cortex and it remains unclear whether similar effects occur following stimulation over other brain regions. We ass...

Brain connectivity can be estimated through many analyses applied to electroencephalographic (EEG) data. However, substantial heterogeneity in the implementation of connectivity methods exist. Heterogeneity in conceptualization of connectivity measures, data collection, or data pre-processing may be associated with variability in robustness of meas...

Objective: Electroconvulsive therapy (ECT) is highly effective for treatment-resistant depression (TRD) but may be associated with adverse cognitive effects. Magnetic seizure therapy (MST) is a promising alternative convulsive treatment with a safer cognitive profile. Although there is emerging evidence for the efficacy of MST for TRD as an acute t...

Late-life depression is common and often inadequately managed using existing therapies. Depression is also associated with increased markers of inflammation, suggesting a potential role for anti-inflammatory agents. ASPREE-D is a sub-study of ASPREE, a large multi-centre, population-based, double-blind, placebo-controlled trial of aspirin vs placeb...

COVER ILLUSTRATION In our paper, we examined and developed the capacity to robustly personalise the spatial targeting of transcranial magnetic stimulation (TMS) for the treatment of depression based on brain connectivity. Optimisation of the dorsolateral prefrontal cortex (DLPFC) stimulation target is based on functional connectivity (FC) with the...

Background: How “success” is defined in clinical trials of deep brain stimulation (DBS) for refractory psychiatric conditions has come into question. Standard quantitative psychopathology measures are unable to capture all changes experienced by patients and may not reflect subjective beliefs about the benefit derived. The decision to undergo DBS f...

Brain connectivity can be estimated through a wide number of analyses applied to electroencephalographic (EEG) data. However, substantial heterogeneity in the implementation of connectivity methods exist. Heterogeneity in conceptualization of connectivity measures, data collection, or data pre-processing may be associated with variability in robust...

Despite more than 25 years of research establishing the antidepressant efficacy of repetitive transcranial magnetic stimulation, there remains uncertainty about the depth and breadth of this evidence base, resulting in confusion as to where repetitive transcranial magnetic stimulation fits in the therapeutic armamentarium in the management of patie...

Background: Many patients with major depressive disorder (MDD) experience substantial impairment despite the availability of efficacious treatments. We performed a systematic review and meta-analysis to compare antidepressant outcomes in MDD with or without physical or psychiatric comorbidities. Methods: Pubmed, EMBASE, and PsycInfo were searched...

Objectives: Changes in brain connectivity have been observed within the default mode network (DMN) in chronic low back pain (CLBP), however the extent of these disruptions and how they may be related to CLBP requires further examination. While studies using seed-based analysis have found disrupted functional connectivity in the medial prefrontal c...

Cognitive impairment is highly prevalent in schizophrenia and treatment options are severely limited. A greater understanding of the pathophysiology of impaired cognition would have broad implications, including for the development of effective treatments. In the current study we used a multimodal approach to identify neurophysiological markers of...