Neuroimaging in Psychiatry: From Bench to Bedside

This perspective considers the present and the future role of different neuroimaging techniques in the field of psychiatry. After identifying shortcomings of the mainly symptom-focussed diagnostic processes and treatment decisions in modern psychiatry, we suggest topics where neuroimaging methods have the potential to help. These include better understanding of the pathophysiology, improved diagnoses, assistance in therapeutic decisions and the supervision of treatment success by direct assessment of improvement in disease-related brain functions. These different questions are illustrated by examples from neuroimaging studies, with a focus on severe mental and neuropsychiatric illnesses such as schizophrenia and depression. Despite all reservations addressed in the article, we are optimistic that neuroimaging has a huge potential with regard to the above-mentioned questions. We expect that neuroimaging will play an increasing role in the future refinement of the diagnostic process and aid in the development of new therapies in the field of psychiatry

Angry expressions strengthen the encoding and maintenance of face identity representations in visual working memory

This work was funded by a BBSRC grant (BB/G021538/2) to all authors.Peer reviewedPreprin

Functional imaging reveals working memory and attention interact to produce the attentional blink

Copyright @ 2012 Massachusetts Institute of Technology PressIf two centrally presented visual stimuli occur within approximately half a second of each other, the second target often fails to be reported correctly. This effect, called the attentional blink (AB; Raymond, J. E., Shapiro, K. L., & Arnell, K. M. Temporary suppression of visual processing in an RSVP task: An attentional blink? Journal of Experimental Psychology, Human Perception and Performance, 18, 849-860, 1992], has been attributed to a resource "bottleneck," likely arising as a failure of attention during encoding into or retrieval from visual working memory (WM). Here we present participants with a hybrid WM-AB study while they undergo fMRI to provide insight into the neural underpinnings of this bottleneck. Consistent with a WM-based bottleneck account, fronto-parietal brain areas exhibited a WM load-dependent modulation of neural responses during the AB task. These results are consistent with the view that WM and attention share a capacity-limited resource and provide insight into the neural structures that underlie resource allocation in tasks requiring joint use of WM and attention.This research was supported by a project grant (071944) from the Wellcome Trust to Kimron Shapiro

Excessive response to provocation rather than disinhibition mediates irritable behaviour in Huntington’s disease

BackgroundIrritable and impulsive behaviour are common in Huntington’s disease (HD: an autosomal dominant disorder causing degeneration in cortico-striatal networks). However, the cognitive mechanisms underlying these symptoms remain unclear, and previous research has not determined if common mechanisms underpin both symptoms. Here we used established and novel tasks to probe different aspects of irritable and impulsive behaviour to determine the neural mechanisms involved.MethodsWe recruited a cohort of 53 gene positive HD participants and 26 controls from non-affected family members and local volunteers. We used established questionnaire measures of irritability in HD (Snaith Irritability Scale, Problem Behaviours Assessment) and impulsivity [Urgency, Premeditation Perseverance, Sensation-seeking, Positive urgency scale (UPPSP), Barratt Impulsivity Scale], in addition to cognitive tasks of provocation, motor inhibition, delay discounting and decision making under uncertainty. We used generalised linear models to determine differences between cases and controls, and associations with irritability in the HD group.ResultsWe found differences between cases and controls on the negative urgency subscale of the UPPSP, which was associated with irritability in HD. The frustrative non-reward provocation task also showed differences between cases and controls, in addition to predicting irritability in HD. The stop signal reaction time task showed case-control differences but was not associated with irritability in HD. None of the other measures showed group differences or predicted irritability in HD after correcting for confounding variables.DiscussionIrritability in HD is mediated by excessive response to provocation, rather than a failure of motor inhibition

ZNF804A genotype modulates neural activity during working memory for faces

Copyright © 2013 S. Karger AG, Basel.Peer reviewedPublisher PD

So pretty! The neural correlates of self-other vs familiar-other attractiveness comparisons.

Previous research has demonstrated that comparing two persons activates a frontoparietal network associated with numbers and nonsocial magnitudes. However, it is unclear whether this network is also recruited by comparisons involving the self. Self-reflection engages self-serving motivations (e.g., the maintenance of a positive self-image) and is associated with specific brain structures, such as the medial prefrontal cortex (MPFC), the anterior insula (AI) and the anterior cingulate cortex (ACC). Self-other comparisons may thus rely on distinct neural activity. To clarify this question, we used fMRI and asked female participants to compare their own attractiveness (or the attractiveness of a familiar woman) to pictures of unknown women. Participants were slower for comparisons with targets whose attractiveness was similar to their own (or their familiar other). Yet although this behavioral result resembles the distance effect reported for nonsocial magnitudes, at the brain level, it was linked to the activity of the AI, the ACC and the MPFC. The effect of distance in these regions was stronger for self-other than familiar-other comparisons. We interpret these results in relation to previous literature in social psychology and social neuroscience

Dissecting the neurocomputational bases of patch-switching

The survival and well-being of humans require solving the patch-switching problem: we must decide when to stop collecting rewards in a current patch and travel somewhere else where gains may be higher. Previous studies suggested that frontal regions are underpinned by several processes in the context of foraging decisions such as tracking task difficulty, and/or the value of exploring the environment. To dissociate between these processes, participants completed an fMRI patch-switching learning task inspired by behavioral ecology. By analyzing >11,000 trials collected across 21 participants, we found that the activation in the cingulate cortex was closely related to several patch-switching-related variables including the decision to leave the current patch, the encounter of a new patch, the harvest value, and the relative forage value. Learning-induced changes in the patch-switching threshold were tracked by activity within frontoparietal regions including the superior frontal gyrus and angular gyrus. Our findings suggest that frontoparietal regions shape patch-switching learning apart from encoding classical non-learning foraging processes. These findings provide a novel neurobiological understanding of how learning emerges neurocomputationally shaping patch-switching behavior with implications in real-life choices such as job selection and pave the way for future studies to probe the causal role of these neurobiological mechanisms

Functional magnetic resonance imaging neurofeedback-guided motor imagery training and motor training for Parkinson's Disease: randomized trial

Objective: Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF) uses feedback of the patient’s own brain activity to self-regulate brain networks which in turn could lead to a change in behavior and clinical symptoms. The objective was to determine the effect of NF and motor training (MOT) alone on motor and non-motor functions in Parkinson’s Disease (PD) in a 10-week small Phase I randomized controlled trial. Methods: Thirty patients with Parkinson’s disease (PD; Hoehn and Yahr I-III) and no significant comorbidity took part in the trial with random allocation to two groups. Group 1 (NF: 15 patients) received rt-fMRI-NF with MOT. Group 2 (MOT: 15 patients) received MOT alone. The primary outcome measure was the Movement Disorder Society—Unified PD Rating Scale-Motor scale (MDS-UPDRS-MS), administered pre- and post-intervention “off-medication”. The secondary outcome measures were the “on-medication” MDS-UPDRS, the PD Questionnaire-39, and quantitative motor assessments after 4 and 10 weeks. Results: Patients in the NF group were able to upregulate activity in the supplementary motor area (SMA) by using motor imagery. They improved by an average of 4.5 points on the MDS-UPDRS-MS in the “off-medication” state (95% confidence interval: −2.5 to −6.6), whereas the MOT group improved only by 1.9 points (95% confidence interval +3.2 to −6.8). The improvement in the intervention group meets the minimal clinically important difference which is also on par with other non-invasive therapies such as repetitive Transcranial Magnetic Stimulation (rTMS). However, the improvement did not differ significantly between the groups. No adverse events were reported in either group. Interpretation: This Phase I study suggests that NF combined with MOT is safe and improves motor symptoms immediately after treatment, but larger trials are needed to explore its superiority over active control conditions

Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions

Open Access funded by Wellcome Trust Under a Creative Commons license Acknowledgments This research was supported by the Wellcome Trust (grant number 077185/Z/05/Z) and the Welsh Assembly Government through the Wales Institute of Cognitive Neuroscience.Peer reviewedPublisher PD