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

"Distracters" do not always distract : Visual working memory for angry faces is enhanced by incidental emotional words.

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A Novel, Fast, Reliable, and Data-Driven Method for Simultaneous Single-Trial Mining and Amplitude—Latency Estimation Based on Proximity Graphs and Network Analysis

Both amplitude and latency of single-trial EEG/MEG recordings provide valuable information regarding functionality of the human brain. In this article, we provided a data-driven graph and network-based framework for mining information from multi-trial event-related brain recordings. In the first part, we provide the general outline of the proposed methodological approach. In the second part, we provide a more detailed illustration, and present the obtained results on every step of the algorithmic procedure. To justify the proposed framework instead of presenting the analytic data mining and graph-based steps, we address the problem of response variability, a prerequisite to reliable estimates for both the amplitude and latency on specific N/P components linked to the nature of the stimuli. The major question addressed in this study is the selection of representative single-trials with the aim of uncovering a less noisey averaged waveform elicited from the stimuli. This graph and network-based algorithmic procedure increases the signal-to-noise (SNR) of the brain response, a key pre-processing step to reveal significant and reliable amplitude and latency at a specific time after the onset of the stimulus and with the right polarity (N or P). We demonstrated the whole approach using electroencephalography (EEG) auditory mismatch negativity (MMN) recordings from 42 young healthy controls. The method is novel, fast and data-driven succeeding first to reveal the true waveform elicited by MMN on different conditions (frequency, intensity, duration, etc.). The proposed graph-oriented algorithmic pipeline increased the SNR of the characteristic waveforms and the reliability of amplitude and latency within the adopted cohort. We also demonstrated how different EEG reference schemes (REST vs. average) can influence amplitude-latency estimation. Simulation results revealed robust amplitude-latency estimations under different SNR and amplitude-latency variations with the proposed algorithm

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

Deficits in reality and internal source monitoring of actions are associated with the positive dimension of schizotypy

People with schizophrenia have deficits in retrieving the source of memory information. Research has focused on two types of judgements: reality monitoring (discriminating internally-generated stimuli from external information) and internal source monitoring (distinguishing two different internal sources). The aim of the current study was to assess the relation between schizotypy and both types of source memory in healthy volunteers. One hundred and two participants completed two source memory tasks: one involved the completion of well-known word pairs (e.g. Fish and? ) and the other was an action based task (e.g. nod your head). At test participants needed to indicate whether the act had been performed or imagined by themselves, performed by the experimenter, or was new. The positive dimension of schizotypy was positively correlated with errors in internal source monitoring i.e. confusing participant performed and imagined acts. Furthermore, the same dimension of schizotypy was also positively associated with reality monitoring errors i.e. confusing participant performed/imagined with experimenter performed items. However, these relationships were not found in the word pair task. Our findings suggest that there might be overlap in the processes required to retrieve source information from memory, particularly for actions, and the occurrence of unusual experiences in healthy volunteers

ZNF804A genotype modulates neural activity during working memory for faces

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