Off-resonance artifacts correction with convolution in k-space (ORACLE).

Off-resonance artifacts hinder the wider applicability of echo-planar imaging and non-Cartesian MRI methods such as radial and spiral. In this work, a general and rapid method is proposed for off-resonance artifacts correction based on data convolution in k-space. The acquired k-space is divided into multiple segments based on their acquisition times.

FMRI in patients with motor conversion symptoms and controls with simulated weakness.

Background: Conversion disorder (motor type) describes weakness that is not due to recognized disease or conscious simulation but instead is thought to be a "psychogenic" phenomenon. It is a common clinical problem in neurology but its neural correlates remain poorly understood.

Objective: To compare the neural correlates of unilateral functional weakness in conversion disorder with those in healthy controls asked to simulate unilateral weakness.

Correlations between fMRI activation and individual psychotic symptoms in un-medicated subjects at high genetic risk of schizophrenia.

Background: It has been proposed that different types of psychopathology in schizophrenia may reflect distinguishable pathological processes. In the current study we aimed to address such associations in the absence of confounders such as medication and disease chronicity by examining specific relationships between fMRI activation and individual symptom severity scores in un-medicated subjects at high genetic risk of schizophrenia.

Methods: Associations were examined across two functional imaging paradigms: the Hayling sentence completion task, and an encoding/retrieval task, comprising encoding (at word classification) and retrieval (old word/new word judgement).

Event-related fMRI of word classification and successful word recognition in subjects at genetically enhanced risk of schizophrenia.

Background: Verbal declarative memory is a core deficit in schizophrenia patients, seen to a lesser extent in unaffected biological relatives. Neuroimaging studies suggest volumetric differences and aberrant function in prefrontal and temporal regions in schizophrenia patients compared to controls. These deficits are also reflected in the small number of similar investigations in unaffected biological relatives.

A visual joke fMRI investigation into Theory of Mind and enhanced risk of schizophrenia.

Theory of Mind (ToM) or mentalizing is the ability of individuals to determine the intentions and behavior of others. This ability is known to be compromised in schizophrenia and has been shown to fluctuate with symptom severity. Neuropsychological investigations into relatives of individuals with schizophrenia have shown that some relatives also show a deficit in this area of social cognition.

The effects of escitalopram on working memory and brain activity in healthy adults during performance of the n-back task.

Rationale: Psychotropic medication affects cognition and brain function, making it a potential confounder in functional neuroimaging studies of psychiatric patients.

Objective: To determine whether the sub-acute administration of an antidepressant (escitalopram) would induce differences in cognitive performance and associated brain function, which could be observed within the normal power of a functional imaging study.

Materials And Methods: Healthy adults (N=10) received a short course of escitalopram (10 mg/day for 7 days).

Functional imaging as a predictor of schizophrenia.

Background: Prospective studies of young individuals at high risk of schizophrenia allow the investigation of whether neural abnormalities predate development of illness and, if present, have the potential to identify those who may become ill.

Methods: We studied young individuals with at least two relatives with the disorder. At baseline functional magnetic resonance imaging (fMRI) scan, none met criteria for any psychiatric disorder, but four subjects subsequently developed schizophrenia.

Functional disconnectivity in subjects at high genetic risk of schizophrenia.

Schizophrenia is a highly heritable psychotic disorder. It has been suggested that deficits of the established state arise from abnormal interactions between brain regions. We sought to examine whether such connectivity abnormalities would be present in subjects at high genetic risk for the disorder.

Repeatability of motor and working-memory tasks in healthy older volunteers: assessment at functional MR imaging.

Purpose: To prospectively determine the repeatability of functional magnetic resonance (MR) imaging brain activation tasks in a group of healthy older male volunteers.

Materials And Methods: Local research ethics committee approval and informed consent were obtained. Sixteen men with a mean age of 69 years +/- 3 (standard deviation) performed finger-tapping and N-back (number of screens back) working-memory tasks.

The functional anatomy of inspection time: an event-related fMRI study.

Twenty healthy young adults underwent functional magnetic resonance imaging (fMRI) of the brain while performing a visual inspection time task. Inspection time is a forced-choice, two-alternative visual backward-masking task in which the subject is briefly shown two parallel vertical lines of markedly different lengths and must decide which is longer. As stimulus duration decreases, performance declines to chance levels.