Sustained attention in psychosis: Neuroimaging findings

Abstract

To provide a systematic review of scientific literature on functional magnetic resonance imaging (fMRI) studies on sustained attention in psychosis. We searched PubMed to identify fMRI studies pertaining sustained attention in both affective and non-affective psychosis. Only studies conducted on adult patients using a sustained attention task during fMRI scanning were included in the final review. The search was conducted on September 10 th , 2013. 15 fMRI studies met our inclusion criteria: 12 studies were focused on Schizophrenia and 3 on Bipolar Disorder Type Ⅰ (BDI). Only half of the Schizophrenia studies and two of the BDI studies reported behavioral abnormalities, but all of them evidenced significant functional differences in brain regions related to the sustained attention system. Altered functioning of the insula was found in both Schizophrenia and BDI, and therefore proposed as a candidate trait marker for psychosis in general. On the other hand, other brain regions were differently impaired in affective and non-affective psychosis: alterations of cingulate cortex and thalamus seemed to be more common in Schizophrenia and amygdala dysfunctions in BDI. Neural correlates of sustained attention seem to be of great interest in the study of psychosis, highlighting differences and similarities between Schizophrenia and BDI. Key words: Sustained attention; Affective psychosis; Non-affective psychosis; Schizophrenia; Bipolar disorder; Functional magnetic resonance imaging; Insula Core tip: In the present paper, we systematically reviewed functional magnetic resonance imaging studies investigating sustained attention in affective and nonaffective psychosis. We found that differences between cases (patients, unaffected relatives of psychotic probands) and controls in terms of functional activation of sustained attention system structures were detectable even when the groups performed comparably. In particular, the insular cortex seems to be a trait marker for psychosis in general, whereas other regions (thalamus, cingulate cortex, amygdala) seem to be differently impaired in affective and non-affective psychosis.

Associations between cognition and serotonin receptor 1B binding in patients with major depressive disorder – A pilot study

“…Regarding the amygdala, it has been shown in meta-analyses of fMRI research that the amygdala of patients with affective disorder is more activated during a task measuring sustained attention compared to controls (Sepede et al, 2014). Rumination, an activity negatively associated with sustained attention, has been shown to be positively associated to increased amygdala reactivity as well as abnormal metabolic activity in the hippocampus in MDD subjects (Mandell et al, 2014).…”

Theoretical Modeling of Cognitive Dysfunction in Schizophrenia by Means of Errors and Corresponding Brain Networks

“…A recent imaging study applied an fMRI paradigm of the dual response AX-CPT test version (i.e., Lesh et al, 2013 ). Significant differences in activation patterns between patient and control groups were found in all studies selected by Sepede et al (Sepede et al, 2014 ), even in case the patients performed comparable to the control group (e.g., Eyler et al, 2004 ). All of the mentioned studies support the finding of the attentional deficit in schizophrenia tested in CPT variants.…”

“…First study combining fMRI with CPT task in schizophrenia was performed by Volz et al (Volz et al, 1999 ). Systematic review of scientific literature on fMRI studies using a sustained attention task was published by Sepede et al (Sepede et al, 2014 ). The review included 11 studies of patients with schizophrenia, of which four studies used the CPT test paradigm: 2 studies used CPT-X (i.e., Eyler et al, 2004 ; Honey et al, 2005 ) and 2 studies CPT-IP (i.e., Volz et al, 1999 ; Salgado-Pineda et al, 2004 ).…”

“…All of the mentioned studies support the finding of the attentional deficit in schizophrenia tested in CPT variants. This deficit was mainly related to hypoactivity in anterior and posterior cingulate cortex and in the right prefrontal cortex (Sepede et al, 2014 ). Thalamus activation results are inconsistent, reported to be either hyperactivated in SZ patients during CPT (Honey et al, 2005 ), or hypoactivated (Volz et al, 1999 ; Salgado-Pineda et al, 2004 ).…”

Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain

“…The insular cortex is located at the junction of the frontal, parietal, and temporal lobes and serves as a central regulatory hub that integrates motor control and sensory, autonomic, and salient stimuli, which are important for sustained attention (22,25). Multiple functional neuroimaging studies have linked attention deficits in patients with schizophrenia and bipolar disorder to abnormalities in the insular cortex (31). Our findings of an association of methylene blue intake with increased activity memory paradigms, and investigate the neuroimaging correlates of the effects of methylene blue on neural networks (5,18).…”