Visual imagery and false memory for pictures:a functional magnetic resonance imaging study in healthy participants

BACKGROUND: Visual mental imagery might be critical in the ability to discriminate imagined from perceived pictures. Our aim was to investigate the neural bases of this specific type of reality-monitoring process in individuals with high visual imagery abilities. METHODS: A reality-monitoring task was administered to twenty-six healthy participants using functional magnetic resonance imaging. During the encoding phase, 45 words designating common items, and 45 pictures of other common items, were presented in random order. During the recall phase, participants were required to remember whether a picture of the item had been presented, or only a word. Two subgroups of participants with a propensity for high vs. low visual imagery were contrasted. RESULTS: Activation of the amygdala, left inferior occipital gyrus, insula, and precuneus were observed when high visual imagers encoded words later remembered as pictures. At the recall phase, these same participants activated the middle frontal gyrus and inferior and superior parietal lobes when erroneously remembering pictures. CONCLUSIONS: The formation of visual mental images might activate visual brain areas as well as structures involved in emotional processing. High visual imagers demonstrate increased activation of a fronto-parietal source-monitoring network that enables distinction between imagined and perceived pictures

One-carbon metabolism and stress in chilfren and adolescents with psychosis risk syndrome: preliminary data

Resumen del trabajo presentado en el Congress of the Schizophrenia International Research Socieaty (SIRS), celebrado del 4 al 8 de abril de 2020A dysregulation in one-carbon metabolism, involving folate, vitamin B12 and homocysteine (Hcys) could be implicated in the physiopathology of schizophrenia (for a review, Frankenburg, 2007). Higher Hcys levels have been associated with the disease compared to healthy controls in adults as well as in children and adolescents (Levere et al, 2014). Up to our knowledge, there are no studies in children and adolescents at risk for schizophrenia and other psychosis (Psychosis Risk Syndrome, PRS) testing the one-carbon metabolism parameters. Only a few groups have published results focused only in this population (for a review, Tor et al, 2018). This study aims to compare blood parameters associated with one-carbon metabolism, the clinical and demographic characteristics and stressful life events of a sample of children and adolescents with PRS and healthy controls (HC).Peer reviewe

Brain activation areas during perception and encoding in 25 participants, after controlling for sex and verbal IQ.

<p>Brain activation areas during perception and encoding in 25 participants, after controlling for sex and verbal IQ.</p

Activation maps consistent with false remembering of pictures in participants with high visual imagery.

<p>Brain activity differences between high- (n = 7) vs. low- (n = 9) visual imagery score subgroups when controlling for verbal IQ, sex, auditory hallucination proneness, and delusion proneness (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169551#pone.0169551.t004" target="_blank">Table 4</a>). Activations are shown over the SRI24 structural template for illustration purposes only. A) Activation of the left middle frontal gyrus and bilateral activation of the inferior and superior parietal lobes during the false remembering of non-presented pictures when compared to correct remembering of words presented as words (contrast WP > WW). B) Activation of the left inferior and superior parietal lobe during the false remembering of non-presented pictures when compared to correct remembering of presented pictures (contrast WP > PP).</p

Brain activation differences between high (7 participants) and low (9 participants) visual imagery score subgroups during recall, after controlling for verbal IQ, sex, auditory hallucination proneness, and delusion proneness.

<p>Brain activation differences between high (7 participants) and low (9 participants) visual imagery score subgroups during recall, after controlling for verbal IQ, sex, auditory hallucination proneness, and delusion proneness.</p

Activation maps consistent with false subsequent remembering of pictures in participants with high visual imagery.

<p>Activation maps consistent with false subsequent remembering of pictures in participants with high visual imagery.</p

Brain activation differences between high (7 participants) and low (8 participants) visual imagery score subgroups during encoding, after controlling for verbal IQ, sex, auditory hallucination proneness, and delusion proneness.

<p>Brain activation differences between high (7 participants) and low (8 participants) visual imagery score subgroups during encoding, after controlling for verbal IQ, sex, auditory hallucination proneness, and delusion proneness.</p

Brain activation areas during recall in 24 participants, after controlling for sex and verbal IQ.

<p>Brain activation areas during recall in 24 participants, after controlling for sex and verbal IQ.</p

Gene co-expression architecture in peripheral blood in a cohort of remitted first-episode schizophrenia patients

A better understanding of schizophrenia subtypes is necessary to stratify the patients according to clinical attributes. To explore the genomic architecture of schizophrenia symptomatology, we analyzed blood co-expression modules and their association with clinical data from patients in remission after a first episode of schizophrenia. In total, 91 participants of the 2EPS project were included. Gene expression was assessed using the Clariom S Human Array. Weighted-gene co-expression network analysis (WGCNA) was applied to identify modules of co-expressed genes and to test its correlation with global functioning, clinical symptomatology, and premorbid adjustment. Among the 25 modules identified, six modules were significantly correlated with clinical data. These modules could be clustered in two groups according to their correlation with clinical data. Hub genes in each group showing overlap with risk genes for schizophrenia were enriched in biological processes related to metabolic processes, regulation of gene expression, cellular localization and protein transport, immune processes, and neurotrophin pathways. Our results indicate that modules with significant associations with clinical data showed overlap with gene sets previously identified in differential gene-expression analysis in brain, indicating that peripheral tissues could reveal pathogenic mechanisms. Hub genes involved in these modules revealed multiple signaling pathways previously related to schizophrenia, which may represent the complex interplay in the pathological mechanisms behind the disease. These genes could represent potential targets for the development of peripheral biomarkers underlying illness traits in clinical remission stages after a first episode of schizophrenia

Association of Structural Magnetic Resonance Imaging Measures With Psychosis Onset in Individuals at Clinical High Risk for Developing Psychosis: An ENIGMA Working Group Mega-analysis

The ENIGMA clinical high risk (CHR) for psychosis initiative, the largest pooled neuroimaging sample of individuals at CHR to date, aims to discover robust neurobiological markers of psychosis risk