Publications by authors named "Luz M Alliende"

Background: Individuals at clinical high risk (CHR) for psychosis experience subtle emotional disturbances that are traditionally difficult to assess, but natural language processing (NLP) methods may provide novel insight into these symptoms. We predicted that CHR individuals would express more negative emotionality and less emotional language when compared to controls. We also examined associations with symptomatology.

View Article and Find Full Text PDF
Article Synopsis
  • Youth at clinical high risk for psychosis (CHR) experience higher levels of stigma compared to a control group without psychotic symptoms, indicating that stigma plays a significant role in their lives.
  • CHR youth face both perceived devaluation (negative views from others) and internalized mental health stigma, with perceived devaluation being more closely linked to depressive symptoms rather than positive symptoms.
  • The study suggests that addressing the stigma surrounding mental health is crucial for improving the mental well-being of CHR youth, particularly in relation to managing depression.
View Article and Find Full Text PDF

Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women's worse outcomes in gender-unequal countries.

View Article and Find Full Text PDF

Background: Psychosis is related to neurochemical changes in deep-brain nuclei, particularly suggesting dopamine dysfunctions. We used an magnetic resonance imaging-based technique called quantitative susceptibility mapping (QSM) to study these regions in psychosis. QSM quantifies magnetic susceptibility in the brain, which is associated with iron concentrations.

View Article and Find Full Text PDF

Background And Hypothesis: Abnormal functional connectivity between brain regions is a consistent finding in schizophrenia, including functional magnetic resonance imaging (fMRI) studies. Recent studies have highlighted that connectivity changes in time in healthy subjects. We here examined the temporal changes in functional connectivity in patients with a first episode of psychosis (FEP).

View Article and Find Full Text PDF

One of the proposed neural mechanisms involved in working memory is coupling between the theta phase and gamma amplitude. For example, evidence from intracranial recordings shows that coupling between hippocampal theta and cortical gamma oscillations increases selectively during working memory tasks. Theta-gamma phase-amplitude coupling can also be measured non-invasively through scalp EEG; however, EEG can only assess coupling within cortical areas, and it is not yet clear if this cortical-only coupling is truly memory-specific, or a more general phenomenon.

View Article and Find Full Text PDF

Background: Educational attainment is associated with wellbeing and health, but patients with schizophrenia achieve lower levels of education than people without. Several effective interventions can ameliorate this situation. However, the magnitude of the education gap in schizophrenia and its change over time are unclear.

View Article and Find Full Text PDF

22q11.2 deletion syndrome (22q11.2DS) is a genetic neurodevelopmental disorder that represents one of the greatest known risk factors for psychosis.

View Article and Find Full Text PDF

Previous studies have suggested that subjects participating in schizophrenia research are not representative of the demographics of the global population of people with schizophrenia, particularly in terms of gender and geographical location. We here explored if this has evolved throughout the decades, examining changes in geographical location, gender and age of participants in studies of schizophrenia published in the last 50 years. We examined this using a meta-analytical approach on an existing database including over 3,000 studies collated for another project.

View Article and Find Full Text PDF

The 22q11 deletion syndrome is a genetic disorder associated with a high risk of developing psychosis, and is therefore considered a neurodevelopmental model for studying the pathogenesis of schizophrenia. Studies have shown that localized abnormal functional brain connectivity is present in 22q11 deletion syndrome like in schizophrenia. However, it is less clear whether these abnormal cortical interactions lead to global or regional network disorganization as seen in schizophrenia.

View Article and Find Full Text PDF

Although people with schizophrenia (PSZ) exhibit robust and reliable deficits in working memory (WM) capacity, the neural processes that give rise to this impairment remain poorly understood. One reason for this lack of clarity is that most studies employ a single neural recording modality-each with strengths and weaknesses-with few examples of integrating results across modalities. To address this gap, we conducted a secondary analysis that combined data from an overlapping set of subjects in previously published electroencephalographic and functional magnetic resonance imaging studies that used nearly identical working memory tasks (visual change detection).

View Article and Find Full Text PDF
Article Synopsis
  • The study examines cognitive performance in 1175 Latin American individuals, including 864 with schizophrenia and 311 controls, to understand the impact of socioeconomic status (SES) and clinical factors.
  • Patients with schizophrenia demonstrated poorer cognitive abilities than non-affected individuals across all measured domains, and their cognitive performance was significantly influenced by factors like education and income.
  • The research highlights that while patients did not exhibit accelerated cognitive aging, their cognitive abilities were more adversely affected by lower SES, emphasizing the impact of demographic and socioeconomic challenges in low- and middle-income countries.
View Article and Find Full Text PDF

Background: Cannabis use among young people in Chile has increased significantly in the last years. There is a consistent link between cannabis and psychosis.

Aim: To compare cannabis use in patients with a first episode of psychosis and healthy controls.

View Article and Find Full Text PDF

Background: Social and environmental factors such as poverty or violence modulate the risk and course of schizophrenia. However, how they affect the brain in patients with psychosis remains unclear.

Aims: We studied how environmental factors are related to brain structure in patients with schizophrenia and controls in Latin America, where these factors are large and unequally distributed.

View Article and Find Full Text PDF

Resting-state functional MRI activity is organized as a complex network. However, this coordinated brain activity changes with time, raising questions about its evolving temporal arrangement. Does the brain visit different configurations through time in a random or ordered way? Advances in this area depend on developing novel paradigms that would allow us to shed light on these issues.

View Article and Find Full Text PDF

Social and environmental factors are known risk factors and modulators of mental health disorders. We here conducted a nonsystematic review of the neuroimaging literature studying the effects of poverty, urbanicity, and community violence, highlighting the opportunities of studying non-Western developing societies such as those in Latin America. Social and environmental factors in these communities are widespread and have a large magnitude, as well as an unequal distribution, providing a good opportunity for their characterization.

View Article and Find Full Text PDF

Attentional mechanisms have been studied mostly in specific sensory domains, such as auditory, visuospatial, or tactile modalities. In contrast, attention to internal interoceptive visceral targets has only recently begun to be studied, despite its potential importance in emotion, empathy, and self-awareness. Here, we studied the effects of shifting attention to the heart using a cue-target detection paradigm during continuous EEG recordings.

View Article and Find Full Text PDF