Reward-based option competition in human dorsal stream and transition from stochastic exploration to exploitation in continuous space.

Primates exploring and exploiting a continuous sensorimotor space rely on dynamic maps in the dorsal stream. Two complementary perspectives exist on how these maps encode rewards. Reinforcement learning models integrate rewards incrementally over time, efficiently resolving the exploration/exploitation dilemma. Working memory buffer models explain rapid plasticity of parietal maps but lack a plausible exploration/exploitation policy. The reinforcement learning model presented here unifies both accounts, enabling rapid, information-compressing map updates and efficient transition from exploration to exploitation. As predicted by our model, activity in human frontoparietal dorsal stream regions, but not in MT+, tracks the number of competing options, as preferred options are selectively maintained on the map, while spatiotemporally distant alternatives are compressed out. When valuable new options are uncovered, posterior ß1/α oscillations desynchronize within 0.4 to 0.7 s, consistent with option encoding by competing ß1-stabilized subpopulations. Together, outcomes matching locally cached reward representations rapidly update parietal maps, biasing choices toward often-sampled, rewarded options.

Adolescent-to-adult gains in cognitive flexibility are adaptively supported by reward sensitivity, exploration, and neural variability.

Cognitive flexibility exhibits dynamic changes throughout development, with different forms of flexibility showing dissociable developmental trajectories. In this review, we propose that an adolescent-specific mode of flexibility in the face of changing environmental contingencies supports the emergence of adolescent-to-adult gains in cognitive shifting efficiency. We first describe how cognitive shifting abilities monotonically improve from childhood to adulthood, accompanied by increases in brain state flexibility, neural variability, and excitatory/inhibitory balance. We next summarize evidence supporting the existence of a dopamine-driven, adolescent peak in flexible behavior that results in reward seeking, undirected exploration, and environmental sampling. We propose a neurodevelopmental framework that relates these adolescent behaviors to the refinement of neural phenotypes relevant to mature cognitive flexibility, and thus highlight the importance of the adolescent period in fostering healthy neurocognitive trajectories.

Aperiodic EEG and 7T MRSI evidence for maturation of E/I balance supporting the development of working memory through adolescence.

Adolescence has been hypothesized to be a critical period for the development of human association cortex and higher-order cognition. A defining feature of critical period development is a shift in the excitation: inhibition (E/I) balance of neural circuitry, however how changes in E/I may enhance cortical circuit function to support maturational improvements in cognitive capacities is not known. Harnessing ultra-high field 7 T MR spectroscopy and EEG in a large, longitudinal cohort of youth (N = 164, ages 10-32 years old, 347 neuroimaging sessions), we delineate biologically specific associations between age-related changes in excitatory glutamate and inhibitory GABA neurotransmitters and EEG-derived measures of aperiodic neural activity reflective of E/I balance in prefrontal association cortex. Specifically, we find that developmental increases in E/I balance reflected in glutamate:GABA balance are linked to changes in E/I balance assessed by the suppression of prefrontal aperiodic activity, which in turn facilitates robust improvements in working memory. These findings indicate a role for E/I-engendered changes in prefrontal signaling mechanisms in the maturation of cognitive maintenance. More broadly, this multi-modal imaging study provides evidence that human association cortex undergoes physiological changes consistent with critical period plasticity during adolescence.

Adolescent neurocognitive development and decision-making abilities regarding gender-affirming care.

Recently, politicians and legislative bodies have cited neurodevelopmental literature to argue that brain immaturity undermines decision-making regarding gender-affirming care (GAC) in youth. Here, we review this literature as it applies to adolescents' ability to make decisions regarding GAC. The research shows that while adolescence is a time of peak risk-taking behavior that may lead to impulsive decisions, neurocognitive systems supporting adult-level decisions are available given deliberative processes that minimize influence of short-term rewards and peers. Since GAC decisions occur over an extended period and with support from adult caregivers and clinicians, adolescents can engage adult-level decision-making in this context. We also weigh the benefits of providing GAC access during adolescence and consider the significant costs of blocking or delaying GAC. Transgender and non-binary (TNB) adolescents face significant mental health challenges, many of which are mitigated by GAC access. Further, initiating the GAC process during adolescence, which we define as beginning at pubertal onset, leads to better long-term mental health outcomes than waiting until adulthood. Taken together, existing research indicates that many adolescents can make informed decisions regarding gender-affirming care, and that this care is critical for the well-being of TNB youth. We highlight relevant considerations for policy makers, researchers, and clinicians.

Identifying high school risk factors that forecast heavy drinking onset in understudied young adults.

Heavy alcohol drinking is a major, preventable problem that adversely impacts the physical and mental health of US young adults. Studies seeking drinking risk factors typically focus on young adults who enrolled in 4-year residential college programs (4YCP) even though most high school graduates join the workforce, military, or community colleges. We examined 106 of these understudied young adults (USYA) and 453 4YCPs from the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) by longitudinally following their drinking patterns for 8 years from adolescence to young adulthood. All participants were no-to-low drinkers during high school. Whereas 4YCP individuals were more likely to initiate heavy drinking during college years, USYA participants did so later. Using mental health metrics recorded during high school, machine learning forecasted individual-level risk for initiating heavy drinking after leaving high school. The risk factors differed between demographically matched USYA and 4YCP individuals and between sexes. Predictors for USYA drinkers were sexual abuse, physical abuse for girls, and extraversion for boys, whereas 4YCP drinkers were predicted by the ability to recognize facial emotion and, for boys, greater openness. Thus, alcohol prevention programs need to give special consideration to those joining the workforce, military, or community colleges, who make up the majority of this age group.

Multi-dimensional predictors of first drinking initiation and regular drinking onset in adolescence: A prospective longitudinal study.

Early adolescent drinking onset is linked to myriad negative consequences. Using the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) baseline to year 8 data, this study (1) leveraged best subsets selection and Cox Proportional Hazards regressions to identify the most robust predictors of adolescent first and regular drinking onset, and (2) examined the clinical utility of drinking onset in forecasting later binge drinking and withdrawal effects. Baseline predictors included youth psychodevelopmental characteristics, cognition, brain structure, family, peer, and neighborhood domains. Participants (N=538) were alcohol-naïve at baseline. The strongest predictors of first and regular drinking onset were positive alcohol expectancies (Hazard Ratios [HRs]=1.67-1.87), easy home alcohol access (HRs=1.62-1.67), more parental solicitation (e.g., inquiring about activities; HRs=1.72-1.76), and less parental control and knowledge (HRs=.72-.73). Robust linear regressions showed earlier first and regular drinking onset predicted earlier transition into binge and regular binge drinking (ßs=0.57-0.95). Zero-inflated Poisson regressions revealed that delayed first and regular drinking increased the likelihood (Incidence Rate Ratios [IRR]=1.62 and IRR=1.29, respectively) of never experiencing withdrawal. Findings identified behavioral and environmental factors predicting temporal paths to youthful drinking, dissociated first from regular drinking initiation, and revealed adverse sequelae of younger drinking initiation, supporting efforts to delay drinking onset.

Elevada prevalencia de malformaciones anorrectales en recién nacidos a gran altitud

Introducción. Las malformaciones anorrectales son un grupo de anomalías congénitas de etiología multifactorial, en las que intervienen diversos factores genéticos y ambientales. Los habitantes de regiones de gran altitud están expuestos a hipoxia hipobárica crónica, lo que se ha asociado a una mayor prevalencia de varias anomalías congénitas. Objetivo. El objetivo del estudio es investigar la prevalencia al nacimiento de malformaciones anorrectales en La Paz, Bolivia. Material y métodos. Se realizó un estudio transversal. Los casos fueron recolectados en el Hospital de la Mujer ubicado en La Paz, Bolivia, a una altitud promedio de 3600 metros sobre el nivel del mar. Resultados. De 56206 nacidos vivos registrados durante el periodo de estudio, 30 recién nacidos presentaban malformaciones anorrectales, lo que arrojaba una prevalencia de 5,34 por 10000 nacidos vivos. Esta prevalencia era superior a la prevalencia de 3 por 10000 nacidos vivos registrada anteriormente en la literatura. Conclusiones. Nuestro estudio muestra que la prevalencia de malformaciones anorrectales es mayor en la población de altura de La Paz, Bolivia, en comparación con la prevalencia previamente reportada en la literatura. Se necesitan más investigaciones para identificar los factores genéticos y ambientales subyacentes que contribuyen a esta mayor prevalencia, además de mejorar el diagnóstico y los sistemas de vigilancia.

Introduction. Anorectal matformations are a group of congenital anomalies that have a multifactorial etiology, involving various genetic and environmental factors. Inhabitants living at high-altitude regions are exposed to chronic hypobaric hypoxia, which has been associated with a higher prevalence of congenital anomalies. Objective. It was aimed to investígate the prevalence of anorectal malformations in newborns from La Paz, Bolivia. Material and methods. We conducted a cross-sectional study. Newborns data were collected at the Hospital de la Mujer located in La Paz, Bolivia, at an average altitude of 3600 masl. Results. Out of 56,206 live births were registered during the study period. 30 newborns had anorectal malformations, resulting in a prevalence of 5.34 per 10,000 live births. This prevalence was higher than the previously reported in the literature, 3 per 10,000 live births. Conclusions. Our study depicts the prevalence of anorectal malformations is higher in the population of La Paz-Bolivia living at high-altitude, this when compared to previously reported prevalence in the literature. Further research is needed to identify the underlying genetic and environmental factors that contribute to this increased prevalence, as well as to improve diagnosis and monitoring systems.

Defectos del tubo neural en recien nacidos en el hospital de la mujer / Neural tube defects in newborns in women's hospital

OBJETIVO: Conocer la prevalencia al nacimiento de los defectos del tubo neural en recién nacidos del Hospital de la Mujer, La Paz, Bolivia, período comprendido entre el año 2008 - 2017. DISEÑO METODOLÓGICO: Observacional, descriptivo, de corte transversal, retrospectivo. LUGAR: Hospital de la Mujer, a 3650 m.s.n.m. La Paz, Bolivia. MÉTODOS: Se examinaron los expedientes clínicos de todos los recién nacidos del Hospital de la Mujer, en período ya establecido. Para la detección de anomalías congénitas, se utilizaron libros de registro de nacimientos. Se ingresaron los datos a una base Excel, se procedió al análisis de los mismos a través del uso de la estadística descriptiva. RESULTADOS: Se recurrió a registros de 58120 expedientes de recién nacidos, se presentaron 1269 casos con Anomalías Congénitas (2.2%) con una prevalencia al Nacimiento (PN) de 21.83/10.000 RN (22.57/10.000 RN vivos). De dichos 1269 casos, 69 (5.44%) correspondieron a Defectos del Tubo Neural (DTN), con una PN de 11.87/10.000 RN (12.27/10.000 RN vivos), 59.42% DTN asociados al sexo masculino. El tipo de DTN más frecuente evidenciado fue Mielomeningocele (52.17%), y los DTN mortinatos representan el 17.39%. CONCLUSIONS: La llamativa diferencia encontrada, (en relación a la predilección por el sexo masculino), podría sugerir la presencia de una carga genética cuantitativamente mayor (propia de la población estudiada) en la etiología de los DTN en nuestro medio, ya que cuando las condiciones multifactoriales como los DTN afectan al sexo menos frecuentemente descrito, se puede asumir un peso mayor de los factores genéticos en relación a factores ambientales, siguiendo conceptos de heredabilidad y la teoría del umbral para este modo de herencia, sin embargo, somos conscientes que se requiere un tamaño de muestra mayor para arribar a conclusiones más certeras, dichos factores se adicionan al subregistro y posibles sesgos de registro evidenciados durante la realización del estudio.

OBJECTIVE: To know the prevalence at birth of neural tube defects in newborns at Hospital de La Mujer, La Paz, Bolivia, 3650 m.a.s.l, period between 2008 - 2017. PLACE: Women's Hospital, La Paz, Bolivia. METHODS: Observational, descriptive, cross-sectional, retrospective. The clinical records of all newborns were examined, in an already established period. For the detection of congenital anomalies, birth registration books were used. The data were entered into an Excel database, and analyzed through the use of descriptive statistics. RESULTS: 58120 newborn records were examined, 1269 cases with Congenital Anomalies (2.2%) with a prevalence at Birth (PB) of 21.83/10.000 RN (22.57/10.000 RN alive) were presented. Of these 1269 cases, 69 (5,44%) corresponded to Neural Tube Defects (NTD), with a PB of 11.87/10,000 RN (12.27/10,000 RN alive), 59.42% DTN associated with the male sex. The most frequent type of NTD evidenced was Myelomeningocele (52.17%), and stillborn DTNs represented 17.39%. CONCLUSIONS: The distinctive difference found (predilection of NTD for the male sex), could suggest the presence of a quantitatively greater genetic load (typical of the population studied) in the etiology of NTDs in our environment, since when multifactorial conditions affect the less frequently described sex, a greater weight of genetic factors can be assumed compared to environmental factors, following concepts of heritability and the threshold theory for this mode of inheritance; however, we are aware that a larger sample size is needed to arrive at more accurate conclusions, these factors are added to the underreporting and possible recording biases evidenced during the study.

Reivindicando la manía confusa / Claiming delirious mania. A case report

Objetivo: Con el presente artículo se pretende hacer una revisión mediante la exposición de un caso clínico de la clínica, el diagnóstico y el tratamiento de la manía confusa. Caso clínico Mujer de 36 años diagnosticada de trastorno bipolar tipo I que ingresa en psiquiatría por presentar un cuadro brusco consistente en irritabilidad, inquietud, expansividad, alteraciones conductuales y discurso incoherente. Durante el ingreso se objetiva deterioro en la atención, orientación y memoria, confusión, fluctuación del comportamiento y pensamiento, y alteraciones en la psicomotricidad. Resultados La manía confusa se presenta de forma abrupta con sintomatología maniforme, psicótica y confusional, pudiendo complicarse con clínica catatoniforme. Se deben descartar causas orgánicas del cuadro y realizar diagnóstico diferencial con otros síndromes neuropsiquiátricos. El tratamiento de primera línea consiste en benzodiacepinas y TEC. Conclusiones Reconocer este cuadro clínico es relevante para instaurar tratamiento precoz y evitar las complicaciones derivadas, así como la morbimortalidad. (AU)

Objectives: The objective of this article is to review, through the presentation of a case report, the symptoms, diagnosis and treatment of delirious mania. Case report We present a 36-year-old woman diagnosed with bipolar I disorder who was admitted to psychiatry ward for presenting an abrupt episode consisting of irritability, restlessness, expansiveness, behavioral disturbances and incoherent speech. During admission, the patient was observed to have a global worsening consisting of deterioration in attention, orientation and memory, confusion, fluctuation of the symptoms and alterations in psychomotor skills. Results Delirious mania presents abruptly with manifest, psychotic and confusional symptoms, and can be complicated by catatoniform symptoms. Organic causes of the condition should be ruled out as well as a performing a differential diagnosis with other neuropsychiatric syndromes. First-line treatment consists of benzodiazepines and ECT. Conclusions Recognizing delirious mania is relevant to establish early treatment and avoid derived complications, morbidity and mortality. (AU)

Glucogénesis: caracterización clínica - patológica del primer caso descrito en Bolivia en un paciente pediátrico / Glycogen storage disease: first clinicopathologic pediatric case described in Bolivia

Las glucogenosis son enfermedades hereditarias del metabolismo del glucógeno. Se reconocen más de 12 tipos y afectan principalmente al hígado y al músculo, mismas que se clasifican según la enzima defectuosa y el órgano afectado. Presentamos el caso de un niño de 4 años y 6 meses con hepatomegalia importante, retardo del crecimiento pondoestatural, extremidades delgadas, facies con mejillas redondas. Sus exámenes laboratoriales revelaron: hipoglicemia, hiperlipidemia, hiperuricemia y sus estudios imagenológicos evidenciaron hepatomegalia difusa severa. El estudio histopatológico concluyó con glucogenosis, no pudiendo definirse el tipo, por la imposibilidad de realizar pruebas específicas de histoquímica en Bolivia. El paciente es seguido por consulta externa, bajo indicaciones dietéticas para prevenir complicaciones.

Glycogen storage diseases are inherited metabolic disorders of glycogen metabolism. There are over 12 types, they may affect primarily the liver and muscle. They are classified and the affected tissue. The case of a 4 y 6m old-male infant is presented, with growth retardation, thin limbs, rounded cheeks. Laboratory testing showed hypoglycemia, hyperlipidermia, hyperuricemia. Imagenoly testing showed severe diffuse hepatomegaly. Histopathology concluded in glycogen storage disease, the enzyme deficiency could not be established because of the unavailability of these test in Bolivia. The patient is followed by consult, diet therapy to prevent complications.

Valoración psiquiátrico-forense del riesgo de radicalización terrorista en el enfermo mental / Forensic-psychiatric assessment of the risk of terrorist radicalisation in the mentally ill patient

Introducción: La valoración psiquiátrico-forense del riesgo de radicalización terrorista en el enfermo mental tiene especial interés para la evaluación de la peligrosidad criminal; especialmente a raíz de las recientes investigaciones sobre los denominados lobos solitarios, que indican una elevada prevalencia de enfermedad mental dentro de este tipo de terroristas. Metodología: Análisis de la validez predictiva del Protocolo de Evaluación de Radicalización Terrorista (TRAP-18) para predecir futuros incidentes violentos de carácter extremista en una muestra representativa de 44 pacientes con trastorno mental grave en situación de exclusión social y con antecedentes penitenciarios. Resultados: El análisis de curvas ROC indicó que la puntuación total de la TRAP-18 (AUC 1,00, p = 0,018) tiene una alta validez predictiva. Conclusiones: El TRAP-18 podría resultar una útil herramienta para la valoración del riesgo de radicalización terrorista en el enfermo mental; especialmente en el colectivo de personas con trastorno mental grave en situación de exclusión social y con antecedentes penitenciarios, los cuales presentan un mayor riesgo potencial de radicalización terrorista como lobos solitarios

Introduction: The forensic-psychiatric assessment of the risk of terrorist radicalisation in the mentally ill patient is of special interest for the evaluation of criminal dangerousness. This particularly relevant in ligh of the recent investigations into so-called lone-wolves, which indicate a high prevalence of mental illness within this type of terrorist. Methodology: Analysis of the predictive validity of the Terrorist Radicalisation Assessment Protocol (TRAP-18) to predict future violent incidents of an extremist nature in a representative sample of 44 patients with severe mental illness in situations of social exclusion and with a prison history. Results: The ROC Curves analysis indicated that the total score of TRAP-18 (AUC 1.00, P=.018) has a high predictive validity. Conclusions: TRAP-18 could be a useful tool for assessing the risk of terrorist radicalisation in the mentally ill patient,; especially in the group of people with severe mental illness in situations of social exclusion and with a prison record, who have a greater potential risk of terrorist radicalistion as lone-wolves

Conducta delictiva en las personas sin hogar con trastorno mental grave / Criminal behavior among homeless individuals with severe mental illness

Introducción. Varios estudios estadounidenses han investigado la conducta delictiva en las personas sin hogar con trastorno mental grave. Pero hasta la fecha ninguno se ha realizado en España. Metodología. Estudio observacional retrospectivo, en una muestra de 118 pacientes, seleccionados de un programa de atención psiquiátrica para personas sin hogar con trastorno mental grave. Se analizaron los factores asociados a la conducta delictiva mediante la comparación de 2 grupos, con y sin antecedentes penales. Resultados. El 24,6% de la muestra tenía algún antecedente penal y el 58,6% de este grupo había ingresado en prisión. Se encontraron diferencias significativas entre ambos grupos para las variables: sexo, condenas pendientes, duración del sinhogarismo, comorbilidad con politoxicomanía, conciencia de enfermedad y gravedad de los síntomas psicóticos. Conclusiones. En la población de personas sin hogar con trastorno mental grave, con independencia del sexo, la coexistencia de comorbilidad con politoxicomanía y una duración prolongada del sinhogarismo, constituyen el factor de riesgo más importante para la conducta delictiva

Introduction. Several US studies have investigated the criminal behaviour among homeless individuals with severe mental illness. But to date, no studies have been carried out in Spain. Method. A retrospective observational study was conducted on a sample of 118 patients selected from a psychiatric care program for homeless individuals with severe mental illness. Factors associated with criminal behaviour were analysed by comparing 2 groups, with and without criminal records. Results. Of the total sample studied, 24.6% had a criminal record, and 58.6% of them had entered prison. Significant differences between groups were found for the variables of gender, pending sentences, duration of homelessness, multiple substance use, disease awareness, and severity of psychotic symptoms. Conclusions. In the population of homeless individuals with severe mental illness, regardless of gender, the co-existence of comorbidity with multiple substance use, and a prolonged duration of homelessness, is the most important risk factor for criminal behavior