Eine interessante Studie:
Significance
Sex is an important biological factor that influences human behavior, impacting brain function and the manifestation of psychiatric and neurological disorders. However, previous research on how brain organization differs between males and females has been inconclusive. Leveraging recent advances in artificial intelligence and large multicohort fMRI (functional MRI) datasets, we identify highly replicable, generalizable, and behaviorally relevant sex differences in human functional brain organization localized to the default mode network, striatum, and limbic network. Our findings advance the understanding of sex-related differences in brain function and behavior. More generally, our approach provides AI–based tools for probing robust, generalizable, and interpretable neurobiological measures of sex differences in psychiatric and neurological disorders.
Abstract
Sex plays a crucial role in human brain development, aging, and the manifestation of psychiatric and neurological disorders. However, our understanding of sex differences in human functional brain organization and their behavioral consequences has been hindered by inconsistent findings and a lack of replication. Here, we address these challenges using a spatiotemporal deep neural network (stDNN) model to uncover latent functional brain dynamics that distinguish male and female brains. Our stDNN model accurately differentiated male and female brains, demonstrating consistently high cross-validation accuracy (>90%), replicability, and generalizability across multisession data from the same individuals and three independent cohorts (N ~ 1,500 young adults aged 20 to 35). Explainable AI (XAI) analysis revealed that brain features associated with the default mode network, striatum, and limbic network consistently exhibited significant sex differences (effect sizes > 1.5) across sessions and independent cohorts. Furthermore, XAI-derived brain features accurately predicted sex-specific cognitive profiles, a finding that was also independently replicated. Our results demonstrate that sex differences in functional brain dynamics are not only highly replicable and generalizable but also behaviorally relevant, challenging the notion of a continuum in male-female brain organization. Our findings underscore the crucial role of sex as a biological determinant in human brain organization, have significant implications for developing personalized sex-specific biomarkers in psychiatric and neurological disorders, and provide innovative AI-based computational tools for future research.Quelle: Deep learning models reveal replicable, generalizable, and behaviorally relevant sex differences in human functional brain organization (Ganze Studie)
Hier ein paar Übersichten aus der Studie:
In der Studie sind noch einige dieser Ergebnisse, die in der Tat sehr deutliche Abgrenzungen zwischen Männern und Frauen ergeben.
Aus der Studie:
Significantly, we found that brain features associated with the DMN most reliably distinguished between female and male brains, a finding consistent at both regional and network levels with large effect sizes (d > 2.0). This finding resolves previously inconsistent reports of sex differences (26, 27, 29, 37, 38, 71). Through consensus analysis, we further identified the posterior cingulate cortex, precuneus, and ventromedial prefrontal cortex nodes of the DMN as the most consistent discriminators between sexes. The DMN plays a critical role in integrating self-referential information processing and monitoring of the internal mental landscape (72, 73), including introspection, mind-wandering, and autobiographical memory retrieval (71, 72, 74). These cognitive processes may differ between females and males, potentially influencing self-regulation, beliefs, and social interactions. Sex-specific differences in the DMN may also influence how females and males recall past experiences, form self-concepts, or engage in perspective-taking.
Our findings underscore the pivotal role of the DMN in elucidating sex differences in brain functionality and advance our understanding of how
these differences influence various cognitive and social behaviors.
Notably, network analysis also revealed large differences in the striatum and limbic networks (d > 1.5). While the striatum has not been a primary focus of investigations into sex-specific differences in the functional organization of the human brain, there is a considerable evidence for sexual dimorphism in its anatomy (20, 29). The striatum is important for learning cue associations, habit formation, reinforcement learning, and reward sensitivity (75). In parallel, we also observed significant differences in the limbic network which includes, most prominently, the orbitofrontal cortex (65). The orbitofrontal cortex is involved in learning and reversal of stimulus-reinforcement associations, and correction of behavioral responses when they are no longer appropriate because previous reinforcement contingencies have changed (76). The human orbitofrontal cortex is also implicated in representing the reward value, expected reward value, and subjective pleasantness of reinforcers (77). This link to subjective pleasantness could provide a basis for investigating the limbic network’s role in sex differences in hedonic experiences.
Collectively, our findings suggest that females and males differ in how they engage dynamic functional circuits involved in both self-referential
and internal mental processes, reward sensitivity, reinforcement learning, and subjective experiences of pleasure. Notably, the DMN, striatum, and limbic network are also loci of dysfunction in psychiatric disorders with female or male bias in prevalence rates, including autism, attention deficit disorders, depression, addiction, schizophrenia, and Parkinson’s disease all of which have sex-specific sequelae and outcomes (78–86). Our findings may therefore offer a template for investigations of sex differences in vulnerability to individual psychiatric and neurological disorders.
The final goal of our study was to determine whether sex differences in functional brain organization predict cognitive profiles differently in females and males. Despite extensive research on the anatomical and functional basis of sex differences, the behavioral significance of brain features that differentiate between sexes has remained unclear, reflecting ongoing debates regarding sex differences in brain and behavioral measures (63, 87–92). Critically, the brain features identified by XAI that reliably distinguished functional brain organization between sexes also predicted unique cognitive profiles in females and males. These profiles were derived from a principal component analysis of a comprehensive cognitive assessment using the widely used NIH toolbox (64), revealing three key components: general intelligence, response inhibition and processing speed, and delay discounting and reward sensitivity. Although the reliability of sex differences in neurotypical behavior has been contentious (63, 87, 88, 90), clinical studies in neurodevelopmental and psychiatric disorders have consistently pointed out that males display more externalizing problems while females tend to exhibit internalizing
problems (6, 7, 86). Finally, it is noteworthy that in contrast to our stDNN-based sex-specific findings, static functional connectivity identified sex-invariant, but not sex-specific, brain features predictive of cognitive profiles in both sexes. These results suggest that dynamic and static functional connectivity approaches may serve as complementary tools for the identification of sex-specific and sex-invariant brain features underlying individual differences in cognition.
Neue Techniken bringen eben neue Einsichten und es wird insofern immer dünner für Leute, die „Blank Slate“ Theorien vertreten.
Ich denke die Verfahren werden immer mehr verfeinert werden und wir werden da noch viele interessante Studien sehen.
Alles Evolution 