Creativity: a (white) matter of connectivity In a cohort of 142 young adults, we probed how figural creative ideation maps onto white matter microstructure, aiming to challenge and refine the dominant view that creativity is driven by widely distributed brain networks. Figural creativity was assessed with the Test for Creative Thinking–Drawing Production, and its neural correlates were examined using two diffusion imaging metrics: quantitative anisotropy (QA) and fractional anisotropy (FA). Connectometry analyses uncovered robust, widespread positive associations between creative performance and white matter integrity, with the strongest effects in corticostriatal, corticopontine, and corticospinal pathways; commissural fibers such as the corpus callosum; and key association tracts including the inferior fronto-occipital fasciculus. Together, these results spotlight sensory, motor, and sensorimotor tracts as core conduits for figural creative ideation, rather than mere supporting players. QA consistently outperformed FA in detecting these creativity-related patterns, underscoring the value of deploying multiple white matter metrics in creativity research. By directly contrasting QA and FA, this study sharpens our understanding of the structural neural architecture underpinning creative processes and highlights the unique power of QA to capture microstructural features that are especially critical for figural creative performance.
A cortical output channel for perceptual categorization Perceptual categorization transforms graded sensory inputs into discrete representations that support decision-making. While the auditory cortex is causally important for this process, a specific circuit location where continuous physical inputs are transformed into discrete decision variables remains unknown. Here, we address this by performing longitudinal two-photon imaging of layer 5 (L5) extratelencephalic (ET) neurons alongside L2/3 and L5 intratelencephalic (IT) populations in mice learning a categorization task. With learning, L5 ET neurons underwent pronounced tuning shifts and developed robust categorical responses, whereas L2/3 and L5 IT neurons did not. This transformation is not merely an intrinsic feature of the cell type but is dynamically controlled by task engagement, emerging only during active decision-making. Using a generalized linear model, we confirmed that categorical selectivity in L5 ET neurons reflects genuine sensory encoding rather than being a by-product of choice-driven activity. These findings identify L5 ET neurons as a cortical output channel to categorize stimuli into a decision variable to guide actions.
Are there norms of rationality for perception? Evaluating experience-forming processes under Bayesian norms According to the rationality of perception thesis, perceptual processes and experiences can be rationally appraised. This thesis raises the questions of whether there can be norms of rationality for perception, and what they could be. Here, to answer these questions, we consider Bayesian norms as possible candidates. Analysing two Bayesian models of perceptual anomalies in schizophrenia, we argue that experience-forming processes can be rationally appraised according to probabilism. After suggesting that violations of probabilism in perception are accompanied by fragmented conscious experiences and can involve epistemic and practical costs, we clarify the implications of our contribution for the rationality of perception thesis and Bayesian approaches to perception.
Perceptual Contaminants to Assessments of Visuospatial Working Memory: The Influences of Path Clutterness and Endpoint Crowding Identifying individual differences in various cognitive constructs has important implications for settings such as clinical and educational assessments. Yet, cognitive tasks themselves often do not measure a single construct. As such, there is value in understanding the mixture of constructs involved in cognitive task performance, as this would allow target constructs to be better isolated. For example, tasks assessing visuospatial working memory (VSWM), in addition to measuring the “of interest” processes of encoding and maintenance, also involve lower-level perceptual processes. Here, we examined perceptual contaminant effects on VSWM using a modified Corsi Block Tapping Task, in which participants observed and reproduced sequences of spatial locations. Two forms of perceptual interference were manipulated: path clutterness, in which distractors appeared near the virtual path connecting successive targets, and endpoint crowding, in which distractors appeared near the target locations themselves. Endpoint crowding produced clear decrements in task performance, whereas path clutterness produced no detectable changes in performance. These findings indicate that perceptual processes, specifically visual crowding, influence VSWM assessment. This underscores the importance of accounting for perceptual processes in the design and interpretation of working memory measures.
Age and reading ability shape white matter development across the lifespan: A cross-sectional study Reading is supported by neural systems that change across the lifespan, yet the development of reading-related white matter remains underexplored, particularly in non-alphabetic writing systems. This cross-sectional study examined white matter-reading associations in 126 Mandarin Chinese readers aged 7 to 77 years. Diffusion tensor imaging quantified fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in seven pairs of bilateral reading-related tracts: the arcuate fasciculus (AF), superior longitudinal fasciculus (SLF I, II, and III), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), and uncinate fasciculus (UF). Most tracts showed nonlinear age-related trajectories, with FA generally following an inverted U-shaped pattern and MD, AD, and RD showing opposite U-shaped patterns; by contrast, FA in the left ILF and right UF increased linearly with age. In addition, word reading efficiency was positively associated with FA in the bilateral AF, bilateral SLF III, and right SLF II. These FA effects were accompanied by lower RD across all significant tracts and lower MD in the right-hemisphere tracts. Sentence reading fluency showed a more limited association with FA, mainly involving the right AF. Further, age moderated the association between word reading efficiency and FA in the right AF and right SLF II: better word reading fluency predicted higher FA at younger ages, whereas the association became weak in adulthood and negative at older ages. These findings reveal heterogeneous maturation of reading-related white matter pathways and highlight both stable and age-dependent structural correlates of reading fluency across the lifespan in Chinese readers.
The shifting landscape of brain-wide myelination across the human lifespan Despite the central role of myelination in brain function and plasticity, its characterization remains fragmented, with existing studies typically constrained either spatially, by focusing on selected brain structures, or temporally, by covering only limited age ranges. Here, we provide a comprehensive brain-wide map of myelination across the lifespan, leveraging T1w/T2w ratios from 214 brain regions in individuals aged 0–100 years. This fine-grained spatiotemporal mapping reveals regional heterogeneity and timing differences in myelination and demyelination, uncovering fundamental organizational principles that govern myelin dynamics across the lifespan. Our analysis also reveals that changes in T1w/T2w ratio across all brain regions follow a triphasic pattern: rapid infancy growth (primary myelination phase), adolescence and adulthood reacceleration (secondary myelination phase), and late-life decline (demyelination). To complement our analysis, we examined regional brain volume and cortical thickness to determine how macroscale structural changes are related to microscale myelination across the lifespan. Our work provides a comprehensive population-level reference for characterizing normative myelination trajectories and for interpreting alterations associated with myelin-related neurological disorders.
Dynamic fMRI networks of human emotion The experience of emotions is that of dynamic, time-changing processes. Yet, many functional MRI (fMRI) studies of emotion average across time to focus on maps of static activations, overlooking the temporal dimension of emotional responses. In this study, we used time-resolved fMRI, group spatial independent component analysis (ICA), dual regression, and Gaussian curve fitting to examine both the spatial and temporal properties of whole-brain networks during a behavioral task. This task included trials that spanned over 25 s of watching short, emotionally evocative movie clips, making emotion-related decisions, and an intertrial rest period. We identified four whole-brain networks with unique spatial and temporal features that mapped onto different stages of the task. A network activated early in the course of the task included perceptual and affective evaluation regions, while two later networks supported semantic interpretation and decision-making, and a final network aligned with default mode activity. Both spatial and temporal properties of all four networks were modulated by the emotional content of the movie clips. Our findings extend current models of emotion by integrating temporal dynamics with large-scale network activity, offering a richer framework for understanding how emotions unfold across distributed circuits. Such temporal-spatial markers of emotional processing may prove valuable for identifying and tracking alterations in clinical populations.
Common and Distinct Neural Substrates for Approach- and Avoidance-Motivated Actions The motivation to approach rewards and avoid negative outcomes often guides human action. However, whether these opposing motivations for actions engage common or distinct neural pathways in humans remains unresolved. To address this, we conducted a functional magnetic resonance imaging study using a ready–set–go task with potential monetary gains (approach) and losses (avoidance) in 29 healthy individuals (18 males and 11 females). At the prefrontal level, the ventromedial prefrontal cortex and dorsomedial prefrontal cortex were preferentially activated by the anticipation of gains and losses, respectively, indicating distinct cortical representations of approach and avoidance motivations. At the subcortical level, the dorsolateral ventral midbrain (VM) was engaged during the anticipation of both gains and losses, whereas the ventromedial VM was selectively activated by gain anticipation. Crucially, dorsolateral VM activity was positively correlated with the subsequent peak grip force but not the reaction time (RT), suggesting its role in transmitting motivational signals to downstream motor circuits. At the motor cortical level, the activity of the primary motor cortex was correlated with both the grip force and RT. Together, these findings suggest a hierarchical circuit in which approach and avoidance motivations are distinctly represented in the prefrontal cortex, partially converge in the VM, and ultimately influence motor cortex activity to generate motor output. This framework provides evidence that opposing motivations engage both distinct and shared neural pathways and that their integration through subcortical–cortical interactions enables motivational signals to shape human motor action.