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Although memory is known to play a key role in creativity, previous studies have not isolated the critical component processes and networks. We asked participants to generate links between words that ranged from strongly related to completely unrelated in long-term memory, delineating the neurocognitive processes that underpin more unusual versus stereotypical patterns of retrieval. More creative responses to strongly associated word-pairs were associated with greater engagement of episodic memory: in highly familiar situations, semantic, and episodic stores converge on the same information enabling participants to form a personal link between items. This pattern of retrieval was associated with greater engagement of core default mode network (DMN). In contrast, more creative responses to weakly associated word-pairs were associated with the controlled retrieval of less dominant semantic information and greater recruitment of the semantic control network, which overlaps with the dorsomedial subsystem of DMN. Although both controlled semantic and episodic patterns of retrieval are associated with activation within DMN, these processes show little overlap in activation. These findings demonstrate that controlled aspects of semantic cognition play an important role in verbal creativity.

Decomposition of whole-brain functional connectivity patterns reveals a principal gradient that captures the separation of sensorimotor cortex from heteromodal regions in the default mode network (DMN). Functional homotopy is strongest in sensorimotor areas, and weakest in heteromodal cortices, suggesting there may be differences between the left and right hemispheres (LH/RH) in the principal gradient, especially towards its apex. This study characterised hemispheric differences in the position of large-scale cortical networks along the principal gradient, and their functional significance. We collected resting-state fMRI and semantic, working memory and non-verbal reasoning performance in 175 + healthy volunteers. We then extracted the principal gradient of connectivity for each participant, tested which networks showed significant hemispheric differences on the gradient, and regressed participants’ behavioural efficiency in tasks outside the scanner against interhemispheric gradient differences for each network. LH showed a higher overall principal gradient value, consistent with its role in heteromodal semantic cognition. One frontotemporal control subnetwork was linked to individual differences in semantic cognition: when it was nearer heteromodal DMN on the principal gradient in LH, participants showed more efficient semantic retrieval—and this network also showed a strong hemispheric difference in response to semantic demands but not working memory load in a separate study. In contrast, when a dorsal attention subnetwork was closer to the heteromodal end of the principal gradient in RH, participants showed better visual reasoning. Lateralization of function may reflect differences in connectivity between control and heteromodal regions in LH, and attention and visual regions in RH.

There is a paucity of systematic experimental studies on the group effect of dragloads in pile foundations. This paper reports on a series of 1-g model tests that were conducted on single piles as well as 2 × 2 and 3 × 3 pile groups with various pile spacings to investigate the influence of soil compressibility, pile installation method, pile end constraint, and pile spacing on dragload development in the piles. The results indicate that soil compressibility significantly influences the magnitude of dragloads developed in single piles and piles in a group. However, the effect of soil compressibility on the group effect (a measure of dragload reduction) is negligible. Pile spacing is the most significant factor that influences group effect, followed by the number and position of piles. The group effect can reach 50% for a spacing of 3D (where D denotes pile diameter), but becomes negligible for a spacing of 7D. The influence of pile end constraint and pile installation method on group effect is comparatively insignificant. Although group effects of the suspending piles are marginally lower than those of end-bearing piles under otherwise identical conditions, the dragloads on the suspending piles correspond to tensile forces and are detrimental to concrete piles.

The flexible retrieval of knowledge is critical in everyday situations involving problem solving, reasoning and social interaction. Current theories emphasise the importance of a left-lateralised semantic control network (SCN) in supporting flexible semantic behaviour, while a bilateral multiple-demand network (MDN) is implicated in executive functions across domains. No study, however, has examined whether semantic and non-semantic demands are reflected in a common neural code within regions specifically implicated in semantic control. Using functional MRI and univariate parametric modulation analysis as well as multivariate pattern analysis, we found that semantic and non-semantic demands gave rise to both similar and distinct neural responses across control-related networks. Though activity patterns in SCN and MDN could decode the difficulty of both semantic and verbal working memory decisions, there was no shared common neural coding of cognitive demands in SCN regions. In contrast, regions in MDN showed common patterns across manipulations of semantic and working memory control demands, with successful cross-classification of difficulty across tasks. Therefore, SCN and MDN can be dissociated according to the information they maintain about cognitive demands.

How concepts are coded in the brain is a core issue in cognitive neuroscience. Studies have focused on how individual concepts are processed, but the way in which conceptual representation changes to suit the context is unclear. We parametrically manipulated the association strength between words, presented in pairs one word at a time using a slow event-related fMRI design. We combined representational similarity analysis and computational linguistics to probe the neurocomputational content of these trials. Individual word meaning was maintained in supramarginal gyrus (associated with verbal short-term memory) when items were judged to be unrelated, but not when a linking context was retrieved. Context-dependent meaning was instead represented in left lateral prefrontal gyrus (associated with controlled retrieval), angular gyrus, and ventral temporal lobe (regions associated with integrative aspects of memory). Analyses of informational connectivity, examining the similarity of activation patterns across trials between sites, showed that control network regions had more similar multivariate responses across trials when association strength was weak, reflecting a common controlled retrieval state when the task required more unusual associations. These findings indicate that semantic control and representational sites amplify contextually relevant meanings in trials judged to be related.

Decomposition of whole-brain functional connectivity patterns reveals a principal gradient that captures the separation of sensorimotor cortex from heteromodal regions in the default mode network (DMN); this gradient captures the systematic order of networks on the cortical surface. Functional homotopy is strongest in sensorimotor areas, and weakest in heteromodal cortices, suggesting there may be differences between the left and right hemispheres (LH/RH) in the principal gradient, especially towards its apex. This study characterised hemispheric differences in the position of large-scale cortical networks along the principal gradient, and their functional significance. We collected resting-state fMRI and semantic and non-verbal reasoning task performance in 175+ healthy volunteers. We then extracted the principal gradient of connectivity for each participant and tested which networks showed significant hemispheric differences in gradient value. We investigated the functional associations of these differences by regressing participants’ behavioural efficiency in tasks outside the scanner against their interhemispheric gradient difference for each network. LH showed a higher overall principal gradient value, consistent with its role in heteromodal semantic cognition. One frontotemporal control subnetwork was linked to individual differences in semantic cognition: when it was nearer heteromodal DMN on the principal gradient in LH, participants showed more efficient semantic retrieval. In contrast, when a dorsal attention subnetwork was closer to the heteromodal end of the principal gradient in RH, participants showed better visual reasoning. Lateralization of function may reflect differences in connectivity between control and heteromodal regions in LH, and attention and visual regions in RH.

While the multiple-demand network plays an established role in cognitive flexibility, the role of default mode network is more poorly understood. In this study, we used a semantic feature matching task combined with multivoxel pattern decoding to test contrasting functional accounts. By one view, default mode and multiple-demand networks have opposing roles in cognition; consequently, while multiple-demand regions can decode current goal information, semantically-relevant default network regions might decode conceptual similarity irrespective of task demands. Alternatively, default mode regions might show sensitivity to changing task demands like multiple-demand regions, consistent with evidence that both networks dynamically alter their patterns of connectivity depending on the context. Our task required participants to integrate conceptual knowledge with changing task goals, such that successive decisions were based on different features of the items (colour, shape and size). This allowed us to simultaneously decode semantic category and current goal information using a whole-brain searchlight decoding approach. As expected, multiple-demand regions represented information about the currently-relevant conceptual feature, yet similar decoding results were found in default mode network regions, including angular gyrus and posterior cingulate cortex. Semantic category irrespective of task demands could be decoded in lateral occipital cortex, but not in most regions of default mode network. These results show that conceptual information related to the current goal dominates the multivariate response within default mode network. In this way, default mode network nodes support flexible memory retrieval by modulating their response to suit active task goals, alongside regions of multiple-demand cortex.Significance StatementWe tested contrasting accounts of default mode network (DMN) function using multivoxel pattern analysis. By one view, semantically-relevant parts of DMN represent conceptual similarity, irrespective of task context. By an alternative view, DMN tracks changing task demands. Our semantic feature matching task required participants to integrate conceptual knowledge with task goals, such that successive decisions were based on different features of the items. We demonstrate that DMN regions can decode current goal, alongside multiple-demand regions traditionally associated with cognitive control. The successful decoding of goal information plus largely absent category decoding effects within DMN indicates that this network supports flexible semantic cognition.

The innovative sintered insulation shale (SIS) blocks could use as thermal insulation masonry units to construct the green architecture applying the adaptive construction measures. Above all, the seismic behavior of the wall with an opening should clarify in order to apply in earthquake region. Besides the comparative solid wall, the behavior of typical window-type and door-type walls analyzed under the cyclic lateral loads incorporating with the constant vertical load to achieve the purpose. The main variable of the specimens was the size of the opening. Hence, all the walls were with the same innovative construction measure and geometry parameter. The failure mechanism, energy dissipation, damping ratio, lateral stiffness, deformation and strength capacity conducted according to the record data. Based on the results, the opening caused the weaker masonry parts showing serious damage in wall piers and masonry under the opening, which mainly induced for the lack of restrained condition around the opening. In other words, it changed the failure mechanism. Furthermore, the contribution of RC level bonds and tie-columns to the specimen increased as the opening showing the greater strain than yield strain after the maximum strength, which need to take into account their participation in the lateral resistance calculation. The impact of opening still presented in the decreased lateral stiffness and energy dissipation, smaller ductility and shear strength. The reduced portion would result in the opening wall acting as the weaker part in the SIS masonry structure. In addition, the theoretical equations acquired through Strut-and-Tie method proposed considering the failure mechanism and opening impact. The reduction factors for decreased stiffness and angle of masonry strut, relative stiffness between the RC components and masonry parts applied to conduct the calculation of the maximum strength. Compared with the experimental results, the proposed equations showed enough accurate prediction on the maximum shear resistance.

Emerging studies have emphasized the importance of the fidelity of cortical representation in forming enduring episodic memory. No study, however, has examined whether there are age-related reductions in representation fidelity that can explain memory declines in normal aging. Using functional MRI and multivariate pattern analysis, we found that older adults showed reduced representation fidelity in the visual cortex, which accounted for their decreased memory performance even after controlling for the contribution of reduced activation level. This reduced fidelity was specifically due to older adults' poorer item-specific representation, not due to their lower activation level and variance, greater variability in neuro-vascular coupling, or decreased selectivity of categorical representation (i.e., dedifferentiation). Older adults also showed an enhanced subsequent memory effect in the prefrontal cortex based on activation level, and their prefrontal activation was associated with greater fidelity of representation in the visual cortex and better memory performance. The fidelity of cortical representation thus may serve as a promising neural index for better mechanistic understanding of the memory declines and its compensation in normal aging.