Scene-construction theory explains how spatially coherent event models support memory and imagination, although parts of their temporal organisation are less fully specified. Here we develop Mind Time as a theory of temporal organisation drawing on autobiographical memory and navigation to explain how events are related to one another and to a selected temporal origin across scales. Separating these represented relations from the operations that produce and revise them accommodates evidence for a distributed hippocampal–cortical system, including temporal judgements possible despite impaired episodic construction. Comparative findings constrain inferences about component capacities without resolving claims about subjective experience. The central theoretical proposal is that, during active construction, revising a temporal relation changes the information available to a represented self within the relevant history before a particular consequence is requested. An experiment would test whether this inferred state changes in advance and is available for use in subsequent imagination. Transpersonal extended Mental Time Travel (teMTT) extends this prediction to communication, through which a temporal revision should change another person's later reconstruction or planning. Together, Mind Time and teMTT specify how temporal relations constrain what a represented self can know or do, and how revising those relations changes subsequent reconstruction or planning.
Object categorization depends not only on the current visual input but also on prior knowledge. However, whether different types of prior knowledge influence object categorization with the same temporal profile remains unclear. In this study, we combined a cue–target matching paradigm with event-related potentials (ERPs) to compare the effects of category knowledge and contextual knowledge on object categorization. Category knowledge was manipulated at the superordinate, intermediate, and basic levels, whereas contextual knowledge was based on typical color and scene information. The behavioral results showed that cue–target congruency affected task performance, with different patterns observed across cue conditions. The ERP results further revealed that prior knowledge influenced multiple stages of processing, but the temporal pattern varied across conditions. Category knowledge showed level-dependent effects across intermediate, conflict, and later processing stages, whereas contextual knowledge was associated mainly with P2 and N400 modulation. These findings suggest that different types of prior knowledge contribute to object categorization with different temporal dynamics and that these differences may be related to how the relevant information is structured and used during cue–target matching.
Language disorganisation is a core feature of schizophrenia with significant functional consequences. However, its neurophysiological substrates remain poorly characterised, particularly in the early stages of the illness. This study investigated whether first-episode schizophrenia (FES) is associated with disruption in the organisation of language-network lateralisation, using both static and dynamic functional connectivity metrics in the EEG beta band. Thirty-one FES patients and 32 age-matched healthy volunteer subjects (HVS) underwent resting-state 64-channel EEG. Source-level connectivity was estimated using the weighted phase lag index with sliding windows, yielding 979 connectivity matrices per participant. Brain network states (BNS) were identified via k-means clustering. Static connectivity was obtained by time-averaging. Temporal features, graph-theoretical metrics, and language-network laterality indices were extracted for both whole-network and language-specific analyses. Group comparisons used permutation-based tests with family-wise error correction. Static connectivity yielded no significant group differences in any metric. Dynamic analysis identified six BNS. FES showed a significant increase in the variability of the temporal dynamics and graph-theory features of BNS5, a state characterised by parieto-occipital dominance. The core language network laterality index was significantly reduced in FES within BNS1, a state characterised by auditory-visual dominance. BNS1 occurrence correlated negatively with language disorganisation scores. Dynamic BNS-specific language network metrics correlated with verbal fluency performance exclusively in FES. These findings demonstrate that language dysfunction in early psychosis is expressed as state-dependent disruption of brain network stability and language lateralisation, detectable only through dynamic connectivity analysis.
Striatal activity during episodic memory retrieval is a robust phenomenon observed across various stimulus types and experimental paradigms. Previous research suggests that the ventral striatum and the caudate contribute differentially to retrieval processes: ventral striatal activity is posited to vary with the intrinsic reward of successful retrieval, whereas caudate activity is attributed to effortful cognitive control. The present fMRI study aimed to test the overarching hypothesis that these striatal subregions make distinct contributions to episodic retrieval and to further specify their functional roles. To this end, we employed a word-picture paired-associates learning paradigm in which words served as cues in two consecutive cued-recall tests that were separated by 24 h. Participants indicated the specificity of their associative memories, enabling characterization of striatal response profiles as a function of associative memory specificity and treatment of memory specificity as a proxy for the intrinsic reward associated with retrieval success. Rather than being not readily compatible with a role of the caudate in effortful post-retrieval control, the results suggest that elevated caudate activity during successful recall reflects pre-retrieval control or involuntary orienting to salient mnemonic information. In contrast, rather than reflect intrinsic reward itself, ventral striatal activity varied with the discrepancy between expected and actual intrinsic reward elicited by retrieval outcomes-that is, a metacognitive reward prediction error. Moreover, ventral striatum signaled the relevance of retrieved information and modulated its re-encoding to facilitate future retrievals.
