Deployment of neural resources for temporal attention across the senses

Our sense of time is omnipresent and inextricably connected to how we engage with the world around us. Paying attention to temporal structure allows us to optimally prepare for likely future events. Despite this importance, how aspects of time are represented in the brain and the neural resources dedicated to processing temporal information are not well understood. In the first funding period, we established a cross-species behavioural paradigm and identified key cortical networks that support the precise extraction of temporal structure in the context of statistical learning. Across species, an expectation about the temporal structure of sensory events was accumulated across trials and led to faster reaction times. The key networks supporting this task included parietal and prefrontal cortical regions in both humans and mice, with specific behavioural strategies for predicting the temporal structure corresponding to microstructural changes in parietal regions and subcortical structures in humans as well as changes in functional connectivity on the circuit level in mice. On the single-cell level, temporal expectations could be decoded from neuronal activity in the mouse parietal cortex, indicating the importance of this region for predictive processing of temporal structure. Remarkably, activation in hippocampal subregions and related posterior midline cortical networks (precuneus/retrosplenial cortex) were affected by the temporal context, with differences between younger and older adults. However, it remains unclear how the orienting of temporal attention specifically relates to memory function and the capacity for cognitive reserve across these key networks during ageing. In the upcoming funding period, we will investigate semantically-driven versus statistically-driven temporal expectations and their role in establishing stable memory traces using advanced neuroimaging techniques across species. Specifically, in WP1, we will investigate how different domains of temporal attention (semantically-driven versus statistically-driven) facilitate motor responses and memory recall across ageing; in WP2, we will tag cellular engrams formed during temporal orienting and assess the influence of their manipulation on posterior midline cortical circuits and the adaptive behaviour resulting from temporal attention across ageing; and in WP3, we will model the trajectory of the learning dynamics during temporal processing and evaluate the potential for temporal cognition to act as a cognitive reserve mechanism across ageing. Taken together, the results from the second funding period will allow us to dissociate automatic (statistical) from intentional (semantic) aspects of temporal cognition across ageing, and to develop interventional strategies into the third funding period.