Expansion of off-site percutaneous coronary intervention centres significantly reduces ambulance driving time to primary PCI in the Netherlands.

INTRODUCTION: In patients with ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI)-mediated reperfusion is preferred over pharmacoinvasive reperfusion with fibrinolysis if transfer to a PCI centre can be ensured in ≤120 min. We evaluated the ambulance driving time to primary PCI centres in the Netherlands and assessed to what extent ambulance driving times were impacted by the expansion of off-site PCI centres. METHODS AND RESULTS: We calculated the driving routes from every Dutch postal code to the nearest PCI centre with (on-site) or without (off-site) surgical back-up. We used data from ambulance records to estimate the ambulance driving time on each route. There were 16 on-site and 14 off-site PCI centres. The median (interquartile range) time to on-site PCI centres was 18.8 min (12.2-26.3) compared with 14.9 min (8.9-20.9) to any PCI centre (p < 0.001). In postal code areas that were impacted by the initiation of off-site PCI, the median driving time decreased from 25.4 (18.2-33.1) to 14.7 min (8.9-20.9) (p < 0.001). Ambulance driving times of >120 min were only seen in non-mainland areas. CONCLUSION: Based on a computational model, timely ambulance transfer to a PCI centre within 120 min is available to almost all STEMI patients in the Netherlands. Expansion of off-site PCI has significantly reduced the driving time to PCI centres.

Between-subject variability in the influence of mental imagery on conscious perception.

Mental imagery and visual perception rely on similar neural mechanisms, but the function of this overlap remains unclear. One idea is that imagery can influence perception. Previous research has shown that imagining a stimulus prior to binocular presentation of rivalling stimuli increases the chance of perceiving the imagined stimulus. In this study we investigated how this effect interacts with bottom-up sensory input by comparing psychometric response curves for congruent and incongruent imagery in humans. A Bayesian hierarchical model was used, allowing us to simultaneously study group-level effects as well as effects for individual participants. We found strong effects of both imagery as well as its interaction with sensory evidence within individual participants. However, the direction of these effects were highly variable between individuals, leading to weak effects at the group level. This highlights the heterogeneity of conscious perception and emphasizes the need for individualized investigation of such complex cognitive processes.

Convolutional neural network-based encoding and decoding of visual object recognition in space and time.

Representations learned by deep convolutional neural networks (CNNs) for object recognition are a widely investigated model of the processing hierarchy in the human visual system. Using functional magnetic resonance imaging, CNN representations of visual stimuli have previously been shown to correspond to processing stages in the ventral and dorsal streams of the visual system. Whether this correspondence between models and brain signals also holds for activity acquired at high temporal resolution has been explored less exhaustively. Here, we addressed this question by combining CNN-based encoding models with magnetoencephalography (MEG). Human participants passively viewed 1,000 images of objects while MEG signals were acquired. We modelled their high temporal resolution source-reconstructed cortical activity with CNNs, and observed a feed-forward sweep across the visual hierarchy between 75 and 200 ms after stimulus onset. This spatiotemporal cascade was captured by the network layer representations, where the increasingly abstract stimulus representation in the hierarchical network model was reflected in different parts of the visual cortex, following the visual ventral stream. We further validated the accuracy of our encoding model by decoding stimulus identity in a left-out validation set of viewed objects, achieving state-of-the-art decoding accuracy.

The role of the frontal eye fields in oculomotor competition: image-guided TMS enhances contralateral target selection.

In order to execute a correct eye movement to a target in a search display, a saccade program toward the target element must be activated, while saccade programs toward distracting elements must be inhibited. The aim of the present study was to elucidate the role of the frontal eye fields (FEFs) in oculomotor competition. Functional magnetic resonance imaging-guided single-pulse transcranial magnetic stimulation (TMS) was administered over either the left FEF, the right FEF, or the vertex (control site) at 3 time intervals after target presentation, while subjects performed an oculomotor capture task. When TMS was applied over the FEF contralateral to the visual field where a target was presented, there was less interference of an ipsilateral distractor compared with FEF stimulation ipsilateral to the target's visual field or TMS over vertex. Furthermore, TMS over the FEFs decreased latencies of saccades to the contralateral visual field, irrespective of whether the saccade was directed to the target or to the distractor. These findings show that single-pulse TMS over the FEFs enhances the selection of a target in the contralateral visual field and decreases saccade latencies to the contralateral visual field.