[The post-covid era: a call on the resilience of physicians, patients and community]. / Het tijdperk na de coronacrisis.

The coronacrisis was a serious threat for health care and society. By its complexity and deep uncertainty the pandemic showed that patients, physicians and health care need more resilience and flexibility to manage similar future stressors. Moreover, the pandemic uncovered growing disparities in health among citizens, the close links between health care and other societal domains and the fact that we still have only limited power to manage complex new challenges for our global health. We have to adopt another way of managing health care and society to get grip on similar complex medical problems, which we will probably have to face in the future as well. Physicians cannot manage these by themselves. Governments also have to act to diminish social inequality, and create incentives for interdisciplinary collaboration, which together may make citizens and professionals experience coherent and resilient health care management.

Oscillatory Mechanisms of Response Conflict Elicited by Color and Motion Direction: An Individual Differences Approach.

Goal-directed behavior requires control over automatic behavior, for example, when goal-irrelevant information from the environment captures an inappropriate response and conflicts with the correct, goal-relevant action. Neural oscillations in the theta band (∼6 Hz) measured at midfrontal electrodes are thought to form an important substrate of the detection and subsequent resolution of response conflict. Here, we examined the extent to which response conflict and associated theta-band activity depend on the visual stimulus feature dimension that triggers the conflict. We used a feature-based Simon task to manipulate conflict by motion direction and stimulus color. Analyses were focused on individual differences in behavioral response conflict elicited across different stimulus dimensions and their relationship to conflict-related midfrontal theta. We first confirmed the presence of response conflict elicited by task-irrelevant motion and stimulus color, demonstrating the usefulness of our modified version of the Simon task to assess different sensory origins of response conflict. Despite titrating overall task performance, we observed large individual differences in the behavioral manifestations of response conflict elicited by the different visual dimensions. These behavioral conflict effects were mirrored in a dimension-specific relationship with conflict-related midfrontal theta power, such that, for each dimension, individual midfrontal theta power was generally higher when experienced response conflict was high. Finally, exploratory analyses of interregional functional connectivity suggested a role for phase synchronization between frontal and parietal scalp sites in modulating experienced conflict when color was the task-relevant visual dimension. Highlighting the importance of an individual differences approach in cognitive neuroscience, these results reveal large individual differences in experienced response conflict depending on the source of visual interference, which are predicted by conflict-related midfrontal theta power.

Multiple visual objects are sampled sequentially.

When acting in a complex visual environment, it is essential to be able to flexibly allocate attention to parts of the visual scene that may contain goal-relevant information. The paper by Jia et al. provides novel evidence that our brains sequentially sample different objects in a visual scene. The results were obtained using "temporal response functions," in which unique electroencephalographic (EEG) signals corresponding to the processing of 2 continuously presented objects were isolated in an object-specific way. These response functions were dominated by 10-Hz alpha-band activity. Crucially, the different objects were sequentially sampled at a rate of about 2 Hz. These findings provide important neurophysiological insights into how our visual system operates in complex environments.

Protecting visual short-term memory during maintenance: Attentional modulation of target and distractor representations.

In the presence of distraction, attentional filtering is a key predictor of efficient information storage in visual short-term memory (VSTM). Yet, the role of attention in distractor filtering, and the extent to which attentional filtering continues to protect information during post-perceptual stages of VSTM, remains largely unknown. In the current study, we investigated the role of spatial attention in distractor filtering during VSTM encoding and maintenance. Participants performed a change detection task with varying distractor load. Attentional deployment to target and distractor locations was tracked continuously by means of Steady-State Visual Evoked Potentials (SSVEPs). Analyses revealed that attention strongly modulated the amplitude of the second harmonic SSVEP response, with larger amplitudes at target compared to distractor locations. These attentional modulations commenced during encoding, and remained present during maintenance. Furthermore, the amount of attention paid to distractor locations was directly related to behavioral distractor costs: Individuals who paid more attention to target compared to distractor locations during VSTM maintenance generally suffered less from the presence of distractors. Together, these findings support an important role of spatial attention in distractor filtering at multiple stages of VSTM, and highlight the usefulness of SSVEPs in continuously tracking attention to multiple locations during VSTM.

Cognitive enhancement: it's about time.

Voelker et al. (2016) discuss the intriguing possibility that faster response times after training result from changes in white matter pathways, and propose that frontal theta activity is important for inducing these changes. We argue that, depending on the specific cognitive processes and brain networks targeted by training, oscillatory activity in other frequency bands could produce similar changes in white matter. Such changes can have a profound effect on brain function and performance if they optimize the timing of information transmission through neural networks. It is not about frequency or speed per se; it is about time.

Proactive, but Not Reactive, Distractor Filtering Relies on Local Modulation of Alpha Oscillatory Activity.

Filter mechanisms that prevent irrelevant information from consuming the limited storage capacity of visual STM are critical for goal-directed behavior. Alpha oscillatory activity has been related to proactive filtering of anticipated distraction. Yet, distraction in everyday life is not always anticipated, necessitating rapid, reactive filtering mechanisms. Currently, the oscillatory mechanisms underlying reactive distractor filtering remain unclear. In the current EEG study, we investigated whether reactive filtering of distractors also relies on alpha-band oscillatory mechanisms and explored possible contributions by oscillations in other frequency bands. To this end, participants performed a lateralized change detection task in which a varying and unpredicted number of distractors were presented both in the relevant hemifield, among targets, and in the irrelevant hemifield. Results showed that, whereas proactive distractor filtering was accompanied by lateralization of alpha-band activity over posterior scalp regions, reactive distractor filtering was not associated with modulations of oscillatory power in any frequency band. Yet, behavioral and post hoc ERP analyses clearly showed that participants selectively encoded relevant information. On the basis of these results, we conclude that reactive distractor filtering may not be realized through local modulation of alpha-band oscillatory activity.

Biasing neural network dynamics using non-invasive brain stimulation.

Recently, non-invasive brain stimulation (NBS) has been discovered as a tool to improve human performance on a wide variety of tasks. Although these observations are highly intriguing, the underlying mechanisms of such enhancements are still poorly understood. Here, we argue that in order to advance our understanding of these mechanisms it is necessary to focus on intrinsic network dynamics in the brain. Taking into account well-known network dynamics, increased excitation in one particular network or brain region may necessarily lead to inhibition of an opposing network (and vice versa). As a consequence, observed behavioral improvements due to NBS may emerge from a shift in the balance between (competing) neural networks in the brain, implicating that behavioral enhancement due to stimulation most likely comes with a cost or side effect. We conclude that more elaborate experimental designs are essential for a better understanding of the relationship between network interactions and the behavioral effects of NBS.

Brain connectivity and high functioning autism: a promising path of research that needs refined models, methodological convergence, and stronger behavioral links.

Here we review findings from studies investigating functional and structural brain connectivity in high functioning individuals with autism spectrum disorders (ASDs). The dominant theory regarding brain connectivity in people with ASD is that there is long distance under-connectivity and local over-connectivity of the frontal cortex. Consistent with this theory, long-range cortico-cortical functional and structural connectivity appears to be weaker in people with ASD than in controls. However, in contrast to the theory, there is less evidence for local over-connectivity of the frontal cortex. Moreover, some patterns of abnormal functional connectivity in ASD are not captured by current theoretical models. Taken together, empirical findings measuring different forms of connectivity demonstrate complex patterns of abnormal connectivity in people with ASD. The frequently suggested pattern of long-range under-connectivity and local over-connectivity is in need of refinement.

Elderly with autism: executive functions and memory.

Cognitive autism research is mainly focusing on children and young adults even though we know that autism is a life-long disorder and that healthy aging already has a strong impact on cognitive functioning. We compared the neuropsychological profile of 23 individuals with autism and 23 healthy controls (age range 51-83 years). Deficits were observed in attention, working memory, and fluency. Aging had a smaller impact on fluency in the high functioning autism (HFA) group than in the control group, while aging had a more profound effect on visual memory performance in the HFA group. Hence, we provide novel evidence that elderly with HFA have subtle neuropsychological deficits and that the developmental trajectories differ between elderly with and without HFA in particular cognitive domains.