Periodic Reporting for period 1 - ORCA (Oscillatory long-Range Coherence in Attention) Reporting period: 2016-08-01 to 2018-07-31 Summary of the context and overall objectives of the project Attention -the ability to focus selectively on task relevant information and resist distraction- plays a critical role in many everyday life situations, such as in school or while driving. With an almost constant stream of information reaching us through smart phones and computers, our world becomes increasingly distracting, requiring enhanced attentional capabilities. This calls for new approaches to improve attention, also benefiting patients populations suffering from attention deficits. Is it possible to safely improve attention without medication? And how does the brain actually guides attention and resist distractions? Our research project set out to answer these questions by applying a novel brain stimulation technique, transcranial alternating current stimulation (tACS). In the first study, we assessed the effects of stimulation on spatial attention performance, while simultaneously measuring neural activity using electroencephalogram (EEG). Unfortunately, we did not find the expected effects of stimulation on attention or neural activity. Because this finding contradicts previous findings, we currently are unsure whether it is possible to modulate spatial attention with tACS. In a second study we focused on manipulating vigilant attention instead of spatial attention. This kind of attention is particularly important in settings that require you to focus attention for a long time on an generally uneventful task, such as driving a car or air traffic control. In this study we found a frequency-specific effect on performance. Although further research is needed, this finding offers promising tools to improve vigilant attention. Taken together, in our research project we were able to modulate vigilant attention, but not spatial attention. In the future, these initial results could lead to methods to improve (vigilant) attention and thereby prevent the harmful effects of deteriorating attention. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far For the first project we tested twenty-three participants on three different sessions (total of 69 sessions) while applying different stimulation settings on each session. Participants performed a spatial attention task while we recorded performance on the task as well as neural activity using EEG. Behavioral as well as neural data were analyzed. We found no spatially selective effects of stimulation on behavioral data or neural data, indicating that the stimulation had no effect, or a general effect on for example arousal. These findings were presented on one international conference and one national conference. In addition, a paper describing the findings was published in an open-source peer-reviewed journal. For the second project, we tested 101 participants in a between-subject design. Participants were tested with two different stimulation frequencies. After analysis of the behavioral data, we found that although performance on the task declined over time (which is expected in this task), the degree of performance decline was different for the two stimulation conditions. This means that we potentially found a tool to reduce the performance decrement that is often found on tasks requiring vigilant attention. We are currently writing a paper on these findings. I also contributed to a review paper on the use of brain stimulation to improve attention. This paper was published in 2017. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) The findings in our second study suggest a frequency-specific role for the medial frontal cortex in vigilant attention. This finding corroborates with current theoretical frameworks about the role of the medial frontal cortex in attention. However, we are the first to show a causal role. If further research indeed shows that we can limit performance decrements in attention, this can prevent hazardous situations in the future. For example, if we could monitor oscillatory brain activity in truck drivers and boost this activity by applying brain stimulation when it tends to drop, we might be able to prevent road accidents. Such a feedback loop could also be applied in other professions, like air traffic controllers. Spatial attention modulated alpha lateralization, but tACS did not affect this top-down effect.
