Measuring electrophysiological changes induced by sub-concussive impacts due to soccer ball heading.

A growing body of research suggests that impacts to the head, including sub-concussive impacts, carry risks for long-term detrimental effects on cognition and brain health. Despite the potential for negative health consequences associated with sub-concussive impacts, there is currently no reliable and objective method used in clinical practice to assess whether a particular sub-concussive impact affected the brain. In this preliminary study, we developed a machine-learning classifier to detect changes in brain electrophysiological activity following sub-concussive impacts that occur during soccer ball heading.

Estimating the statistical power to detect set-size effects in contralateral delay activity.

The contralateral delay activity (CDA) is an event-related potential component commonly used to examine the online processes of visual working memory. Here, we provide a robust analysis of the statistical power that is needed to achieve reliable and reproducible results with the CDA. Using two very large EEG datasets that examined the contrast between CDA amplitude with set sizes 2 and 6 items and set sizes 2 and 4 items, we present a subsampling analysis that estimates the statistical power achieved with varying numbers of subjects and trials based on the proportion of significant tests in 10,000 iterations.

No Evidence for an Object Working Memory Capacity Benefit with Extended Viewing Time.

Visual working memory is the ability to hold visual information temporarily in mind. A key feature of working memory is its starkly limited capacity, such that only a few simple items can be remembered at once. Prior work has shown that this capacity limit cannot be circumvented by providing additional encoding time, whether providing just 200 ms or up to 1300 ms, capacity is still limited to only three to four items.

Visual search and the N2pc in children.

While there is growing understanding of visual selective attention in children, some aspects such as selection in the presence of distractors are not well understood. Adult studies suggest that when presented with a visual search task, an enhanced negativity is seen beginning around 200 ms (the N2pc) that reflects selection of a target item among distractors. However, it is not known if similar selective attention-related activity is seen in children during visual search.