Decoding accuracies as well as ERP amplitudes do not show between-task correlations

Some participants consistently show large, and others small activations in Electroencephalography (EEG) and other neuroimaging studies. Similarly, decoding accuracies in Brain-Computer-Interface (BCI) vary between subjects, in extreme cases labelled “BCI-Illiteracy”. Here, we investigate whether a switch of task within an event-related design could be sufficient to alleviate low performance. We compare event-related-potentials (ERP) component amplitudes, as well as offline balanced decoding-accuracy based on deep convolutional networks, between seven event-related tasks. ERP effect amplitudes and decoding accuracies were correlated within all tasks, but not between any pairwise tasks. Further, 39/40 subjects had above average performance in at least one task. Two cautious conclusions can be drawn, with the appropriate limitations of power (n=40) and the caveats of interpreting null-findings: 1) The lack of effect amplitude correlations shows that between-subject variability cannot be purely explained by a task-agnostic effects like skull thickness. 2) The lack of decoding accuracy correlations shows promise for ERP-based BCIs: replacing the task could be an effective way to combat “BCI-Illiteracy”. ### Competing Interest Statement The authors have declared no competing interest.