  This paper presents a dataset containing recordings of the
electroencephalogram (EEG) and the electromyogram (EMG) from eight subjects who
were assisted in moving their right arm by an active orthosis device. The
supported movements were elbow joint movements, i.e., flexion and extension of
the right arm. While the orthosis was actively moving the subject's arm, some
errors were deliberately introduced for a short duration of time. During this
time, the orthosis moved in the opposite direction. In this paper, we explain
the experimental setup and present some behavioral analyses across all
subjects. Additionally, we present an average event-related potential analysis
for one subject to offer insights into the data quality and the EEG activity
caused by the error introduction. The dataset described herein is openly
accessible. The aim of this study was to provide a dataset to the research
community, particularly for the development of new methods in the asynchronous
detection of erroneous events from the EEG. We are especially interested in the
tactile and haptic-mediated recognition of errors, which has not yet been
sufficiently investigated in the literature. We hope that the detailed
description of the orthosis and the experiment will enable its reproduction and
facilitate a systematic investigation of the influencing factors in the
detection of erroneous behavior of assistive systems by a large community.
