The use of brain computer interface (BCI) devices in research and applications has exploded in recent years. Applications such as lie detectors that use functional magnetic resonance imaging (fMRI) to video games controlled using electroencephalography (EEG) are currently in use. These developments, coupled with the emergence of inexpensive commercial BCI headsets, such as the Emotiv EPOC ( http://emotiv.com/index.php ) and the Neurosky MindWave, have also highlighted the need of performing basic ergonomics research since such devices have usability issues, such as comfort during prolonged use, and reduced performance for individuals with common physical attributes, such as long or coarse hair. This paper examines the feasibility of using consumer BCIs in scientific research. In particular, we compare user comfort, experiment preparation time, signal reliability and ease of use in light of individual differences among subjects for two commercially available hardware devices, the Emotiv EPOC and the Neurosky MindWave. Based on these results, we suggest some basic considerations for selecting a commercial BCI for research and experimentation. STATEMENT OF RELEVANCE: Despite increased usage, few studies have examined the usability of commercial BCI hardware. This study assesses usability and experimentation factors of two commercial BCI models, for the purpose of creating basic guidelines for increased usability. Finding that more sensors can be less comfortable and accurate than devices with fewer sensors.

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Background New technologies are emerging that may be able to help individuals engage in healthier eating behaviors. One paradigm to test the efficacy of a technology is to determine its effect relative to environmental cues that are known to cause individuals to overeat. Objective The purpose of this work was to independently investigate two questions: 1) How does the presence of a technology that provides bite count feedback alter eating behavior?; and 2) How does the presence of a technology that provides bite count feedback paired with a goal alter eating behavior? Design Two studies investigated these research questions. The first study tested the effects of a large and small plate crossed with the presence or absence of a device that provided bite count feedback on intake. The second study tested the effects of a bite count goal with bite count feedback again crossed with plate size on intake. Both studies used a 2×2 between subjects design. Participants/setting In the first study, 94 subjects (62 female, Age 19.0±1.6 years, BMI 23.04±3.6) consumed lunch in a laboratory. The second study examined 99 subjects (56 female, Age 18.5±1.5 years, BMI 22.73±2.70) under the same conditions. Intervention In both studies subjects consumed a single-course meal, using either a small or large plate. In the first study participants either wore or did not wear an automated bite counting device. In the second study all participants wore the bite counting device and were given either a low bite count goal (12 bites) or a high bite count goal (22 bites). Statistical Analyses Effect of PLATE SIZE, FEEDBACK, and GOAL on consumption (grams) and number of bites taken were assessed using 2×2 ANOVAs. As adjunct measures, the effects of serving size, bite size (grams per bite), post-meal satiety and satiety change were also assessed. Results In the first study there was a main effect of PLATE SIZE on grams consumed and number of bites taken such that eating from a large plate led to greater consumption (p=.001) and a greater number of bites (p=.001). There was also a main effect of FEEDBACK on consumption and number of bites taken such that those who received feedback consumed less (p=.011) and took fewer bites (p<.001). In the second study there was a main effect of PLATE SIZE on consumption such that those eating from a large plate consumed more (p=.003) but did not take more bites. Further analysis revealed a main effect of GOAL on number of bites taken such that those who received the low goal took fewer bites (p<.001) but did not consume less. Conclusion Providing feedback on the number of bites taken from a wearable intake monitor can reduce overall intake during a single meal. Regarding the first research question, providing feedback significantly reduced intake in both plate size groups and reduced the overall number of bites taken. Regarding the second research question, participants were successful in eating to their goals. However, individuals in the low goal condition appeared to compensate for the restric...

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