Brain-to-brain transfer of information has been illustrated between a pair of rats (Pais-Vieira et al. 2013). We evaluate the scientific validity of this study. First, the rats receiving the electrical stimulation were performing at 62 to 64% correctness when chance was 50% correctness using one of two discrimination paradigms, tactile or visual. This level of performance is not sustainable without being imbedded within a behavioural paradigm that delivers reward periodically. Second, we estimated that the amount of information transferred between the rats was 0.004 bits per second employing the visual discrimination paradigm and 0.015 bits per second employing the tactile discrimination paradigm. The reason for these low transfer scores (i.e. rates that are 1 to 2 orders of magnitude lower than that transferred by brain-machine interfaces) is that overall the rats were performing close to chance. Nevertheless, based on these results Pais-Vieira et al. have suggested that the next step is to extend their studies to multiple brain communication. We would suggest that the information transfer rate for brain-to-brain communication be enhanced before performing such an experiment. Note that the information transfer rate for human language can be as high as 40 bits per second (Reed and Durlach 1998).
For more information see: Tehovnik EJ & Teixeira e Silva Z (2014) Brain-to-brain interface for real-time sharing of sensorimotor information: a commentary. OA Neurosciences, Jan 01;2(1):2.