Abstract: The ultimate goal of the brain science, including now hot ‘brain-computer interface’ researches, is to read the mind to predict our behaviors, including conscious experiences. Do you believe that scalp-recorded EEG can read full complexity of human mind? Perhaps yes, if we can use a state-of-art high-density recording system? However, I have several reasons to say no. To argue this issue, I will first introduce a concept, effective degrees of freedom (DOF) in scalp-recorded EEG in terms of temporal independence. Secondly, I will show some data to propose that effective DOF of scalp-recorded EEG seems around 10-30 at a time regardless of the number of electrodes. Third, I will compare this situation with electrocorticography (ECoG) data, in which sensors are directly placed on the surface of the brain, to show that ECoG’s effective DOF is dramatically larger than scalp measurements. These observations predicts that even if we can use ultra-high-density sensor array system (even as dense as hairs), it is only as good as conventional high density sensor array (128-256 ch). I once called it Makoto’s pessimism. These observations also predict that a true ground-breaking advance in the brain science needs a hardware breakthrough, namely chronically implanted, ultra-high-density wireless (CI-UHD-WL) ECoG system, and its collective database to perform data mining. However, the field of EEG research does not seem to realize this fact and possibility. Finally, I will discuss a thought experiment of launching a venture company that sells ECoG dogs whose minds owners can read with smartphones. This commercial-based, scientifically ambitious company should provide 1) proof of concept for the all-time CI-UHD-WL ECoG recordings, including development of critical hardware and surgical technologies which can be transferred to humans as a next step, 2) novel neuroscientific findings which should be also useful for medicine, particularly epileptology, and 3) an unprecedented level of inter-species communication with man’s best friend.
Link to the recorded seminar on the SFI YouTube channel: https://www.youtube.com/watch?v=lRyZxt2WeKk&feature=youtu.be&t=3205