Ethical Practice in the Era of Advanced Neuromodulation

Therapeutic and scientific approaches to neurological and psychiatric disorders have led to advanced technologies for neuromodulation, such as deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), and brain-machine interfaces (brain-computer interfaces; BMI/BCI). The interactive approaches between external environment and brain function via BMI/BCI may provide novel insights into “free will”, as well as decision-making and action planning processes of human agents. Indeed, BMI/BCI instruments can already be applied in “real-time” translation systems linking brain activity and computer commands, such as computer cursor movement, spelling devices, and wheelchair control. Such advances enable human agents “interfaced” with computers to manipulate external instruments efficiently and to express one’s basic intentions.

In this article, I introduce recent advances in BMI/BCI and other related technologies being developed globally, and the ethical implication of their practice for neurological patients in Japan.

“Neuromodulation” in Computational Context

“Neuromodulation” can be defined as a technology to modulate brain function for realising more improved quality of life (QOL) for both healthy people and patients and people with disabilities (Fukushi and Sakura 2008). There are two procedures implementing neuromodulation in humans, i.e., pharmacological and computational ones (Fukushi and Sakura 2008; Husain and Mehta 2011; Synofzik 2007). Pharmacological procedures are not the main focus in this article. Briefly, it has been recognised that psychotropic drugs can alter people’s daily performance by enhancing the memory, concentration, social communication, etc. (Husain and Mehta 2011). Computational procedures, such as DBS, TMS, and BMI/BCI, have been developed considerably for this half century.

DBS is an electrical stimulation technology via chronically implanted electrodes to subcortical structures. It was originally developed by Benabid and his colleagues in the 1980s, and the original purpose for DBS application to the target patient was a treatment of movement disorders (Wichmann and DeLong 2006; Okun et al. 2010). After almost three decade of DBS application in the clinical scene, it is extensively used for various types of neurological disorders including essential tremor, dystonia, ballismus, and chorea (Montgomery 2004; Wichmann and DeLong 2006) as well as vegetative state (Schiff et al. 2011; Yamamoto et al. 2012, 2010; Yamamoto and Katayama 2005).

TMS, another neurostimulating technology, is a relatively new technology, and is considered among the “non-invasive” and “safer” stimulation procedures (Steven and Pascal-Leone 2006). TMS produces magnetic field by electric current flowing through a coil of wire, and it is categorised by three types of stimulation pulses: single-, paired-, and repetitive (rapid-rate) types (Quintana 2005). The safety criteria of TMS parameters in the guidelines of International Federation of Clinical Neurophysiology (IFCN) published in 1999 was not precisely defined to cover various types of disorders (Hallet et al. 1999; see also Fukushi and Sakura 2008). Since then, it has been extensively discussed how the effect of TMS differs across stimulating procedures (single pulse, paired pulse, and repeated), purpose of stimulation (clinical or non-clinical), subject’s characteristics (sex, age, vital condition, neurological history, etc.), and target brain structures (Gilbert et al. 2004; Machii et al. 2006, Quintana 2005). In 2009, the guidelines were fully revised with considerable numbers of analyses and discussions among researchers and clinicians (Rossi et al. 2009).

BMI/BCI is a technology developed for the purpose of connecting living brain structure and computer(s) directly, in order to manipulate instruments. The possibility of this technology has been discussed in the late 20th century and the number of laboratories dealing with BMI/BCI has been expanded in this decade (Guger et al. 2011; Mikhail et al. 2011). Neurophysiological approaches using non-human primates have contributed significantly to make this technology applicable for human subjects, and recent advances in noninvasive BMI/BCI for human subjects are remarkable (Birbaumer et al. 2008; Cecotti 2011; Fifer et al. 2012). For example, most of BMI/BCI instruments succeed to apply “real-time” translation system between brain activity and computer command, and a variety of instrumental options are getting available for BMI/BCI manipulation, such as computer cursors, spelling devices, wheelchairs, and so on (Millán et al. 2010; Mak and Wolpow 2009). These advances...