The effect of age on human motor electrocorticographic signals and implications for brain–computer interface applications

Abstract

Electrocorticography (ECoG)-based brain-computer interface (BCI) systems have emerged as a new signal platform for neuroprosthetic application. ECoG-based platforms have shown significant promise for clinical application due to the high level of information that can be derived from the ECoG signal, the signal's stability, and its intermediate nature of surgical invasiveness. However, before long-term BCI applications can be realized it will be important to also understand how the cortical physiology alters with age. Such understanding may provide an appreciation for how this may affect the control signals utilized by a chronic implant. In this study, we report on a large population of adult and pediatric invasively monitored subjects to determine the impact that age will have on surface cortical physiology. We evaluated six frequency bands--delta (<4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13-30 Hz), low gamma band (30-50 Hz), and high gamma band (76-100 Hz)--to evaluate the effect of age on the magnitude of power change, cortical area of activation, and cortical networks. When significant trends are evaluated as a whole, it appears that the aging process appears to more substantively alter thalamocortical interactions leading to an increase in cortical inefficiency. Despite this, we find that higher gamma rhythms appear to be more anatomically constrained with age, while lower frequency rhythms appear to broaden in cortical involvement as time progresses. From an independent signal standpoint, this would favor high gamma rhythms' utilization as a separable signal that could be maintained chronically.

Ethical considerations in the use of brain-computer interfaces

“…According to current knowledge, the application of BCIs in children is possible. The results are similar to those in adult patients [14,15]. Thus BCIs and NPs are a perceived opportunity to treat children with severe motor disabilities, for example.…”

Usefulness of EGI EEG system in brain computer interface research

“…The use of BCIs in children, if possible using EEG [ 20 ] and electrocorticography (ECoG) [ 21 ], is another source of ethical consideration. The excessive use of BCIs as an artificial way of communication and control, both in healthy and disabled children, can significantly influence development of the young nervous system.…”

Brain Mapping in a Patient with Congenital Blindness – A Case for Multimodal Approaches

“…A 75–115 Hz frequency band, which is in the Gamma range, was used to identify cortical sites active with task performance. An active site was defined as having at least one bin in the range with a statistically significant increase in power (Leuthardt et al, 2007; Miller et al, 2007b; Wu et al, 2010; Roland et al, 2011). The maximum r 2 value for each electrode was then used to plot a topographical activation map on a polygonal mesh of the patient’s brain (Figure 3).…”