Amyotrophic Lateral Sclerosis (ALS, also known as 'Lou Gerhig's disease') is a debilitating and eventually fatal disease in which patients suffer from progressive paralysis. However, they are only losing their movements, their brains and minds remain perfectly intact. Eventually, they become trapped in their own body in what is called a completely locked-in state (CLIS, a total lack of muscle control) and later die of respiratory problems. The patients in a CLIS cannot move and none of their efforts is being rewarded or punished. This means that none of their efforts to move or interact has any consequence whatsoever. It has long been known that helplessness can induce a variety of other disorders such as depression. But there is a plethora of other main brain functions associated with the proper evaluation of sensory feedback stemming from voluntary actions any of which might go awry when there is no such feedback for extended periods of time. ScienceDaily now reports on studies reviewed in an article the journal Psychophysiology that so-called brain-computer interfaces (BCI) can help people with ALS in a CLIS (plenty of acronyms there! ). The researchers desribe studies in which ALS patients are trained to control a computer with brain waves. These brain waves are measured either through the scalp (non-invasive) or with micro-electrodes in the brain (invasive). As the patients entered CLIS, they could use the BCI to communicate with the outside world. The authors claim that this continued communication slows the decay of thought processes occurring in patients with CLIS without BCI. However, none of these techniques seemed to work in patients who had already entered CLIS: After a prolonged CLIS, "what fills the subjective world may consist only of the few remaining external auditory and tactile and visceral sensations bearing no contextual relationship between them. With the lack of reinforcing contingencies controlling the maintenance of the stream of thoughts, they extinguish slowly." So once the deterioration of "thinking" has begun due to the lack of any feedback in CLIS, even BCIs can't bring it back. This report is even more remarkable than the analgesic effect operant control has on pain.
Thursday 09 November 2006 - 09:06:44
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). The researchers desribe studies in which ALS patients are trained to control a computer with brain waves. These brain waves are measured either through the scalp (non-invasive) or with micro-electrodes in the brain (invasive). As the patients entered CLIS, they could use the BCI to communicate with the outside world. The authors claim that this continued communication slows the decay of thought processes occurring in patients with CLIS without BCI. However, none of these techniques seemed to work in patients who had already entered CLIS: After a prolonged CLIS, "what fills the subjective world may consist only of the few remaining external auditory and tactile and visceral sensations bearing no contextual relationship between them. With the lack of reinforcing contingencies controlling the maintenance of the stream of thoughts, they extinguish slowly." So once the deterioration of "thinking" has begun due to the lack of any feedback in CLIS, even BCIs can't bring it back.
