Author: vaughanbell

I’ve just found this fascinating case study in American Journal of Physical Medicine and Rehabilitation about a man who lost conscious control over one of his hands after brain injury and suffered involuntary public masturbation episodes as a result.

Involuntary masturbation as a manifestation of stroke-related alien hand syndrome

Ong Hai BG, Odderson

Am J Phys Med Rehabil. 2000 Jul-Aug;79(4):395-8.

Alien hand syndrome is a perplexing and uncommon clinical diagnosis. We report an unusual manifestation of alien hand syndrome in a 73-yr-old man with a right anterior cerebral artery infarct affecting the right medial frontal cortex and the anterior portion of the corpus callosum. We conclude that alien hand syndrome should be considered in patients who present with a feeling of alienation of one or both upper limbs accompanied by complex purposeful involuntary movement.

We tend to think of the cognitive impairments after brain injury as the most disabling – things like loss of memory or speech or language impairment, but we often neglect what we might call social impairments.

Especially when the effect is embarrassing, these can have just as strong an impact because many people massively restrict their lives to prevent causing social discomfort to themselves or others.

Link to PubMed entry for study.

I am pleased to see a letter in this week’s Nature that shows that I’m not the only neuroscientist concerned about the coming robot war. Brain researchers Olaf Blanke and Jane Aspell wrote in to warn about the use of brain-machine interfaces, not to control machines with thoughts, but to control thoughts with machines.

Imagine if insights from the field of cortical prosthetics in human and non-human primates were combined with research on bodily self-consciousness in humans. Signals recorded by multi-electrodes implanted in the motor cortex can already be used to control robotic arms and legs. Cognitive cortical prosthetics will allow the use of other cortical signals and regions for prosthesis control. Several research groups are investigating indications that the conscious experience of being in a body can be experimentally manipulated.

The frontal and temporoparietal signals that seem to be involved encode fundamental aspects of the self, such as where humans experience themselves to be in space and which body they identify with (O. Blanke and T. Metzinger Trends Cogn. Sci. 13, 7‚Äì13; 2009). If research on cortical prosthetics and on the bodily self were applied to humans using brain-controlled prosthetic devices, there might be no clear answer to Clausen’s question: which of them is responsible for involuntary acts?

It may sound like science fiction, but if human brain regions involved in bodily self-consciousness were to be monitored and manipulated online via a machine, then not only will the boundary between user and robot become unclear, but human identity may change, as such bodily signals are crucial for the self and the ‘I’ of conscious experience. Such consequences differ from those outlined by Clausen for deep brain stimulation and treatment with psychoactive drugs.

The letter is a follow-up to a recent Nature piece on potential new ethical issues raised by the development of implantable brain technology.

Unfortunately, these sort of in-house scientific debates rarely do much to raise the public consciousness about the importance of such issues.

However, I have high hopes for the future. Not least because a new film in the Terminator documentary series is soon to be released.

Link to letter in Nature.

In C.S. Lewis’ Narnia novel The Voyage of the Dawn Treader the heroes find a man stranded on an island where dreams come true. They initially express delight but the man rages “Fools!” “Do you hear what I say? This is where dreams – dreams, do you understand? – come to life, come real. Not daydreams: dreams.”

But dreams can come to life and the effect is no less fantastical. In REM sleep behaviour disorder (RBD), normal sleep paralysis breaks down and sleepers act out their dreams – giving observers a remarkable insight into the dreaming mind.

An article recently published in Neurology charted the range of sleep behaviours seen in people with neurological disturbances such as narcolepsy, Parkinson’s disease or other types of dementia, all of which can trigger the problem.

Incidental cases of nonviolent behaviors during RBD included masturbating-like behavior and coitus-like pelvic thrusting, mimicking eating and drinking, urinating and defecating, displaying pleasant behaviors (laughing, singing, dancing, whistling, smoking a fictive cigarette, clapping and gesturing “thumbs up”), greeting, flying, building a stair, dealing textiles, inspecting the army, searching a treasure, and giving lessons. Speeches were mumbled or contained logical sentences with normal prosody [voice tone, rhythm and stress].

The paper also contains two case studies which describe, in detail, exactly what each patient was doing when they were acting out their dreams. This is from the description of ‘Patient 2’:

These behaviors, which occurred with eyes closed, were complex, various, and usually accompanied with sentences resembling a teacher with children (first sequence) or a captain inspecting his troop (second sequence): “(Professorial) Can we all return to our seats! (pause) (Overbearing) What do you do, standing there in the middle? (pause) Remove your finger away from the switch! (pause) Well, if that’s so, I’ll take the numbers. (Ironic) And . . . late! (pause). (Professorial) Get back to your seats. I’m going to start.”

Mumbles for 6 minutes. Then: “(bossy) Raise your hands, raise your hands, raise your hands, I said raise! I didn’t say to pull away! I said: raise your hands!” Here the patient quickly raised his left arm and waved his hand it as if he were showing something. “(Bossy and rhythmic) Halt! (pause) Halt! (pause) Halt!” Three minutes later, he shouted “(Bossy, like in a military parade) Attention! Gentleman, please, attention! (pause) Halt, halt, I said! (pause) Halt, I said!”

This study specifically focused on the less researched non-violent sleep behaviours, as the disorder is more typically associated with acting out aggressive dreams.

This is possibly because the disturbances that cause the disorder also affect the content of the dreams.

An earlier study found that patients with the disorder reported having more aggressive dreams, even though they were not more aggressive in waking life.

It’s a fascinating article and worth reading in full as it contains many ‘wow, that’s amazing’ moments, both for the scientific insights, and the windows into the mental life of sleep.

Link to Neurology article on sleep behaviours.
Link to PubMed entry for same.