Year: 2009

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.

For the first time, the brain structure of male-to-female transsexuals has been investigated in living individuals using MRI brain scans, helping to fuel the debate over the possible neural basis of gender identity.

The scientific article, shortly to appear in the neuroscience journal NeuroImage, used MRI brain scans and a technique called voxel based morphometry to compare grey matter in a group of male-to-female transexuals to groups of males and females who have never had gender-identity concerns.

This is not the first time that brain structure has been compared in this way, but earlier studies had been based on post-mortem comparisons. These three studies had found that certain areas in male-to-female transsexuals more commonly resembled the equivalent area in females than males.

This has led some researchers to go as far as suggesting that perhaps the differences are present from birth and that gender-identity difficulties could result from the body and brain following different paths as the developing foetus begins to develop into a specific sex.

However, one difficulty is that all the transgender people examined in these post-mortem studies had been on oestrogen treatment to feminize their bodies, and it hasn’t been clear whether the differences were due to the effect of this hormone rather than something present before.

This new study, led by neuroscientist Eileen Luders, specifically recruited male-to-female transsexuals who had never taken oestrogen and, being in living people, wasn’t affected by whatever led to the person’s death.

In contrast to previous investigations, this new study found that male-to-female transsexuals grey-matter was similar in most areas of the brain to the male rather than female comparison group.

Except, that is, for one area, the putamen, a deep brain structure that forms part of the basal ganglia – known for its wide range of functions and connections to the frontal lobes and action control areas.

Because we know so little about the neuroscience of self-image and gender-identity it’s almost impossible to draw any conclusions for the fact that this specific area seems more ‘feminine’, or that the majority of the other areas seem more ‘masculine’ in terms of size.

What this study does do, however, is add to the increasing evidence that there are some detectable neurological differences in the brains of transgendered people. We’re just not in a position to say much about the significance of this yet.

Link to PubMed entry for ‘in press’ paper.