New dawn in brain-machine interfacing

Scientists have made a breakthrough in their efforts to bring paralysed people the ability to use thought power alone to control artificial limbs, and to interact with computers and other electrical devices.

John Donoghue and colleagues implanted a tiny array of electrodes into the brain of a 25-year-man who is unable to move his arms or legs following a knife wound that severed his spinal cord. The brain implant allowed him to use his thoughts to check emails, play a simple computer game, change channels and volume on a TV, and to control a robotic arm. It is the first time an implant of this kind has been tested in a human.

The electrode array was implanted into the part of the man's brain that, prior to his injury, would have controlled his left arm. By forming the intention to move his arm, neurons were activated in this region, their pattern of firing was recorded by the implant and then an external computer converted the neuronal firing into a command for a mouse cursor or robotic arm.

The findings represent a significant advance on at least three fronts – the man was able to achieve this control within a few minutes of practice; he was able to chat with researchers while he was exerting mental control of the cursor, TV or robot arm; and his control was in all directions, rather than just left and right or up and down. This is in contrast to non-invasive brain-machine interfaces that rely on recording the surface electrical activity of the brain. They require weeks or months of training, demand the user’s full attention when in operation, and, until recently, only allowed one-dimensional cursor control. This new study also shows that several years after paralysis, neurons that were previously involved in controlling limbs still respond to the will to move.

However, significant hurdles remain. As well as involving surgery and the risk of infection, the device used in this trial was connected by wires to bulky computing equipment and required constant fine tuning. A fully-implantable, wireless device would be preferable. Moreover, the precise control we achieve with our natural limbs depends on constant sensory feedback from touch and proprioception – the sense of where our limbs are in space. Scientists have a long way to go before they 'close the loop' by mimicking this kind of feedback.
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Hochberg, L.R., Serruya, M.D., Friehs, G.M., Mukand, J.A., Saleh, M., Caplan, A.H., Branner, A., Chen, D., Penn, R.D. & Donoghue, J.P. (2006). Neuronal ensemble control of prosthetic devices by a human with tetraplegia. Nature, 442, 164-171. Open access.

Link to accompanying videos. Open access.

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Why marginalised minorities may be wary of intergroup contact

When people from different social groups mix, they generally come away with a more positive attitude towards the other social group. However, this benefit is not always symmetrical - people from a minority group are less likely to emerge with improved attitudes. It depends on how they perceive the experience, and how they perceive the dynamics between their social group and the majority group.

Nick Hopkins and Vered Kahani-Hopkins have explored such perceptions by analysing some of the diverse positions on inter-faith dialogue adopted by British Muslims in the 1990’s. For example, they found speakers at one event arguing that inter-faith dialogue was unhelpful until the Muslim community was fully united and better organised.

One speaker said: “At present interfaith dialogue is conducted on both sides by individuals and groups who have no interest in Islam. Under such circumstances interfaith dialogue becomes a tool through which the religious rights of one group - Muslims - are slowly eroded away”.

Hopkins told The Digest: “It seems that for some minority group activists, interventions involving contact could be problematic because they are perceived as undermining group members’ abilities to act collectively and bring about social change”.

However, this was not a feeling held by all Muslims at the time. Hopkins and Kahani-Hopkins also analysed a 1997 report by the Runneymede Trust - ‘Islamaphobia: a challenge for us all’ which represented an important strand of Muslim opinion. The report emphasised the need for inter-group contact if Islamaphobia were to be overcome, and mentioned “the importance of practical projects which require people from different communities and faiths to work as partners on the resolution of shared problems, and to make common cause to other bodies”.

The researchers believe it is only through this kind of careful, qualitative analysis of how people think about inter-group dynamics that a more realistic, politically sophisticated understanding of how different groups feel about intergroup contact can be achieved.
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Hopkins, N. & Kahani-Hopkins, V. (2006). Minority group members’ theories of intergroup contact: A case study of British Muslims’ conceptualisations of ‘Islamaphobia’ and social change. British Journal of Social Psychology, 45, 245-264.

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