Questions such as these are difficult to answer because it's always difficult to distinguish diminished capacity to resist a temptation from a diminished motivation to resist. People who tell us they literally can't resist might be deceiving themselves, or they might be looking for a convenient excuse.

There are two ways we can attempt to discover whether people who say that they can't control their behaviour really are suffering from some kind of diminished capacity.

First, we can gather as much behavioural evidence as possible: with enough evidence, we might be able to build an overwhelming case that a group of people genuinely suffer from diminished capacity.

When we see the costs - social, financial, physical and psychological - that drug addicts pay to continue using, we have good reason to think they have a diminished capacity to resist.

The second way we can proceed is to use scientific evidence that bypasses people's reports about what they can and can't do. Again, the case of drug addiction is a good example: some of the neurological changes in the brain of addicts seem to be changes in areas involved in self-control.

What about sex?

Recently, a group of researchers at UCLA attempted to resolve the question whether sex addiction is genuinely an addiction, utilising the second method.

Using EEG, which measures electrical activity on the surface of the brain, they determined that people who met the diagnostic criteria for "hypersexuality" did not find sexual stimuli any more compelling than did control subjects.

This is unlike the response seen in drug addicts, who find drug-related stimuli much more attention-grabbing than do unaddicted controls.

This research has been interpreted as showing that sex addiction isn't real. In the terms I used above, it might be taken to show that purported sex addicts do not lack the capacity to control their behaviour.

They simply lack the motivation; they might be morally condemned (if they are harming their families, say) rather than given a medical excuse.

But we shouldn't place too much weight on this study. The researchers looked for a likely correlate of a difficulty controlling behaviour, but there are many others possible correlates. Continue reading

Sources

• Neil Levy in The Conversation
• Image: SF Gate

Neil Levy is Head of Neuroethics at The Florey Institute of Neuroscience and Mental Health.

This remarkable helicopter-control system is the work of a group of scientists at the University of Minnesota led by engineering professor Bin He. What sets it apart is that controlling its flight requires absolutely no actual movement for the pilot—no button-pushing or throttle-pulling. Instead of a conventional remote, users control the vehicle with a EEG (electroencephalography) cap studded with 64 electrodes, which detect electrical activity in different parts of the brain near the scalp, effectively reading their minds.

The system, first demonstrated in April and now fully described in an article published today in the Journal of Neural Engineering, is part of the burgeoning study of brain-computer interfaces—direct communication pathways between brains and computerized or robotic devices. In recent years, scientists have created mind-controlled robotics that can feed someone chocolate or help them drink coffee, but this is the first instance of a flight vehicle controlled entirely by thought.

The system relies upon previous EEG and other neurological research by the team, which identified which activity patterns in the brain correlated with thoughts such as "make a fist with your right hand" and "make a fist with both hands." These sorts of movement-oriented thoughts occur mostly in the motor cortex, an area of the brain responsible for control of the body. The EEG cap is sensitive enough only to detect activity relatively close to the scalp—which is where the motor cortex is located—so the scientists were able to program their EEG software to distinguish between these relevant thought patterns in particular.

As a result, when the system senses one of the specified thoughts, it converts the thought ("make a fist with my right hand") into a command for the helicopter ("turn right") and then sends the signal to the vehicle over Wi-Fi. With that, voilà: a thought-controlled helicopter. Continue reading

Sources

• Smithsonian.com
• Image: wired.co.uk