Author: vaughanbell

Nobel prize-winning neuroscientist Eric Kandel has been asked to describe four advances in neuroscience from the past year that inspire optimism in an article for Edge.

His choices demonstrate an eclectic interest in modern mind and brain science.

The first is the discovery that MicroRNA is involved in synaptic connections and the second is advances in the understanding of how the hippocampus might store spatial information.

Kandel’s third choice is the discovery that single genes might lead to quite profound changes in social behaviour.

Perhaps his fourth choice is the most interesting, however. He cites neuroscientific evidence for the effectiveness of psychotherapy in treating mental illness, particularly for a type of therapy called cognitive behavioural therapy or CBT.

CBT is the most comprehensively researched of all the psychotherapies.

It has been shown to be as effective, if not more effective, than medication for anxiety and depressive disorders in randomised controlled trials, although best results are usually reported when both medication and CBT are combined, particularly in moderate or severe cases.

Recently, researchers have started to use brain scanning techniques to see how the function of the brain changes after CBT treatment.

Link to Kandel’s article ‘A Neuroscience Sampling’ from Edge.

Neurologist Prof Kevin Nelson and colleagues have just published a study in the journal Neurology showing that out-of-body experiences and near death experiences are more likely to occur in people who have unusual experiences when falling asleep or waking.

Science Daily reports that:

They found that an out-of-body experience is statistically as likely to occur during a near death experience as it is to occur during the transition between wakefulness and sleep. Nelson suggests that phenomena in the brain’s arousal system, which regulates different states of consciousness including REM sleep and wakefulness, may be the cause for these types of out-of-body displays.

Hallucinations and free-form ideas are very common in the period of entering sleep (called the hypnagogic state) and the period of waking (called the hypnopompic state).

Artists and visionaries throughout history have found inspiration from these unusual sleep-related experiences, as recounted in a recent Fortean Times article.

Link to coverage from Science Daily.
Link to coverage from the Daily Telegraph.
Link to PubMed entry for scientific paper.

Wired magazine has a fascinating feature article about an operation to implant deep brain stimulation electrodes in a patient with Parkinson’s disease. Crucially, the article is written the patient himself.

Deep brain stimulation involves inserting permanent electrodes into the brain to pump tiny pulses of electricity into key areas.

It’s most commonly used as a treatment for Parkinson’s disease which causes problems with the ‘motor loop’ – a network of brain areas that control movement (actually there are two main ones, the direct and indirect).

This is why patients with Parkinson’s disease have trouble moving and have a visible tremor.

The loops consist of a series of areas that might boost activity or reduce activity in subsequent parts of the loop.

Damage to any of these areas might mean that the following area might not get enough activation (like with a faulty accelerator), or might be too active because it is not being damped down correctly (like with a faulty brake).

Neurosurgeons can try and restore balance in this loop by either damping down an area by surgery (e.g. a pallidotomy) or by increasing activation at an area by deep brain stimulation.

This is exactly the treatment that Steven Guile, the author of the Wired article, describes.

I’ll be kept awake for the entire procedure. During the surgery I will talk and move my limbs on command, which helps Team Hubris know which part of my brain is being poked.

Unfortunately, this also means I’m conscious when [neurosurgeon] Henderson produces what looks like a hand drill and uses it to burr two dime-sized holes into the top of my skull. It doesn’t hurt, but it’s loud.

Team Hubris is installing a deep brain stimulator, essentially a neurological pacemaker, in my head. This involves threading two sets of stiff wires in through my scalp, through my cerebrum ‚Äî most of my brain ‚Äî and into my subthalamic nucleus, a target the size of a lima bean, located near the brain stem. Each wire is a little thinner than a small, unfolded paper clip, with four electrodes at one end. The electrodes will eventually deliver small shocks to my STN. How did I get into this mess? Well, I have Parkinson’s disease. If the surgery works, these wires will continually stimulate my brain in an attempt to relieve my symptoms.

The article is a wonderful tale of neurosurgery from the inside and a great guide to some of the science and medicine of the condition.

There’s also a fantastic a video segment where Gulie narrates and explains the operation.

Link to Wired article ‘A Shock to the System’ (via Neurophilosopher).

BBC Radio 4 recently broadcast a documentary on the long-term effects of ecstasy (MDMA) now that the ‘E Generation’ are in their 40s.

The documentary looks at the evidence for long-term effects of ecstasy and dispels some of the myths that were promoted in anti-ecstasy campaigns of the early 90s (for example, the famously flawed brain scans presented to suggest that ecstasy leaves functional ‘holes’ in the brain).

It is clear that such scare stories about the drug’s damaging effects were greatly exaggerated.

The evidence does suggest, however, that heavy and / or long-term ecstasy use does lead to mild to moderate cognitive impairment in some people (memory seems particularly sensitive to change).

There is still a need for much more systematic research in this area, particularly as the evidence on whether these long-term impairments get better is quite mixed.

The programme is presented by Dr John Marsden who has researched the impact and neuroscience of ecstasy and talks to a number of people who were heavy ecstasy users in the past.

Link to ‘The E Generation at 40’ with audio.