Month: November 2006

The New York Times has covered a recently published brain-scanning study of five individuals who ‘speak in tongues’ – an experience also known as glossolalia – where someone appears to be speaking in an incomprehensible language over which they seem to have no control.

This is usually linked to religious and spiritual worship, particularly for Christians in the charismatic tradition (there’s some footage on YouTube).

A team of researchers, led by Dr Andrew Newberg, used a type of brain-imaging called SPECT to compare blood flow differences in the brain between when participants were singing hymns and when they were speaking in tongues.

The main findings were that when participants were speaking in tongues compared to when they were singing, there was a decrease in activity in the prefrontal cortex, the tip of the left temporal lobe and a deep brain structure called the caudate nucleus (see image on right).

Although brain areas are known to have multiple functions, the prefrontal cortex is known to be involved in cognitive control, while the left temporal pole is associated with naming and the caudate nucleus has been associated with the ability to switch between multiple languages.

The authors suggest that these findings may indicate a loosening of control over language functions in the brain, potentially leading to the production of apparently unstructured language that the participants experience as outside their control.

Notably, there were also relative increases in activity in the left parietal lobe (linked to our sense of body and spatial awareness) and the amygdala – an area known to be heavily involved in emotion.

These findings were a lot harder to explain, however, although the parietal lobe in particular has been linked to meditation, although a previous study found the area showed decreased, not increased activity, as was the case in this instance.

However, this is not the first time that neuroscientists have studied speaking in tongues.

Dr Michael Persinger reported a case in 1984 where he used EEG recordings to look at the electrical activity in the brain of a 20 year-old female who experienced the same phenomenon.

The graph on the left shows EEG recordings taken from the temporal lobes during a period of speaking in tongues that show increased ‘spike events’.

This indicates that, like the more recent Newberg study, changes in temporal lobe function may be an important part of the experience.

Interestingly, people with temporal lobe epilepsy are known to be more likely to have religious or mystical experiences during seizures.

One of my favourite case studies is of 25 year-old female patient with temporal lobe epilepsy who had “seizures characterized by repetition of certain religious statements and a rather compulsive kissing behavior”.

Well, they do say God moves in mysterious ways.

Link to NYT article ‘A Neuroscientific Look at Speaking in Tongues’.
Link to abstract of SPECT study on speaking in tongues.

The Washington Post investigates the neuroscience of lying in a recent article on whether new brain-scanning technologies will be able to separate facts from falsehoods.

This technology is of particular interest to governments interested in whether neuroscience can get more reliable information from suspects, and to companies willing to pay to ‘interrogate’ clients about their truthfulness.

The article mentions a company called No Lie MRI Ltd which claims to use “the first and only direct measure of truth verification and lie detection in human history”, which surely must violate any number of laws regarding truthfulness in product advertising – considering that the recent research on fMRI lie detection suggests a poor reliability with current methods.

Presumably, they took their own lie detection test and convinced themselves they were telling the truth.

This is not to say that this technology will develop in the future to be more reliable, though.

This prospect has sparked concern about the potential legal (pdf) and ethical issues of this technology and spurred the American Civil Liberties Union to submit a freedom of information request to the US Government earlier this year to see if they are already using fMRI ‘lie detection’ on terrorist suspects.

Some of the hype around brain-scan lie detection harks back to similar claims that were made for the polygraph tests in the past, despite evidence of their poor reliability and high levels of false positives.

Whether fMRI based lie detection turns out to be anything other than a similarly unreliable detection method (but with prettier pictures) remains to be seen.

Nevertheless, one method which does seem to be generating a lot of interest is the Guilty Knowledge Test (pdf), which relies on the fact that the brain tends to produce reliably different automatic responses for items that are recognised compared to items that aren’t.

The idea behind this is that you could show items to suspects that were taken from the ‘crime scene’ and look for the traces of successful recognition measured from the brain.

This technique is now reliable enough that it is starting to be admissible in court. The success of this technique has given researchers hope that successful lie detection may be possible for more than simple recognition situations.

Nevertheless, as every good conman knows, the best lies have a kernel of truth and it’s not clear how well these techniques will detect economies of truth when compared to outright whoppers.

Link to article ‘Brain on Fire’ from The Washington Post.

I went to the exhibition I posted about yesterday on visual cognition in painting and surgery at the Royal College of Surgeons and was a bit under-whelmed to be honest.

It was interesting, but was really just some colourful information boards about the study and research project.

However, the Hunterian Museum is always excellent, and I happened across this exhibit of a skull with three trepanation holes in it, and evidence of syphilitic caries (cavities in the skull caused by infection).

There’s no other information about it, except it is pre-1831.

It isn’t known whether the hole-drilling operation was an attempt to ‘treat’ the infection by syphilis, but it is likely, owing to the fact that syphilis often leads to neurosyphilis.

Neurosyphilis is known to cause a number of neurological and psychiatric consequences – psychosis being the most well-known.

Some say that Dracula author Bram Stoker, was suffering from neurosyphilis when he wrote his final, and frankly weird, last novel The Lair of the White Worm.

The Hunterian Museum has an online catalogue, called SurgiCat that allows you to search the museum records and indexes.

A search for ‘trephining’ (an alternative name for trepanation) brings up a number of surgical kits used for the purpose and various bits of skull and brain-covering that show evidence of hole-drilling.