Feeds:
Posts
Comments

Archive for April, 2007

broca.jpgNature is running a nice news article on the re-localization of Broca’s language area in the brain, and has as feature about it in their latest podcast.

Pierre Paul Broca originally described patient cases in which the patient suffered speech production deficits following injury to the left frontal hemisphere. However, a revisit to Broca’s original papers (see translations here and here), combined with a modern scanning of the preserved remains of Broca’s patients, has revealed that what has been called Broca’s area in modern times does not correspond to the areas implicated by Broca in his patient descriptions and neuroanatomical descriptions.

The story is interesting, but I’m amazed that the excitement is running so high. After all, lots of papers have already dethroned Broca’s (and Wernicke’s) area in the role of language processing. Take the example of the special issue of Cognition on language. Basically, what we know about language in the brain is beyond the talk (!) about Broca and Wernicke, and especially the models they suggested. Rather, both language comprehension and production require a larger neural symphony, and with substantial internal redundancy. IOW, Broca’s area can participate in comprehension, and Wernicke can play a part in production.

Nevertheless, the Nature news article is a good read, and I always recommend the Nature podcast.

-Thomas

Advertisements

Read Full Post »

levy.jpgMost of the neuroethics literature is written by neuroscientists, but now Cambridge University Press has published a book on neuroethics by philosopher Neil Levy: Neuroethics. Challenges for the 21st Century. Philosophers are famously opposed to anything coming from the neurosciences so it will interesting to see what Levy has to say! Actually, Levy has for some time posted on Adam Kolber’s great Neuroethics and Law blog, so some of his views will already be know to many.

Last November Levy was interviewed on The Philosopher’s Stone at ABC Radio National. I can’t find the audiofile for that interview – leave a message in the comments if you can – but here’s a transcript of it.

-Martin

Read Full Post »

brain-reading.jpgBack in February, BBC ran a story about fMRI researchers – shock, horror! – now being able to read people’s minds. In actual fact, the story was a bit more benign. Using a fairly new (and little used) type of fMRI analysis called “multivariate analysis” researchers such as Geraint Rees and John-Dylan Haynes are presently attempting to associate individual mental states with specific patterns of BOLD signal activity. If the mental states of interest can be precisely delineated it is possible to determine if a subject is “in” mental state A or B just from looking at the scanned fMRI data. For instance, in one experiment, described in the BBC story, subjects were asked to either subtract or add numbers shown on a screen without telling the experimenters which of the two potential choices they actually went with. Just by looking at the obtained scans Haynes and his colleagues were able to infer, in 70 % of the cases, whether the subject chose to add or substract – thus, to some degree, being able to “read” the subjects’ hidden intentions. Of course, in reality, the experimenters’ mind reading ability was extremely limited, being focused on only two, highly simple, forced choices. (If you want to read a good presentation of the mind reading possibilities offered by multivariate analysis, see this paper by Rees and Haynes.)

Yet, with all the recent talk about fMRI lie detection and what have you, work such as Haynes and Rees’ on multivariate analysis raises a number of interesting neuroethical questions. On May 9, Haynes is convening a bunch of top-notch speakers to discuss these questions, including Daniel Langleben (of fMRI lie detection fame), Adrian Owen, Henrik Walther, and Thomas Metzinger. He presents the colloquium with the following words:

Every thought is associated with a characteristic pattern of activation in the brain. By training a computer to recognize these patterns, it becomes possible to read a person’s thoughts from patterns of their cerebral activity. In this way a person’s brain activity can betray their thoughts and emotions, can gives clues whether they are lying, or can even predict what they are about to do.

This recent progress in brain science has made completely new insights into thought processes possible. We can now investigate how thoughts are stored in the brain, or how intentions unconsciously arise and affect our behavior. But these findings are not just of interest for the scientific disciplines involved. They have important implications for our understanding of human nature. Also, they lay foundations for important applications: For example, with the help of a “brain computer interfaces”, paralysed patients can control technical devices solely “with the power of their thoughts”.

In the 11th Berlin Colloquium, brain scientists from the USA, Canada and Europe will present this new field of “brain-reading”, while at the same time providing a forum for discussion on the future perspectives of these methods. In particular, the ethical question will be of interest, to which extent such “thought technology” is compatible with “mental privacy”.

It should be well worth your time going.

-Martin

Read Full Post »

hjernep1grafik620×120_istoc.jpg

And while we’re in the talk of media coverage, I should mention to those who understand Danish that the Danish Broadcast Company, or DR, has a documentary series on their primary radio channels, P1. The series is called “Hjernerejsen” (loosely translated to “The brain travel”) and it covers topics such as emotions and bonding, brain maturation, transhumanism and neuroethics.In the program called “the soul is in the brain”, I starred in an interview about the new ideas that neuroscience brings to our traditional thoughts about personality and self. My co-interviewees were Jesper Mogensen and Albert Gjedde, both well-renowned neuroscientists both within and outside Scandinavia.

In a coming topic on the senses (tomorrow, April 19.), I speak about how neuroscience can be used in marketing, aka neuromarketing.

The series can be found here, and DR does a nice podcast: http://podcast.dr.dk/p1/rssfeed/tema_torsdag.xml (copy and paste into your preferred podcasting program)

Read Full Post »

tawspvidcastshowpromo.jpgLiving in Denmak I had never heard of The Agenda, a tv program broadcasted by Canadian network TV Ontario, undtil Wodek Szemberg, one of the program’s producers, contacted me last week. However, as it turns out, from time to time The Agenda covers topics of interest to those of us interested in neuroscience and neuroethics. Last Thursday’s program, for instance, contained a discussion on brain plasticity prompted by a new book by psychologist Norman Doidge: The brain that changes itself. In addition to Doidge, the guests on the show included Jordan Peterson, Robert Sawyer, Bruce Wexler, and Judy Illes. Illes, of course, debates the neuroethical concequences of brain plasticity research. You can even get the program as podcast and watch it at home at your own leisure.

– Martin

Read Full Post »

Is it possible to identify a psychiatric disorder using a structural brain scan? According to a team of researchers from Europe and Australia this can indeed be the case. In a recently published study in NeuroImage, researchers Carles Soriano-Mas et al. demonstrate that structural brain scans can identify subjects suffering from obsessive-compulsive disorder (OCD) with a 93.1% classification accuracy (for a whole-brain comparison). In addition, individual variance in OCD symptom severity was correlated with the measured neural differences. In other words, the more you suffer from OCD the more you are likely to stick out in the analysis as an oddball, compared to a healthy norm.

Here is an image showing the structural differences between OCD patiens (n=72) and healthy controls (n=72):

brain1.png

In the image, the heat scale indicates regions where OCD patients differ significantly from controls at the whole brain level. Interestingly, when the researchers focused on the most intense regions the predictive value of the brain scans dropped to 76.6% accuracy. This means that a whole-brain approach is the optimal for determining whether a subject is suffering from OCD.

The study clearly demonstrates that neuroscience is moving in the direction of single-subject analysis, and the application of advanced analysis methods to determine whether a given individual is structurally (or functionally) within the normal range. If the means are there, when will we see them being used — and misused? After all, if a brain scan has the close to 100% accuracy of telling whether a person is suffering from OCD, why not use it in the clinic right away? Or better, why not expect applicants to an important company position take such a scan? After all, if you suffer from OCD, you are less likely to be able to be in such a position, right? And while we’re at it, why not try for a similar approach for depression, anxiety, stress and introversion?

Are we right in being sceptical towards the application of such measures of psychic health? Methodological problems aside, should such a measure provide a robust assessment tool, why should we not use it? After all, psychological testing is really aimed at uncovering who people are. Apply for a top position and you are likely to be submitted to psychological and cognitive profiling. If scanners provide a better accuracy, would it not be preferable to use this method? Since society has decided to allow psychological and IQ testing, such measures should really be just another improved method. As a consequence, we should not be surprised to see them being used pretty soon — if they are not already in the stores.

The solutions are far from clear in the muddy waters following the blazing trail of neuroscience. As neuroscientific methods move along and create new opportunities, new problems arise, too. What is important is to bring these issues up front in the media and other forums of such debate. Neuroethics is as important as ever.

– Thomas

Read Full Post »