Happy Anniversary Encephalon!

Double congrats go to Mo the Neurophilosopher. Not only has the Encephalon neuroscience blogging carnival seen it’s first year anniversary, Encephalon masterbrain Mo has been welcomed aboard the scienceblogs.com network! His scienceblog can be found here.

It’s been nearly 3 months since I last wrote anything here and I should probably give a few updates. I was recently in Chicago for every brain imager’s annual favorite, the Organization for Human Brain Mapping conference. All in all, I really enjoyed the conference and the city. A few highlights:

- Marcus Gray from University College London had an interesting poster entitled ‘A cortical potential for cardiac function’ (now in PNAS). From the abstract:

Emotional trauma and psychological stress can precipitate cardiac arrhythmia and sudden death through arrhythmogenic effects of efferent sympathetic drive. Patients with preexisting heart disease are particularly at risk. Moreover, generation of proarrhythmic activity patterns within cerebral autonomic centers may be amplified by afferent feedback from a dysfunctional myocardium. An electrocortical potential reflecting afferent cardiac information has been described, reflecting individual differences in interoceptive sensitivity (awareness of one’s own heartbeats). To inform our understanding of mechanisms underlying arrhythmogenesis, we extended this approach, identifying electrocortical potentials corresponding to the cortical expression of afferent information about the integrity of myocardial function during stress. We measured changes in cardiac response simultaneously with electroencephalography in patients with established ventricular dysfunction.

- Gray’s work is somewhat representative of a general emphasis on biomarkers and predictive imaging at this year’s conference.

- This year, diffusion tensor imaging, (DTI), dynamic causal modelling (DCM), multi-modal imaging, as well as lie-detection were in vogue. I remember resting-state fMRI being the cat’s meow at the 2005 conference in Toronto. Oh the times, they are a changin’…

- I think everyone’s favorite memory from the conference program was that of a video involving monkeys and robots. Enough said.

- On other studies, Dr. Nicholas Schiff had a very interesting talk on limited states of consciousness in the clinic. You may remember Dr. Schiff’s name splashed in the headlines last summer on a very interesting case of a man who ‘woke up’ after being in a minimally conscious state. Yes, DTI pops up here too. Dr. Schiff recently talked at a workshop on neuroethics and limited states of consciousness as part of ongoing work at Stanford’s Neuroethics unit.

There are many more highlights but I should leave off now. What I will leave off with is a note that the 27th edition of Encephalon will be hosted right here in two weeks time. That’s Monday, July 16th. If you’d like to contribute, don’t be shy, send in any post you may have that’s neuro-related!

Send an email to: encephalon[dot]host[at]gmail[dot]com.

Things that I would be particularly interested in reading relate to blogging and funding. If you have an opinion as to how science blogging could be a tool (or not) for raising awareness about the need for funding, or have some interesting statistics, please send it in! The debate over stem cell research is certainly important, but I’d be interested in something that looks at the issue more broadly (many of you out there can sympathize with the penny pinching scientists are forced to endure, or end up finding financial pressures destructive). Another issue that caught my attention at the OHBM town hall meeting involved a debate about whether or not the conference should consider holding a future meeting in Cuba. Posts related to conferences and political pressures would also be well received. i.e. Should scientists be concerned about conferences being held in countries with conflicting political ideals? Could scientific conferences be held in more developing countries to bring attention to overlooked research programs?

And now for some brainial stimulation of the broab:

montreal neurological institute podcasts

they’re short and sweet, around 5 minutes a piece, and posted about once a month. the focus is more on the operational ins and outs of the institute, but those of us in the field should find them quite interesting and timely. the pair of podcasts on CIHR funding is particularly important.

link to the mni podcasts from the montreal neurological institute.

law and the brain

Much blogable ado has been made about the New York Times article ‘The Brain on the Stand‘ by Jeffrey Rosen (and I would say quite rightly so). While the article shows nuance in the opinions of brain imagers, and as much as I would fully recommend you read the entire article, Rosen really does sum things up quite nicely:

As the new technologies proliferate, even the neurolaw experts themselves have only begun to think about the questions that lie ahead. Can the police get a search warrant for someone’s brain? Should the Fourth Amendment protect our minds in the same way that it protects our houses? Can courts order tests of suspects’ memories to determine whether they are gang members or police informers, or would this violate the Fifth Amendment’s ban on compulsory self-incrimination? Would punishing people for their thoughts rather than for their actions violate the Eighth Amendment’s ban on cruel and unusual punishment? However astonishing our machines may become, they cannot tell us how to answer these perplexing questions. We must instead look to our own powers of reasoning and intuition, relatively primitive as they may be.

As Stephen Morse puts it, neuroscience itself can never identify the mysterious point at which people should be excused from responsibility for their actions because they are not able, in some sense, to control themselves. That question, he suggests, is “moral and ultimately legal,” and it must be answered not in laboratories but in courtrooms and legislatures. In other words, we must answer it ourselves.

Another interesting thing: the article mentions the Center for Cognitive Liberty and Ethics. It’s worth a gander for some interesting reports and outlines some spooky issues ranging from brain ‘fingerprinting’ to psychotropic weapons.

another excerpt from ‘a picture is worth 1000 words, but which 1000?’

it’s about time i started to put some excerpts from the neuroethics book edited by judy illes.  here’s another wonderful ditty from chapter 11:  a picture is worth 1000 words, but which 1000? 

italics are mine.

…from ch. 11 in Neuroethics…

What constitutes a ‘significantly greater’ activation than another, is in a way, in the eye of the beholder… lowering the threshold will create more regions that are statistically significant, whereas raising the threshold will reduce the number of significant regions. The choice of the threshold is largely determined by convention among researchers, rather than absolute standards. Reporting brain activation patterns is therefore primarily a statistical interpretation of a very complex dataset, and may be interpreted differently by different researchers. (Canli and Amin 2002)

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

While group averages are vital for achieving acceptable signal-to-noise ratios, individual differences, from both anatomical and functional variability may become diluted and overshadowed (Beaulieu 2001; President’s Council on Bioethics 2004). When dealing with single-subject data, as is the case for presurgical planning, it is often desirable to minimize false-negative voxels in order to avoid erroneously excising potentially healthy tissue (M. P. Kirschen et al., under review). Outside the clinical setting, we can easily extend these considerations to any analytic objective set to pinpoint activation areas for function in individuals:

…the image of an activation pattern from a poorly designed study is visually indistinguishable from one based on an exemplary study. It takes a skilled practitioner to appreciate the difference. Therefore, one great danger lies in the abuse of neuroimaging data for presentations to untrained audiences such as courtroom juries. What can be easily forgotten when looking at these images is that they represent statistical inferences, rather than absolute truths. (Canli and Amin 2002)

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

Lastly, the interpretability of fMRI activation maps is dependent on how the data are displayed. The colour-coded statistical maps are usually overlaid on high-resolution anatomical MR images to highlight the brain anatomy. There are several media for displaying these composite images. The most rigorous is to overlay the functional data onto single anatomical slices in any imaging plane. While this is the most comprehensive means of examining the data, it is often difficult to localize the activations to a particular region, given a particular scan plane, and researchers are limited in the number of slices they can include in a publication or lecture. Alternatively, the activation maps can be presented on a three-dimensional rendered brain. While this technique gives good visualization of prominent external brain structures, internal regions like the hippocampus or basal ganglia are not well characterized on these models. Researchers often use both of these techniques to examine data, but ultimately choose the one that best highlights the main results of the study for presentation.

Since basic research is usually done to infer characteristics bearing on populations, the extension to individual applications is challenged by a scarcity of normative data that can support, for example, conclusions of abnormal activation (Rosen and Gur 2002). There are risks that measures will vary between individuals or that the meaning of data compared with normal individuals will be difficult to establish. Abnormality and predictive validity could even be more problematic in the context of real-world behaviours, especially those that are potentially value laden or culturally determined (Illes et al., 2003).