Blogging SfN2010

Exciting news (from my perspective): the Stanford Neuroblog has been selected as an official Neuroblog for the 2010 Society for Neuroscience meeting!

The announcement was posted online this morning, and is available at the SfN Interactive website.

During the course of the meeting, at least one post per day will be published, generally covering topics of cognition and behavior, but aiming to highlight new/interesting research in a variety of fields. New posts will be announced via twitter, using the @stanfordneuro handle.

For new visitors drawn to the Stanford Neuroblog from the SfN announcement, welcome! For more information about who is responsible for the content of this blog, please visit the About page (link at right).

[Live Blogging] Neuroscience in the Courtroom

Starting at 5:30 pm, the Stanford Interdisciplinary Group for Neuroscience and Society is sponsoring a discussion of neuroscience evidence in the courtroom. The event will feature experts in neuroscience and law, including: David Faigman (Professor of Law, Hastings College of Law), Marcus Raichle (Professor of Radiology, Neurology, Neurobiology,and Biomedical Engineering, Washington University), Anthony Wagner (Professor of Psychology, Stanford) and Hank Greely (Professor of Law, Stanford Law School). Panelists will be "discussing recent attempts to introduce expert testimony based on brain imaging tests, including fMRI lie detection".

[UPDATE: This discussion is being recorded and will be available online at a later time: I will post the link as soon as it is published.]

I will be providing live updates during the course of  the discussion - note timestamps for the correct temporal progression of events.

5:31 pm: We'll be getting started in just a few minutes. Looking around the room, I see a couple of neuroscientists are present, including the formidable Bill Newsome. There also appear to be many law students present, so I expect a broadly tuned presentation of both neuroscience and law.

5:34 pm: A note that those interested in the sponsoring organization, the Stanford Interdisciplinary Group for Neuroscience and Society, can find out more about them at their website.

5:36 pm: Hank Greely is introducing the various panelists and the topics for the evening.

The first speaker will be Anthony Wagner. He studies memory issues in fMRI. The second speaker will be Faigman. He is a leading expert on scientific evidence. The third speaker is Dr. Marcus Raichle - he is a neurologist by training who is well known for his work on functional imaging (in particular PET scanning).

The stated objective for SIGNS is to study how neuroscience will be affecting our culture. Greely points out that a revolution in neuroscience has special implications for our culture and our laws because discoveries about how the brain works will directly bear upon our knowledge of how our subjective mental behaviors are generated. In particular, discoveries in 6 areas will have particular impact: Prediction, "Mind-reading" [i.e. correlating and interpreting physical changes in brains in terms of thoughts], Criminal Responsibility [i.e. the question of free will and implications for criminal law; the use of neuroscience to determine whether defendants possess the physical mind state necessary for prosecution], End of Life Care [discussing the recent New England Journal of Medicine article regarding vegetative states and brain imaging], Treatment [of neurological diseases and conditions, from Alzheimers to kleptomania to other "social pathologies"], and lastly Enhancement [e.g. "memory pills"]. Today, these issues have begun to find their way into courtrooms.

Since Jan 2006 (first introduction of neuroimaging in the courtroom) there have been over 30 cases in which neuroimaging was brought up as evidence. Some examples of cases: the use of neuroimaging to "prove" that the defendant was a psychopath, to show that defendants were in chronic pain (particularly useful in deciding cases of disability), and of course, lie detection. Of note: expect in New Mexico, courts do not accept polygraphs as evidence. fMRI lie detection has been around in peer reviewed journals since 2002, and there are currently 2 companies that will use fMRI to declare whether you are telling the truth. In May of this year, two court cases (on a sexual harassment case, another a fraud case) almost allowed reports generated by these companies as evidence to support the defendants. In both of these cases, the judges decided not to allow the evidence, but either for different reasons.

5:54: Now Anthony Wagner will discuss research on using fMRI to detect lies. Tony introduces himself as a cognitive neuroscientist who primarily studies executive function. A few years ago, he became involved in the intersection between neuroscience and law, and today he will be presenting a high level summary requested by a judge to discuss whether fMRI can be used to detect lies.

Overview of published literature: "There are no relevant published data that unambiguously answer whether fMRI-based neuroscience methods can detect lies at the individual-instance level. No relevant data on the sensitivity and specificity of fMRI-based lie detection." In his background research, Tony found 32 peer-reviewed papers with 28 unique data sets. Of these papers, there are 2 categories: one (21 papers) that exclusively reprots group-level data (these cannot answer whether fMRI can detect individual lies; the other group (11 papers) report whether they can detect if an individual i s"lying", but Tony will argue that fundamental methodological limitations render these studies uninformative.

The main strategy for these studies involves subjects being instructed to lie. The prevalent paradigm is that of the guilty knowledge/concealed information paradigm.

Conclusions from the group level studies: there is an activation difference between lie and truth conditions somewhere in the brain, there is considerable across-study variability in brain regions (this may be due to differences in the methodologies and analyses), meta-analyses reveal some across-study consistency, regions observed are not specific to deception, and lastly some of these studies attempt to figure out why certain brain areas are active during deception. However, none of these studies document specificity and selectivity at the individual-subject and individual-question level, and so have relatively little legal relevance.

Of the 11 peer-reviewed studies that do examine the individual-subject/question level, three tasks are generally used. Used are modified Guilty Knowledge Tasks: subjects are presented envelope containing two cards or pick a # between 3 and 8 - deny possession of one of the two cards, deny having chosen the number. A study by Langeleben and Davatzikos reported 90% sensitivity and 85% specificity, but there is a motor confound b/c one response more frequent that the other: classifier could jsut be detecting difference in action selection demands between lie and truth trials. If you eliminate the motor confound (a la Monteleone et al, 2009), analysis at the individual-subject level drops to 71% of subjects showed greater MPRC activation on lie vs truth trials. Suggests above chance discrimination between lie and truth w/in an individual but doesn't tell us whether fMRI can discriminate between subjects who are lying and those who are telling the truth as all subjects in the study were instructed to lie. Another study (Hankun et al, 2008) reported greater activity to target vs control stimuli when instructed to lie about target, but also greater activity when simply passively viewing target vs control stimuli - suggesting that deceptive behavior is NOT required to observe the brain response. Garner et al 2009 saw a difference in BOLD activity between stimuli that subjects were asked to remembered more so than novel stimuli, irrespective of demands to lie.

A couple of studies looked at mock-crime studies, where subjects are asked to lie about location of money in a room. These studies found high-variability in whether individuals subjects demonstrated lie>truth effects in brain regions observed in the group-level analyses. In other studies, subjects were asked to lie about a mock theft, deny possession of items they were instructed to "steal". In these studies, the analysis observed 3 barin regions showing differential activation: ACC, OFC, and IFG. The company using this paradigm compared the number of voxel in these areas during baseline to during the task, and assume that if there are more voxels activated during the task than during a truth trial, then the subject in lying. Detection rates are estimated to fall between 71% and 86%. A similar voxel counting approach was used to discriminate whether subjects had destroyed a CD or whether they had merely watched video of someone else destroyed a CD - reporting 100% accuracy or identifying those who had destroyed the CD, but 67% false positives for those who watched the video. This suggests a major confound in that these methods may pick up memory signals that may have nothing to do with active participation in a crime - richly imagining an event may be enough to trigger a false positive identification of a lie.

Wrapping up, Tony Wagner reiterates that many forensically relevant factors have not been investigated, including the magnitude of the stakes, the effects of stress, the retention interval (time between the critical events and fMRI scanning), the effect of having practiced telling the same lie, the content of the lie (emotional valiancy), susceptibility to countermeasures, robustness of methods across subpopulations, difference between instructive vs subject-initiated deception.

6:00 pm Now David Faigman will discuss admissibility standards from the perspective of a law professor. He notes that from a lawyers perspective, science is a tool, and important issues are what confidence intervals are necessary for admissibility standards. Raichle contends that under certain contexts, it might be useful to admit neuroscience evidence without strong confidence intervals.

But to back up, he notes the important aspects to determine admissibility. 1) Qualifications: what are the minimum qualifications for calling an expert witness to present neuroscience evidence. From the laws perspective, they expect researchers at first, but as the technology becomes generally accepted, then technicians (possibly w/o a graduate degree) can be called as expert witnesses - DNA evidence is a good example of this transition. So qualifications becomes a question of what the testifiers are testifying to. 2) Relevancy: the science must be able to respond to a specific legal question. For example, having neuroscience discussing lack of volitional control is all well and good, but is it relevant to culpability and responsibility in the legal sense - to claim insanity you cannot claim lack of volitional control in a criminal context, instead it depends on showing that the defendant could not tell right from wrong. A note though that lack of volitional control is a component of civil commitment law (as in for labeling a defendant as a sexual predator, and determining whether the person in question should be put in jail). 3) Reliability and validity: judges must evaluate this - they have the power to determine whether a particular scientific process is valid - several factors can be used during this determination, including testing, error rate, peer-review, publication and general acceptance. This standard (Daubert standard) applies to all expert witnesses in federal courts, as dictated by a Supreme Court decision. Many state courts use the Frye Rule, which merely requires that the methods are generally accepted in the field - this depends on how rigorous the individual field is - there are some obvious issues with this (an example from David Faigman is that tea-leaf reading is generally accepted by tea-leaf readers). However, another standard (Rule 403) says that if the evidence would be too prejudicial, overwhelming the probative value of the evidence, the science should not be admitted into the case.

David Faigman notes that in general, juries do not understand science, and so are not adequately prepared to evaluate expert scientific testimony.

6:41 pm Now Marcus Raichle will discuss his experiences as an expert witness. He notes that he has only been an expert witness twice: once during a malpractice suit involving Stanford Hospital, and then for his knowledge of neuroscience, as a counter witness against the director of Cephos, one of the two companies offering fMRI lie detection. He says that he felt unprepared for the experience, not knowing what would be expected of him. He describes the lawyer for the defense, and the experience of having lawyers manipulate science for the purposes of the law. In particular, he recalls the difficulty of describing a complex scientific story to a judge. Raichle states that if he had to act as an expert witness again, he would need to more carefully consider how he would present the scientific story.

6:49 Questions are now being solicited from the audience.

Question 1 for Marcus: Did he felt that any arguments played better than others against the fMRI lie detection? Answer: He felt that the distinction between group data and individual results in the peer-reviewed literature was lost in the context of the court, and that Cephos is generalizing findings from group data onto the individual, without repeating the paradigm utilized at the group level with the individual. In addition, he notes that discussions of the statistical issues by the scientists went over the heads of the judge.

Question 2: The distinction between for-profit companies and academic neuroscientists: and what are the roles of the academics in making statements about the validity of the fMRI lie-detection? Answer: David Faigman notes that most scientists avoid being expert witnesses. Regarding consensus statements, they may be less important for individual cases, but more for general guidelines for judges, although the usefulness of such statements will likely be context-dependent.

Question 3: Would Marcus recommend that scientists be expert witnesses? Answer: He wouldn't dissuade people (later saying, yes). He found the experience highly educational, although he says that he wouldn't want to do it all too often, if only because of the inordinate amount of preparation necessary.

Question 4: The studies on the validity of fMRI seem a bit simplistic, not leaving many gray areas. What can the science claim about more complex positions. From the neuroscientists, does complexity matter in the brain? Answer: Tony Wagner and Hank Greely note that this question lies at the heart of the unresolved issues in neuroscience and detection of deception. As time passes, the representation of memories is altered at the neuronal level - making references to research showing that re-consolidation of memory (recalling a particular memory) results in alteration of that memory. This has major implications if the defendant has told the same lie multiple times, with a true memory and false memory potentially unresolvable via fMRI - although this question has not been directly tested in scientific settings. Marcus notes that an important factor is the behavior being studied, not just the picture of the fMRI.

Question 5: How might fMRI alter defendants rights to remain silent/avoid self-incrimination? Answer: Faigman states that constitutional law trumps evidence based law, but if the test becomes incredibly accurate, then there would be an expectation that the evidence would be presented (although the lawyers would be constitutionally presented from mentioning this expectation). A more pressing constitutional issue would be if a defendant wanted to use this evidence, but are not allowed by law - in this case an argument could be made that the defendant has a constitutional right to present the evidence. Hank Greely notes that the 5th amendment only applied to spoken testimony, so fMRI images taken from passive viewing paradigms (not requiring speech) might not be covered by the amendment, although Greely predicts that the courts will eventually rule it to be covered.

Question 6: What is the legal history of denying polygraphs, and what would be the necessary improvements needed to re-allow polygraphs into the courts? Answer: It was excluded because it just wasn't reliable. Also, there is a ban from calling witnesses to provide a credibility assessment - the polygraph has been treated as a credibility machine and therefore may be banned in that context. But the ultimate reasoning has been that the polygraph is unreliable. So in order to re-allow the polygraph, you would have to show substantial improvements in reliability. In Faigman's opinion, in the future, the determination of scientific evidence will need to be more context dependent - although he notes that Hank Greely most likely disagrees with him. So depending on what the outcome being determined with the help of the evidence (e.g. holding a new trial versus capital punishment), it might be more acceptable to use evidence with a possibility of a false positive. Greely notes that reliability is not the only question - there are also questions about whether the use of fMRI (or other scientific evidence) might unfairly prejudice a jury. Wagner notes that polygraphs are used often outside the context of the court - for example used during the determination of whether a suspect should be interrogated further by lawyers/police. Raichle notes that some suspects may confess merely after being confronted with the threat of a polygraph/fMRI. Faigman notes that from the perspective of the law enforcement, the polygraph is better than the fMRI, because they use it primarily as an interrogation tool.

Question 7: In the 11 studies on individual-subjects all the flaws seem a bit simplistic. Why hasn't a good study been designed? Answer by Wagner: He is unsure why the study design has not been better. Over the 20 year history of neuro-imaging, there are many good studies, and many poorly designed studies, and many of those poorly designed studies were conducted at the beginning. fMRI is a young field, and fMRI use in lie-detection is an even younger field, and with maturity will hopefully come better and better studies. Within the field of neuro-imaging, scientists are cognizant that their research is being applied within the purview of the law, and there is a realization amongst researchers that better science needs to be conducted. Greely notes that funding is very difficult to acquire - the major funding source is from for-profit companies.

Hank Greely closes the discussion by thanking the panelists for their participation. He notes that this is the first of a quarterly series (the next is on Monday, Jan 24th). Those interested in getting on the SIGNS mailing list should email Hank Greely at hgreely@stanford.edu.

---End of Live Blogging Event----

Physics of the Wet-Dog Shake

If you haven't already, be sure to check out the highly entertaining (and informative) recent article in Wired Magazine about a team of researchers who studied the physics of why wet animals shake their fur. The researchers, led by Andrew Dickinson from Georgia Institute of Technology, built a mathematical model to explain why wet dogs (and other animals) shake their fur, and to determine the optimum shake speed to achieve this goal. Their research, published in the journal Fluid Dynamics, calculates that by shaking their fur, animals generate enough centrifugal force to overcome the surface tension that normally binds water to fur (see abstract, printed below, for details). Testing their model required filming various wet animals (including dogs, rats, mice, and a bear) shaking their fur dry; these have been edited into the below, frankly adorable, video.

The Wet-Dog Shake. Dickerson A, et al. Abstract: "The drying of wet fur is a critical to mammalian heat regulation. In this fluid dynamics video, we show a sequence of films demonstrating how hirsute animals to rapidly oscillate their bodies to shed water droplets, nature's analogy to the spin cycle of a washing machine. High-speed videography and fur-particle tracking is employed to determine the angular position of the animal's shoulder skin as a function of time. X-ray cinematography is used to track the motion of the skeleton. We determine conditions for drop ejection by considering the balance of surface tension and centripetal forces on drops adhering to the animal. Particular attention is paid to rationalizing the relationship between animal size and oscillation frequency required to self-dry."

"No one expects scientists to look like scientists any more..."

“When he had first started working at the centre, he had liked to think that he was unexpectedly cool-looking for such a job. Now he knew that he surprised no one, that no one expected scientists to look like scientists any more.” The preceding quotation, from the book Kraken by China Mieville, hit a note with me. It seems obvious to think that scientists are not all white, forty-to-fifty year old men with thick glasses and with poor social skills. Scientists can and do come from a wide variety of backgrounds, and while they often share an intellectual curiosity and desire to learn about the world, this doesn’t necessarily make them nerds or geeks as one might classically think.

The question of the perception of scientists may seem mundane, but it is an important consideration for a couple of reasons. The first is that attracting bright and hard-working people with diverse points of view to science is important to ensure high-quality research. This means reaching out to people of many backgrounds and interests. Translation: not just the nerds. The second reason is that communicating the results of scientific research to a broader community is critical. Think of all of the debates going on today where scientific research is needed for an informed policy: climate change, disease control, genetically modified crops, and many others. If the public doesn’t understand what makes someone a scientist, or misunderstands how science works, then citizens will be less likely to trust research as a whole.

I clearly am not the only person to think about these issues. There are many interesting projects whose goal is to communicate a more “complete” picture of who scientists are to a general public. Drawings of Scientists is a program which concentrates on children. Groups of children were invited to visit Fermilab, a particle physics laboratory in Illinois. Prior to their visit, the children drew pictures of scientists and described what they thought scientists were like. After their visit, the students drew new pictures and wrote again about what makes a scientist. The before and after pictures are often quite dramatic - even changing race or gender in some instances. And while it is clear that the scientists they were talking to were emphasizing that scientists are real people, it is also gratifying to see that the kids were responding to that message. For example, seventh-grader Amanda wrote in her “after” picture: “Anyone can be a scientist. I saw people walking around in sweatshirts and jeans. Who knows? Maybe I can be a scientist.” Clearly, getting to know scientists can help kids to learn that science is a field which can appeal to a wide variety of people. It may even encourage them to try science themselves.

Another presentation of scientists transcending stereotypes comes from a web series titled “The Secret Life of Scientists and Engineers,” by the makers of NOVA. This video series features one scientist or engineer every two weeks, and talks to them about their science and their outside-of-work activities. They have a huge range of subjects, from aerospace engineers to ethnobotanists, with a huge range of “secret lives,” from pagent queen to sailor. The latest release features Rachel Collins, microbiologist and pro wrestler. The series has been nominated for an Emmy, and won a Streamy (made-for-the-internet video award) for Best Reality or Documentary Series. It does a fantastic job of meshing science with life stories, communicating that there is much more to scientists than research. The enthusiasm that the subjects have for every aspect of their lives, professional and recreational, is contagious.

To better communicate science to a general public, it is necessary to de-mystify the scientist. By showing that scientists have personalities outside of the lab, projects like Fermilab’s educational outreach and the Secret Life of Scientists and Engineers show that science itself is not out of reach to non-scientists. And as a scientist, I am also reminded that I can have a fun secret life of my own!

A tale of two rodents: exploring the mechanisms of natural seizure resistance

In my lab’s weekly lab meeting, a Brazilian post-doctoral researcher, Leo Faria presented a research article entitled Distinctive Hippocampal CA2 subfield of the Amazon Rodent Proechimys. This particular rodent, the Guyenne Spiny rat, is an example about how natural evolution might produce unique examples of adaptation that are ideal substrates for advancing basic knowledge of brain function.

Proechymis Guyanensis (The Guyenne Spiny rat) is native to the Amazon basin, found in parts of Brazil, Colombia, French Guyana, Guyana, Surinam and Venezuela. It is a member of the spiny rat group of rodents, which are closely related to guinea pigs and chinchillas, though they more resemble rats. Like other members of the Echimyidae family, spiny rats can break off their tails when attacked (though their tails do not regenerate). Members of the spiny rat family can be terrestrial (living on land), arboreal (living in trees) or fossorial (living underground), with almost all members herbivorous.

Why are the Guyenne Spiny rats interesting to a neuroscientist? For the simple reason that they appear resistant to most of the common models of inducible epilepsy.

Some background: epilepsy is a neurological disorder that affects approximately 50 million people worldwide and is characterized by recurrent seizures (1). The exact mechanisms underlying the development of epilepsy (epileptogenesis) are still an area of intense research, but several pathophysiological causes have been identified, including traumatic brain injuries and several genetic mutations. Research laboratories that study epilepsy commonly use chemical induction protocols, wherein a chemical is introduced to a rodent brain that can induce epileptogenesis. A particular flavor of epileptic seizure is termed status epilepticus, which is characterized by the development of a persistent seizure lasting longer than 30 minutes, and in human patients represents 10-20% of all first seizures (2). Chemical induction of status epilepticus within the laboratory can result in later development of chronic epilepsy in rodent models. Within a laboratory setting the injection of either Pilocarpine (a non-selective agonist of the cholinergic muscarinic receptor) or kainate (an agonist of an ionotrophic glutamate receptor) will induce status epilepticus and lead to the development of spontaneous chronic seizures. Both pilocarpine and kainate administration are used to model the pathogenesis of a particularly common form of epilepsy, temporal lobe epilepsy.

Pilocarpine and kainate injection are both well-tested methods of inducing epilepsy in rodents; however, the Guyenne Spiny-rats are completely resistant. Following injection of either of these substances, the spiny rats will fail to experience status epilepticus and will not go on to develop chronic epilepsy. The exact cellular mechanisms allowing this remarkable insensitivity are currently unknown. The research article presented during lab meeting looked at morphological differences between the brains of the Spiny rats and the more common research animal, the Wistar rat. The researchers found distinctive differences in the hippocampal CA2 subfield (which has been recently implicated in seizure generation), with the spiny rats displaying greater neuronal disorganization, larger regional size, as well as several other differences in the density of specific neuronal subtypes.

How does this difference cause resistance to epileptogenesis in the spiny rats? One hypothesis presented in the research article is that increased density of inhibitory neurons within the hippocampus might prevent the development of hyper-excitation. Unfortunately, the paper was not able to make any definitive conclusions regarding the exact mechanisms underlying seizure resistance in Spiny rats. A curious point brought up by Leo during my lab meeting was that the natural habitat of the spiny rats overlaps with the habitat of Pilocarpus jaborandi, the plant from which Pilocarpine is derived.

Have the Guyenne Spiny rats developed their seizure resistance in response to natural selection pressures established by the presence of a plant with pro-seizure properties? It’s possible. What is certain is that these animals have the potential to advance knowledge of how specific brain areas contribute to pathological epileptogenesis, as well as informing research into the prevention and treatment of a tragically debilitating neuronal disorder.

The Astronaut Diaries

In a publication released by NASA this past summer, we are given a glimpse into the day-to-day lives of astronauts living aboard the International Space Station(ISS). Space travel has come a long way in the past half-century and it is therefore becoming increasingly important to establish day-to-day living conditions in space which are conducive to productivity and mental well-being. In acknowledgement of this fact, NASA performed a study aimed at analyzing the importance of various factors on the happiness of astronauts living in the ISS. To do this, they asked ten astronauts performing six-month stays on the ISS to keep regular journals of their experiences. Scientists then analyzed these journals based on subject and positivity/negativity to help determine ways to improve life in space. The results are fascinating: they give both a unique insight into what it is like to live in space, and a broader message about causes of stress in extreme isolation. The study came up with recommendations for ways in which to improve life on the space station. A primary source of stress was the effect of work schedules, especially schedules which allotted too little time for a given activity. Constantly feeling behind can really get to you, especially if you feel the need to give up what little “downtime” you have in order to catch up. One journal comment reads, “We are, by nature and by training, performance and goal-oriented. We tend to feel bad about ourselves if we do not complete the plan. I am aware of this and have consciously tried to get perspective on this and not feel that I must complete all tasks and in the given time. However, I think there is an underlying frustration that builds when I do not complete everything on time."

A second source of stress was often tedious or trivial maintenance work, especially if the procedures were needlessly confusing. When the station shifted to larger crews, these tasks could be shared among more people, leading to less frustration overall. The study also recommends taking recommendations from the astronauts about tasks whose instructions don’t fully correspond to the task. For example, one astronaut noted that in the instructions, a particular button was referred to by one label, whereas on the object itself the button was labeled differently. The study contains a large number of journal excerpts, which can help to get an “inside view” on various topics related to living conditions in space. Here are a few I enjoyed to give you an idea:

[on food] “We are getting tired of eating chicken all the time.”

[leisure] “Saturday night we watched a contemporary Russian movie for 3 hours—with good Soviet-capitalist type discussion of the value of the Russian aristocracy.”

[the views] “I took a peek out the side-facing JEM windows one evening, without camera in hand, and was so mesmerized that I ended up gazing upon the Earth for an entire 90 minute orbit. A hundred times I thought “I should go grab the camera” but I decided to just try to capture this one orbit with my own eyes and burn it into my brain.”

[scheduling] "One thing is for sure—I’m ready for the weekend. The past couple of days of reduced sleep and eating opportunities have added a little strain. I felt it especially yesterday. Today, the fatigue and hunger are present but not the strain."

The study is quite readable, so if you want to get to read some selections from the diaries of astronauts, this is your chance!

New hit or classic oldie: it's the difference between singing to fight and singing to love.

Reported last week in ScienceShot (a division of Science magazine) is news of a report due to be published in the journal The American Naturalist, that two different categories of birdsong evolve at radically different speeds. The paper, titled Independent Cultural Evolution of Two Song Traditions in the Chestnut-Sided Warbler was written  by Bruce Byers, Kara Belinsky and R. Alexander Bentley, and describes the cultural transmission of songs sung by a population of chestnut‐sided warblers over a 19 year period. Specifically, the authors detail 2 types of songs sung by male warblers, one which is used to attract females, the other which is used to challenge another male. The main finding is that while the courtship songs persisted virtually unchanged in the populations discography during the 19 year study, the challenge songs displayed rapid and nearly continual changes. This distinction lead the authors to conclude that "in songbirds, multiple independent cultural traditions and probably multiple independent learning predispositions can evolve concurrently, especially when different signal classes have become specialized for different communicative functions."

What mechanisms underlie the different rates of song evolution? The authors discuss this at length, comparing the cultural pressures at work in the songbird community that might allow diversity to flourish in the fight songs, but constrain the mutation of courtship songs. Why would such constraint of mating song diversity be advantageous?  "Stereotyped song forms that are few in number and shared widely among males provide unambiguous species identification (Marler 1960; Emlen 1972) and facilitate comparisons of individuals’ vocal performance (Zahavi 1980), especially if the stereotyped song also has features that make it difficult to perform (Ballentine et al. 2004; Podos and Nowicki 2004)."

The ScienceShot report extrapolates from this paper a comparison to human culture, comparing warbler fight songs to the yearly trends in baby names and pop music, and mating songs to the "strains of Jingle Bells [that] conjure holiday spirit year after year." And while the connection to holiday tunes is too tenuous for my taste, the question of what mechanisms underlie the  concurrent, yet independent evolution of multiple cultural traditions within the warbler population could plausibly provide anthropologists with quantifiable data suitable for modeling such cultural evolution amongst human populations.

Wanted: Primary Figures for Publication. Auxiliary Material Need Not Apply.

The other month I was sitting down to read a journal article; the topic was dopaminergic signaling underlying both positive and negative motivational signals, which, all in all, seemed pretty darn interesting. Happily, I downloaded the article, and, feeling inspired and virtuous, downloaded the supplemental materials. Before settling in for an in-depth read, I skimmed over both files. Length of article: 6 pages.

Length of supplemental material: 34 pages.

Gulp.

In general, I am not a big fan to supplemental material. The above example is, admittedly, extreme, but anyone who has read a paper published since 2003 has experienced the frustration of wading through massive volumes of supplementary materials. As the daughter of an editor, I’m a fan of streamlined writing – I’m moderately irritated by tangential figures that clutter the logical flow of a journal article. Modest irritation becomes distinct dislike anytime supplemental figures vastly outnumber normal figures. Such unhappiness is only compounded when critical information (methods, interesting data, important analyses) is relegated to the supplemental material.

Normally, I ignore supplemental sections; when pressed for time, I am unwilling to synthesize the massive of information too often packed into the supplemental material section. As a reader, the large volume of supplemental material frustrates me, especially given a tendency for that material to be less carefully constructed than the prime-time figures. As a past (and future) author, I contemplate nervously the possible demands for supplementary results that reviews have (and will) make on me.

It turns out that the Journal of Neuroscience agrees with me on both counts.

In the August 11^th issue of the journal, John Maunsell, Editor-in-Chief, announced that as of November 1, 2010, the Journal of Neuroscience will no longer be publishing supplemental material.

The society of Neuroscience council came to the decision to remove the supplemental material section for multiple reasons, all of which I sympathize with as both a reader and writer. In the official notice, Maunsell notes that the volume of supplemental material associated with articles published in J. Neurosci. has grown exponentially since the section’s introduction in 2003, and appears on track to surpass the size ( in megabytes per article) of the main article itself (see figure). In the opinion of the journal, this sheer volume adversely affects the peer review process. Among the concerns cited is that the large volume makes it unlikely that reviewers will provide adequately in-depth evaluations of supplemental materials. Furthermore, the availability of a supplemental material section encourages reviewers to make additional (potentially excessive) demands for further analyses and experiments, the threat of which encourages authors to preemptively include extraneous, often tangential material in their initial submission. Furthermore, Maunsell and company are concerned with the tendency for critical material such as “methods that are essential for replicating the experiments, analyses that are central to validating the results, and awkward observations” to end up in the supplemental section. In their view, this “undermines the concept of a self-contained research report by providing a place for critical material to get lost.”

Maunsell states that the Journal of Neuroscience has considered, and rejected, several solutions to the problem, including setting limits on the amount and content of supplemental material, demanding thorough examination of material by reviewers, and official hosting of non-peer reviewed supplemental material. Therefore, in order to “maintain the integrity and value of peer-reviewed articles”, the Journal of Neuroscience has chosen to remove the supplemental material section, “requiring that each submission be evaluated and approved as a complete, self-contained scientific report”.

Authors will be allowed to list a URL pointing to supplemental material on a site they maintain, but this material will not be peer-reviewed, and will be labeled as such by the journal. One critical use for the supplemental material section is the inclusion of forms of data such as videos, which cannot be printed. To allow the inclusion of such data, the journal will allow authors to embed movies of 3-D models into the online PDF copy of their articles.

This is a major move on the part of an eminent scientific journal. Personally, I support their decision – and the responses from others in my lab have been similarly positive. I believe this move will force submissions to J. Neurosci to be constructed with more care. Furthermore, while the supplemental material section has the potential to serve a useful function, I agree with the journals attempt to reduce the reliance of authors on the presence of supplemental material to support their supposedly self-contained scientific stories.

What do you think? Is the wholesale removal of the supplemental material section a drastic response? Is the removal of the section from the Journal of Neuroscience less critical than if Science or Nature (who enforce stricter limits on article length) followed suit? Will this change make you more or less likely to submit to the Journal of Neuroscience? Would you be more likely to read/enjoy an article lacking supplementary figures due to official mandate? Please, discuss in the comments.

The full announcement can be viewed online at the Journal of Neuroscience: Maunsell, J. The Journal of Neuroscience, August 11, 2010, 30(32):10599-10600

One thousand brains are better than two

Common wisdom teaches us that individual ingenuity is essential for advancing human knowledge. However, it is becoming increasingly evident that the opposite can be the case: a large group of properly organized people can accomplish intellectual tasks impossible for individuals or small groups. I first realized the power of this idea when the New York Times Magazine published its Year in Ideas: 2009. The article “Massively Collaborative Mathematics,” describes an experiment performed by Cambridge mathematician Timothy Gowers. Professor Gowers challenged readers of his blog to attempt to make progress on the Density Hales-Jewett Theorem, a previously unsolved mathematical theorem. Six weeks later, the network of collaborating mathematicians had solved the problem. Using networks of people to solve math problems has not stopped there, either. At the website MathOverflow.net, mathematicians can ask each other research-level math problems -- problems that they are working on which they would like to ask others’ opinions about.

Mathematicians are not the only people who are harnessing the power of social networks to solve academic problems. While computers are still having a tough time telling the difference between a picture of a dog and a picture of a cat, humans seem to have an innate ability to recognize and identify visual patterns. A recent article in Nature News discusses several projects which are harnessing this ability: Foldit invites users to strategize about folding proteins, Stardust@home lets people examine pictures for interstellar particles, and Galaxy Zoo centers around classifying features of galaxies. It’s worth a read, as it gives a nice history of distributed science projects and gives an interesting analysis of the emerging field of citizen science

To be fair, it’s not as though throwing people at a problem is always sufficient to solve it. The experiments highlighted above share a common feature: the ability to make incremental progress. For example, solving math theorems requires the analysis of many possible solutions, most of which are wrong. By cooperating, you can ensure that methods which don’t work aren’t tried over and over again, streamlining the solution process. Similarly, in dataset classifications like Galaxy Zoo, the important thing is going through huge numbers of datapoints; each classification brings you one step further.

The idea that collaboration can take you to places you wouldn’t (or couldn’t) otherwise go isn’t new. But as science is currently performed, many experiments are done either completely alone or with a very small number of collaborators. As we learn more and more, collaboration may become even more essential. The amount that any one person can know is limited, but by discussing ideas and thinking with a group, we can overcome individual gaps in knowledge and make further and faster progress than would otherwise be possible.

I anticipate that the ability to harness networks of people to solve problems will be an increasingly useful skill as the technological infrastructure to support such large-scale collaborations increases. If used properly, large-scale collaborations may bring us to many new and exciting places. The trick to successful distributed science will be two-fold. A scientist must be able to first identify whether his or her problem of interest can attain an incremental solution, and must secondly be able to convince others that it is worth working on. This could be in the form of designing a game, like the creators of Foldit, or by enlisting other interested scientists through on- or off-line networking. It is certainly true that not all problems can be solved this way, but I look forward to seeing what new breakthroughs are made through distributed research.

The Disordered Brain: Charlie Rose Interview pt. 10

The tenth segment of the Charlie Rose Brain Series is now available for viewing. We've posted previously about this series, which features top neuroscientists discussing major concepts in their fields. Co-hosted by Charlie Rose and Dr. Eric Kandel, the Brain Series is a fantastic introduction to the field of neuroscience that can be enjoyed by scientists and non-scientists alike. In this most recent installment, entitled The Disordered Brain, Rose and Kandel are joined by John Donoghue of Brown University, Mahlon Delong of Emory University, Nancy Bonini of the University of Pennsylvania, John Krakauer of Columbia University. Together, they discuss neurological disorders, including Huntington's disease, Parkinson's Disease, stroke, and spinal cord injury, covering current research both on the neurological bases of these diseases and palliative/curative treatments. As with other segments, Dr. Kandel kicks off the episode with a brief introduction to neurological disorders, discussing the historical research conducted by Broca and Wernicke, as well as the research conducted by the guest panelists.

Previous segments in the Charlie Rose Brain Series can be viewed online at the official website of the Charlie Rose show. Additionally, each segment webpage features a comment section, where viewers can discuss the topics featured in the episode.