Experimental Neuroethics

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Photo credit: Timothy Epp, Shutterstock

Four years ago, Neil Levy gave the concluding lecture at the first Brain Matters conference in Halifax. He alerted the audience of neuroethicists to the fact that the field of philosophy was undergoing a revolution – rather than muse from their armchairs in the ivory tower, a group of renegade philosophers were carrying out real experiments, asking people what their intuitions were about central issues in philosophy. Dubbed experimental philosophy, the new initiative was met with more than passing resistance from traditional philosophers. The apostate experimental philosophers responded by developing a logo of a burning armchair.

The landmark experiment was carried out by Josh Knobe, and its findings subsequently became known as the Knobe effect (you can watch a great recreation of the phenomenon in this YouTube video). Essentially, what Josh did was repurpose an old method from social psychology called the contrastive vignette technique (CVT) [1]. At its simplest, the CVT involves designing a pair of vignettes that carefully describe a particular situation (in the case of experimental philosophy, one that is often morally charged) but crucially differ in one detail, hence the term contrastive. Respondents see one and only one version of the vignette, and are then asked questions about what they have just read, with responses commonly recorded as a numerical rating on a Likert scale. By comparing the averaged responses between separate groups of people who have read the vignettes, the experimenter can systematically investigate the effects of small changes (of which the respondents are entirely unaware) upon attitudes towards nearly any topic. The experimental philosophers tend to use the technique to explore the meaning of concepts. Neil Levy pointed out that this same approach could, in principle, be applied to the full range of issues in neuroethics.

Neil’s presentation struck me like a thunderbolt. I had come to the field of neuroethics with a background in cellular and molecular biology, and had spent much of my career as a card-carrying reductionist: as a graduate student in the 1980’s, I championing the then-novel technique of recording from single neurons in freely moving animals, and as a postdoc I moved on to the better controlled (if less naturalistic) technique of patch clamp analysis of identified neurons in slices of brains. My subsequent rise through the ranks of academia was one in which I applied quantitative rigor to every question that I asked, and in the circles in which I traveled, this was lauded as the ultimate way to provide reproducible (and by inference, meaningful) results. I saw at once that the CVT opened the door towards doing something similar in the field of neuroethics.

My research group at the National Core for Neuroethics has embraced the use of contrastive vignettes wholeheartedly, and with a nod to the experimental philosophy camp, we call the approach Experimental Neuroethics. The team is applying the technique to a range of issues in contemporary neuroethics, probably best exemplified by our recent publications exploring public attitudes towards cognitive enhancement [2] as well as the acceptability of overt and covert nudges [3].

If the vignettes appear simple, I can assure you that properly crafting them is hard work. We begin with a carefully considered hypothesis and regularly find that the hypothesis morphs substantially (usually into something much more insightful) as the process unfolds. We then compose two or more contrastive vignettes, working hard to have the vignettes as minimally contrastive as possible (one word differences between vignettes is the ultimate goal, but this is often not feasible). Finally, we develop questions; we like to have the wording of the questions always be identical irrespective of the contrastive nature of the vignette.

Then the real fun begins. After a day or two, we assemble as a team and attack our previous work. Inevitably, we find it wanting in some respect. Sometimes, embarrassingly so. We find it best to begin by asking whether the vignette and the questions directly address the hypothesis. Sometimes that means that the hypothesis changes. Nearly always, that means that the vignette changes. This process is repeated again and again, over days and weeks and sometimes months (yes, and even sometimes years!) until we have a set of vignettes that get to the heart of the matter.

At some point late in the process we carry out cognitive pre-testing. This involves sharing the vignette and the questions with someone who has no particular expert knowledge (friends of friends are likely culprits), and debriefing them about what they read. We are sometimes amazed to find that what we intended for people to glean from a vignette is at odds with their reading of the vignette. That sends us back to the drawing board.

We also run some metrics to determine whether the words we have used are understandable by a general audience. We use online readability tests such as this one to establish the educational level required for understanding the vignette; our goal is that no more than a high school education is required. Finally, we launch the survey, recruiting respondents from amongst the thousands of people who have signed up on Amazon’s Mechanical Turk – they’re more representative of the real population and aren’t as blatantly WEIRD as typical undergraduate samples. And then we hold our breath.

Once the data is analyzed, we get mired once again in deep discussion. For it is not just the quantitative aspect of Experimental Neuroethics that it satisfying (to me), but also that the data gives us an entirely new benchmark for engaging in the process of wide reflective equilibrium. Throughout this process we remain aware that an ought can not derive from is, but having the data at hand, our version of ought is very much informed by the is. Ultimately, our data emerge in concert with our normative insights, and then one more advantage of Experimental Neuroethics is realized: it is easy for others to replicate our experiments, or even to improve them by taking our vignettes and modifying them to further test their own. This iterative process of replication, critique, and systematic modification has proven to be a robust strategy for advancing insights into the nature of biological and physical phenomena. Only time will tell whether Experimental Neuroethics catches fire in our discipline as it has in the field of philosophy (where it remains controversial). If it does, we can trace it back to Neil’s presentation in Halifax….

[Cross posted at the Neuroethics Blog]


[1] Burstin K, Doughtie E, Raphaeli A. Contrastive Vignette Technique: An indirect Methodology Designed to Address Reactive Social Attitude Measurement1. Journal of Applied Social Psychology. 1980;10(2):147–65.

[2] Fitz NS, Nadler R, Manogaran P, Chong EWJ, Reiner PB. Public attitudes toward cognitive enhancement. Neuroethics. 2013 doi: 10.1007/s12152-013-9190-z.

[3] Felsen G, Castelo N, Reiner PB. Decisional enhancement and autonomy: public attitudes towards overt and covert nudges. Judgment and Decision Making. 2013;8(3):202–13.

Racing to restoring cognitive function

Wisdom may come with age, but so too does an inexorable decline in cognitive abilities. Whether it is speed of processing, working or long-term memory, it all starts to go downhill as people move into their 30s, and continues as they enter their 40s and beyond (click on the figure for the details). What to do? Some people do crossword puzzles.Mostly they just worry. A few sign up for one of the many brain fitness software suites out there, but do they really work? The answer has mostly been maybe. Until now.

Before getting to the breakthrough, let’s briefly see what the state of affairs were last week. Many studies have shown improvements with brain training, but the gain is mainly in the game; overall, cognitive function is usually not affected. Getting better at a game is all well and good, but that is not what people are after.

One study was a clear exception. In 2008, Jaeggi et al. published a paper in PNAS which showed that one particular game – the N-back task – improved not just task performance but also fluid intelligence. This was met with a great deal of excitement, and you can find many N-back tasks on the internet. But the N-back is hard. It’s also pretty boring. I suppose that is why I have struggled with maintaining a regular practice of N-back training. While no one has disputed Jaeggi et al’s findings, the field was rocked on its heels in 2010 when Adrian Owen and his colleagues at Cambridge published a paper in Nature in which they tested 11,430 people (!!) in Britain. What they reported was that “in every one of the cognitive tasks that were trained, no evidence was found for transfer effects to untrained tasks, even when those tasks were cognitively closely related.” [Notably, the N-back task was not included in the study.]  At the time I wrote that more than anything, Owen’s results were likely to spur further investigation.

And so they have.  In a very thoughtfully designed set of experiments published this past week in Nature, Adam Gazzaley’s group at UCSF report that they have developed a new game called Neuroracer that not only improves the ability of older adults to multitask, but it also improves cognitive control, working memory, and attention; all of these are cognitive domains that are known to degrade in normal aging.  The experiments are exceedingly carefully carried out – there is both an active control group who had a slightly different task and a no-contact control group; neither showed any benefit. [It is not clear whether the game would have a similar effect in younger adults, but you can be sure that those data, and more, are in the pipeline.] What is remarkable is the degree to which the Neuroracer was able to restore cognitive function.

I have not played the Neuroracer game myself, but I know from discussions with Adam that his objective was to solve not just the efficacy side of the equation, but also to make the game interesting. Although it was not discussed in the article, if Neuroracer satisfies this criterion as well, it represents a doubly important advance in the field.

Adam visited us in November 2011 and I had a chance to sit down to talk with him about the degradation of attention that accompanies multitasking in the modern world. The video can be found below.

Neuroscience in the public sphere

Here at Neuroethics at the Core, we have been trumpeting the rise of neuroessentialist thinking in the eyes of the public for some time (here and here and here), and it represents one of the two pillars of my research program in neuroethics. In today’s issue of Neuron, there is a great paper by O’Connor et al. entitled “Neuroscience in the Public Sphere“. The  abstract sums it up rather well:

The media are increasingly fascinated by neuroscience. Here, we consider how neuroscientific discoveries are thematically represented in the popular press and the implications this has for society. In communicating research, neuroscientists should be sensitive to the social consequences neuroscientific information may have once it enters the public sphere.

There are a few points that I would like to highlight. First, as my graduate student Roland Nadler relayed in an email to me last night after we both had a first glance at the paper:

…this is a fantastic article from start to finish. Worth really savoring as an example of how to do the normative stuff well, and its lessons are important for us to avoid producing stuff that could be tarred as neurotrash. Particularly neat that they get the definition of neuroessentialism right. Their discussion of it near the end is trenchant. It makes it clear that some philosophical work needs to be done to save neuroessentialism from the pitfalls of essentialism tout court - as they rightly point out, the latter is some bad juju.
On the topic of neuroessentialism, I particularly liked their final paragraph:

Neuroscience does not take place in a vacuum, and it is important to maintain sensitivity to the social implications, whether positive or negative, it may have as it manifests in real-world social contexts. It appears that the brain has been instantiated as a benchmark in public dialogue, and reference to brain research is now a powerful rhetorical tool. The key questions to be addressed in the coming years revolve around how this tool is employed and the effects this may have on society’s conceptual, behavioral, and institutional repertoires.

Not only do O’Connor et al. provide thoughtful normative comments, they also carried out empirical work, employing content analysis to study the themes that arise most frequently in the popular press. At the top of the list is enhancement of the brain, which represented 28.3% of the articles retrieved from the LexisNexis database. As this just so happens to be the other pillar of my research program, how could I not like this paper?

Excellent stuff.

Use it or lose it

As the technology of memorializing dialogue (in stone, no less) came into vogue, Socrates famously admonished Phaedrus his protegé Plato on its dangers: if people are able to write everything down, their ability to remember what was said will diminish. Plato, being an early version of an early adopter, memorialized the debate, and that is why the apocryphal story is with us today. But even without a grounding in modern neurobiology, Socrates had a valid point: the plasticity of our brains are such that the less we use them for a given function, the more our ability to carry out that function is impaired.

This becomes a tricky issue when thinking about the world in which we live today. In a thoughtful essay over at The Atlantic, Evan Selinger reviews a number of arguments for and against the use of ‘apps’ to make us, as he puts it in his title, a better person. What Evan is particularly concerned with are digital willpower enhancements: the suite of technologies that have been developed to help us do everything from not being distracted by a tweet to refrain from eating more than we would like. Continue reading

TDCS does not reduce the authenticity objection

In an essay in recent issue of Current Biology, a team of neuroscientists and philosophers examine the neuroethics of transcranial direct current stimulation (TDCS), a relatively inexpensive means of modifying human brain activity that is touted as potentially being at the forefront of a new wave of cognitive enhancement. The article has garnered a great deal of interest in the press (for example here and here and here), and the reasons are unsurprising: the prospect of a device that is cheap (probably), safe (maybe), and effective (time will tell) is something akin to the holy grail of cognitive enhancement. If the initial claims for TDCS hold up, the device may have an impact the practice of enhancement in the relatively near term. As a result, the urgency with which our community must think through the relevant ethical issues intensifies. Continue reading

A modest proposal: introduce bioethical review into the drug approval process

There has been raucous furor over the decision of Kathleen Sibelius, the Secretary of Health and Human Services in the Obama administration, to overrule the FDA’s approval of the drug known as Plan B One-Step as an over-the-counter drug. It has never previously transpired that the FDA has been overruled on a matter that falls under its jurisdiction such as this, and FDA Commissioner Margaret Hamburg issued a carefully worded response which, given that Sibelius is her boss, was remarkable for its forthrightness: Continue reading

Cognitive training as a bona fide therapeutic

The New Scientist reports that Brain Plasticity, Inc. a developer of cognitive training games, has entered into discussions with the FDA to market one of its brain training software packages as a bona fide therapeutic. The issue is of interest on many accounts, and the New Scientist article covers many of the obvious ones that were discussed at the Entertainment Software and Cognitive Neurotherapeutics Society meeting held last week in San Francisco.  Noteworthy among them are the hope that FDA approval will bring validity to a field that has both serious practitioners and charlatans others who cut corners, as well as the concern that FDA approval might slow down progress, as the approval process is likely to be glacial compared to the pace of change in software development.

But if we unpack this a bit, we find that there are deeper levels of significance, and at least one of these are is worthy of further discussion. Continue reading