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.

Graphic Warnings on Cigarettes: Nudge or Shove? A Neuro-Perspective

Although the topic of cigarette packaging regulation may not leap immediately to mind when one thinks “neuroethics,” this Bob Greene opinion piece over at CNN nonetheless touched off a stimulating discussion among some of us at the Core recently. The neuroethics connection, in fact, struck us as quite natural: our group has researched (and blogged about) the ethics of “nudging” frequently of late, and, as I worded it when I first emailed the article around, “certainly the images at issue here are a kind of behavioural nudge.” The question that we grappled with was whether the kind of nudge that the graphic warning labels provide is warranted in the case of cigarettes. And, indeed, that discussion called my original characterization into question. Do these labels truly constitute a nudge – a subtle biasing technique that makes a particular option more cognitively accessible than another while preserving the freedom to choose between them – or are they something more akin to a “shove?”

One of the least gruesome of the proposed images for cigarette packs.

As with any highly politicized issue, the question of whether cigarettes ought to be labeled with disturbing imagery is likely to be filleted into oblivion by pundits, bloggers, legal experts, economists, et cetera, et cetera. All I hope to do here, then, is sketch some ways in which the view from neuroethics – informed as it is by philosophy and the cognitive sciences – can shed some interesting and hopefully useful light on the question. 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

The trolley problem and the evolution of war

The trolley problem is a famous thought experiment in philosophy, and runs something like this.

A runaway trolley is hurtling down a track. Five people have been tied to the track directly in front of the trolley, but there is a switch which allows the trolley to be diverted to an alternative track where one person has been tied to the track. You are standing at the switch and see the disaster unfolding. What do you do?  Most people answer that they would flip switch, killing one to save five – classic utilitarian thinking. The trolley problem has been embellished in a variety of interesting ways. The most famous of these is called the fat man problem: 5 people are tied to the track as before, but now there is a fat man on a bridge over the track, and if you push him off, he will fall before the train, stopping it and saving 5 people as before; of course, the fat man dies in the process. People who were willing to pull the switch to save 5 people tend to be reluctant to push the fat man off the bridge. Philosophers suggest that this reluctance is based upon deontological thinking, where one’s deep-seated values determine one’s actions rather than cool rational thought. Continue reading

Neuroethics Journal Club: Judging Mens Rea

The National Core for Neuroethics had a lively journal club discussion recently on a paper by Bertram Malle and Sarah Nelson that dealt with “the tension between folk concepts and legal concepts of intentionality.” As I was presenting the paper and facilitating the discussion, I decided to blog about it to share some of the highlights with our readers and crystallize my own thoughts on the matter, stirred up as they were by the proceedings.

The basic gist of the paper is as follows. Malle and Nelson identify “the valid and precise use of the concepts of mental states in reasoning about the defendant’s actions and in assigning responsibility, blame, and punishment” as a central challenge in creating a system of criminal adjudication. (One interesting point to consider going forward is how these same issues might apply to the context of torts, where instead of the epistemic criterion being “beyond a reasonable doubt” one is instead prompted to consider “the balance of evidence.”) In legal contexts, the term used to refer to the mental states in question is mens rea, Latin for “guilty/sinful mind.”

The specific mental state that the paper is concerned with is intention, especially as it relates to intentional action. In the grand tradition of experimental philosophy (though it really wasn’t yet a tradition in 2003!), Malle and Nelson find the by-now familiar faults with how these concepts have been developed in legal theory and philosophy – with theories of intentional action checked primarily against the intuitions of a small, non-representative group of participants in the debate, leading to a confusing mismatch between how the law asks us to use concepts, and how we (generally) are inclined to actually use them.

The paper explores the possibility of replacing the contorted and awkward legal concept of intentionality (here used as a synonym for intentional action) with a “folk” theory, one which Malle and a then-lesser-known Joshua Knobe had already undertaken to construct via several studies. Malle’s rationale is that, should the folk concept of intentionality prove to be consistent in its use and appropriate to the goals of law, it will be a natural successor to the status quo. Continue reading

Does the Science of “Prosocial Behaviour” Smuggle in a Political Prior?

Over at Pharyngula, PZ Myers’ reliably lively ScienceBlogs province, a recent post offers some incisive treatment of a philosophically arresting debate between Sam Harris and sundry interlocutors, most prominently Sean Carroll. The topic – whether science can answer moral questions, or, more perilously rendered, whether one can, in fact, derive “ought” from “is” – exerts a tidal attraction upon my blogging muscles, but I can resist for now; Myers’ relevance to this entry issues specifically from a choice bit of phraseology in his write-up.

When Harris claims that the discernment of human well-being (and hence of utility-maximizing courses of action) is a purely empirical matter, Myers finds him guilty of “smuggling in an unscientific prior in his category of well-being.” What I want to explore after the jump is the following possibility:

It may be that the developing body of work in neuroscience and psychology probing various morally charged phenomena has been smuggling in a politically loaded prior under the terminologically neutral guise of the category “prosocial behaviour.”

Continue reading

Neuroethics, qu’est que c’est?

I’ll admit that it may seem odd, or perhaps even unnecessary, to begin a post on a neuroethics blog to query the meaning of neuroethics. Although barely into its 8th year as an academicized field of study, the area of inquiry called “neuroethics” has developed a professional society, an academic journal devoted to issues that fall within the bioethics-neuroscience scope, another bearing its namesake, books (e.g., here, here, here, and here), and a few blogs (e.g., here & here) — including this one. Although the Dana Foundation’s “Neuroethics: Mapping the Field” conference is often credited as jump-starting neuroethics, it appears others have being ‘doing neuro-ethics’ well before the conference took shape (see, for instance, Gillett and also Churchland).

In an influential paper, Adina Roskies attempted to define neuroethics by demarcating the “ethics of neuroscience” from the “neuroscience of ethics”(Roskies does note, however, that these two aims can be pursued independently but also tend to affect one another). Roskies original account described the ethics of neuroscience as being somewhat akin to what has been a traditional focus of bioethics research, namely, the ethics of something, e.g., conducting neuroscience research with humans, the ethics of neurotechnology (e.g. deep-brain stimulation) and guidelines for research and clinical practice. The neuroscience of ethics focuses on how philosophical notions of free will, identity and other aspects of moral cognition can be explored through understanding how the brain works. Perhaps a simplistic explanation, since the paper was published in 2002 Roskies’ conception has had an impact on how neuroethics has taken shape. Continue reading

The Science of Love: A Neuroethics Journal Club

Last week, the Core celebrated an early Valentine’s Day by breaking open a box of chocolates and engaging in a lively journal club discussion on Love. The paper, a seminal piece by Aron et. al (Reward, Motivation, and Emotion Systems Associated With Early-Stage Intense Romantic Love), set the stage for a rich exchange on topics ranging from the neurobiology of love and sex, to the rise of folk neuroscience and potential applications of a “love potion”.

The conversation opened with an anecdote from my experience as a research assistant at Stanford, where I worked in conjunction with Art Aron on a exploration of romantic love and analgesia (Younger et. al, in submission).

The story went something like this:

When I began working on the ‘love project,’ I was a nineteen year-old who, like most people of my age and generation, believed that romantic love was nothing short of supernatural. Raised on a steady diet of Disney Princess stories and bubblegum pop, my first exposure to the neurobiology of love was shocking and uncomfortable.

The body of scientific literature seemed to taunt me from the pages of PubMed. ‘Of course there is no cupid shooting arrows! Unless ‘cupid’ is a cute way of saying, “dopamine-rich areas associated with mammalian reward and motivation systems” (Aron et. al). Love happens in your brain!’ Not only that, the literature snickered, love is not special to your brain; it happens in everyone’s brains via roughly the same mechanism.

It was like finding out that ‘Santa’ is just your mom in a red bathrobe.

Although I was certainly disillusioned,  my discomfort ran deeper than the discovery of a tangible truth behind love’s mystery. Below are some of the questions that plagued me during my initial investigation, as well as a some of the journal club musings in response. Continue reading

Does multitasking change your brain?

There has been quite a bit of interest in multitasking of late, most recently with a series of posts over at the Britannica Blog with contributions from Maggie Jackson, Howard Rheingold, Heather Gold, and Nicholas Carr.  The posts are quite interesting, and dovetail nicely with the thoughtful presentation by Frank Schirrmacher over at Edge entitled “The Age of the Informavore.”  I highly recommend the entire set to get an idea of what popular thinking is about multitasking.

From our perspective here at the Core, the real question is one that Schirrmacher addresses in his talk: is multitasking changing our brains?  Nicholas Carr’s infamous Atlantic piece “Is Google Making us Stupid” really set the stage, and it bears repeating that everything that we do affects the way that our brains work.  Especially so when we have something like multitasking that is inherently rewarding.  But the unanswered question is whether it is good for you.  The science is unresolved. Continue reading