Neuroscience Basics for Lawyers - Oliver R. Goodenough and Micaela Tucker

• Citation: Vol. 62 No. 3
• Publication year: 2011

Neuroscience Basics for Lawyers

by Oliver R. Goodenough* and Micaela Tucker**

Neuroscience is, without a doubt, one of the "hot" disciplines in contemporary science. The advances in neuroscience have come from a cycle of technological and conceptual developments that have led to new models not only of how we think but also of how thought translates into behavior. Neuroscience has spawned a number of interdisciplinary offspring-among them "neurolaw," the application of the insights of neuroscience to problems of law and vice versa.¹ The Mercer University, Walter F. George School of Law Symposium from which this volume of the Mercer Law Review has emerged is but one manifestation of a rapidly increasing interest in neurolaw.

As a prelude to diving into the discussions-and sometimes de-bates-that a neurolaw approach provokes in legal scholarship, a reader should have at least an introductory understanding of the brain and of the tools and models that make up the cognitive revolution. This Article is intended to provide just such an introduction. Those who wish to follow up with additional study have a flood of resources at their disposal. These range from popular works² to short scholarly treat-ments³ and on to more challenging, graduate-level compendiums.⁴

* Professor of Law, Vermont Law School. Faculty Fellow, Berkman Center for Internet & Society, Harvard Law School. Harvard College (B.A., magna cum laude, 1975); University of Pennsylvania (J.D., cum laude, 1978). Member, State Bars of New York and Pennsylvania (inactive).

** Assistant Attorney General, Office of the Attorney General of Vermont, Montpelier. Rice University (B.A., with honors, 1994); Vermont Law School (J.D., cum laude, 2009). Member, State Bar of Vermont.

1. See Oliver R. Goodenough & Micaela Tucker, Law and Cognitive Neuroscience, 6 Ann. Rev. L. & Soc. Sci. 61 (2010).

2. see, e.g., sandra aamodt & sam wang, welcome to your brain: why you lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday

Life (2009); Rita Carter et al., The Human Brain Book (1st American ed. 2009).

3. See, e.g., Oliver R. Goodenough & Kristin Prehn, A Neuroscientific Approach to Normative Judgment in Law and Justice, 359 Phil. Trans. R. Soc. Lond. B. 1709 (2004);

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Undergraduate texts can serve as very useful entry-level guides,⁵ and there are many online resources as well.⁶ Most of the information set out in this Article can and should be sourced authoritatively to these and similar works rather than to this introductory Article.⁷

I. Technical Developments

Neurolaw has been made possible as a field of study by the technological advances that have fueled cognitive neuroscience more generally. Until relatively recently, science was largely unable to study the actual workings of the brain while the brain engaged in thought and guided behavior. Getting inside the skull of a living person was a near impossibility. For some years, psychology focused on behavior-the outward manifestation of a mental process.⁸ To the extent that the underlying processes were considered, the discussion was based on a certain amount of self-reporting and internal reflection. The impenetrability of the mental "black box" was not fully complete, however. Lesion cases, such as those involving injuries from strokes, war wounds, or industrial accidents like the famous Phineas Gage case, provided some

Owen D. Jones et al., Brain Imaging for Legal Thinkers: A Guide for the Perplexed, 2009 STAN. TECH. L. REV 5.; Paul J. Zak, Neuroeconomics, 359 PHIL. TRANS. R. SOC. LOND. B. 1737 (2004).

4. See, e.g., MICHAEL S. GAZZANIGA, THE COGNITIVE NEUROSCIENCES (4th ed. 2009); HUMAN BRAIN FUNCTION (Richard S. J. Frackowiak et al. eds., 2d ed. 2004).

5. See, e.g., BERNARD J. BAARS & NICOLE M. GAGE, COGNITION, BRAIN, AND

CONSCIOUSNESS: INTRODUCTION TO COGNITIVE NEUROSCIENCE (2d ed. 2010); MICHAEL S. GAZZANIGA ET AL., COGNITIVE NEUROSCIENCE: THE BIOLOGY OF THE MIND (3d ed. 2009).

6. The website of the Law and Neuroscience Project at www.lawneuro.org and its bibliographic resource at www.lawneuro.org/Resources/Bibliography.aspx are good starting points for an explanation of neurolaw. At the scholarly level, the Interdisciplinary Research Centre for Neurosciences of the Johannes Gutenberg-University of Mainz has compiled an extensive online bibliography of neuroethics, http://www.linguistik. unimainz.de/schlesewsky/publications, that includes many sources relating to neuroscience and law. A bibliography aimed at law and the biological sciences more generally is available at http://law.vanderbilt.edu/seal/resources.htm.

7. A reasonable compendium of neurolaw scholarship can be found in Goodenough & Tucker, supra note 1. At the risk of leaving good work unmentioned, the following compendium volumes provide concentrated doses of work at the intersection of law, morality, and neuroscience: LAW AND THE BRAIN (Semir Zeki & Oliver R. Goodenough eds., 2006); LAW, MIND AND BRAIN (Michael Freeman & Oliver R. Goodenough eds., 2009); 2 MORAL PSYCHOLOGY: THE COGNITIVE SCIENCE OF MORALITY (Walter Sinnott-Armstrong ed.,

2008); NEUROSCIENCE AND THE LAW: BRAIN, MIND, AND THE SCALES OF JUSTICE (Brent Garland ed., 2004); THE IMPACT OF BEHAVIORAL SCIENCES ON CRIMINAL LAW (Nita A. Farahany ed., 2009).

8. See B.F. SKINNER, SCIENCE AND HUMAN BEHAVIOR (1953); JOHN B. WATSON,

BEHAVIORISM (Norton 1924).

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information about anatomical function.⁹ The limits, however, on what could be known about living brain processes in humans made behaviorism a reasonable and often fruitful approach.

Over the past two decades, this picture has changed radically. Science has discovered progressively more sensitive and powerful techniques for investigating the electrical, neurochemical, and metabolic correlates of brain function linked to particular kinds of thoughts, tasks, and behaviors. The black box of the brain became amenable to study after all, and the results have been spectacular.

Early technologies for capturing data on the processes of thought included various kinds of external electrical measurements. Some external electrical measurements-such as galvanic skin conductance-measure systemic electrical properties across wide swaths of the body. Other measurements-like electroencephalography (EEG) and magneto-encephalography (MEG)-provide information on patterns of electrical activity within the brain. These measures are quite precise as to the timing of activity; they are much less successful at providing localization information.

II. NEUROIMAGING

The most widely recognized breakthroughs have involved scanning techniques known collectively as neuroimaging. These technologies look for an attribute or by-product of some brain function-often linked to heightened metabolism in an active area-which can be detected by a targeted external mechanism, even when located deep in the brain. Directional measurements-often referred to as "slices"-are made and then subjected to complex mathematical processing called tomography, resulting in a reliable mapping of the distribution of the selected attribute onto the brain. When these measurements are captured and paired with the mental activity and behavior stimulated by specific experimental tasks and stimuli, neuroimaging can create increasingly useful models of the workings of thought.

Early on, positron emission tomography (PET) scans played an important role. In this technique, a short-lived radioactive isotope is bound into a targeted molecule. A dose of this combination is injected

9. See, e.g., ANTONIO R, DAMASIO, DESCARTES' ERROR: EMOTION, REASON, AND THE

HUMAN BRAIN (1994); LAWRENCE WEISKRANTZ, BLINDSIGHT: A CASE STUDY AND IMPLICATIONS (1986); John M. Harlow, Passage ofan Iron Bar Through the Head, 39 B. MED. SURGICAL J. 389 (1848); Roger W. Sperry, Hemisphere Deconnection and Unity in Conscious Awareness, 23 AM. PSYCHOL. 723 (1968); Reading about Phineas Gage, DEAKIN UNIVERSITY (last updated Jan. 28, 2010), http://www.deakin.edu.au/hmnbs/psychology/ga gepage/PgRead.php.

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into the bloodstream of the subject, and its decay provides a measurable tracer for the differential distribution ofthe target molecule in the body. In traditional PET approaches to brain scanning, oxygen and glu-cose-both are associated with metabolism in the brain-were often used as the basis for the tracer. By establishing the location of heightened metabolism during a particular mental task, we can infer that the location is doing some ofthe work involved in the targeted cognition. A lowered metabolism can suggest that activity in the area is in some way inhibited in the performance of the task.

PET has limitations ofspatial resolution and temporal sensitivity, and its use of injected radioactivity restricts the number of times an individual can be an experimental subject. In recent years, much ofthe functional scanning...