Owen D. Jones

Law, Responsibility, and the Brain

Brain-imaging studies have reinvigorated the neurophilosophical and legal debate of whether we are free agents in control of our own actions or mere prisoners of a biologically determined brain.

Endowment Effects in Chimpanzees

Human behavior is not always consistent with standard rational choice predictions. Apparent deviations from rational choice predictions provide a promising arena for the merger of economics and biology [1-6]. Although little is known about the extent to which other species exhibit these seemingly irrational patterns [7-9], similarities across species would suggest a common evolutionary root to the phenomena. The present study investigated whether chimpanzees exhibit an endowment effect, a seemingly paradoxical behavior in which humans tend to value a good they have just come to possess more than they would have only a moment before [10-13]. We show the first evidence that chimpanzees do exhibit an endowment effect, by favoring items they just received more than their preferred items that could be acquired through exchange. Moreover, the effect is stronger for food than for less evolutionarily salient objects, perhaps because of historically greater risks associated with keeping a valuable item versus attempting to exchange it for another [14, 15]. These findings suggest that many seeming deviations from rational choice predictions may be common to humans and chimpanzees and that the evaluation of these through a lens of evolutionary relevance may yield further insights in humans and other species.

Corticolimbic gating of emotion-driven punishment

Determining the appropriate punishment for a norm violation requires consideration of both the perpetrators state of mind (for example, purposeful or blameless) and the strong emotions elicited by the harm caused by their actions. It has been hypothesized that such affective responses serve as a heuristic that determines appropriate punishment. However, an actors mental state often trumps the effect of emotions, as unintended harms may go unpunished, regardless of their magnitude. Using fMRI, we found that emotionally graphic descriptions of harmful acts amplify punishment severity, boost amygdala activity and strengthen amygdala connectivity with lateral prefrontal regions involved in punishment decision-making. However, this was only observed when the actors harm was intentional; when harm was unintended, a temporoparietal-medial-prefrontal circuit suppressed amygdala activity and the effect of graphic descriptions on punishment was abolished. These results reveal the brain mechanisms by which evaluation of a transgressors mental state gates our emotional urges to punish.

Neuroscientists in Court

Neuroscientific evidence is increasingly being offered in court cases. Consequently, the legal system needs neuroscientists to act as expert witnesses who can explain the limitations and interpretations of neuroscientific findings so that judges and jurors can make informed and appropriate inferences. The growing role of neuroscientists in court means that neuroscientists should be aware of important differences between the scientific and legal fields, and, especially, how scientific facts can be easily misunderstood by non-scientists, including judges and jurors.

From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms.

The social welfare provided by cooperation depends on the enforcement of social norms. Determining blameworthiness and assigning a deserved punishment are two cognitive cornerstones of norm enforcement. Although prior work has implicated the dorsolateral prefrontal cortex (DLPFC) in norm-based judgments, the relative contribution of this region to blameworthiness and punishment decisions remains poorly understood. Here, we used repetitive transcranial magnetic stimulation (rTMS) and fMRI to determine the specific role of DLPFC function in norm-enforcement behavior. DLPFC rTMS reduced punishment for wrongful acts without affecting blameworthiness ratings, and fMRI revealed punishment-selective DLPFC recruitment, suggesting that these two facets of norm-based decision making are neurobiologically dissociable. Finally, we show that DLPFC rTMS affects punishment decision making by altering the integration of information about culpability and harm. Together, these findings reveal a selective, causal role for DLPFC in norm enforcement: representational integration of the distinct information streams used to make punishment decisions.

Calcium-Dependent But Action Potential-Independent BCM-Like Metaplasticity in the Hippocampus

The Bienenstock, Cooper and Munro (BCM) computational model, which incorporates a metaplastic sliding threshold for LTP induction, accounts well for experience-dependent changes in synaptic plasticity in the visual cortex. BCM-like metaplasticity over a shorter timescale has also been observed in the hippocampus, thus providing a tractable experimental preparation for testing specific predictions of the model. Here, using extracellular and intracellular electrophysiological recordings from acute rat hippocampal slices, we tested the critical BCM predictions (1) that high levels of synaptic activation will induce a metaplastic state that spreads across dendritic compartments, and (2) that postsynaptic cell-firing is the critical trigger for inducing that state. In support of the first premise, high-frequency priming stimulation inhibited subsequent long-term potentiation and facilitated subsequent long-term depression at synapses quiescent during priming, including those located in a dendritic compartment different to that of the primed pathway. These effects were not dependent on changes in synaptic inhibition or NMDA/metabotropic glutamate receptor function. However, in contrast to the BCM prediction, somatic action potentials during priming were neither necessary nor sufficient to induce the metaplasticity effect. Instead, in broad agreement with derivatives of the BCM model, calcium as released from intracellular stores and triggered by M1 muscarinic acetylcholine receptor activation was critical for altering subsequent synaptic plasticity. These results indicate that synaptic plasticity in stratum radiatum of CA1 can be homeostatically regulated by the cell-wide history of synaptic activity through a calcium-dependent but action potential-independent mechanism.

Law and Neuroscience in the United States

Neuroscientific evidence is increasingly reaching United States courtrooms in a number of legal contexts. Just in calendar year 2010, the U.S. legal system saw its first evidentiary hearing in federal court on the admissibility of functional magnetic resonance imaging (fMRI) lie-detection evidence; the first admission of quantitative electroencephalography (qEEG) evidence contributing in part to a reduced sentence in a homicide case; and a U.S. Supreme Court ruling explicitly citing brain development research. Additional indicators suggest rapid growth. The number of cases in the U.S. involving neuroscientific evidence doubled from 2006 to 2009. And since 2000, the number of English-language law review articles including some mention of neuroscience has increased fourfold. In 2008 and again in 2009, more than 200 published scholarly works mentioned neuroscience. The data clearly suggest that there is growing interest on the part of law professors, and growing demand on the part of law reviews, for scholarship on law and the brain (Shen 2010). In addition, a number of symposia on law and neuroscience have been held in the United States over the past few years, and despite the notable youth of the field, courses in Law and Neuroscience have been taught at a number of U.S. law schools. This vivid interest in neurolaw, from both scholars and practitioners, is born of the technological developments that allow noninvasive detection of brain activities. But despite the rapid increase of legal interest in neuroscientific evidence, it remains unclear how the U.S. legal system – at the courtroom, regulatory, and policy levels – will resolve the many challenges that new neuroscience applications raise. The emerging field of law and neuroscience is being built on a foundation joining: (a) rapidly developing technologies and techniques of neuroscience; (b) quickly expanding legal scholarship on implications of neuroscience; and (c) (more recently) neuroscientific research designed specifically to explore legally relevant topics. With the institutional support of many of the country’s top research universities, as well as the support of the John D. and Catherine T. MacArthur Foundation, among other private foundations and public funding agencies, the U.S. is well positioned to continue contributing to international developments in neurolaw. This chapter provides an overview of notable neurolaw developments in the United States. The chapter proceeds in six parts. Section 1 introduces the development of law and neuroscience in the United States. Section 2 then considers several of the evidentiary contexts in which neuroscience has been, and likely will be, introduced. Sections 3 and 4 discuss the implications of neuroscience for the criminal and civil systems, respectively. Section 5 reviews three special topics: lie detection, memory, and legal decision-making. Section 6 concludes with brief thoughts about the future of law and neuroscience in the United States. As judges, lawyers, legislators, and the public become more acquainted with neuroscientific evidence, and as neuroscience continues to produce more legally relevant findings, it is likely that we will see continued expansion of law and neuroscience in the United States.

Parsing the Behavioral and Brain Mechanisms of Third-Party Punishment.

The evolved capacity for third-party punishment is considered crucial to the emergence and maintenance of elaborate human social organization and is central to the modern provision of fairness and justice within society. Although it is well established that the mental state of the offender and the severity of the harm he caused are the two primary predictors of punishment decisions, the precise cognitive and brain mechanisms by which these distinct components are evaluated and integrated into a punishment decision are poorly understood. Using fMRI, here we implement a novel experimental design to functionally dissociate the mechanisms underlying evaluation, integration, and decision that were conflated in previous studies of third-party punishment. Behaviorally, the punishment decision is primarily defined by a superadditive interaction between harm and mental state, with subjects weighing the interaction factor more than the single factors of harm and mental state. On a neural level, evaluation of harms engaged brain areas associated with affective and somatosensory processing, whereas mental state evaluation primarily recruited circuitry involved in mentalization. Harm and mental state evaluations are integrated in medial prefrontal and posterior cingulate structures, with the amygdala acting as a pivotal hub of the interaction between harm and mental state. This integrated information is used by the right dorsolateral prefrontal cortex at the time of the decision to assign an appropriate punishment through a distributed coding system. Together, these findings provide a blueprint of the brain mechanisms by which neutral third parties render punishment decisions. SIGNIFICANCE STATEMENT Punishment undergirds large-scale cooperation and helps dispense criminal justice. Yet it is currently unknown precisely how people assess the mental states of offenders, evaluate the harms they caused, and integrate those two components into a single punishment decision. Using a new design, we isolated these three processes, identifying the distinct brain systems and activities that enable each. Additional findings suggest that the amygdala plays a crucial role in mediating the interaction of mental state and harm information, whereas the dorsolateral prefrontal cortex plays a crucial, final-stage role, both in integrating mental state and harm information and in selecting a suitable punishment amount. These findings deepen our understanding of how punishment decisions are made, which may someday help to improve them.

Variables influencing the neural correlates of perceived risk of physical harm

Many human activities involve a risk of physical harm. However, not much is known about the specific brain regions involved in decision making regarding these risks. To explore the neural correlates of risk perception for physical harms, 19 participants took part in an event-related fMRI study while rating risky activities. The scenarios varied in level of potential harm (e.g., paralysis vs. stubbed toe), likelihood of injury (e.g., 1 chance in 100 vs. 1 chance in 1,000), and format (frequency vs. probability). Networks of brain regions were responsive to different aspects of risk information. Cortical language- processing areas, the middle temporal gyrus, and a region around the bed nucleus of stria terminalis responded more strongly to high- harm conditions. Prefrontal areas, along with subcortical ventral striatum, responded preferentially to high- likelihood conditions. Participants rated identical risks to be greater when information was presented in frequency format rather than probability format. These findings indicate that risk assessments for physical harm engage a broad network of brain regions that are sensitive to the severity of harm, the likelihood of risk, and the framing of risk information.

Economics, Behavioral Biology, and Law

This article compares the relevance to law of two unexpectedly similar fields: economics and behavioral biology. It first examines the assumptions, core concepts, methodological tenets, and emphases of the two fields. It then compares the interdisciplinary fields of law and economics, on one hand, with law and behavioral biology, on the other—highlighting not only important similarities but also important differences. The article subsequently explores ways that biological perspectives on human behavior may, among other things, improve economic models and the behavioral insights they generate. The article concludes that although there are important differences between the two fields, the overlaps between economics and biology warrant even greater congress between these two disciplines, and expanded exchange between the legal thinkers interested in each of them.