CHAPTER 5 Thinking about the Brain: What Is the Meaning of Neuroscience Knowledge and Technologies for Capital Mitigation?
Valerie Hardcastle, PhD
Rationale for This Chapter
Neuroscience evidence presents defense attorneys with some of their most vexing dilemmas as they litigate the guilt and mitigation phases of capital cases. Other chapters in this book introduce guidelines for the strategic use of mental health and neuroscience evidence, and it is important for the mitigation team also to have the "view from 35,000 feet." A fundamental understanding of the strengths and weaknesses of this complex domain of knowledge and technology enables counsel to effectively utilize them in specific cases. This chapter makes the following points:
• Neuroscience is a longstanding and significant presence in state and federal courts. Psychologists, neuropsychologists, psychiatrists, and other behavioral health professionals are frequently employed as expert witnesses for capital case mitigation.
• Brain scans represent a new kind of neuroscience evidence, and although the use of scans is still limited, it is trending toward more frequent use. The numerous types of brain scans are discussed in this chapter.
• Any thoughtful analysis of brain scan technologies reveals that they present with complex advantages and disadvantages because of the constraints on their validity. In fact, it is contraindicated to use brain scans as an independent source of evidence to support nonresponsibility or mitigation claims.
• However, it is reasonable, and sometimes advisable, to use brain scan data as one component of an evidentiary presentation that also includes long-validated protocols such as psychological testing, psychiatric evaluation, and psychosocial assessment.
• Recent scholarly overviews of the uses of neuroscience in criminal courts have found attorneys who ignored neuroscientific evidence in capital cases to be "ineffective" in their representation of their clients by appellate courts. This is especially true when such evidence clearly existed and was not utilized for mitigation.
• These overview studies also reveal that the use of neuroscientific evidence in general, and brain scans in particular, should not be considered automatically as a double-edged sword that prosecutors can wield to present aggravating factors (such as future dangerousness), but each case requires a careful risk analysis regarding the use of this kind of evidence.
• If the outcomes of using neuroscience appear mixed or even confusing when tracked across different jurisdictions and cases, it is because we are currently in the midst of a legal sea change. Consequently, defense attorneys and mitigation teams need to track the emergence of neuroscience technologies, the rapid changes in brain and behavior knowledge development, and their impacts on how judges and juries might consider such evidence for mitigation.
Introduction
Renowned legal historian Lawrence Friedman is surely right: "Methods of punishment are related to what is happening in the larger world."1 Brains and brain data are increasingly part of our everyday vernacular, as demonstrated by everything from the surging popularity of brain-training apps and programs to President Obama's public announcement of the $18 billion BRAIN initiative, which followed President Bush's pronouncement of the 1990s as the "Decade of the Brain." As a result, the brain and its functioning have, for better or worse, become pop-culture fixtures in the twenty-first century.2
Our current cultural fascination with things brain-based cannot help but influence how brains and brain data are viewed in the criminal justice system. An analysis of the content of press articles published between 2000 and 2010 in the United States shows a marked increase in neurobiological explanations offered for criminal behavior. In particular, the number of articles on this topic retrieved from newspapers more than tripled between the first half of the analysis period to the second half; importantly, the most popular theme discussed was the connection of brain data to the question of responsibility.3 That brains are related to reasoning, decision making, behavior, and ultimately to responsibility for action is almost a truism today. Introducing relevant brain evidence (broadly conceived) into mitigation for capital offences is becoming part of standard practice.
The exact frequency of admission of neuroscience evidence into legal contexts is unknown,4 although both surveys of clinical neuropsychologists and data from case citations in the legal database LexisNexis Academic involving neuropsychologists shows that neuropsychological testimony and evidence have become fairly routine since the turn of the century.5 In addition, citation queries from LexisNexis Academic and Westlaw databases indicate that more than 800 criminal cases from 1992 to 2012 used some type of neuroscience data in support of a defendant's claim.6 Although this is a relatively small number of published appellate decisions, the number is steadily increasing.7 Most often, structural neuroimaging data (e.g., CT and MRI) are admitted as evidence of certain neural diseases or of physical damage to the brain.8
This chapter discusses the types of brain data that might be used in supporting a claim of cognitive or affective deficiency in a defendant, as well as the challenges in using these data. It also briefly describes the history of admitting psychological and brain-based evidence into the courtroom, how such evidence is used today, and what warnings we can glean about introducing brain data from the case history. Ultimately, this chapter argues that neuroscience evidence has a significant role to play in capital cases, but it works effectively only if used in conjunction with a comprehensive social history and other converging behavioral health data (e.g., psychological test results). Perhaps most important: attorneys and mitigation teams must have an understanding of what brain data can and cannot show.
Types of Tests Available
The types of available "neuro" tests are divided into two broad categories: behavioral and imaging. Behavioral tests are those that ask individuals to respond to a variety of prompts, either through a physical demonstration or by answering questions verbally or in written form. Imaging tests are those that record brain structure or brain activity by measuring related brain parameters, such as electrical discharge and cerebral blood flow. Following are brief descriptions of the types of tests available for each category.
Types of Behavioral Tests
Neurological Examination
A neurological examination is a clinical assessment to determine whether there are any dysfunctions of the nervous system. This examination includes patient history and physical examination of the head, neck, eyes, reflexes, motor skills, coordination, gait, and sensory abilities and possibly blood work, nerve conduction studies, lumbar punctures, and tumor biopsy. Neurological examinations can be used both to screen for potential problems and to investigate apparent abnormalities. The goal of this type of examination is to arrive at a differential diagnosis: to rule out potential causes and to discover the likely causes. These examinations are used to diagnose diffuse damage to the brain (as is found with dementia and encephalopathy) and local damage (as may be found with a brain tumor or stroke).
Neuropsychological Assessments
Neuropsychological assessments measure mental functions that have been definitively linked to brain areas or circuits; they are the best way to uncover and document a defendant's level of cognitive, emotional, and executive performance. Normally used to assess the degree of impairment in cognition or behavior after a brain injury or neu-ropathological process, they can also be used to help diagnose what the brain injury, impairment, or disorder might be. These tests quantify capacity or ability in such psychological domains as orientation and alertness, memory, intelligence, language, sensory perception and processing, impulsivity and self-regulation, motor functioning, attention, problem solving, planning, speed of processing, organization, and affective responses. The tests used are well known and well calibrated to normal functioning. Usually, the results from any particular series of tests are compared with the results of people in the general population matched by age, education, and race/ethnicity. In capital trials, we would most commonly be testing the effects of fetal alcohol syndrome, substance use disorder, traumatic brain injury, intellectual disability, dementia, schizophrenia, bipolar disorder, and posttraumatic stress syndrome. However, we can also find significant cognitive impairments with Parkinson's disease, epilepsy, depression, and other brain or mental disorders.
Psychiatric Evaluation
Similar to psychological evaluations, psychiatric evaluations seek to quantify mental functioning, but the focus is specifically on possible mental disorders and how they might be impacting a patient's ability to live a successful life. Today, most psychiatrists approach mental illness as a neurobiological problem—it is a disease of the brain. Often in forensic situations, patients are tested to determine risks: whether patients should be admitted to or discharged from a facility, what setting is appropriate for care and what type of therapy they might need, whether they are or will continue to be dangerous, whether they are competent. The best evaluations combine a standardized battery of tests with a more informal, unstructured interview. The combination allows psychiatrists to quantify and benchmark their patients' performance as well as to provide a more individualized assessment of their issues.
We close this section by also mentioning behavioral genetic testing. This is not a behavioral test; it is a genetic one that tries to establish a...
