A four-part working bibliography of neuroethics: part 2 – neuroscientific studies of morality and ethics

Background Moral philosophy and psychology have sought to define the nature of right and wrong, and good and evil. The industrial turn of the twentieth century fostered increasingly technological approaches that conjoined philosophy to psychology, and psychology to the natural sciences. Thus, moral philosophy and psychology became ever more vested to investigations of the anatomic structures and physiologic processes involved in cognition, emotion and behavior - ultimately falling under the rubric of the neurosciences. Since 2002, neuroscientific studies of moral thought, emotions and behaviors have become known as – and a part of – the relatively new discipline of neuroethics. Herein we present Part 2 of a bibliography of neuroethics from 2002–2013 addressing the “neuroscience of ethics” – studies of putative neural substrates and mechanisms involved in cognitive, emotional and behavioral processes of morality and ethics. Methods A systematic survey of the neuroethics literature was undertaken. Bibliographic searches were performed by accessing 11 databases, 8 literature depositories, and 4 individual journal searches, and employed indexing language for National Library of Medicine (NLM) Medical Subject Heading databases. All bibliographic searches were conducted using the RefWorks citation management program. Results This bibliography lists 397 articles, 65 books, and 52 book chapters that present (1) empirical/experimental studies, overviews, and reviews of neural substrates and mechanisms involved in morality and ethics, and/or (2) reflections upon such studies and their implications. These works present resources offering iterative descriptions, definitions and criticisms of neural processes involved in moral cognition and behaviors, and also provide a historical view of this field, and insights to its developing canon.


Introduction and background
Throughout much of recorded history, humans have sought to define the nature of right and wrong, and good and evil. Since antiquity, such questions have been the focus of moral philosophy. However, empirical and experimental movements of the late nineteenth century drew scientific attention to philosophical questions, and the queries of moral philosophy became the focus of the then nascent discipline of psychology. The industrial turn of the twentieth century fostered increasingly technological approaches that conjoined psychology to the natural sciences. Philosophical speculation, and psychological observation and experimentation became ever more rooted in, and vested to investigations of the anatomic structures and physiologic processes involved in cognition, emotion and behavior. Thus, studies of moral philosophy and moral psychology became the province of brain research, ultimately falling under the rubric of the neurosciences, which became firmly established as a titular field in the middle-to-late 1970s [1]. Important contributory literature from the 1960s through early 2000s is provided below.
Since 2002, neuroscientific studies of moral thought, emotions and behaviors have become known asand a part ofthe relatively new discipline of neuroethics [2]. As a field, neuroethics' focus is not limited to studies of neural bases of morality, but also centers upon those ethical issues that are fostered by neuroscientific research and its various implications and applications in clinical medicine and the public sphere. Thus, as the tools and techniques of neuroscience become more sophisticated and precise, the questions raised by neuroscience and neuroethics may be equally, or even more pressing as those answered [3]. How can -and will-the brain sciences inform concepts of morality, ethics and law? Will understanding the structure and functions of brain networks and processes involved in social interactions, emotions and behaviors alter constructs of "free will," culpability, and responsibility? Can neuroscientific information provide a basis for guiding how we should behave, either as individuals or as actors-in-community? Will the brain sciences foster a "new ethics" of neuroethics, and if so, how might these new ideas-and perhaps idealscomport with long held traditions and norms of morality and ethics on an ever more pluralistic world stage?
The late William Safire concluded his introductory remarks to the 2002 Dana Foundation conference "Neuroethics -Mapping the Field" by congratulating the attendees for tackling "…the challenge of carving out a new territory for an old philosophical discipline" [4] by examining the neural mechanisms of morality. The following bibliography reflects this challenging "new territory", as presented in published works from 2002-2013. These works are experimental, empirical, and/or hypothetical. In some cases the position is inquisitive, in others speculative, and in others a critical perspective is taken (of approaches used to exemplify and study ethical dilemmas, of the prior and current descriptions of psychological processes of human relations, and of concepts of morality and ethics, more generally).

Methods
Methods for systematically searching relevant literature devoted to neuroethics are identical to those utilized in Part 1 of this bibliography [5]. Search strategies utilizing MeSH (Medical Subject Headings: http://www.ncbi.nlm. nih.gov/mesh/) indexing terms were used for generating bibliographies from PubMed and National Library of Medicine (NLM) Catalog. MeSH includes ethics-related terms developed for BIOETHICSLINE, a specialty database devoted to bioethical issues produced for NLM by the Kennedy Institute of Ethics from 1975-2000. Other databases were searched using descriptors specific to those databases. The searches were limited to work published from 2002 to 2013.
The following databases were searched to produce this bibliography: As in Part 1 of this bibliography [5], the RefWorks citation manager program was utilized to eliminate duplicate reference citations.

Results
The following reference citations provide a listing of 397 articles, 65 books, and 52 book chapters that afford (1) empirical/experimental studies, overviews, and reviews of neural substrates and mechanisms involved in morality and ethics, and/or (2) reflections upon such studies and their implications.