Philosophy of psychology is concerned with the philosophical foundations of the study of psychology. It deals with both epistemological and ontological issues and shares interests with other fields, including philosophy of mind and theoretical psychology. Philosophical and theoretical psychology are intimately tied and are therefore sometimes used interchangeably or used together. However, philosophy of psychology relies more on debates general to philosophy and on philosophical methods, whereas theoretical psychology draws on multiple areas. Epistemology Some of the issues studied by the philosophy of psychology are epistemological concerns about the methodology of psychological investigation. For example: What constitutes a psychological explanation? What is the most appropriate methodology for psychology: mentalism, behaviorism, or a compromise? Are self-reports a reliable data-gathering method? What conclusions can be drawn from null hypothesis tests? Can first-person experiences (emotions, desires, beliefs, etc.) be measured objectively? Ontology Philosophers of psychology also concern themselves with ontological issues, like: Can psychology be theoretically reduced to neuroscience? What are psychological phenomena? What is the relationship between subjectivity and objectivity in psychology? Relations to other fields Philosophy of psychology also closely monitors contemporary work conducted in cognitive neuroscience, cognitive psychology, and artificial intelligence, for example questioning whether psychological phenomena can be explained using the methods of neuroscience, evolutionary theory, and computational modeling, respectively. Although these are all closely related fields, some concerns still arise about the appropriateness of importing their methods into psychology. Some such concerns are whether psychology, as the study of individuals as information processing systems (see Donald Broadbent), is autonomous from what happens in the brain (even if psychologists largely agree that the brain in some sense causes behavior (see supervenience)); whether the mind is "hard-wired" enough for evolutionary investigations to be fruitful; and whether computational models can do anything more than offer possible implementations of cognitive theories that tell us nothing about the mind (Fodor & Pylyshyn 1988). Related to the philosophy of psychology are philosophical and epistemological inquiries about clinical psychiatry and psychopathology. Philosophy of psychiatry is mainly concerned with the role of values in psychiatry: derived from philosophical value theory and phenomenology, values-based practice is aimed at improving and humanizing clinical decision-making in the highly complex environment of mental health care. Philosophy of psychopathology is mainly involved in the epistemological reflection about the implicit philosophical foundations of psychiatric classification and evidence-based psychiatry. It aims is to unveil the constructive activity underlying the description of mental phenomena.