ABSTRACT
There is no region of human cerebral cortex whose functional assignments are as puzzling to us as the human prefrontal cortex (HPFC). Over one hundred years of observation and experimentation has led to several general conclusions about its overall functions. The prefrontal cortex (PFC) is important for modulating higher cognitive processes such as social behavior, reasoning, planning, working memory, thought, concept formation, inhibition, attention, and abstraction. Yet, unlike the research conducted in other cognitive domains such as object recognition or lexical/semantic storage, there has been little effort to propose and investigate in detail the underlying cognitive architecture(s) that would capture the essential features and computational properties of the higher cognitive processes presumably supported by the HPFC. Since the processes that are attributed to the HPFC appear to constitute the most complex and abstract of cognitive functions, many of which are responsible for the internal guidance of human behavior, a critical step in understanding the functions of the human brain requires us to adequately describe the cognitive topography of the HPFC. The purpose of my presentation is to argue for the validity of a representational research framework to understand HPFC functioning in humans. This framework suggests that by postulating the form of the various units of representation (in essence, the elements of memory) stored in PFC, it will be much easier to derive clear and testable hypotheses that will enable rejection or validation of this and other frameworks. My colleagues and I have labeled the set of HPFC representational units alluded to above as a structured event complex (SEC). In Section 12.4, I will detail my hypotheses about the SEC’s representational structure and features and I will attempt to distinguish the SEC framework from other cognitive models of HPFC function. Before doing so, I will briefly summarize the key elements of the biology and structure of the HPFC, the evidence of its general role in cognition based on convergent evidence from lesion and neuroimaging studies, some key models postulating the functions of the HPFC, then briefly argue for a rationale that specifies why there must be representational knowledge stored in the PFC, present a short primer on the SEC framework that I have adapted, and finally offer some suggestions about future directions for research of HPFC functions using the SEC framework to motivate an understanding about decision-making, reasoning, planning, and the economic brain.
