Inhibition in Cognition, from the American Psychological Association's Decade of the Brain Series, is derived from a conference held in March of 2005 at the University of Texas–Arlington. The intended audiences are students and investigators interested in cognitive processes; indeed, as noted in the preface, this volume could provide an excellent foundation for a graduate seminar on cognitive processes. Chapters vary in their relevance and accessibility for those who are not cognitive researchers as this forum presents a complex array of paradigms and theories. In general, the chapters are well-written and succinct but there are segments that include detailed descriptions of cognitive research that are less accessible to those not directly involved in the field. It should be emphasized that this forum focuses on cognitive processes with little reference to affect or emotion and therefore is probably of little relevance for the clinical psychologist. Portions of the pathology and psychopathology section, however, do address core issues in understanding specific disorders. There are some discussions of child development and applications to pediatric populations but these are not prominent foci in the discussions.
The reader who is primarily interested in the neural substrates of cognition will be struck by the initial cautionary note by MacLeod regarding the potential fallacy of drawing strong conclusions about the nature of cognitive processes from current understandings of neural mechanisms. Specifically, MacLeod notes that these are different levels of analysis and the existence of both cognitive and neural inhibition does not require a relation between the two. However, there is ongoing reference to studies of neural correlates throughout the book, including Lustig, Hasher and Zack's discussion of evidence to suggest that there is both a common neural network for different inhibitory functions and distinct regions of activation associated with these. An integrative model presented by Levine and Brown in the latter section of this book discusses implications of neural inhibition for some cognitive functions.
Five major sections address research in areas of attention, memory and language, development and aging, and pathology and psychopathology. The section on attention and performance includes complex discussions of issues in backward inhibition and negative priming. Within the section on memory and language, the Redick, Heitz and Engle discussion of working memory and inhibition may be of particular interest, given the recent developments in clinical measures of working memory. The discussion includes a critical review of evidence to suggest that working memory capacity determines inhibitory capacity. The section on development and aging is largely focused on normal adult aging research though Reyna and Mills do include a discussion of developmental psychology studies. The pathology and psychopathology section includes Faust and Balota's comprehensive review and interpretation of findings with dementia of the Alzheimer's type (DAT), and an integrative discussion by Nigg and colleagues of findings from the Michigan State University ADHD Project that constitutes an essential review of current understandings of cognitive inhibition in ADHD that is particularly accessible to the clinician.
The forum indirectly addresses the typically simplistic references to inhibitory processes in clinical neuropsychology. There are many core issues brought to the fore in this discussion including issues of definition, measurement and interpretation. Regarding definition of inhibition, the forum presents differing perspectives on what constitutes inhibition. Discussions include distinctions between inhibition and interference, and at the more molar level, distinctions between disinhibition and impulsivity. There are careful discussions of inhibitory versus noninhibitory explanations for task performance on instruments that are commonly utilized in neuropsychological research. The forum also addresses key conceptual issues in the study of inhibition in cognition including evidence for different inhibitory processes and differing mechanisms at different processing levels. While there is a tendency to try to identify authors as either “ínhibitophiles” or “inhibitophobes”, a true spectrum of views is expressed. Clearly, this forum will cause many neuropsychologists to move from a fuzzy inhibitophilic stance, to a more nuanced view of the field.
The successful intent of this forum was to provide a comprehensive discussion of current understandings of inhibition in cognition that then sets the stage for future research. The more clinically oriented reader will find value in portions of the book, including sections on normal lifespan development, DAT and psychopathology but the most appropriate audiences are those who study cognitive processes. There is repeated reference to the need for more refined measures that are derived from task analyses. For those who utilize clinical neuropsychological instruments, this forum will lay to rest any fantasy that, in contrast with multidimensional clinical measures, research instruments clearly capture pure components of cognitive processes.
