- Email: [email protected]
The Three Dimensions of Stuttering
The Three Dimensions of Stuttering: Neurology, Behaviour, and Emotion, 2nd edition R. Logan, London: Whurr Publications, 1999 Reviewed by DALE EVAN METZ State University of New York, Genesco, NY
In the second edition of The Three Dimensions of Stuttering: Neurology, Behaviour, and Emotion, Dr. Robert Logan proposes a theory of stuttering that integrates “learning, emotion, and neurology into a theoretical framework that can . . . explain the acquisition and maintenance of stuttering behaviour” (Logan, 1999, p. 6). The development of such a theory is a daunting task in and of itself. But, Logan takes an additional step by asserting that his theory “should do more than explain; it should also generate new treatments” for stuttering (p. 6). The 86 pages of text is organized into 5 chapters. The first 3 chapters review past and current literature regarding neurophysiologic functions of limbic system and cortical structures, conditioned responses that have their origins in the limbic system, and neuroimaging research of stuttering. The last two chapters proffer diagnostic and treatment strategies based ostensibly on the literature review and model of stuttering developed in the first 3 chapters. Chapter 1 is devoted to establishing an integral role of limbic system structures, particularly the amygdala, to the development and maintenance of stuttering. Logan draws on several brain ablation studies in animals and electrical stimulation and lesion studies in humans to establish that subcortical structures can produce motoric speech disruptions by providing aberrant input to the cortex. It is argued that such subcortically based speech disruptions comprise core stuttering behaviors (e.g., tonic and/or clonic blocks). The second chapter further establishes a linkage among limbic system functions, learning, and conditioned behaviors. The author invokes Brutten and Shoemaker’s (1967) two-factor theory to account for primary (tonic and/or clonic blocks) and secondary (idiosyncratic) stuttering behaviors. Two-factor theory is woven into the limbic system model developed in the previous chapter. The third chapter regards recent neuroimaging research and stuttering. Research results, albeit sometimes conflicting, suggest that stuttering behavior is associated with widespread over-activations of motor areas on the cerebrum Address correspondence to Dr. D.E. Metz, State University of New York, Department of Communicative Disorders and Sciences, 1 College Circle, 208C Sturgess Hall, Genesco, NY 14454
J. FLUENCY DISORD. 25 (2000), 387–388 © 2000 Elsevier Science Inc. All rights reserved. 655 Avenue of the Americas, New York, NY 10010
0094-730X/00/$–see front matter PII S0094-730X(00)00033-4
388
BOOK REVIEW
including the primary motor strip of the right hemisphere and premotor cortex. It is argued that over-activation of the motor areas in the CNS during stuttering is related to abnormal input from the limbic system. Chapter 4 is devoted to a brief diagnostic protocol for the assessment of stuttering. Logan argues that standard objective measures, like stuttering frequency counts, etc., need to be accompanied with assessments of the child’s emotional reactions to his or her stuttering. This chapter is shy on specifics and is only loosely tied to the research presented in chapters 1 and 2. Treatment issues are covered in the last chapter. Logan suggests that traditional treatment regimes used with children must go beyond treating only the overt symptoms of stuttering. He suggests that the conditioned emotional responses originating from subcortical structures must also be targeted. The speech-language pathologist will clearly need more specifics and additional outside sources if he or she wishes to incorporate Logan’s ideas into clinical practice. There are a number of interesting ideas and positions developed in this book, but it falls short of constituting a compelling unified theory with direct treatment implications. Logan has done a reasonable job integrating extant brain research into his model. But, as acknowledged in chapter 1, none of the reported neurophysiological research (the research that forms the pivotal argument of the limbic system’s potential contribution to motor speech disruption) regarded stuttering. Also, abnormal cerebral motor strip activation patterns that appear to be associated with stuttering cannot be linked isomorphically to aberrant input from subcortical structures. As for theory leading to practice, the diagnostic and therapeutic procedures discussed in the last 2 chapters are only partially yoked to the neurophysiological research discussed in the first 3 chapters. In summary, researchers may find Logan’s suggestions for future inquiry useful, and clinicians may gain a new perspective on stuttering that could potentially enhance therapeutic efforts. The book could be used profitably as a supplemental text in an advanced fluency class or seminar. It surely could instigate lively scholarly debate.
In the second edition of The Three Dimensions of Stuttering: Neurology, Behaviour, and Emotion, Dr. Robert Logan proposes a theory of stuttering that integrates “learning, emotion, and neurology into a theoretical framework that can . . . explain the acquisition and maintenance of stuttering behaviour” (Logan, 1999, p. 6). The development of such a theory is a daunting task in and of itself. But, Logan takes an additional step by asserting that his theory “should do more than explain; it should also generate new treatments” for stuttering (p. 6). The 86 pages of text is organized into 5 chapters. The first 3 chapters review past and current literature regarding neurophysiologic functions of limbic system and cortical structures, conditioned responses that have their origins in the limbic system, and neuroimaging research of stuttering. The last two chapters proffer diagnostic and treatment strategies based ostensibly on the literature review and model of stuttering developed in the first 3 chapters. Chapter 1 is devoted to establishing an integral role of limbic system structures, particularly the amygdala, to the development and maintenance of stuttering. Logan draws on several brain ablation studies in animals and electrical stimulation and lesion studies in humans to establish that subcortical structures can produce motoric speech disruptions by providing aberrant input to the cortex. It is argued that such subcortically based speech disruptions comprise core stuttering behaviors (e.g., tonic and/or clonic blocks). The second chapter further establishes a linkage among limbic system functions, learning, and conditioned behaviors. The author invokes Brutten and Shoemaker’s (1967) two-factor theory to account for primary (tonic and/or clonic blocks) and secondary (idiosyncratic) stuttering behaviors. Two-factor theory is woven into the limbic system model developed in the previous chapter. The third chapter regards recent neuroimaging research and stuttering. Research results, albeit sometimes conflicting, suggest that stuttering behavior is associated with widespread over-activations of motor areas on the cerebrum Address correspondence to Dr. D.E. Metz, State University of New York, Department of Communicative Disorders and Sciences, 1 College Circle, 208C Sturgess Hall, Genesco, NY 14454
J. FLUENCY DISORD. 25 (2000), 387–388 © 2000 Elsevier Science Inc. All rights reserved. 655 Avenue of the Americas, New York, NY 10010
0094-730X/00/$–see front matter PII S0094-730X(00)00033-4
388
BOOK REVIEW
including the primary motor strip of the right hemisphere and premotor cortex. It is argued that over-activation of the motor areas in the CNS during stuttering is related to abnormal input from the limbic system. Chapter 4 is devoted to a brief diagnostic protocol for the assessment of stuttering. Logan argues that standard objective measures, like stuttering frequency counts, etc., need to be accompanied with assessments of the child’s emotional reactions to his or her stuttering. This chapter is shy on specifics and is only loosely tied to the research presented in chapters 1 and 2. Treatment issues are covered in the last chapter. Logan suggests that traditional treatment regimes used with children must go beyond treating only the overt symptoms of stuttering. He suggests that the conditioned emotional responses originating from subcortical structures must also be targeted. The speech-language pathologist will clearly need more specifics and additional outside sources if he or she wishes to incorporate Logan’s ideas into clinical practice. There are a number of interesting ideas and positions developed in this book, but it falls short of constituting a compelling unified theory with direct treatment implications. Logan has done a reasonable job integrating extant brain research into his model. But, as acknowledged in chapter 1, none of the reported neurophysiological research (the research that forms the pivotal argument of the limbic system’s potential contribution to motor speech disruption) regarded stuttering. Also, abnormal cerebral motor strip activation patterns that appear to be associated with stuttering cannot be linked isomorphically to aberrant input from subcortical structures. As for theory leading to practice, the diagnostic and therapeutic procedures discussed in the last 2 chapters are only partially yoked to the neurophysiological research discussed in the first 3 chapters. In summary, researchers may find Logan’s suggestions for future inquiry useful, and clinicians may gain a new perspective on stuttering that could potentially enhance therapeutic efforts. The book could be used profitably as a supplemental text in an advanced fluency class or seminar. It surely could instigate lively scholarly debate.