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In a recent, fascinating article, Nishikawa et al1 describe their encounter with “three patients with callosal lesions who sometimes could not perform whole body actions as they intended because another intention emerged in competition with the original one.” Believing that “no specific term has yet been coined for this symptom,” they “tentatively” named it “conflict of intentions.”
In fact, however, this symptom was described by Bleuler in his Textbook of psychiatry, which first appeared in English translation in 1924. Bleuler termed it “inner negativism,” and noted that when “patients make an effort to start an action . . . a counter-impulse, or only a mere blocking appears and hinders them in its execution.” Such inner negativism could prevent “the simplest acts like eating. The spoon is arrested half way up to the mouth and must finally be put down again.”
The great service of Nishikawa et al is to demonstrate the localising value of this symptom to the corpus callosum; it would be a disservice to medical history, however, to rename it.
We are very grateful for Dr Moore's interest and comments on our article. We believe that the value of our study lies, firstly, in having rediscovered the significance of a symptom in some cases of partial callosal disconnection. The literature has been largely silent about this except for a few episodic descriptions in case reports. Secondly, we link it to the so called callosal disconnection syndromes by clarifying its clinical features and discussing possible pathogenic mechanisms. We gave the symptom a new label—“conflict of intentions”—because it differs from any other callosal symptoms and cannot be explained by established disconnection theories, given that this symptom manifests itself without being confined to one half of the body.
Dr Moore comments that the symptom we reported has already been described in Eugen Bleuler's classic textbook and termed “inner negativism” (“innerer Negativismus” in the original). He asserts that assigning new terminology to an essentially identical symptom would be a disservice to medical history. We disagree.
We consider that the terminology used in descriptive symptomatological studies is conceptually different from that used in studies that take into account both phenomenology and pathogenesis. In Bleuler's textbook, “inner negativism” appeared in the chapters about general descriptive symptomatology and schizophrenia. Our “conflict of intentions”, on the other hand, is a purely neuropsychological term meant to denote a particular type of callosal disconnection syndrome. We hypothesise links between psychopathological phenomena and underlying pathogenic neural mechanisms. In other words, we do not intend to equate the neuropsychological term “conflict of intentions” with the purely descriptive term “inner negativism.”
We agree that the symptom described by Bleuler has much in common with that seen in our patients. Indeed, we hope that our speculations about the conflict of intentions will help to elucidate the neural mechanisms of some well known psychiatric symptoms such as ego disturbances in schizophrenia, and ego dystonic experiences in obsessive compulsive disorders. In the future, these symptoms may be explained in terms of the dynamics among intentional, responsive, and automatic factors in behaviour, or among their respective main neural substrates—that is, the left and right cerebral hemispheres and lower neural systems—which we assume to be elements for explaining general human behaviour. Until such a unifying theory is established, we think it may not be such a disservice to medical history to preserve a distinction between the developmental processes of descriptive psychiatry and neuropsychology by retaining both terms, Bleuler's “inner negativism” and our “conflict of intentions”.