Effect of False Body Maps on Stuttering Development

Loss of awareness of stuttering events is a well-known phenomenon to which any stutterer who has viewed a video recording of his own speech can attest. An extreme manifestation is “le petite mort,” a name given by Van Riper to the actual loss of consciousness that can occur in severe stuttering.  (I remember my own horror at viewing a video of my eyes rolling back into my head during severe blocks I could not remember.) What apparently happens here is that the periaqueductal gray (PAG) in the brain stem, triggered by the amygdala, sends messages to nerve pathways that would normally convey signals of painful or aversive sensory inputs, that block awareness of the input. This is a highly adaptive trait, in that the person can continue basic life functions in the presence of emotional or physical damage, potentially fleeing or controlling a highly dangerous situation. It explains why people in catastrophic accidents do not initially feel pain; and why stutterers can continue to speak when they are experiencing chaotic speech events that would probably cause a fluent speaker to stop dead in his/her tracks.

Given the similar neurological reactions to emotional and physical pain, it is interesting to explore the possible implications of the filtering out of  body signals during emotionally painful stuttering events.  Such an events might include, for example, a particularly violent tremor, a twisted tongue pushed forward out of the mouth, jaws locked in a hyper-extended open position, or any other movement caused by a reaction to loss of speech control.  Note that, while these are events commonly labeled as “escape behaviors,” they are the result of virtually automatic reactions that occur below the level of immediate awareness.

I’m keying off  a discussion that can be found on page 111 ff in Antonio Damasio’s 2003 book, Looking for Spinoza, in which he notes that “the brain effectively eliminates from the central body maps [involved in the creation of feeling states] the patterns of activity that would permit the experience of pain.” (It has been known for some time that physical pain and aversive events that cause emotional pain are handled in similar ways by the brain.)

To understand why such a system would be present in humans, we only need to consider the importance of speech in human survival.  But that’s another subject, and a very complex one at that.

To continue to the point, lack of awareness of the various tensions, tremors and maladaptive movements and postures involved in the loss of speech control associated with stuttering would quite possibly result in the creation of a “false body map” — a sort of hallucination of normalcy that would: 1) deprive the stutterer of  feedback required to determine if the speech system was ready and optimised for fluent speech, 2) enable the stutterer to persist in the attempt to speak in the presence of a disabled speech system; resulting, however, in continued stuttering.

Given our knowledge of the pervasive role of conditioning in human behavior, such a circumstance could not be positive for the maintenance of fluent speech. Particularly when it would enable the massed repetition of negative conditioniing events.

I happened to be reading a stuttering listserv awhile ago and noted one correspondent bitterly complaining that he was blissfully unaware of his childhood stuttering until he received speech therapy.

However, given the concept of “false body maps,” could interrupting this blissful state be yet another argument for the value of early intervention?