The
Psychological Clinic
Copyright, 1928, by Lightner Witmer, Editor
Vol.
XVII,
No. 1
March,
PSYCHOLOGICAL CONCOMITANTS
C^BON A
PSYCHOBIOCHEMJCAL
the
OF HIGH ALVEOLAR
DIOXIDE
STUDY OF THE ETIOLOGY OF STAMMERING
By Henry E. (From
1928
Starr,
Ph.D.
Psyclioiiochemical Laboratory and Clinic of the Department of Psychology of the University of Pennsylvania) Eeceivea
for
publication February 18,
1928
Introductory In
former study of the metabolic etiology of stammering,1 I stated that the salivary pH and its determinants in the case of lethargic stammerers, indicated the importance of the role of a
carbon dioxide in the general diathesis. Further research of a strictly biochemical nature2 tended to corroborate this indication. It became apparent, however, that for a more direct study of the problem, it was necessary to determine the carbon dioxide more
content of the alveolar air of the so-called
"sub-breathing"
stam-
various stages of his progress toward recovery. The determination of alveolar carbon dioxide is readily made analysis of expired air. The tension, or partial pressure, of
merer at
by the
C02 thus ascertained very closely approximates that of the arterial blood of the subject. For a prolonged research upon psychological clinical subjects, this method is obviously preferable to direct blood analysis. Perhaps the most convenient method for the determination of the carbon dioxide content of alveolar air 1
Starr, Henry
considered
as
an
E.
Hydrogen Ion Concentration of the Mixed Saliva Fatigue and of Emotional Excitation and applied Metabolic Etiology of Stammering. Am. J. Psychol. 1922, The
Index of
to a Study of the xxxiii, 394-418. 2 Starr, Henry
E.
The Determination of the
tion of Human Mixed Saliva.
Starr, Henry
E.
Human Mixed Saliva.
Hydrogen Ion Concentra1922, liv, 43-54. the Hydrogen Ion Concentration of 1922, liv, 55-64.
J. Biol. Chem.
Variations in J. Biol. Chem.
THE PSYCHOLOGICAL CLINIC
2
is that of Fridericia.3
This
method,
while not the most delicate,
sufficiently exact, in experienced hands, for the purposes of this research and for general clinical use. It was employed throughout
is
the present
study and to minimize analyst, all of the
errors
arising
from the personal
determinations reported in this individual.
factor of the
paper were made by the same For more than two years the Fridericia method has been a part of the regular psychobiochemical examination given at intervals to stammerers
undergoing
treatment in the
Speech
Clinic
University. Almost without exception, subjects displaying definite physical stigmata of deficient habits of breathing have a
of this
alveolar carbon dioxide tension at their first examination.
high
Many others, usually lethargic in general reactions, but betraying no
air
pronounced anatomical equally heavily loaded
evidence of
"sub-breathing,"
with carbon dioxide.
In the
exhale case
of
both groups or types, as habits of breathing improve, alveolar C02 diminishes. And para passu, usually comes correction of stammering. When ready for dismissal as "cured," the alveolar carbon dioxide tension The *
high
approximates
normal average values.4
correlation just indicated
was
so
apparent that, in
See Fridericia, L. S. Berl. Tclin. Woch. 1914, li, 1268. Poulton, Brit. Med. J. 1915, ii, 392. The Speech Clinic of the University of Pennsylvania, under the direction of Dr. E. B. Twitmyer, has been curing stammerers of various types for more than a quarter of a century. Today many public schools of the better grade are conducting classes for the correction of speech defects, It is, therefore, somewhat amusing to and conducting them successfully. note, en passant, the following statement which appeared recently in a scientific journal. "As is well known, chronic stammerers are rarely, if ever, entirely cured of their speech defects. All sorts of physical and mental training fail." This statement serves, in part, to introduce the personal recollections of a stammering girl's feelings with regard to her wet nurse at about the age Even her description of her sensations during nursing in the of 5 months. first six weeks of her life are gravely recorded and apparently accepted as quite veracious by the writer of the article. After a psychoanalytic consideration, he concludes with a solemn warning against regarding all stammerers as solely oral erotics, reminding the reader that he must also be on the watch for anal and urinary erotism. Those interested in the curiosa of stammering literature are referred to L. Pierce Clark, M.D., New York, "A Study of the Psychogenesis of Stammerers," Jnl. Nerv. and Ment. Dis. 1926, lxiii, 238-245. 4
HIGH ALVEOLAR CARBON DIOXIDE
3
1926, the writer reported on it briefly before the American Psychological Association.5 Since then, the evidence has been cumulative and conclusive, involving several factors not heretofore reported. Experimental The Fridericia method requires a certain amount of intelligent co-operation on the part of the subject, who, without either holding his breath or taking a preliminary deep breath, must blow into the apparatus when told to do so by the examiner. It is
therefore not adapted to young children, the very stupid, or the quite highly excitable of any age. Consequently the stammerers and others reported upon in this study may be said to be a selected group, in the sense of being able to co-operate to the extent of blowing when told to do so. In all cases where there was any doubt as to the actuality of co-operation of the subject, or the validity of the findings, the results have been excluded from this
report.
Fifty determinations made upon thirty-five normal college reported as controls. For although the literature upon alveolar carbon dioxide is replete with "normals," the "normals" as therein considered are not classified as to psychological traits or reaction patterns. Physiological chemistry until quite recently has been practically entirely under the iEgis of medicine. As a result, in most of its literature, anyone or anything is reported as "normal" which is not so grossly pathological as to require medical treatment. The "normals" and other subjects considered in this study were all well'' from the point of view of pathology, according to preliminary medical examination. In addition, the normals, herein regarded as such, were so diagnosed by competent men are
?'
clinical psychologists?not mere psychometrists. Fifty determinations of alveolar carbon dioxide tension of 19 cured stammerers, originally of the sub-breathing type, are included in this report. The criteria for the diagnosis of "cured" in this research so
diagnosed
or
more
are
in the
that the
patients so regarded themselves, and after the lapse of a Clinic, Speech
were
year
have not returned to the Clinic for further treatment
5 Starr, Henry E. Physiological Chemistry in the Service of Psychology illustrated by Determinations of Alveolar Carbon Dioxide Tension and the Hemoglobin Content of the Blood, correlated with Clinical Diagnoses. Abstr.
as
in
Psychol.
Bui.
1927, xxiv,
186-187.
4
THE PSYCHOLOGICAL CLINIC
which they are urged to do in ease of a relapse. As a matter of fact, subjects who do relapse are not slow to accept this invitation to return for further treatment. A chart (No. 4) showing the "rise and fall" of such a patient is presented in this article. One hundred alveolar carbon dioxide tensions of an equal number of sub-breathing stammerers at the time of their initial examination are also included in this study. To ascertain whether or not a high blood content of C02 per se, promptly and invariably produce stammering, six normal subjects were placed and kept on a high carbohydrate
does,
diet until their alveolar
C02 was considerably increased. The employed was adequate in calories, vitamines, mineral salts and protein. Examination of the urine was made each morning to note any appearance of glycosuria.6 None of the six subjects diet
referred to in the present paper had any idea that their habits of speech might be affected, but were under close observation to detect any indication of incipient stammering. The element of
thereby eliminated. instance, the specimens of alveolar air were taken i.e., after the normal rise in alveolar C02 following ingestion of the midday meal, and before the evening meal
suggestion
was
In every about 3 p.m., the was
taken.7
Inasmuch as it is the partial pressure or tension of the alveolar which closely approximates that of the arterial blood, it is therefore a more direct and definite indication of the conditions obtaining in the circulatory system than is the alveolar carbon
C02
dioxide per cent. Consequently, the barometric pressure was carefully noted at the time of each analysis, and the tension calculated volume per cent X (baroby the usual formula of Tension metric pressure 40), when the temperature is constant, as it =
?
is when the Fridericia method is
properly
conducted.
The tension
The qualitative test was that of Benedict, the osazone test being employed for confirmation. When both yielded positive results, Benedict's quantitative method was employed. 7 That digestive activity is accompanied generally by a rise in alveolar was CO, pointed out by Higgins, Am. J. Physiol. 1914, xxxiv, 114. For a confirmatory and illustrative table of findings on six normal subjects, see Starr, Henry E., J. Biol. Chern., 1922, liv, 57, Table 1. The rise as shown in that table may range from 0.0 per cent to 0.6 per cent.?Cf. subject GXT, alveolar COa 20 mins. before eating was 5.45 per cent, 40 mins. after eating, 6.05 per cent. 8
HIGH ALVEOLAR CARBON DIOXIDE or
partial
meters of
5
pressure thus calculated
mercury.8
The 40
tension of water vapor at
mm.
is, of course, in terms of millideducted in the equation are for
body temperature. Results
The results obtained in the studies just indicated are presented in the following Charts. In the charts the value of the nearest whole number is taken in each case and the plotting done in terms of relative frequency, except, of course, in the individualistic
Charts 4 and 5. Discussion Charts 1, 2 and 3, with Table 1, indicate quite clearly that while virtually all of the alveolar C02 values are within the physiologically normal limits, there is a very definite range characteristic of each group. The Normals tend toward the lower limits 'and the
the not
The Cured group
occupies a general movement toward lower values characteristic of the psychologically normal, but altogether coinciding therewith. Perhaps this latter condition
sub-breathers crowd the upper. rather intermediate
indicates that in
position, showing
some cases
a
the treatment should have been
con-
tinued. Chart 4 shows a typical curve of a stammerer in process of The subject, R.A., came to the Speech Clinic in December, 1925, discharged himself as "cured" in May, 1926, went He returned on a prolonged summer vacation and had a relapse. treatment.
to the Clinic for treatment in
September
and
was
again speaking
normally in December, 1926. Chart 5 illustrates well the increase and decrease in carbon dioxide tension in response to dietetic changes as above described. It also illustrates an unsuccessful attempt to produce an experi*
See Henderson and
Morriss,
J. Biol. Chem.
1917, xxxi,
217.
It is unfortunate for the interest of scientific accuracy that alveolar CO* is so frequently reported in terms of per cent rather than tension or partial " Even J. S. Haldane in his epoch making work on Kespiration''
pressure.
(Yale University Press, 1922) has reported many of his most interesting and important tables of results in terms of per cent, without any indication of the barometric pressure obtaining at the time of the determination. There is no doubt that his assumption of approximate constancy of barometric pressure in It is to be the course of his experiments was justified. regretted, however, that he has set a precedent which is a dangerous assumption for lesser lights to make.
THE PSYCHOLOGICAL CLINIC
IQ.
n_r JLTL 30 AlvtoliLr
C02
Twsion iH*W Chart 1
Alveolar C02 tensions in in normal normal subjects Relative Relative frequency of Alveolar
30
ftheoldY CO2 Te/vs/o/v
M Chart Chart 22
Relative Relative
frequency frequency
of of Alveolar Alveolar
C02 C02
in cured cured tensions in tensions
subjects subjects
n_TL 4=L
^
3?M"a Uokr CO, W3?
T
^
Chart 33 Chart
Relative frequency stammerers of Alveolar in sub-breathing stammerers Alveolar C02 Relative tensions in frequency of C02 tensions
HIGH ALVEOLAR CARBON DIOXIDE
7
Table i
Significant Values in Charts 1, 2 and 3 Alveolar Carbon Dioxide tension in the following: Chart S} Stammerers Chart 1, Normals Chart 2, Cured
Significant
Value mm.
Hg.
mm.
Hg.
mm.
Minimum
30
Maximum
52
57
60
Median
41
45
50
33
Hg.
40
Mode
41
46
49
Mean
40.50
44.76
50.29
mental stammer by a brief period of overloading the system with C02. In each of the normal cases thus experimented upon there did result an uncomfortable lassitude and in several a certain In no slowness of speech most marked in periods of fatigue.
however, has a true stammer been produced thus far. It is quite evident that the sub-breathing stammerer is overloaded with carbon dioxide. Not over-loaded beyond physiological limits to such an extent as to be classified as pathological, he is over-loaded beyond the limits of the psychologically normal. As he improves under treatment?largely by means of intensive breathing exercises?his alveolar C02 diminishes and with it, of course, the partial pressure of carbon dioxide in the blood. His improveHis behavior throughout bement is not alone in his speech. His alertia is increased and he becomes more comes more vigorous. active. Not until such a point is reached is he amenable to simple case,
speech training. We have, then, in the alveolar carbon dioxide determination a means of ascertaining the treatment required by any subject who is identified as a "sub-breather."9 The value of the determination as an index is not affected by the problem of whether or not it is the carbon dioxide per se which does the damage. The partial pressure of C02 may be merely indicative of the excessive
or
deficient amount of
some
other subtle
'The general symptomatology of the "sub-breather," as the term is used in this paper, embraces both slow and shallow breathing, with occasional deep inspirations, high alveolar C02 and a tendency toward lethargy. Another part of the picture is a distinctly low salivary pH. In 1922 I stated that this group constituted about 74 per cent of the stammerers applying After six years further to the Clinic for treatment. study, I believe 80 (See Starr, H. E. Am. J. per cent to be a closer estimate. xxxiii
Psychol,
pp.
415-416.)
THE PSYCHOLOGICAL CLINIC
(JHART Chart 44
Fluctuations of Alveolar Carbon Dioxide concomitant with variations in
speech
of R.A. K.A.
5
lp
Chart 5 The Alveolar Carbon Dioxide tension of a normal loaded with
carbohydrate, but,
diet subject, upon a diet adequate. (Determinations each day.)
otherwise
made at 3 to 4 p.m.
over-
HIGH ALVEOLAR CARBON DIOXIDE
9
metabolic factor which is of primary etiological importance. Undoubtedly the question of adequacy of oxygenation is involved. The role of oxygen in the metabolic etiology of stammering, however, constitutes a separate research from that reported upon in this paper. It is now being attacked from several angles in this Psychobiochemical Laboratory.10 Another possibility which at once suggests itself and which is also being studied here, is that of the elaboration within the organism of a toxin or toxins which may
attack certain parts of the nervous mechanism of speech. This paper, however, is limited to a consideration of the role of carbon dioxide. It is a physiological truism that, speaking somewhat broadly, rate of breathing is under neural control, largely a function of the vagus; depth of breathing is under hormone control?and carbon dioxide is the chief hormone involved, either directly or in-
specifically
its effect upon the hydrogen ion concentration of the blood. With such nicety of precision does the regulation usually take place that, as Haldane has pointed out, there is most frequently but little change in alveolar C02 per cent under various conditions of quiet and exercise. At need the respiratory center,
directly through
doubt the pneumotaxic center, responds to the stimulus of increased carbon dioxide given off into the blood stream in increased metabolism, by increasing the depth of respiration. It is, indeed, no
only in emergencies that both depth and rate are increased for preservation of the organism. Ordinarily rate and depth vary
the
rather inversely so that the actual total ventilation tends to remain Yet in the case of about 80 per cent of stammerers, we are faced squarely by a group, with high partial pressure of arterial carbon dioxide, who nevertheless breathe both slowly and shallowly, with only an occasional deep inspiration. As a matter of fact their respiration appears to resemble the apneustic breathing described by Lumsden, or rather a mean between pneumotaxic constant.
and
apneustic.
the typical sub-breather's lethargic behavior, liable to imbalance, however, there may be noted what might well be interpreted as the toxic effects of excessive amounts of carbon dioxide. The same is true, albeit to a lesser degree, of the normals who In
became lethargic on a high carbohydrate diet, with concomitantly high alveolar C02. For while carbon dioxide is a powerful respiraThe results will soon be published as the doctorate thesis of Max "A under the caption: Hemato-Kespiratory Study of 100 Consecutive Cases of Stammering." 10
Trumper
10
THE PSYCHOLOGICAL CLINIC
tory stimulant, yet in excessive
amounts it is
recognized
as
a
general depressent. It appears not improbable, then, that the apparent anomaly of the behavior of the sub-breathing stammerer arises from a faulty pneumotaxic respiratory center, relatively insensitive to its normal hormonic stimulus, or with an abnormally high threshold, so that the organism is forced to tolerate an unusually high partial pressure of carbon dioxide in the blood stream. with this hypo-function of the respiratory center, the individual may react in other respects normally or with heightened sensitivity to carbon dioxide, the accumulation of which in his blood may render him lethargic. The tendency toward lassitude
Along
lethargy was apparent in the normal subjects as just noted when, by means of diet, their alveolar C02 was raised to levels comparable to these obtaining in general among the sub-breathers. A damper thus being put upon the mental activity of the sub-breather, to attempt to train him in new habits of speech before his system is freed of the excess carbon dioxide is folly. He is in a mental haze of lowered receptivity. Obviously his resistance to modifiability is increased above normal levels. Not until breathing exercises or diet or both have begun to show definite results in terms of reduction of partial pressure of alveolar CO? can any improvement in speech take place. To this theory may be objected the fact that certain stammerers who present the general syndrome of the sub-breather do well in certain branches of athletics. Instead of conflicting with the general thesis, however, these particular cases appear confirmatory. In terms of response to a stimulus, a "high threshold" is but another term for "increased tolerance." Such individuals, and I could name at least seven, are able to function in their daily life normally, except as to speech, despite their over-load of carbon Their tolerance is high or some compensatory factor dioxide. is at work. At all events, on the basis of the theory here presented, there is a high threshold obtaining in the respiratory center. It would, therefore, indeed be strange if these subjects could not tolerate a greater accumulation of C02 and other products of fatigue than can a normal individual.11 Consequently, their endurance in athletic contests, whether boxing, wrestling, or playing or
u
The products of fatigue tend to increase the blood hydrion concentration, to unusually high values of which the respiratory center miist be relatively insensitive if it is relatively insensitive to carbon dioxide stimulation, which amounts at least indirectly to the same thing.
HIGH ALVEOLAR CARBON DIOXIDE
11
croquet or ping-pong, would necessarily be greater than that of a normal person. A careful study of the "superiority" of these sub-breathers in any athletic contest has shown that what made them "superior" was merely endurance?never alertia. A more difficult problem now presents itself. Of two indi-
tennis,
viduals with equally high alveolar carbon dioxide tension, why does one stammer and the other speak without stammering ? There are at least two answers to this question just as there are at least two
types involved. As to the first group,
obviously lethargic sub-breathers: they lethargic to the extreme that they make but little attempt to speak. If they tried to speak more than they do?they would stammer. This is in no sense intended to dodge the issue. In both clinical and private practice, the writer has encountered many such. For practical and scientific purposes this type may be con-
are so
sidered
as
stammerers.
quite different. In it we must consider subjects placed upon so high a carbohydrate diet that their alveolar C02 tensions were on par with those of the usual run of stammerers. In the first place, it is not unlikely that, because of their complaints of dullness and lassitude, they were not continued on the prescribed diet long enough to develop characteristic speech symptoms. If they were continued long enough, however, or if a single one of them was, none having developed an experiThe second group is
the
mental' stammer, it would be evident that there must be a fundamental difference between the individual who stammers when his alveolar C02 reaches a certain tension and one who doesn't stammer when his alveolar C02 reaches the same value. That such a fundamental difference does exist is indicated by the overlapping in Charts 1, 2, and 3. It is obvious that further
made of facof metabolic considered in the forthcoming report of A possible the Hemato-Respiratory studies (10) of Trumper. factor in predisposition is the imaginal type of the sub-breathing
tors of
predisposition compensation will be
and
investigation must be compensation. One form
stammerer, which is now being studied in this Clinic. Inasmuch as excessive carbon dioxide tension may depress clarity of kinasethetic imagery, it appears not unlikely that the predominantly
individual with a relatively insensitive pneumotaxic would be predisposed to stammering. A definite center, respiratory
voco-motor
conclusion must await the results of further research.
THE PSYCHOLOGICAL CLINIC
12
Summary
and
Conclusion
1. The alveolar carbon dioxide tension values of 50 determinations of 35 normal controls, 50 determinations of 19 cured former stammerers, and 100 determinations of 100 sub-breathing stammer-
presented graphically in terms of relative frequency. 2. Charts illustrative of C02 tension values of stammerers under treatment and of normals on a high carbohydrate diet are ers, are
included. 3. It is evident that sub-breathing stammerers, constituting about 80 per cent of the stammerers applying to the Speech Clinic for treatment, have characteristically high arterial carbon dioxide partial pressure. As progress toward cure is made, this partial pressure is lowered.
findings of this research indicate that there is relative insensitivity of the pneumotaxic respiratory center of the subbreathing stammerer, resulting in excessive carbon dioxide, deficit of oxygen, and probable elaboration of toxins in the blood stream. Studies of specificity of action, predisposition and compensation are now in progress in this laboratory. 5. The results of this present study render it obvious that the first step in the treatment of the sub-breathing stammerer should be training in adequate habits of breathing. A specific diet to the individual also indicated. is adapted definitely 4. The
Psychological Clinic
Copyright, 1928, by Lightner Witmer, Editor
Vol.
XVII,
No. 1
March,
PSYCHOLOGICAL CONCOMITANTS
C^BON A
PSYCHOBIOCHEMJCAL
the
OF HIGH ALVEOLAR
DIOXIDE
STUDY OF THE ETIOLOGY OF STAMMERING
By Henry E. (From
1928
Starr,
Ph.D.
Psyclioiiochemical Laboratory and Clinic of the Department of Psychology of the University of Pennsylvania) Eeceivea
for
publication February 18,
1928
Introductory In
former study of the metabolic etiology of stammering,1 I stated that the salivary pH and its determinants in the case of lethargic stammerers, indicated the importance of the role of a
carbon dioxide in the general diathesis. Further research of a strictly biochemical nature2 tended to corroborate this indication. It became apparent, however, that for a more direct study of the problem, it was necessary to determine the carbon dioxide more
content of the alveolar air of the so-called
"sub-breathing"
stam-
various stages of his progress toward recovery. The determination of alveolar carbon dioxide is readily made analysis of expired air. The tension, or partial pressure, of
merer at
by the
C02 thus ascertained very closely approximates that of the arterial blood of the subject. For a prolonged research upon psychological clinical subjects, this method is obviously preferable to direct blood analysis. Perhaps the most convenient method for the determination of the carbon dioxide content of alveolar air 1
Starr, Henry
considered
as
an
E.
Hydrogen Ion Concentration of the Mixed Saliva Fatigue and of Emotional Excitation and applied Metabolic Etiology of Stammering. Am. J. Psychol. 1922, The
Index of
to a Study of the xxxiii, 394-418. 2 Starr, Henry
E.
The Determination of the
tion of Human Mixed Saliva.
Starr, Henry
E.
Human Mixed Saliva.
Hydrogen Ion Concentra1922, liv, 43-54. the Hydrogen Ion Concentration of 1922, liv, 55-64.
J. Biol. Chem.
Variations in J. Biol. Chem.
THE PSYCHOLOGICAL CLINIC
2
is that of Fridericia.3
This
method,
while not the most delicate,
sufficiently exact, in experienced hands, for the purposes of this research and for general clinical use. It was employed throughout
is
the present
study and to minimize analyst, all of the
errors
arising
from the personal
determinations reported in this individual.
factor of the
paper were made by the same For more than two years the Fridericia method has been a part of the regular psychobiochemical examination given at intervals to stammerers
undergoing
treatment in the
Speech
Clinic
University. Almost without exception, subjects displaying definite physical stigmata of deficient habits of breathing have a
of this
alveolar carbon dioxide tension at their first examination.
high
Many others, usually lethargic in general reactions, but betraying no
air
pronounced anatomical equally heavily loaded
evidence of
"sub-breathing,"
with carbon dioxide.
In the
exhale case
of
both groups or types, as habits of breathing improve, alveolar C02 diminishes. And para passu, usually comes correction of stammering. When ready for dismissal as "cured," the alveolar carbon dioxide tension The *
high
approximates
normal average values.4
correlation just indicated
was
so
apparent that, in
See Fridericia, L. S. Berl. Tclin. Woch. 1914, li, 1268. Poulton, Brit. Med. J. 1915, ii, 392. The Speech Clinic of the University of Pennsylvania, under the direction of Dr. E. B. Twitmyer, has been curing stammerers of various types for more than a quarter of a century. Today many public schools of the better grade are conducting classes for the correction of speech defects, It is, therefore, somewhat amusing to and conducting them successfully. note, en passant, the following statement which appeared recently in a scientific journal. "As is well known, chronic stammerers are rarely, if ever, entirely cured of their speech defects. All sorts of physical and mental training fail." This statement serves, in part, to introduce the personal recollections of a stammering girl's feelings with regard to her wet nurse at about the age Even her description of her sensations during nursing in the of 5 months. first six weeks of her life are gravely recorded and apparently accepted as quite veracious by the writer of the article. After a psychoanalytic consideration, he concludes with a solemn warning against regarding all stammerers as solely oral erotics, reminding the reader that he must also be on the watch for anal and urinary erotism. Those interested in the curiosa of stammering literature are referred to L. Pierce Clark, M.D., New York, "A Study of the Psychogenesis of Stammerers," Jnl. Nerv. and Ment. Dis. 1926, lxiii, 238-245. 4
HIGH ALVEOLAR CARBON DIOXIDE
3
1926, the writer reported on it briefly before the American Psychological Association.5 Since then, the evidence has been cumulative and conclusive, involving several factors not heretofore reported. Experimental The Fridericia method requires a certain amount of intelligent co-operation on the part of the subject, who, without either holding his breath or taking a preliminary deep breath, must blow into the apparatus when told to do so by the examiner. It is
therefore not adapted to young children, the very stupid, or the quite highly excitable of any age. Consequently the stammerers and others reported upon in this study may be said to be a selected group, in the sense of being able to co-operate to the extent of blowing when told to do so. In all cases where there was any doubt as to the actuality of co-operation of the subject, or the validity of the findings, the results have been excluded from this
report.
Fifty determinations made upon thirty-five normal college reported as controls. For although the literature upon alveolar carbon dioxide is replete with "normals," the "normals" as therein considered are not classified as to psychological traits or reaction patterns. Physiological chemistry until quite recently has been practically entirely under the iEgis of medicine. As a result, in most of its literature, anyone or anything is reported as "normal" which is not so grossly pathological as to require medical treatment. The "normals" and other subjects considered in this study were all well'' from the point of view of pathology, according to preliminary medical examination. In addition, the normals, herein regarded as such, were so diagnosed by competent men are
?'
clinical psychologists?not mere psychometrists. Fifty determinations of alveolar carbon dioxide tension of 19 cured stammerers, originally of the sub-breathing type, are included in this report. The criteria for the diagnosis of "cured" in this research so
diagnosed
or
more
are
in the
that the
patients so regarded themselves, and after the lapse of a Clinic, Speech
were
year
have not returned to the Clinic for further treatment
5 Starr, Henry E. Physiological Chemistry in the Service of Psychology illustrated by Determinations of Alveolar Carbon Dioxide Tension and the Hemoglobin Content of the Blood, correlated with Clinical Diagnoses. Abstr.
as
in
Psychol.
Bui.
1927, xxiv,
186-187.
4
THE PSYCHOLOGICAL CLINIC
which they are urged to do in ease of a relapse. As a matter of fact, subjects who do relapse are not slow to accept this invitation to return for further treatment. A chart (No. 4) showing the "rise and fall" of such a patient is presented in this article. One hundred alveolar carbon dioxide tensions of an equal number of sub-breathing stammerers at the time of their initial examination are also included in this study. To ascertain whether or not a high blood content of C02 per se, promptly and invariably produce stammering, six normal subjects were placed and kept on a high carbohydrate
does,
diet until their alveolar
C02 was considerably increased. The employed was adequate in calories, vitamines, mineral salts and protein. Examination of the urine was made each morning to note any appearance of glycosuria.6 None of the six subjects diet
referred to in the present paper had any idea that their habits of speech might be affected, but were under close observation to detect any indication of incipient stammering. The element of
thereby eliminated. instance, the specimens of alveolar air were taken i.e., after the normal rise in alveolar C02 following ingestion of the midday meal, and before the evening meal
suggestion
was
In every about 3 p.m., the was
taken.7
Inasmuch as it is the partial pressure or tension of the alveolar which closely approximates that of the arterial blood, it is therefore a more direct and definite indication of the conditions obtaining in the circulatory system than is the alveolar carbon
C02
dioxide per cent. Consequently, the barometric pressure was carefully noted at the time of each analysis, and the tension calculated volume per cent X (baroby the usual formula of Tension metric pressure 40), when the temperature is constant, as it =
?
is when the Fridericia method is
properly
conducted.
The tension
The qualitative test was that of Benedict, the osazone test being employed for confirmation. When both yielded positive results, Benedict's quantitative method was employed. 7 That digestive activity is accompanied generally by a rise in alveolar was CO, pointed out by Higgins, Am. J. Physiol. 1914, xxxiv, 114. For a confirmatory and illustrative table of findings on six normal subjects, see Starr, Henry E., J. Biol. Chern., 1922, liv, 57, Table 1. The rise as shown in that table may range from 0.0 per cent to 0.6 per cent.?Cf. subject GXT, alveolar COa 20 mins. before eating was 5.45 per cent, 40 mins. after eating, 6.05 per cent. 8
HIGH ALVEOLAR CARBON DIOXIDE or
partial
meters of
5
pressure thus calculated
mercury.8
The 40
tension of water vapor at
mm.
is, of course, in terms of millideducted in the equation are for
body temperature. Results
The results obtained in the studies just indicated are presented in the following Charts. In the charts the value of the nearest whole number is taken in each case and the plotting done in terms of relative frequency, except, of course, in the individualistic
Charts 4 and 5. Discussion Charts 1, 2 and 3, with Table 1, indicate quite clearly that while virtually all of the alveolar C02 values are within the physiologically normal limits, there is a very definite range characteristic of each group. The Normals tend toward the lower limits 'and the
the not
The Cured group
occupies a general movement toward lower values characteristic of the psychologically normal, but altogether coinciding therewith. Perhaps this latter condition
sub-breathers crowd the upper. rather intermediate
indicates that in
position, showing
some cases
a
the treatment should have been
con-
tinued. Chart 4 shows a typical curve of a stammerer in process of The subject, R.A., came to the Speech Clinic in December, 1925, discharged himself as "cured" in May, 1926, went He returned on a prolonged summer vacation and had a relapse. treatment.
to the Clinic for treatment in
September
and
was
again speaking
normally in December, 1926. Chart 5 illustrates well the increase and decrease in carbon dioxide tension in response to dietetic changes as above described. It also illustrates an unsuccessful attempt to produce an experi*
See Henderson and
Morriss,
J. Biol. Chem.
1917, xxxi,
217.
It is unfortunate for the interest of scientific accuracy that alveolar CO* is so frequently reported in terms of per cent rather than tension or partial " Even J. S. Haldane in his epoch making work on Kespiration''
pressure.
(Yale University Press, 1922) has reported many of his most interesting and important tables of results in terms of per cent, without any indication of the barometric pressure obtaining at the time of the determination. There is no doubt that his assumption of approximate constancy of barometric pressure in It is to be the course of his experiments was justified. regretted, however, that he has set a precedent which is a dangerous assumption for lesser lights to make.
THE PSYCHOLOGICAL CLINIC
IQ.
n_r JLTL 30 AlvtoliLr
C02
Twsion iH*W Chart 1
Alveolar C02 tensions in in normal normal subjects Relative Relative frequency of Alveolar
30
ftheoldY CO2 Te/vs/o/v
M Chart Chart 22
Relative Relative
frequency frequency
of of Alveolar Alveolar
C02 C02
in cured cured tensions in tensions
subjects subjects
n_TL 4=L
^
3?M"a Uokr CO, W3?
T
^
Chart 33 Chart
Relative frequency stammerers of Alveolar in sub-breathing stammerers Alveolar C02 Relative tensions in frequency of C02 tensions
HIGH ALVEOLAR CARBON DIOXIDE
7
Table i
Significant Values in Charts 1, 2 and 3 Alveolar Carbon Dioxide tension in the following: Chart S} Stammerers Chart 1, Normals Chart 2, Cured
Significant
Value mm.
Hg.
mm.
Hg.
mm.
Minimum
30
Maximum
52
57
60
Median
41
45
50
33
Hg.
40
Mode
41
46
49
Mean
40.50
44.76
50.29
mental stammer by a brief period of overloading the system with C02. In each of the normal cases thus experimented upon there did result an uncomfortable lassitude and in several a certain In no slowness of speech most marked in periods of fatigue.
however, has a true stammer been produced thus far. It is quite evident that the sub-breathing stammerer is overloaded with carbon dioxide. Not over-loaded beyond physiological limits to such an extent as to be classified as pathological, he is over-loaded beyond the limits of the psychologically normal. As he improves under treatment?largely by means of intensive breathing exercises?his alveolar C02 diminishes and with it, of course, the partial pressure of carbon dioxide in the blood. His improveHis behavior throughout bement is not alone in his speech. His alertia is increased and he becomes more comes more vigorous. active. Not until such a point is reached is he amenable to simple case,
speech training. We have, then, in the alveolar carbon dioxide determination a means of ascertaining the treatment required by any subject who is identified as a "sub-breather."9 The value of the determination as an index is not affected by the problem of whether or not it is the carbon dioxide per se which does the damage. The partial pressure of C02 may be merely indicative of the excessive
or
deficient amount of
some
other subtle
'The general symptomatology of the "sub-breather," as the term is used in this paper, embraces both slow and shallow breathing, with occasional deep inspirations, high alveolar C02 and a tendency toward lethargy. Another part of the picture is a distinctly low salivary pH. In 1922 I stated that this group constituted about 74 per cent of the stammerers applying After six years further to the Clinic for treatment. study, I believe 80 (See Starr, H. E. Am. J. per cent to be a closer estimate. xxxiii
Psychol,
pp.
415-416.)
THE PSYCHOLOGICAL CLINIC
(JHART Chart 44
Fluctuations of Alveolar Carbon Dioxide concomitant with variations in
speech
of R.A. K.A.
5
lp
Chart 5 The Alveolar Carbon Dioxide tension of a normal loaded with
carbohydrate, but,
diet subject, upon a diet adequate. (Determinations each day.)
otherwise
made at 3 to 4 p.m.
over-
HIGH ALVEOLAR CARBON DIOXIDE
9
metabolic factor which is of primary etiological importance. Undoubtedly the question of adequacy of oxygenation is involved. The role of oxygen in the metabolic etiology of stammering, however, constitutes a separate research from that reported upon in this paper. It is now being attacked from several angles in this Psychobiochemical Laboratory.10 Another possibility which at once suggests itself and which is also being studied here, is that of the elaboration within the organism of a toxin or toxins which may
attack certain parts of the nervous mechanism of speech. This paper, however, is limited to a consideration of the role of carbon dioxide. It is a physiological truism that, speaking somewhat broadly, rate of breathing is under neural control, largely a function of the vagus; depth of breathing is under hormone control?and carbon dioxide is the chief hormone involved, either directly or in-
specifically
its effect upon the hydrogen ion concentration of the blood. With such nicety of precision does the regulation usually take place that, as Haldane has pointed out, there is most frequently but little change in alveolar C02 per cent under various conditions of quiet and exercise. At need the respiratory center,
directly through
doubt the pneumotaxic center, responds to the stimulus of increased carbon dioxide given off into the blood stream in increased metabolism, by increasing the depth of respiration. It is, indeed, no
only in emergencies that both depth and rate are increased for preservation of the organism. Ordinarily rate and depth vary
the
rather inversely so that the actual total ventilation tends to remain Yet in the case of about 80 per cent of stammerers, we are faced squarely by a group, with high partial pressure of arterial carbon dioxide, who nevertheless breathe both slowly and shallowly, with only an occasional deep inspiration. As a matter of fact their respiration appears to resemble the apneustic breathing described by Lumsden, or rather a mean between pneumotaxic constant.
and
apneustic.
the typical sub-breather's lethargic behavior, liable to imbalance, however, there may be noted what might well be interpreted as the toxic effects of excessive amounts of carbon dioxide. The same is true, albeit to a lesser degree, of the normals who In
became lethargic on a high carbohydrate diet, with concomitantly high alveolar C02. For while carbon dioxide is a powerful respiraThe results will soon be published as the doctorate thesis of Max "A under the caption: Hemato-Kespiratory Study of 100 Consecutive Cases of Stammering." 10
Trumper
10
THE PSYCHOLOGICAL CLINIC
tory stimulant, yet in excessive
amounts it is
recognized
as
a
general depressent. It appears not improbable, then, that the apparent anomaly of the behavior of the sub-breathing stammerer arises from a faulty pneumotaxic respiratory center, relatively insensitive to its normal hormonic stimulus, or with an abnormally high threshold, so that the organism is forced to tolerate an unusually high partial pressure of carbon dioxide in the blood stream. with this hypo-function of the respiratory center, the individual may react in other respects normally or with heightened sensitivity to carbon dioxide, the accumulation of which in his blood may render him lethargic. The tendency toward lassitude
Along
lethargy was apparent in the normal subjects as just noted when, by means of diet, their alveolar C02 was raised to levels comparable to these obtaining in general among the sub-breathers. A damper thus being put upon the mental activity of the sub-breather, to attempt to train him in new habits of speech before his system is freed of the excess carbon dioxide is folly. He is in a mental haze of lowered receptivity. Obviously his resistance to modifiability is increased above normal levels. Not until breathing exercises or diet or both have begun to show definite results in terms of reduction of partial pressure of alveolar CO? can any improvement in speech take place. To this theory may be objected the fact that certain stammerers who present the general syndrome of the sub-breather do well in certain branches of athletics. Instead of conflicting with the general thesis, however, these particular cases appear confirmatory. In terms of response to a stimulus, a "high threshold" is but another term for "increased tolerance." Such individuals, and I could name at least seven, are able to function in their daily life normally, except as to speech, despite their over-load of carbon Their tolerance is high or some compensatory factor dioxide. is at work. At all events, on the basis of the theory here presented, there is a high threshold obtaining in the respiratory center. It would, therefore, indeed be strange if these subjects could not tolerate a greater accumulation of C02 and other products of fatigue than can a normal individual.11 Consequently, their endurance in athletic contests, whether boxing, wrestling, or playing or
u
The products of fatigue tend to increase the blood hydrion concentration, to unusually high values of which the respiratory center miist be relatively insensitive if it is relatively insensitive to carbon dioxide stimulation, which amounts at least indirectly to the same thing.
HIGH ALVEOLAR CARBON DIOXIDE
11
croquet or ping-pong, would necessarily be greater than that of a normal person. A careful study of the "superiority" of these sub-breathers in any athletic contest has shown that what made them "superior" was merely endurance?never alertia. A more difficult problem now presents itself. Of two indi-
tennis,
viduals with equally high alveolar carbon dioxide tension, why does one stammer and the other speak without stammering ? There are at least two answers to this question just as there are at least two
types involved. As to the first group,
obviously lethargic sub-breathers: they lethargic to the extreme that they make but little attempt to speak. If they tried to speak more than they do?they would stammer. This is in no sense intended to dodge the issue. In both clinical and private practice, the writer has encountered many such. For practical and scientific purposes this type may be con-
are so
sidered
as
stammerers.
quite different. In it we must consider subjects placed upon so high a carbohydrate diet that their alveolar C02 tensions were on par with those of the usual run of stammerers. In the first place, it is not unlikely that, because of their complaints of dullness and lassitude, they were not continued on the prescribed diet long enough to develop characteristic speech symptoms. If they were continued long enough, however, or if a single one of them was, none having developed an experiThe second group is
the
mental' stammer, it would be evident that there must be a fundamental difference between the individual who stammers when his alveolar C02 reaches a certain tension and one who doesn't stammer when his alveolar C02 reaches the same value. That such a fundamental difference does exist is indicated by the overlapping in Charts 1, 2, and 3. It is obvious that further
made of facof metabolic considered in the forthcoming report of A possible the Hemato-Respiratory studies (10) of Trumper. factor in predisposition is the imaginal type of the sub-breathing
tors of
predisposition compensation will be
and
investigation must be compensation. One form
stammerer, which is now being studied in this Clinic. Inasmuch as excessive carbon dioxide tension may depress clarity of kinasethetic imagery, it appears not unlikely that the predominantly
individual with a relatively insensitive pneumotaxic would be predisposed to stammering. A definite center, respiratory
voco-motor
conclusion must await the results of further research.
THE PSYCHOLOGICAL CLINIC
12
Summary
and
Conclusion
1. The alveolar carbon dioxide tension values of 50 determinations of 35 normal controls, 50 determinations of 19 cured former stammerers, and 100 determinations of 100 sub-breathing stammer-
presented graphically in terms of relative frequency. 2. Charts illustrative of C02 tension values of stammerers under treatment and of normals on a high carbohydrate diet are ers, are
included. 3. It is evident that sub-breathing stammerers, constituting about 80 per cent of the stammerers applying to the Speech Clinic for treatment, have characteristically high arterial carbon dioxide partial pressure. As progress toward cure is made, this partial pressure is lowered.
findings of this research indicate that there is relative insensitivity of the pneumotaxic respiratory center of the subbreathing stammerer, resulting in excessive carbon dioxide, deficit of oxygen, and probable elaboration of toxins in the blood stream. Studies of specificity of action, predisposition and compensation are now in progress in this laboratory. 5. The results of this present study render it obvious that the first step in the treatment of the sub-breathing stammerer should be training in adequate habits of breathing. A specific diet to the individual also indicated. is adapted definitely 4. The
