The number of active sweat glands (PSI, palmar sweat index) as a psychophysiologic parameter

Two laboratory studies were carried out to assess the behavior of the active palmar sweat glands in both an active and a passive coping situation. Stressor in study I was watching a distressing film, in study II mental arithmetic. Subjects were male students, 17 in experiment I, 20 in experiment II. Both experiments involved a 10-minute baseline phase, a 10-minute stress period, and a follow-up of 10 minutes. PSI was assessed at 90-sec intervals and averaged across phases, as were readings in SCL, SCR, heart rate, diastolic and systolic blood pressure. PSI could be determined in 16 subjects of each study. In both experiments PSI increased significantly from baseline to stress (p less than 0.1%) and decreased from stress to follow-up (p less than 0.1%), and thus proved to be the most sensitive indicator for stress. The interrater reliability for counting the number of active sweat glands was high when the area for evaluation was defined unambiguously. Since the assessment of the PSI does not require a sophisticated technology and is thus also applicable in field research, we suggest giving more consideration to this variable.     

The number of active palmar sweat glands (palmar sweat index,PSI) as an activation measure in field studies

The number of active sweat glands within a defined area of a fingertip, called the palmar sweat index (PSI), can be easily determined by means of the plastic fingerprint method. Two experiments were carried out to demonstrate the applicability of this technique in field research and to investigate the properties of the PSI as an activation parameter. In Experiment 1 (in a blood donors’ ward), PSI rose significantly during venous puncture and dropped after the cannula had been installed. In Experiment 2 (in a dental office), PSI values increased when patients were seated in the dental chair and rose to a higher level at the dentist’s entry. Values after treatment were significantly lower. In both experiments, it was observed that the initial assessments yielded higher PSI values. This is best explained as a reaction to the assessment procedure itself, and it is recommended that the first two prints not be used for the determination of baseline values.     

Comparison of sweat bottle and sweat print measures under resting-state conditions

Palmar sweat measurements were obtained under resting-state conditions using both the newly developed sweat bottle technique and the frequently employed sweat print method. Measurement reliability was high for both approaches. The two methods, at least under generally nonstressful conditions, appear to reflect essentially different aspects of palmar sweating.     

The relationship between anxiety, fatigue and spontaneous recovery in stuttering

There is apparently no formalized hypothesis regarding the antecedents of spontaneous recovery of stuttering. Since adaptation and recovery appear to be functionally related, antecedents of adaptation have been considered to be antecedent to spontaneous recovery. Two disparate hypotheses of adaptation which have experimental support are the anxiety hypothesis and the fatigue hypothesis. The present study was initiated to investigate the relationship of anxiety and/or fatigue, if any, to spontaneous recovery. Twenty-one subjects (stutterers) participated in four conditions. Each condition consisted of eight oral readings of a passage. The experimental variables were introduced into the respective conditions after the fifth oral reading. They were: (I) no rest, same passage; (II) rest, same passage; (III) no rest, different passage; and, (IV) rest, different passage. Palmar sweat fingerprints of anxiety were taken concurrently with the first thirty seconds of trials one, three, five, six, seven and eight for all conditions. The results of the investigation led to the conclusions that: (1) there was no necessary relationship between a change in the frequency of stuttering and a change in the anxiety level ; (2) the Hullian concepts of reactive and conditioned inhibition appeared to provide a meaningful approach to the question of spontaneous recovery of stuttering behaviour.     

Articulatory-laryngeal interaction in stutterers and normal speakers: Effects of a bite-block on rapid voice initiation

The purpose of this study was to investigate the effects of restricting jaw movement with a bite-block on the voice reaction times (VRT) of adult stutterers and normal speakers. Ten stutterers and ten normal speakers initiated the sound // as rapidly as possible in response to 1 KHz cues in a nonbite-block and bite-block condition. In the nonbite-block condition all responses were initiated from a mandibular “closed” position. In the bite-block condition the jaw was fixed in a position approximating average jaw displacement for production of // in a VRT task. Results showed the group mean VRTs for the stutterers were significantly longer than for the normal speakers in both experimental conditions. Group mean VRTs were also significantly faster in the bite-block than the nonbite-block condition for both groups. Investigation of individual subject data, however, revealed that unlike the normal speakers, a subgroup of stutterers exhibited atypically long reaction times and an increase in VRTs with the jaw fixed. The possible role of neurophysiological interactions between articulatory and laryngeal behavior in stuttering is discussed.     

The stutterer's reaction to the telephone as a speaking situation

A review of the literature indicates that one of the most commonly feared talking situations among stutterers is speaking on the telephone. One hundred-thirty stutterers who feared speaking on the telephone were interviewed regarding their fear of telephone calling and answering, the age at which they began to fear calling and answering, and their fear reactions to eight specific telephone calling situations.Data was analyzed for all subjects, male/female, black/white, and mild/moderate/ severe stuttering groups. Analysis indicated that telephone calling was judged to be more feared than telephone answering with the exception of the black stutterers. Acquisition of fear of the telephone occured earlier for telephone answering than for calling within most subgroups. When general reactions to the eight telephone situations were considered, the black stutterers had the most severe fear reactions while the male and moderate stutterers had the least severe reactions.     

Brainstem auditory electrical response characteristics of stutterers and nonstutterers: A preliminary report

In the present study, eight adult male stutterers and nonstutterers showed no significant latency or amplitude differences in BSERs recorded in response to monaural and binaural clicks. However, significantly greater variance was found in the stutterers' group under the monaural stimulation condition at click rates of 12/sec and 5/sec. Left and right monaural waveforms were subtracted individually from the binaural waveform. The resultant binaural interaction difference traces were examined to determine auditory tract preference for binaural stimulation. While some subjects from both groups showed no auditory tract preference, it was found that the significant variance between groups for wave V latency was attributable to the subset of stutterers without auditory tract preference. This finding is interpreted as evidence of neurological differences in stutterers' auditory processing at the brainstem level.     

Individual differences in the perception of bodily sensations: The role of trait anxiety and coping style

Thirty young women participated in an experiment in which heart rate, blood pressure, respiration rate, skin conductance level and palmar sweat index were monitored at rest and during the administration of mental arithmetic, mirror drawing and cold pressor tasks. The accuracy of perception of somatic states was estimated by calculating within-subject correlations between four bodily sensations (racing heart, high blood pressure, shortness of breath and sweaty hands) and corresponding physiological parameters, assessed on eight occasions during the experiment. The accuracy of heart rate perception was highest, with a mean correlation between actual heart rate and ratings of racing heart of 0.76 and 66% of participants showing significant within-subject effects. The mean accuracy was 0.55 for systolic blood pressure, 0.48 for respiration rate, 0.47 for skin conductance level, and 0.64 for palmar sweat index. Accurate perception across physiological parameters did not cluster within individuals, and was not dependent on the range either of physiological changes or sensation ratings. Trait anxiety was not significantly associated with accuracy of somatic perception. Subjects with high trait anxiety reported larger increases in shortness of breath during tasks than did low anxious subjects, but this was not reflected in objective physiological measures. Information-seeking coping style, indexed by the monitoring scale of the Miller Behavioral Style Scale, was related to the accuracy of perception of skin conductance level and heart rate. The use of within-subject correlational strategies for assessing individual differences in perception of bodily states is discussed.     

A palmar sweat measure of the effect of drugs on stuttering behavior

The question is asked why drugs designed to affect physiological responses associated with anxiety do not affect stuttering if the antecedent of stuttering is anxiety? Sixteen stutterers and sixteen matched controls each participated in four conditions which were twenty-four hours apart. There were two experimental conditions where the subject received medication prior to participation. One drug was nembutal and the other benzedrine. There were also two control conditions; one in which the subject received a sugar pill and the other where he received nothing. Three simultaneous measures were made of Palmar Sweat Index (PSI), number of non-fluencies, and reading rate. The order of participation among the conditions was counterbalanced.

As a main effect the study indicated that drugs do not affect stuttering. However the interaction of drugs with the order in which drugs were administered was significant. Subjects who received nembutal as the first condition stuttered more on all four conditions than those subjects who received nembutal last. Benzedrine had little effect on stuttering. It was concluded that nembutal causes a release of stuttering and stuttering, once released, gets conditioned to the situation and continues at a high level. Theoretical explanation for such findings is presented.     

Reading abilities of school-age stutterers

The reading abilities of 20 school-age stutterers and their matched normally fluent controls were assessed by means of the Woodcock Reading Mastery Tests. Results indicate that the reading abilities of school-age stutterers are not significantly different from those of school-age normals. Similarly, knowing whether a subject was classified as a stutterer or normally fluent speaker was of minimal assistance in predicting the subject's reading performance. These findings suggest that school-age stutterers' reading abilities are within normal limits. An individual stutterer, just like an individual normally fluent speaker, may exhibit “reading problems”; however, caution should be employed in extrapolating from one individual stutterer's reading performance to the reading abilities of all stutterers.     

Performance differences between stuttering and nonstuttering subjects on a sound fusion task

This study investigated the possibility that there are central auditory level processing differences between stutterers and nonstutterers. The experimental subjects were eight male and three female stutterers ranging in age from 20–45 yr, with a mean age of 31.2 yr. The control group consisted of the same number of males and females, ranging in age from 20–45 yr, with a mean age of 30.1 yr. Each subject participated in a sound fusion task under three variable conditions: 1) group performance (nonstutterers vs. stutterers); 2) ears (right vs. left); and 3) lead-time presentation (0–100 msec). Statistically significant differences were found for lead-time presentation.     

Towards a functional neural systems model of developmental stuttering

This paper overviews recent developments in an ongoing program of brain imaging research on developmental stuttering that is being conducted at the University of Texas Health Science Center, San Antonio. This program has primarily used H₂¹⁵O PET imaging of different speaking tasks by right-handed adult male and female persistent stutterers, recovered stutterers and controls in order to isolate the neural regions that are functionally associated with stuttered speech. The principal findings have emerged from studies using condition contrasts and performance correlation techniques. The emerging findings from these studies are reviewed and referenced to a neural model of normal speech production recently proposed by Jürgens [Neurosci. Biobehav. Rev. 26 (2002) 235]. This paper will report (1) the reconfiguration of previous findings within the Jürgens Model; (2) preliminary findings of an investigation with late recovered stutterers; (3) an investigation of neural activations during a treatment procedure designed to produce a sustained improvement in fluency; and (4) an across-studies comparison that seeks to isolate neural regions within the Jürgens Model that are consistently associated with stuttering. Two regions appear to meet this criterion: right anterior insula (activated) and anterior middle and superior temporal gyri (deactivated) mainly in right hemisphere. The implications of these findings and the direction of future imaging investigations are discussed.

Educational objectives: The reader will learn about (1) recent uses of H₂¹⁵O PET imaging in stuttering research; (2) the use of a new neurological model of speech production in imaging research on stuttering; and (3) initial findings from PET imaging investigations of treated and recovered stutterers.     

Auditory processing and anxiety in stutterers

This study utilized the Synthetic Sentence Identification/Ipsilateral and Contralateral Competing Message subtests and the State-Trait Anxiety Inventory to examine auditory processing deficits, anxiety levels, and the interaction of these two components in 15 adult stutterers and 15 nonstutterers. Results support brainstem auditory processing deficits in stutterers and equalization of cortical functioning between groups. Group differences were not found in anxiety levels. Nonsignificant correlations between anxiety levels and auditory processing were revealed.     

Phonatory initiation,termination, and vocal frequency change reaction times of stutterers

Four types of voice reaction times were investigated for eight adult stutterers and eight control subjects using a vocal shadowing paradigm. These were voice initiation and termination reaction times (VIT and VTT, respectively) and voice frequency-shift intiation and termination reaction times (SIT and STT, respectively). Results indicated that the stutterers were slower in VIT, but were as fast as their control subjects in VTT, SIT, and STT. It was suggested that a laryngeal discoordination problem of stutterers lies primarily in the stage of adduction (turning on the voicing) rather than in the stage of abduction (turning off the voicing) or in finer frequency control at the larynx.     

Reaction time for voiced and whispered /a/ in stutterers and nonstutterers

Recent research reviewed in this article suggests that stutterers' inability to initiate phonation promptly could be a significant factor in the occurence of stuttering. Since stuttering is either completely absent or markedly reduced in frequency during whisper, the present study tested the hypothesis that stutterers do not significantly differ from nonstutterers in reaction time (RT) for the initiation of whispered/a/, whereas the two groups differ significantly in RT for the initiation of voiced /a/. Ten adult stutterers and an equal number of comparable nonstutterers produced prolonged versions of the vowel /a/ using voice and whisper in response to tone stimuli. The results showed that stutteres and nonstutterers did not differ in RT for either voiced or whispered /a/. The stutterers, however, exhibited significantly longer RT to produce voiced /a/ than whispered /a/.     

Lingual vibrotactile threshold shift differences between stutterers and normal speakers during magnitude-estimation scaling

The purpose of this study was to investigate differences in tactile sensory system function between stutterers and normal speakers. This task was accomplished by studying possible tactile threshold shifts occurring during magnitude-estimation scaling of vibratory stimuli presented to the dorsal surface of the tongue. Ten normal speaking men (M age = 19.7 yr.) and 10 stutterers (M age = 25.9 yr.) participated. Analysis suggested that stutterers and normal speakers differ in terms of the responsiveness of the sensory mechanism for the lingual tactile threshold to vibratory stimulus intensities applied at suprathreshold levels. The stutterers and normal speakers performed similarly on all aspects of the magnitude-estimation scaling tasks, but the amount of threshold shift occurring during the scaling procedures was significantly greater for the stutterers at each suprathreshold intensity level employed.     

Predicting employee theft: A quantitative review of the validity of a standardized measure of dishonesty

One tool used in the preemployment setting for the prediction of theft is thePersonnel Selection Inventory (PSI) (London House, 1980). The PSI is a paper and pencil measure containing three scales: honesty, violence/emotional instability, and drugs. This paper focussed on the usefulness of the PSI dishonesty scale in the prediction of employee theft. Criterion-related validity data from 1,806 persons across 23 samples were quantitatively summarized. All samples met predetermined decision rules. The data indicated that the validity of the PSI dishonesty scale was dependent on a severity of consequences moderator. Validity coefficients are highest when the subject's responses are anonymous, when the theft criteria are self-report measures, when the subjects are students, and when the subjects are aware that the investigator has another source of information on their honesty. In all analyses, the validity of the PSI scale was found to be in useful ranges and showed little variance across studies.The opinions expressed in the report are those of the authors, and do not necessarily represent those of any organizations with which the authors are associated. This paper was neither sponsored nor endorsed by the Defense Personnel Security Research and Education Center. Reprints may be obtained from Michael A. McDaniel, Defense Personnel Security Research and Education Center, 99 Pacific Street, Building 455, Suite E, Monterey, CA 93940.     

The number of active sweat glands (PSI, palmar sweat index) in stress caused by blood donation

The number of active sweat glands (PSI), heart rate, systolic (SBP) and diastolic blood pressure (DBP) were assessed every 2 minutes in 109 male blood donors. Three measurements were taken at the beginning (adaptation phase), three later but before blood donation (baseline), one during the venous puncture (phase 3), three thereafter but still during donation (phase 4), and four after removal of the cannula (phase 5). Analysis of variance yielded significant differences between phases; PSI and SBP behaved similarly, decreasing from adaptation to baseline, rising during puncture, and decreasing again thereafter. Mean within-subject correlations between variables were significantly above 0. Between-subjects correlations were significantly negative for PSI and DBP. This is best explained by the influence of age on both variables. Correlations of PSI values as determined by three raters had a mean of 0.90. The study shows that the PSI is a very sensitive indicator of stress that is easily accessible also in field studies.     

Perceptual evaluation of the speech before and after fluency shaping stuttering therapy

An often-cited criterion for assessing the effect of a stuttering therapy is the ability of the stutterers to produce normally fluent speech. Many modern stuttering therapies use special techniques that may produce stutter-free speech that does not sound completely normal. The present study investigates this problem in the framework of the Dutch adaptation of the Precision Fluency Shaping Program.

Pre-, post-, and -year follow-up therapy speech samples of 32 severe stutterers who were treated in a four-week intensive therapy are compared with comparable samples of 20 nonstutterers. For that aim the samples were rated on 14 bipolar scales by groups of about 20 listeners. The results show that the speech of the stutterers in all three conditions differs significantly from the speech of the nonstutterers. The pretherapy speech takes an extreme position on a Distorted Speech dimension, due to the large proportion of disfluencies. The posttherapy speech has extremely low scores on a Dynamics/Prosody dimension, a‘1 while the follow-up therapy speech differs from the normal speech on both dimensions, but now the distances are smaller. These results are discussed in relation to the severity of the stuttering problem in the group of treated stutterers. Finally, implications for future research on therapy evaluation are discussed.     

Stereotypes of stutterers and nonstutterers in three rural communities in Newfoundland

The existence of a negative stereotype of stutterers among residents of three small, rural communities in Newfoundland, Canada was investigated. Members of these communities (n = 106) completed a 25-item semantic differential scale developed by Woods and Williams (1976) which asked them to rate a hypothetical adult male stutterer and nonstutterer. Results indicated that community members perceived hypothetical stutterers in a negative manner in comparison to nonstutterers, despite the fact that 85% of the respondents reported knowing stutterers and 39% reported being related to stutterers. It is suggested the negative stuttering stereotype exists because nonstutterers generalize state to trait anxiety, and because of the nature of the stuttering moment itself. Since this study and previous studies appear to show that the stereotype is not modified by exposure to stutterers, familial relationships, and/or educational background, further research is needed to determine what, if any factor, can modify the pervasive negative stereotype.