Vocal changes in stutterers and nonstutterers when speaking to children

Within the last few years, considerable attention has been devoted to the possibility that the amelioration of stuttering in many novel speaking conditions is a function of vocal changes with or without accompanying modifications in prosodic expression. These formulations have made reference primarily to conditions in which stutterers were induced into one or another novel speech pattern by an external stimulus such as masking noise, a rhythmic cue, or by instructions to sing, or read in unison with another speaker. In contrast, far less attention has been paid to other ameliorative conditions that lack a novel external stimulus or special instructions that direct the stutterer to speak in some unique manner. Speaking or reading to a child is an example of this latter type of condition. The present study was conducted to see if nine adult stutterers and a matched group of nonstutterers would evince vocal changes as they read aloud to another adult, a child, and a child and adult together. There was also a fourth control condition wherein the subjects read to one of the experimenters. Dependent measures of disfluency and stuttering, fundamental frequency, fundamental frequency deviation, fluent reading rate, and peak vocal sound pressure level were made and treated statistically. The major findings of this study indicated that, relative to the control condition, both subject groups exhibited several vocal changes when reading to a child alone and to a child and adult together. In addition, the stutterers experienced a reduction in disfluency, but only when reading to the child alone. The normal speakers exhibited too few disfluencies in the control condition for any meaningful change to occur in that dependent variable. The fact that the stutterers evinced vocal changes in both experimental conditions but a significant drop in disfluency in just one bears importantly on hypotheses that emphasize vocal changes in conditions that ameliorate stuttering.     

Rate changes in the speech of stutterers after therapy

The fluent speaking rate of nine adult male stutterers was compared before and after stuttering intervention. The subjects, ranging in age from 18 to 37 yr (mean, 25 yr, 3 mo), exhibited mild to severe stuttering prior to treatment. The only rate reduction strategy taught to subjects during intervention was to slow the first phoneme or syllable of sentences spoken. In addition, however, subjects significantly reduced their overall rate as determined by measurements made of their fluent speech at the middle of sentences, as well as overall sentence durations (excepting the first word of utterances). The data from this investigation are interpreted relative to the facilitation/simplification hypothesis.     

Vocal changes in stutterers and nonstutterers during high- and low-pitched speech

This study was conducted to provide an indirect test of Wingate's “modified vocalization” hypothesis. In this formulation, the improved fluency that stutterers experience in various novel conditions is attributed to changes in the key correlates of stress, namely, fundamental frequency, vocal SPL, and rate.Normal speakers and stutterers read aloud in an habitual condition following instructions to read at higher- and lower-than-normal pitches. Objective measures were taken of subjects' fundamental frequency, fundamental frequency deviation, vocal SPL, and fluent reading rate. Disfluences were also counted. Findings showed that both stutterers and normals altered several features of voicing from the habitual to the two experimental conditions. Significant condition main effects emerged for fundamental frequency deviation, vocal SPL, fluent reading rate, and disfluency. The only meaningful between-group difference noted showed that the stutterers were more disfluent than the normals across all conditions. Results were interpreted as supporting Wingate's “modified vocalization” position and were discussed relative to how the vocal changes observed might act to promote fluency.     

Analgesic and opioid involvement in the shock-elicited activity and escape deficits produced by inescapable shock

Three experiments examined the involvement of analgesic processes and endogenous opioids in the production of the shuttlebox escape acquisition and unconditioned activity deficits which follow exposure to inescapable shock. Experiment 1 found that the opiate antagonist naltrexone administered before the inescapable shock session interfered with the shuttlebox escape acquisition deficit which would normally follow. Experiment 2 found naltrexone to completely prevent the unconditioned activity deficit. The final experiment revealed that dexamethasone, a synthetic glucocorticoid which abolishes the analgesia produced by inescapable shock, reversed the activity deficit. These results indicate that endogenous opioids may be involved in the production of both the escape acquisition and activity deficits. They also suggest that the analgesia produced by these opioids may participate in the mediation of the activity deficit, even though analgesia is not involved in producing the shuttlebox acquisition deficit.     

Immunization of opioid analgesia: Effects of prior escapable shock on subsequent shock-induced and morphine-induced antinociception

In Experiment 1, it was shown that experience with escapable foot shock 4 hr prior to a session of 80 inescapable tail shocks prevented the occurrence of an analgesic response normally observed immediately following the tail shock. It has been suggested by J. W. Grau, R. L. Hyson, S. F. Maier, J. Madden, and J. D. Barchas (Science, 1981, 213, 1409–1411) that the analgesia that occurs following this number of inescapable tail shocks is mediated by endogenous opioid systems. To further explore the influence of escapable shock on opiate-mediated analgesia, Experiment 2 examined the effects of prior escapable shock on the long-term analgesia reaction that occurs upon brief exposure to shock 20 hr after morphine administration. Rats were given escapable shock, inescapable shock, or no shock 4 hr prior to a morphine injection. Twenty hours following the injection, all subjects received 5 brief foot shocks and were then immediately given tail-flick analgesia tests. Subjects which received inescapable shock or no shock prior to the morphine injection displayed a significant analgesic response. However, subjects which received escapable shock prior to morphine were not analgesic following brief exposure to shock. Thus, escapable shock seems to directly influence the activation of opioid analgesia systems.     

Adaptation to work: An analysis of employee health, withdrawal, and change

J. Rosse and H. Miller (1984, in P. Goodman, R. Atkin et al., Absenteeism: New Approaches to understanding, measuring, and managing employee absence. San Francisco: Jossey-Bass) have proposed a model of employee adaptation that hypothesizes multiple withdrawal behaviors and attempts to change working conditions as alternative forms of adaptation to a dissatisfying work environment. Negative health outcomes are also hypothesized consequences of dissatisfaction with work. In this longitudinal study of 42 new hospital employees, intention to quit, turnover, absence, attempts to change the job, and heatlh disorders were negatively correlated with job satisfaction; lateness and self-report avoidance scale were not. Use of adaptive behaviors was also found to have remedial effects for employee health. Implications for a general model of adaptation are discussed.     

Effects of initial limb position on the accuracy, reaction time and electromyographic patterns of rapid movements

An experiment was performed to determine the effects of initial limb condition on final accuracy of rapid, elbow flexion movements in the horizontal plane. Electromyographic (EMG) recordings were also taken from an agonist (biceps) and antagonist (triceps) muscle by means of bipolar surface electrodes. In the experiment the subject's forearm was passively oscillated by means of an electric motor, and when an auditory buzzer sounded, the subject was required to react as quickly as possible and rapidly move to the previously learned target angle. Thus, movements could be initiated from either static or moving starting positions. The results indicated that general accuracy was not greatly affected by these manipulations, however, constant error and pre-motor reaction time suggested that subjects may have been utilizing initial limb condition information contrary to a mass-spring view. EMG data showed that the timing characteristics of the agonist and antagonist muscles were modulated, depending on the type of movement produced, supporting an impulse-timing model (Wallace 1981).     

Syntactic influences on stuttering in young child stutterers

This study examined the location and rate of stuttering in the spontaneous speech of nine young stutterers (4.0–6.6 yr) in relation to certain aspects of syntax. It was designed to answer the following questions: Is there more stuttering at clause onset (boundary) than at other points in the clause? Does the type of clause influence rate of stuttering? Is there more stuttering on complex than on simple sentences? The syntactic analysis defined 10 clause types (seven pertaining to complex sentences and three pertaining to simple sentences); clause boundaries (taking into account “filler” words occuring in such positions); and hierarchical constituent structure within sentences. Stuttering was found with significantly greater frequency at clause boundaries than at internal (nonboundary) positions of clauses. This was apparent for nine of the 10 clause types, the exception being complement clauses. The word “and” at the beginning of simple and complex sentences provoked a high rate of stuttering. The hierarchical structure within the clause did not influence the location of stuttering, and sentence complexity was not a factor in the rate of stuttering.     

The effects of pacing and masking on stutterers' and nonstutterers' speech initiation times

The present study was undertaken to determine whether pacing and masking would facilitate improved speech initiation times (SITs) both for stutterers and for nonstutterers. All subjects were tested in control, pacing, and masking conditions. The results showed that both stutterers and nonstutterers (1) improved their SITs during the pacing condition as compared with the control condition (p = 0.01), (2) had slower SITs in the masking condition as compared with the control condition (p = 0.05), and (3) had faster SITs during the pacing as compared with the masking condition (p = 0.01). The SIT between-group findings demonstrated that stutterers were slower than nonstutterers across all SIT conditions (p = 0.08). The discussion of these results centers on the facilatory nature of novel stimulation in modifying speech-system functioning.     

Nonspecific elements in therapy with stutterers

Currently, many different strategies are employed by respected professionals working in the area of therapy for persons who stutter. This phenomenon serves as a point of departure for reflections on the nonspecific elements involved in therapy. Drawing on the literature of holistic medicine and psychotherapy these elements are identified as follows: (1) active participation of the client in the therapy process; (2) role of self-management skills; (3) influence of client's expectations regarding treatment; (4) suggestion as a factor in therapy; and (5) the therapeutic relationship.     

A comparison of LRT and VOT values between stutterers and nonstutterers

The experiment reported here found no significant group differences in laryngeal reaction time (LRT) and voice onset time (VOT) values. Rank-order correlations between the stutterers' LRT and VOT values were also nonsignificant. A model of the LRT paradigm is presented that (1) allows for systematic assessment of factors possibly contributing to the failure to replicate the often reported LRT group difference, and (2) is useful in examining the relationship between the LRT experimental condition and normal speaking conditions. We argue that two factors were particularly critical to our results. First, simple reaction time procedures included (1) a warning signal that preceded a response signal by a variable 1–3-sec foreperiod, and (2) a single response. We argue that foreperiod durations exceeded the stutterers' speech posture time for a known response. Second, the stuttering severity rating of our experimental group was less severe than ratings in other experiments.     

A comparison of syntax in young stutterers and nonstutterers

This study compares the syntactic structure of the spontaneous speech of a small group of stutterers and nonstutterers, using a method of constituent analysis. Speech samples were taped during play sessions with subjects, and the tapes were then transcribed and analyzed according to preselected constituent criteria. The stutterers were in the early stages of stuttering and had been diagnosed as stutterers by experienced clinicians. The method of analysis proved to be highly reliable. Differences were found in the number of complete clauses, the number of complex sentences, and in clause types between the two groups.     

Stutterers' voice initiation times during conditions of novel stimulation

The present experiment examined stutterers' voice initiation times (VITs) during conditions of novel stimulation. The experimenters were interested in determining how VITs varied as a function of pacing and masking. Stutterers were examined in control, pacing, and masking conditions. The results indicated that: (1) stutterers significantly improved their VITs in the pacing condition as compared with the control condition (p = 0.005), (2) stutterers had significantly faster VITs in the pacing condition as compared with the masking condition (p = 0.005), and (3) stutterers improved VITs in the masking condition as compared with the control condition (p = 0.075). These results are discussed in terms of the facilatory nature of novel stimulation in modifying speech-system functioning.     

Effects of stimulus ear presentation on the voice reaction time of adult stutterers and nonstutterers

The initial and optimum voice reaction times (VRT) to auditory stimuli presented separately to the left and right ears of ten adult stutterers and ten nonstutterers was investigated. Subjects initiated the neutral vowel sound /Λ/ in response to one hundred 4000 Hz tones of 2.5 sec in duration. The silent intervals between the tones varied randomly. The stimulus cues were divided into five equal response sets of 20 tones each with 10 tones in each set being presented to the right ear and 10 tones to the left ear alternating back and forth. No significant differences were reported between the VRTs for cues presented to the left or right ears for either group. However, the stutterers exhibited voice reaction times which were significantly longer and more variable than those of the nonstutterers. The between- group differences were observed for what appeared to be the “optimum” level of voice initiation for the experimental task. These results lend to the speculative hypothesis that the observed difficulty for adult stutterers to promptly and consistently initiate vocalization may in part be attributable to inherent rather than learned factors.     

The time course of learned helplessness, inactivity, and nociceptive deficits in rats

Four experiments are reported which explore the nature of the effects of inescapable shock on subsequent shuttlebox escape learning. The first experiment demonstrated that shuttle escape deficits dissipate within 48 hr after treatment with inescapable shock. Experiment 2 showed that exposure to inescapable shock suppressed unlearned activity in the shuttlebox and that this activity deficit recovered within 48 hr. Experiment 2A demonstrated that this shuttlebox crossing decrement was at least partly attributable to the inescapability of the shocks. These results suggested that activity factors might partly mediate the shuttle escape learning deficit reported in Experiment 1. Experiment 3 explored the possibility that activity and shuttle escape learning deficits are subserved by the effects of inescapable shock on pain sensitivity. The results supported this notion. It was found that rats were less sensitive to painful stimulation 24 hr after inescapable shock and that this analgesic tendency also dissipated within 48 hr after pretreatment. The implications of these results were discussed.     

Parent-infant resemblance for general and specific cognitive abilities in the Colorado adoption project

Previous publications emanating from the Colorado Adoption Project have reported significant relationships between parental general cognitive ability (g) and infant Bayley MDI scores. The present study compared infant Bayley factor scores representing separable dimensions of infant cognition with parental general and specific cognitive abilities for 182 adoptive families and 164 nonadoptive families. Parent/offspring correlations between 12-month Bayley factors and parental cognitive abilities suggest only minimal relationships for both parental g and specific abilities. At 24 months, more parent/offspring resemblance was present; moreover, Bayley factors that were related to parental cognition tended to be related to parental g, not to specific abilities. The finding of significant parent/offspring relationships at 24 months between biological parents and their adopted-away infants, as well as between nonadoptive parents and their infants, suggests some genetic continuity from infancy to adulthood.     

Voice initiation and termination time in stuttering and nonstuttering children

Voice initiation time (VIT) and voice termination time (VTT) was measured in seven stuttering and eight nonstuttering children ranging in age from 4 yr, 6 mo to 6 yr, 10 mo. The experimental task was the production of /a/ in response to a 1000-Hz pure tone. Voice initiation time was defined as the period of time elapsing between the onset of the auditory stimulus and the onset of the subject's response of /a/, as displayed on an oscilloscope. Voice termination time was defined as the latency between termination of the stimulus tone and the point at which the oscilloscopic signal decreased by 90%. No statistically significant differences were found between the two groups with respect to either VIT or VTT. In addition, no apparent relationships were present among VIT, VTT, or stuttering severity.     

The speech production abilities of stutterers: Recent, ongoing, and future research

Recent and ongoing research into the speech production abilities of stutterers has followed four disparate paths. First, there have been objective studies of physiologic, aerodynamic, and acoustic parameters of stutterers' habitual speech patterns and the patterns they display while speaking in the presence of such novel stimuli as DAF or masking. Second, investigators have undertaken the fiberoptic examination of stutterers' larynges during fluent and stuttered utterances. Third, there have been studies of the speed with which stutterers start and terminate voicing independent of the act of speaking. Finally, there have been investigations of possible perceptible differences between the fluency of stutterers and normal speakers. Each of these four types of research is examined. Tentative conclusions are drawn, and directions for future theorizing and experimentation are suggested.     

A parent-offspring adoption study of cognitive abilities in early childhood

Do cognitive abilities in early childhood relate genetically and/or environmentally to isomorphic abilities in adulthood? Are specific cognitive abilities diffentiated in early childhood in terms of their prediction of adult cognitive abilities? The present study, the first behavioral genetic analysis of specific cognitive abilities in early childhood, explored these questions using parent-offspring data for 186 adopted children and 151 nonadopted children tested in the longitudinal Colorado Adoption Project at 3 years of age and 162 adopted children and 138 nonadopted children tested at 4 years. The children's Stanford-Binet IQ and scores for four specific cognitive abilities (verbal, spatial, perceptual speed, and memory) were correlated with corresponding measures for their parents—the biological and adoptive parents of the adopted children and the natural parents of the nonadopted children. Significant correlations were found between biological mothers' IQ and the IQ of their adopted away offspring at 3 and 4 years of age, suggesting genetic influence for IQ. However, specific cognitive abilities yielded no significant correlations between biological mothers and their adopted-away offspring. These results suggest that substantial genetic continuity exists for IQ from early childhood to adulthood, but not for specific cognitive abilities.