An exploratory factor analysis of action responses to stuttering anticipation

Psychedelics in developmental stuttering to modulate brain functioning: a new therapeutic perspective?

Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.

Reactive Inhibitory Control Precedes Overt Stuttering Events

Research points to neurofunctional differences underlying fluent speech between stutterers and non-stutterers. Considerably less work has focused on processes that underlie stuttered vs. fluent speech. Additionally, most of this research has focused on speech motor processes despite contributions from cognitive processes prior to the onset of stuttered speech. We used MEG to test the hypothesis that reactive inhibitory control is triggered prior to stuttered speech. Twenty-nine stutterers completed a delayed-response task that featured a cue (prior to a go cue) signaling the imminent requirement to produce a word that was either stuttered or fluent. Consistent with our hypothesis, we observed increased beta power likely emanating from the right pre-supplementary motor area (R-preSMA)-an area implicated in reactive inhibitory control-in response to the cue preceding stuttered vs. fluent productions. Beta power differences between stuttered and fluent trials correlated with stuttering severity and participants' percentage of trials stuttered increased exponentially with beta power in the R-preSMA. Trial-by-trial beta power modulations in the R-preSMA following the cue predicted whether a trial would be stuttered or fluent. Stuttered trials were also associated with delayed speech onset suggesting an overall slowing or freezing of the speech motor system that may be a consequence of inhibitory control. Post-hoc analyses revealed that independently generated anticipated words were associated with greater beta power and more stuttering than researcher-assisted anticipated words, pointing to a relationship between self-perceived likelihood of stuttering (i.e., anticipation) and inhibitory control. This work offers a neurocognitive account of stuttering by characterizing cognitive processes that precede overt stuttering events.

Relationships Between Psychological Distress and Affective, Behavioral, and Cognitive Experiences of Stuttering

PURPOSE

People who stutter (PWS) are vulnerable to the development of various psychopathological symptoms, although prevalence data are mixed and less clarity exists about factors that potentially influence their occurrence. The current study sought to shed light on the prevalence of self-reported psychopathology in PWS and aimed to identify relationships between affective, behavioral, and cognitive (ABC) experiences of stuttering and psychological distress (PD).

METHOD

Forty-four PWS were administered the Behavior Assessment Battery (BAB) for Adults who Stutter and the Brief Symptom Inventory-18. The prevalence of clinically significant PD was calculated via BSI-18 global severity index t-score cutoffs. Regression analyses examined relationships between ABC variables of stuttering and PD.

RESULTS

Participants' BAB scores approximated normative values, while the PD score distribution was similar to that of a nonclinical sample. Nine percent of participants met thresholds for clinically significant PD. All ABC correlates of stuttering significantly and positively correlated with PD scores, capturing considerable amounts of shared variance.

CONCLUSIONS

Levels of PD in PWS approximate those of the general community, highlighting the existence of psychologically distressed subgroups of PWS. Speech situation-specific anxiety had the strongest relationship to PD, followed closely by one's report of situation-specific speech disruption. To a lesser but still significant extent, PWS' frequency to which they engage in various avoidance/escape behaviors, as well as their communication attitude, predicted levels of psychopathology. These data inform diagnostic and clinical decision making, drawing attention to factors that should be attended to in treatment.

Reactions and responses to anticipation of stuttering and how they contribute to stuttered speech that listeners perceive as fluent - An opinion paper

The experience of stuttering is wide ranging and includes a variety of perceived and unperceived behaviors and experiences. One of those experiences is anticipation of stuttering. While anticipation of stuttering is commonly discussed in terms of being a prediction of an upcoming event, it has also been equated to an internal realization of stuttering - which is the conceptualization applied here. The aim of this paper is to impress upon the reader that anticipated moments of stuttering (whether at a conscious or subconscious level) must be met with an adaptive reaction or response (which may also occur consciously or subconsciously). While these adaptive reactions and responses may differ based on whether they promote positive or negative communicative behaviors, they still represent adaptations by the speaker. Among the broad category of reactions and responses to anticipation of stuttering are motoric adaptations to speech, which include characteristic stuttering behaviors and other adaptations that may contribute to speech that is perceived by listeners as fluent. An outcome of this conceptualization is, even when adaptations result in listener perceived fluency, the speech of the person who stutters is still controlled by stuttering - meaning that some observable or unobservable adaptation is required. It is critical that speech-language pathologists recognize that the behaviors of people who stutter may reflect reactions and responses to an internal realization of stuttering and observable and unobservable reactions and responses must be considered in both assessments and interventions.

Eliciting Stuttering in School-Age and Adolescent Stutterers in Experimental Settings

PURPOSE

Most neural and physiological research on stuttering focuses on the fluent speech of speakers who stutter due to the difficulty associated with eliciting stuttering reliably in the laboratory. We previously introduced an approach to elicit stuttered speech in the laboratory in adults who stutter. The purpose of this study was to determine whether that approach reliably elicits stuttering in school-age children and teenagers who stutter (CWS/TWS).

METHOD

Twenty-three CWS/TWS participated. A clinical interview was used to identify participant-specific anticipated and unanticipated words in CWS and TWS. Two tasks were administered: (a) a delayed word reading task in which participants read words and produced them after a 5-s delay and (b) a delayed response question task in which participants responded to examiner questions after a 5-s delay. Two CWS and eight TWS completed the reading task; six CWS and seven TWS completed the question task. Trials were coded as unambiguously fluent, ambiguous, and unambiguously stuttered.

RESULTS

The method yielded, at a group level, a near-equal distribution of unambiguously stuttered and fluent utterances: 42.5% and 45.1%, respectively, in the reading task and 40.5% and 51.4%, respectively, in the question task.

CONCLUSIONS

The method presented in this article elicited a comparable amount of unambiguously stuttered and fluent trials in CWS and TWS, at a group level, during two different word production tasks. The inclusion of different tasks supports the generalizability of our approach, which can be used to elicit stuttering in studies that aim to unravel the neural and physiological bases that underlie stuttered speech.

Exploratory factor analysis of shared and specific genetic associations in depression and anxiety

BACKGROUND

Previous genetic studies of anxiety and depression were mostly based on independent phenotypes. This study aims to investigate the shared and specific genetic structure between anxiety and depression.

METHOD

To identify the underlying factors of Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), and their combined scale (joint scale), we employed exploratory factor analysis (EFA) using the eigenvalue of parallel analysis. Subsequently, we conducted a genome-wide association study (GWAS) for these factors. In addition, we utilized LD Score Regression (LDSC) to determine the genetic correlations between the identified factors and four common mental disorders, three sleep phenotypes, and other traits that have been previously linked to anxiety and depression.

RESULTS

The EFA uncovered two factors for the GAD-7 scale, namely nervousness and disturbance, two factors for the PHQ-9 scale, namely negative affect and sleep/appetite disturbance, and four factors for the joint scale, specifically nervousness, anhedonia, sleep/appetite disturbance, and fidget. We identified two genome-wide significant genomic loci, with overlap across GAD-7 factor 1 and joint scale factor 1: rs148579586 (P_GAD-7 = 1.365 × 10^-09, P_{Joint scale} = 1.434 × 1^0-09) and rs201074060 (P_GAD-7 = 3.672 × 10^-09, P_{Joint scale} = 3.824 × 10^-09). Genetic correlations in factors ranged from 0.722 to 1.000 (all p < 1.786 × 10^-3) with 27 of 28 correlations being significantly smaller than one. The genetic correlations with external phenotypes showed small variation across the eight factors.

CONCLUSION

Unidimensional structures can provide more precise scores, which can aid in identifying the shared and specific genetic associations between anxiety and depression. This is a crucial step in characterizing the genetic structure of these conditions and their co-occurrence.

Fostering Positive Stuttering Identities Using Stutter-Affirming Therapy

PURPOSE

School-age children and adolescents frequently have difficulty developing positive identities around their stuttering. Many students experience both physical and social consequences from stuttering. The great lengths that speakers go to try to hide their stuttering and to speak fluently increase their difficulty. As long as school-age children who stutter try to identify as fluent speakers, they will have difficulty lessening the negative impact of stuttering on their lives. Fortunately, many people who stutter also report positive stuttering experiences. Speech-language pathologists can use these positive experiences to help school-age children grow more comfortable with stuttering. They can also help school-age children reduce some of the speaking effort and social stigma that leads them to try to conceal their stuttering in the first place. To accomplish both these goals, I propose a stutter-affirming therapy.

METHOD

This clinical focus article summarizes previous research about identity development in stuttering. I discuss a therapy approach I call stutter-affirming therapy. In elucidating this approach, I discuss practical ways that speech-language pathologists can use to help school-age children develop positive stuttering identities through easier speaking and stuttering. I ground these examples in a case study of a 12-year-old boy who stutters.

DISCUSSION

stutter-affirming therapy focuses on conditioning the speaker's reaction to stuttering in ways that move toward and embrace stuttering (stutterphilic reactions) rather than in ways that move away from and reject stuttering (stutterphobic reactions). Speech-language pathologists can help school-age children who stutter foster positive stuttering identities using the three priorities of stutter-affirming therapy. First, reject fluency by reducing stutterphobic and increasing stutterphilic reactions to stuttering. Second, value stuttering by discovering what speakers gain from it. Third, create an environment in which it is easier to stutter through education, advocacy, disclosure, and voluntary stuttering.

Validity and reliability of safety behaviors questionnaire for Persian adults who stutter: A cultural perspective

INTRODUCTION

Adults who stutter (AWS) are reported to have higher social anxiety compared to those who do not stutter. Previous studies have suggested that safety behaviors, which are cognitive or behavioral strategies used by people with anxiety to prevent negative consequences, are important factors in maintaining anxiety. However, the frequency and types of such behaviors might vary in different cultures. Therefore, the aim of the present study was to develop a transcultural adaptation of Safety Behaviors Questionnaire (Helgadottir et al., 2014) for Persian-speaking AWS and assess its validity and reliability.

METHODS

In the first step, the original English questionnaire was translated into Persian using the International Quality of Life Assessment (IQOLA) method. Then, 17 speech and language pathologists (SLPs) and 5 AWS evaluated all questionnaire items using Likert scales to determine face validity. Finally, 167 Persian-speaking AWS completed the questionnaire to assess its construct validity and reliability. Their responses were analyzed using factor analysis and Cronbach's Alpha.

RESULTS

Some items of the original questionnaire were modified or combined with other similar items after assessing the face validity of the Persian-translated questionnaire. Construct validity analysis categorized the remaining 29 questionnaire items into four factors: general avoidance, practice and control, rehearsal, and choosing safe and easy people. The high Cronbach's Alpha of 0.89 for all items confirmed the internal reliability of the Persian-translated questionnaire.

DISCUSSION/CONCLUSIONS

The results confirmed the psychometric characteristics of the Persian- translated version of the Safety Behaviors Questionnaire (Helgadottir et al., 2014); therefore, speech pathologists can apply it in future clinical and research settings. Similar to Australian AWS, Persian participants of this study self-reported use of various types of safety behaviors frequently.

Activation in Right Dorsolateral Prefrontal Cortex Underlies Stuttering Anticipation

People who stutter learn to anticipate many of their overt stuttering events. Despite the critical role of anticipation, particularly how responses to anticipation shape stuttering behaviors, the neural bases associated with anticipation are unknown. We used a novel approach to identify anticipated and unanticipated words, which were produced by 22 adult stutterers in a delayed-response task while hemodynamic activity was measured using functional near infrared spectroscopy (fNIRS). Twenty-two control participants were included such that each individualized set of anticipated and unanticipated words was produced by one stutterer and one control participant. We conducted an analysis on the right dorsolateral prefrontal cortex (R-DLPFC) based on converging lines of evidence from the stuttering and cognitive control literatures. We also assessed connectivity between the R-DLPFC and right supramarginal gyrus (R-SMG), two key nodes of the frontoparietal network (FPN), to assess the role of cognitive control, and particularly error-likelihood monitoring, in stuttering anticipation. All analyses focused on the five-second anticipation phase preceding the go signal to produce speech. The results indicate that anticipated words are associated with elevated activation in the R-DLPFC, and that compared to non-stutterers, stutterers exhibit greater activity in the R-DLPFC, irrespective of anticipation. Further, anticipated words are associated with reduced connectivity between the R-DLPFC and R-SMG. These findings highlight the potential roles of the R-DLPFC and the greater FPN as a neural substrate of stuttering anticipation. The results also support previous accounts of error-likelihood monitoring and action-stopping in stuttering anticipation. Overall, this work offers numerous directions for future research with clinical implications for targeted neuromodulation.

A Point of View About Fluency

PURPOSE

This article presents several potential concerns with the common usage of the term fluency in the study of stuttering and people who stutter (or, as many speakers now prefer, stutterers). Our goal is to bridge gaps between clinicians, researchers, and stutterers to foster a greater sense of collaboration and understanding regarding the words that are used and meanings that are intended.

METHOD

We begin by reviewing the history of the term fluency. We then explore its usage and current connotations to examine whether the term meaningfully describes constructs that are relevant to the study of the stuttering condition.

RESULTS

By highlighting current research and perspectives of stutterers, we conclude that the term fluency (a) is not fully inclusive, (b) encourages the use of misleading measurement procedures, (c) constrains the subjective experience of stuttering within a false binary categorization, and (d) perpetuates a cycle of stigma that is detrimental to stutterers and to the stuttering community as a whole.

CONCLUSIONS

We recommend that researchers and clinicians cease referring to stuttering as a fluency disorder and simply refer to it as stuttering. Furthermore, we recommend that researchers and clinicians distinguish between moments of stuttering (i.e., what stutterers experience when they lose control of their speech or feel stuck) and the overall lived experience of the stuttering condition.

Temperament is Linked to Avoidant Responses to Stuttering Anticipation

PURPOSE

The purpose of the present study was to examine the degree to which certain temperament constructs predict individual differences in three types of behavioral responses to anticipation among children and adults who stutter (CWS and AWS, respectively): avoidance, physical change, and approach.

METHODS

Participants included 64 CWS (9- to 17-years-old) and 54 AWS (18- to 50-years-old) who completed an online survey package including a temperament questionnaire (Early Adolescent Temperament Questionnaire-Revised for the CWS; Adult Temperament Questionnaire for the AWS) and the Stuttering Anticipation Scale. The data were analyzed separately for CWS and AWS using multivariate multiple regressions to assess how each temperament construct predicted avoidance, physical change, and approach responses to anticipation.

RESULTS

CWS who reported higher levels of shyness were more likely to engage in avoidant behavioral responses when they anticipate an upcoming moment of stuttering. AWS who reported higher levels of orienting sensitivity were more likely to engage in avoidant behavioral responses when they anticipate an upcoming moment of stuttering. No temperament constructs predicted physical change or approach responses to anticipation among either age group.

CONCLUSION

Specific aspects of temperament appear to be linked to the degree that CWS and AWS engage in avoidant behavioral responses to stuttering anticipation. These findings support the continued study of how individual differences impact the internal experience and outward manifestation of stuttering behaviors.