Tips to improve stuttering from the research: "No evidence of altered language laterality in people who stutter across different brain imaging studies of speech and language" (2024, March)

Tips to improve stuttering from the research: "No evidence of altered language laterality in people who stutter across different brain imaging studies of speech and language" (2024, March) The PWS (person who stutters) in me read [this](https://www.biorxiv.org/content/10.1101/2024.03.23.586392v1) research study ([PDF](https://www.biorxiv.org/content/10.1101/2024.03.23.586392v1.full.pdf)): "*No Evidence of Altered Language Laterality in People Who Stutter across Different Brain Imaging Studies of Speech and Language" (2024, March)*. After finishing the 27 pages, I summed up the important points. **Intro:** * Cerebral dominance theory: this refers to competition between two hemispheres for "dominance" over speech, causing altered language lateralisation * Renewed interest in these ideas came from brain imaging findings in people who stutter (PWS) of increased activity in the right hemisphere during speech production or of shifts in activity from right to left when fluency increased * Previous fMRI findings consistently reported an overactive right hemisphere in stuttering during speech tasks but did not statistically compare the functional activity between hemispheres. Therefore, they do not provide direct evidence for altered hemispheric specialisation in people who stutter during language production **Research findings:** * Laterality indices in PWS and typically fluent speakers (TFS) did not differ and Bayesian analyses provided moderate to anecdotal levels of support for the null hypothesis (i.e., no differences in laterality in PWS compared with TFS) * We also reported that covert tasks were substantially more lateralised than overt tasks for both groups * In our findings, covert language tasks were significantly more lateralised compared with overt tasks * Reasons for this might be: * The cortical motor areas that send hundreds of commands to dozens of muscles bilaterally during overt speech production are not involved in covert speech. When the motor cortex is heavily involved in overt articulation, perhaps this bilateral pattern of task-related activity reduces laterality measured by methods that include these areas * Both tasks (covert sentence reading and auditory naming) involved continuous data acquisition during imaging. In contrast, the overt speech production tasks were carried out using sparse sampling to allow participants to hear themselves * With our current datasets, we cannot disentangle possible causes of our finding that covert tasks were more strongly lateralized than overt ones since this factor is confounded with the measurement difference **Discussion**: * We looked at data obtained across different language and speech tasks: overt sentence reading, overt picture description, covert sentence reading, and covert auditory naming. Overt speech refers to audible production of words/sentences, while covert speech refers to imagined speech (silent production of words/sentences with no articulation) * Certain therapeutic interventions for stuttering have demonstrated the potential to enhance neural activity within the left hemisphere of the brain or shift the balance of activity from the right hemisphere to the left during speech production. However, neither of these studies statistically compared the activity between two hemispheres in PWS and controls, which may explain why our results differ from these previous studies that we did not find a difference in laterality **Tips**: (that I extracted) * Improve the shift from rightwards to leftwards dominance - for increased fluency * Stop reinforcing overreliance on the right-hemisphere to use language. So, stop associating language with relying on rightwards dominance. Because: "*Most people rely more on their left hemisphere than their right to use language*" * Don't give up on your fluency goals by blaming: * **rightwards dominance**. Because: "*Laterality indices in PWS and typically fluent speakers (TFS) did not differ. The proportions of the PWS and TFS who were left lateralised or had atypical rightwards or bilateral lateralisation did not differ. We found no support for the theory that language laterality is reduced or differs in PWS compared with TFS. Our findings indicated no difference in the hemispheric specialisation in frontal and temporal regions of PWS compared with typically fluent speakers while performing four different speech and language tasks. In our main findings, we found that PWS and TFS show equivalent levels of language lateralization across a range of tasks. The authors reported that the language was mostly left lateralised in both groups over frontal, temporal and parietal regions without significant differences between groups*" * Stop associating motor execution (the cortical motor areas that send hundreds of commands to dozens of muscles bilaterally) with overt speech production. Because we have also not associated motor execution with covert speech production * Stop associating motor execution with: (1) hearing ourselves, or (2) the perception that others hear (or judge) us. Because: "*Both tasks (covert sentence reading and auditory naming) involved continuous data acquisition during* ***imaging***\*. In contrast, the overt speech production tasks were carried out using sparse sampling to allow participants to\* ***hear themselves***" * Implement certain therapeutic interventions or self-change interventions for stuttering to enhance neural activity within the left hemisphere of the brain or shift the balance of activity from the right hemisphere to the left during speech production * Stop with rightwards lateralization during overt speech. For example, by not relying on the following **four reasons** anymore: inhibition, compensation (reorganisation of function to the right hemisphere), error responses, or statistical thresholding (giving the impression that there is no activity in one hemisphere because it is only visible sub-threshold) * Do self-analyses and ask yourself: Why do I apply these **four reasons** to verbal speaking (overt), and not to imagined speaking (covert)?