Quantitative Electroencephalogram of Posterior Cortical Areas of Fluent and Stuttering Participants during Reading with Normal and Altered Auditory Feedback

1998 ◽  
Vol 87 (2) ◽  
pp. 623-633 ◽  
Author(s):  
Michael P. Rastatter ◽  
Andrew Stuart ◽  
Joseph Kalinowski

In the left and right hemisphere, posterior quantitative electroencephalogram Beta band activity (13.5–25.5 Hz) of seven adult participants who stutter and seven age-matched normal controls was obtained while subjects read text under three experimental conditions of normal auditory feedback, delayed auditory feedback, and frequency-altered feedback. Data were obtained from surface electrodes affixed to the scalp using a commercial electrode cap. Electroencephalogram activity was amplified, band-pass analog-filtered, and then digitized. During nonaltered auditory feedback, stuttering participants displayed Beta band hyperreactivity, with the right temporal-parietal lobe region showing the greatest activity. Under conditions of delayed auditory feedback and frequency-altered auditory feedback, the stuttering participants displayed a decrease in stuttering behavior accompanied by a strong reduction in Beta activity for the posterior-temporal-parietal electrode sites, and the left hemisphere posterior sites evidenced a larger area of reactivity. Such findings suggest than an alteration in the electrical fields of the cortex occurred in the stuttering participants under both conditions, possibly reflecting changes in neurogenerator status or current dipole activity. Further, one could propose that stuttering reflects an anomaly of the sensory-linguistic motor integration wherein each hemisphere generates competing linguistic messages at hyperreactive amplitudes.

1979 ◽  
Vol 22 (1) ◽  
pp. 132-146 ◽  
Author(s):  
Richard Martin ◽  
Samuel K. Haroldson

Twenty adult stutterers were exposed to each of five experimental treatments: time-out, noise, delayed auditory feedback (DAF), “wrong” and metronome. In each session a subject spoke for 20 minutes without treatment (baserate) followed by 30 minutes in one of the five experimental conditions. Before the five treatment sessions, subjects accomplished three pre-experimental tasks: expectancy, changeability, and adaptation tasks. Percent stuttering decreased significantly in all conditions, and stuttering duration reduced significantly in all but the noise condition. The amount of reduction in percent stuttering from baserate to treatment (change score) in time-out was positively related to the change scores in DAF and metronome. Change scores in metronome were positively related to change scores in time-out and “wrong.” Percent stuttering change scores in noise, DAF, and “wrong” were essentially unrelated. Stuttering duration change scores were related only for the time-out and DAF, and metronome and DAF conditions. In general, the pre-experimental expectancy, changeability, and adaptation scores were unrelated to change scores in any of the experimental conditions. Words spoken per minute did not change significantly from baserate to treatment for any experimental condition except time-out.


1982 ◽  
Vol 25 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Richard J. Klich ◽  
Gaylene M. May

Measurements were made of the formant frequencies and formant transitions associated with the vowels/i/,/æ/ and /u/ produced by seven moderate-to-severe stutterers when they read fluently in a control (normal) condition and under four experimental conditions: masking noise, delayed auditory feedback, rhythmic pacing, and whispering. The first and second formantfrequencies in an isolated/hVd/context were more centralized than those reported for nonstutterers. The formant frequencies were centralized even more in reading, but varied little across conditions despite changes in fluency, speaking rates, and vowel duration. Duration and rate of formant transitions also were essentially the same across conditions. These findings and those reported in other studies indicate that stutterers' vowel production is more restricted, spatially and temporally, than nonstutterers'.


1984 ◽  
Vol 59 (1) ◽  
pp. 61-62 ◽  
Author(s):  
Richard Ham ◽  
Donald Fucci ◽  
James Cantrell ◽  
Daniel Harris

The present study was designed to investigate possible residual effects of delayed auditory feedback on paragraph readings performed by normal speaking college students. No residual effect was shown under any of the experimental conditions employed.


1964 ◽  
Vol 7 (4) ◽  
pp. 369-371
Author(s):  
Samuel Fillenbaum

Binaurally asynchronous delayed auditory feedback (DAF) was compared with synchronous DAF in 80 normal subjects. Asynchronous DAF (0.10 sec difference) did not yield results different from those obtained under synchronous DAF with a 0.20 sec delay interval, an interval characteristically resulting in maximum disruptions in speech.


Author(s):  
Elizabeth Schechter

This chapter defends the 2-agents claim, according to which the two hemispheres of a split-brain subject are associated with distinct intentional agents. The empirical basis of this claim is that, while both hemispheres are the source or site of intentions, the capacity to integrate them in practical reasoning no longer operates interhemispherically after split-brain surgery. As a result, the right hemisphere-associated agent, R, and the left hemisphere-associated agent, L, enjoy intentional autonomy from each other. Although the positive case for the 2-agents claim is grounded mainly in experimental findings, the claim is not contradicted by what we know of split-brain subjects’ ordinary behavior, that is, the way they act outside of experimental conditions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul VanGilder ◽  
Ying Shi ◽  
Gregory Apker ◽  
Christopher A. Buneo

AbstractAlthough multisensory integration is crucial for sensorimotor function, it is unclear how visual and proprioceptive sensory cues are combined in the brain during motor behaviors. Here we characterized the effects of multisensory interactions on local field potential (LFP) activity obtained from the superior parietal lobule (SPL) as non-human primates performed a reaching task with either unimodal (proprioceptive) or bimodal (visual-proprioceptive) sensory feedback. Based on previous analyses of spiking activity, we hypothesized that evoked LFP responses would be tuned to arm location but would be suppressed on bimodal trials, relative to unimodal trials. We also expected to see a substantial number of recording sites with enhanced beta band spectral power for only one set of feedback conditions (e.g. unimodal or bimodal), as was previously observed for spiking activity. We found that evoked activity and beta band power were tuned to arm location at many individual sites, though this tuning often differed between unimodal and bimodal trials. Across the population, both evoked and beta activity were consistent with feedback-dependent tuning to arm location, while beta band activity also showed evidence of response suppression on bimodal trials. The results suggest that multisensory interactions can alter the tuning and gain of arm position-related LFP activity in the SPL.


2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Kyoung Lee ◽  
Sang Yoo ◽  
Eun Ji ◽  
Woo Hwang ◽  
Yeun Yoo ◽  
...  

Lateropulsion (pusher syndrome) is an important barrier to standing and gait after stroke. Although several studies have attempted to elucidate the relationship between brain lesions and lateropulsion, the effects of specific brain lesions on the development of lateropulsion remain unclear. Thus, the present study investigated the effects of stroke lesion location and size on lateropulsion in right hemisphere stroke patients. The present retrospective cross-sectional observational study assessed 50 right hemisphere stroke patients. Lateropulsion was diagnosed and evaluated using the Scale for Contraversive Pushing (SCP). Voxel-based lesion symptom mapping (VLSM) analysis with 3T-MRI was used to identify the culprit lesion for SCP. We also performed VLSM controlling for lesion volume as a nuisance covariate, in a multivariate model that also controlled for other factors contributing to pusher behavior. VLSM, combined with statistical non-parametric mapping (SnPM), identified the specific region with SCP. Lesion size was associated with lateropulsion. The precentral gyrus, postcentral gyrus, inferior frontal gyrus, insula and subgyral parietal lobe of the right hemisphere seemed to be associated with the lateropulsion; however, after adjusting for lesion volume as a nuisance covariate, no lesion areas were associated with the SCP scores. The size of the right hemisphere lesion was the only factor most strongly associated with lateropulsion in patients with stroke. These results may be useful for planning rehabilitation strategies of restoring vertical posture and understanding the pathophysiology of lateropulsion in stroke patients.


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