scholarly journals Effect of Stimulus Polarity on Physiological Spread of Excitation in Cochlear Implants

2017 ◽  
Vol 28 (09) ◽  
pp. 786-798 ◽  
Author(s):  
Emily R. Spitzer ◽  
Michelle L. Hughes
Keyword(s):  
Cochlear Implants ◽  
Repeated Measures ◽  
Spatial Separation ◽  
Compound Action Potential ◽  
Mean Amplitude ◽  
Repeated Measures Design ◽  
Electrode Location ◽  
Current Pulses ◽  
Spread Of Excitation ◽  
Within Subjects

AbstractContemporary cochlear implants (CIs) use cathodic-leading, symmetrical, biphasic current pulses, despite a growing body of evidence that suggests anodic-leading pulses may be more effective at stimulating the auditory system. However, since much of this research on humans has used pseudomonophasic pulses or biphasic pulses with unusually long interphase gaps, the effects of stimulus polarity are unclear for clinically relevant (i.e., symmetric biphasic) stimuli.The purpose of this study was to examine the effects of stimulus polarity on basic characteristics of physiological spread-of-excitation (SOE) measures obtained with the electrically evoked compound action potential (ECAP) in CI recipients using clinically relevant stimuli.Using a within-subjects (repeated measures) design, we examined the differences in mean amplitude, peak electrode location, area under the curve, and spatial separation between SOE curves obtained with anodic- and cathodic-leading symmetrical, biphasic pulses.Fifteen CI recipients (ages 13–77) participated in this study. All were users of Cochlear Ltd. devices.SOE functions were obtained using the standard forward-masking artifact reduction method. Probe electrodes were 5–18, and they were stimulated at an 8 (of 10) loudness rating (“loud”). Outcome measures (mean amplitude, peak electrode location, curve area, and spatial separation) for each polarity were compared within subjects.Anodic-leading current pulses produced ECAPs with larger average amplitudes, greater curve area, and less spatial separation between SOE patterns compared with that for cathodic-leading pulses. There was no effect of polarity on peak electrode location.These results indicate that for equal current levels, the anodic-leading polarity produces broader excitation patterns compared with cathodic-leading pulses, which reduces the spatial separation between functions. This result is likely due to preferential stimulation of the central axon. Further research is needed to determine whether SOE patterns obtained with anodic-leading pulses better predict pitch discrimination.

Temporal Changes in Depression Symptoms in Male and Female Collegiate Student-Athletes

2017 ◽  
Vol 11 (4) ◽  
pp. 337-351 ◽  
Author(s):  
Lindsey C. McGuire ◽  
Yvette M. Ingram ◽  
Michael L. Sachs ◽  
Ryan T. Tierney
Keyword(s):  
Repeated Measures ◽  
Student Athletes ◽  
Severe Depression ◽  
Depression Symptoms ◽  
Depression Symptom ◽  
Significant Interaction Effect ◽  
Repeated Measures Design ◽  
Temporal Course ◽  
Clinical Benefits ◽  
Within Subjects

Depression rates in collegiate student-athletes in the literature are varied and inconclusive, and data have only explored depression symptoms utilizing a crosssectional design. The purpose of the current study was to evaluate the temporal course of depression symptoms in student-athletes. Student-athletes (N = 93) from a Division II institution completed six administrations of a brief depression symptom screen once every 2 weeks throughout the fall athletic season. Ten (10.8%) student-athletes’ PHQ-9 surveys were red-flagged for moderate to severe depression symptoms at least once throughout the season. A mixed between-within subjects analysis of variance (ANOVA) revealed a significant interaction effect for time and sex in depression symptom scores, F(3.69, 335.70) = 10.36, p ≤ .001. The repeated-measures design of this study suggests that there are clinical benefits for screening for depression symptoms in student-athletes at multiple intervals throughout an athletic season.

Effects of an Unstable Shoe Construction on Standing Balance in Children with Developmental Disabilities: A Pilot Study

2008 ◽  
Vol 32 (4) ◽  
pp. 422-433 ◽  
Author(s):  
Nerrolyn Ramstrand ◽  
Christina Björk Andersson ◽  
David Rusaw
Keyword(s):  
Pilot Study ◽  
Repeated Measures ◽  
Force Plate ◽  
Developmentally Disabled ◽  
Static Balance ◽  
Disabled Children ◽  
Repeated Measures Design ◽  
Directional Control ◽  
Within Subjects ◽  
Reactive Balance

This study aimed to investigate if prolonged use of shoes incorporating an unstable sole construction could facilitate improvements of balance in a sample of developmentally disabled children. Ten children (six male and four female) aged between 10 and 17 years participated in the study. Children were fitted with shoes incorporating an unstable sole (Masai Barefoot Technology®) and instructed to wear them for a minimum of two hours per day for eight weeks. A within subjects repeated measures design was used. Children were tested prior to receiving the shoes, four weeks after receiving the shoes and eight weeks after receiving the shoes. A force plate capable of rotating about a single axis (NeuroCom International Inc, Oregon) was used to test static balance, reactive balance and directional control. Static balance was not found to be influenced by prolonged use of the footwear; however, significant improvements were noted in children's reactive balance both with the shoes and barefoot. Results suggest that reactive balance can be improved by prolonged and regular use of shoes incorporating an unstable sole construction.

Effects of Stimulus and Recording Parameters on the Air Conduction Ocular Vestibular Evoked Myogenic Potential

2011 ◽  
Vol 22 (07) ◽  
pp. 469-480 ◽  
Author(s):  
Owen D. Murnane ◽  
Faith W. Akin ◽  
J. Kip Kelly ◽  
Stephanie Byrd
Keyword(s):  
Repeated Measures ◽  
Normative Data ◽  
Stimulus Frequency ◽  
Stimulus Level ◽  
Diagnostic Information ◽  
Vestibular Nerve ◽  
Vestibular Evoked Myogenic Potentials ◽  
Repeated Measures Design ◽  
Electrode Location ◽  
Air Conduction

Background: Vestibular evoked myogenic potentials (VEMPs) have been recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) and more recently from the eye muscles (ocular VEMP or oVEMP) in response to air conduction and bone conduction stimuli. Both cVEMPs and oVEMPs are mediated by the otoliths and thereby provide diagnostic information that is complementary to videonystagmography and rotational chair tests. In contrast to the air conduction cVEMP, which originates from the saccule/inferior vestibular nerve, recent evidence suggests the possibility that the air conduction oVEMP may be mediated by the utricle/superior vestibular nerve. The oVEMP, therefore, may provide complementary diagnostic information relative to the cVEMP. There are relatively few studies, however, that have quantified the effects of stimulus and recording parameters on the air conduction oVEMP, and there is a paucity of normative data. Purpose: To evaluate the effects of several stimulus and recording parameters on the air conduction oVEMP and to establish normative data for clinical use. Research Design: A prospective repeated measures design was utilized. Study Sample: Forty-seven young adults with no history of neurologic disease, hearing loss, middle ear pathology, open or closed head injury, cervical injury, or audiovestibular disorder participated in the study. Data Collection and Analysis: The effects of stimulus frequency, stimulus level, gaze elevation, and recording electrode location on the amplitude and latency of the oVEMP for monaural air conduction stimuli were assessed using repeated measures analyses of variance in an initial group of 17 participants. The optimal stimulus and recording parameters obtained in the initial group were used subsequently to obtain oVEMPs from 30 additional participants. Results: The effects of stimulus frequency, stimulus level, gaze elevation, and electrode location on the response prevalence, amplitude, and latency of the oVEMP for monaural air conduction stimuli were significant. The maximum N1-P1 amplitude and response prevalence were obtained for contralateral oVEMPs using a 500 Hz tone burst presented at 125 dB peak SPL during upward gaze at an elevation of 30°. Conclusions: The optimal stimulus and recording parameters quantified in this study were used to establish normative data that may be useful for the clinical application of the air conduction oVEMP.

Evaluation of Speech Recognition in Noise with Cochlear Implants and Dynamic FM

2009 ◽  
Vol 20 (07) ◽  
pp. 409-421 ◽  
Author(s):  
Jace Wolfe ◽  
Erin C. Schafer ◽  
Benjamin Heldner ◽  
Hans Mülder ◽  
Emily Ward ◽  
...  
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Noise Level ◽  
Repeated Measures ◽  
Group Performance ◽  
Signal To Noise Ratio ◽  
Speech Processor ◽  
Repeated Measures Design ◽  
Hearing In Noise ◽  
Speech Recognition In Noise

Background: Use of personal frequency-modulated (FM) systems significantly improves speech recognition in noise for users of cochlear implants (CIs). Previous studies have shown that the most appropriate gain setting on the FM receiver may vary based on the listening situation and the manufacturer of the CI system. Unlike traditional FM systems with fixed-gain settings, Dynamic FM automatically varies the gain of the FM receiver with changes in the ambient noise level. There are no published reports describing the benefits of Dynamic FM use for CI recipients or how Dynamic FM performance varies as a function of CI manufacturer. Purpose: To evaluate speech recognition of Advanced Bionics Corporation or Cochlear Corporation CI recipients using Dynamic FM vs. a traditional FM system and to examine the effects of Autosensitivity on the FM performance of Cochlear Corporation recipients. Research Design: A two-group repeated-measures design. Participants were assigned to a group according to their type of CI. Study Sample: Twenty-five subjects, ranging in age from 8 to 82 years, met the inclusion criteria for one or more of the experiments. Thirteen subjects used Advanced Bionics Corporation, and 12 used Cochlear Corporation implants. Intervention: Speech recognition was assessed while subjects used traditional, fixed-gain FM systems and Dynamic FM systems. Data Collection and Analysis: In Experiments 1 and 2, speech recognition was evaluated with a traditional, fixed-gain FM system and a Dynamic FM system using the Hearing in Noise Test sentences in quiet and in classroom noise. A repeated-measures analysis of variance (ANOVA) was used to evaluate effects of CI manufacturer (Advanced Bionics and Cochlear Corporation), type of FM system (traditional and dynamic), noise level, and use of Autosensitivity for users of Cochlear Corporation implants. Experiment 3 determined the effects of Autosensitivity on speech recognition of Cochlear Corporation implant recipients when listening through the speech processor microphone with the FM system muted. A repeated-measures ANOVA was used to examine the effects of signal-to-noise ratio and Autosensitivity. Results: In Experiment 1, use of Dynamic FM resulted in better speech recognition in noise for Advanced Bionics recipients relative to traditional FM at noise levels of 65, 70, and 75 dB SPL. Advanced Bionics recipients obtained better speech recognition in noise with FM use when compared to Cochlear Corporation recipients. When Autosensitivity was enabled in Experiment 2, the performance of Cochlear Corporation recipients was equivalent to that of Advanced Bionics recipients, and Dynamic FM was significantly better than traditional FM. Results of Experiment 3 indicate that use of Autosensitivity improves speech recognition in noise of signals directed to the speech processor relative to no Autosensitivity. Conclusions: Dynamic FM should be considered for use with persons with CIs to improve speech recognition in noise. At default CI settings, FM performance is better for Advanced Bionics recipients when compared to Cochlear Corporation recipients, but use of Autosensitivity by Cochlear Corporation users results in equivalent group performance.

Comparison of music stimuli to support mindfulness meditation

2019 ◽  
pp. 030573561987849 ◽  
Author(s):  
Abbey L Dvorak ◽  
Eugenia Hernandez-Ruiz
Keyword(s):  
Repeated Measures ◽  
Mindfulness Meditation ◽  
Analysis Of Covariance ◽  
Auditory Stimuli ◽  
Harmonic Progression ◽  
Repeated Measures Design ◽  
Significant Difference ◽  
Within Subjects ◽  
Mindful Attention Awareness Scale ◽  
Post Hoc

The purpose of this study was to compare the effectiveness of and preference for different auditory stimuli in supporting mindfulness meditation. Undergraduate non-musicians ( N = 57) listened to four different auditory stimuli guiding them in a mindfulness meditation: script only (i.e., Script), steady beat (i.e., Beat), beat and harmonic progression (i.e., Harmony), and beat, harmony, and melody (i.e., Melody). This study used a within-subjects repeated-measures design with the four conditions counterbalanced and randomized across participants. Participants rated responses using the Mindful Attention Awareness Scale (MAAS), completed the Absorption in Music Scale (AIMS), and ranked auditory stimuli according to preference and usefulness for mindfulness meditation. A repeated-measures analysis of covariance (ANCOVA) on the MAAS scores, using the AIMS as a covariate, indicated no statistically significant difference between auditory stimuli. However, with the AIMS removed, the analysis revealed significant differences between stimuli, indicating that levels of absorption in music may moderate participants’ responses to auditory stimuli for mindfulness meditation. Friedman analyses of variance (ANOVAs) and post hoc analyses indicated that participant rankings of usefulness and preference were significantly different among conditions, with the Melody and Harmony conditions ranked highest.

List Equivalency of the AzBio Sentence Test in Noise for Listeners with Normal-Hearing Sensitivity or Cochlear Implants

2012 ◽  
Vol 23 (07) ◽  
pp. 501-509 ◽  
Author(s):  
Erin C. Schafer ◽  
Jody Pogue ◽  
Tyler Milrany
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Repeated Measures ◽  
Normative Data ◽  
Normal Hearing ◽  
Published Data ◽  
Repeated Measures Design ◽  
Published Evidence ◽  
Starting Point ◽  
Speech Recognition In Noise

Background: Speech recognition abilities of adults and children using cochlear implants (CIs) are significantly degraded in the presence of background noise, making this an important area of study and assessment by CI manufacturers, researchers, and audiologists. However, at this time there are a limited number of fixed-intensity sentence recognition tests available that also have multiple, equally intelligible lists in noise. One measure of speech recognition, the AzBio Sentence Test, provides 10-talker babble on the commercially available compact disc; however, there is no published evidence to support equivalency of the 15-sentence lists in noise for listeners with normal hearing (NH) or CIs. Furthermore, there is limited or no published data on the reliability, validity, and normative data for this test in noise for listeners with CIs or NH. Purpose: The primary goals of this study were to examine the equivalency of the AzBio Sentence Test lists at two signal-to-noise ratios (SNRs) in participants with NH and at one SNR for participants with CIs. Analyses were also conducted to establish the reliability, validity, and preliminary normative data for the AzBio Sentence Test for listeners with NH and CIs. Research Design: A cross-sectional, repeated measures design was used to assess speech recognition in noise for participants with NH or CIs. Study Sample: The sample included 14 adults with NH and 12 adults or adolescents with Cochlear Freedom CI sound processors. Participants were recruited from the University of North Texas clinic population or from local CI centers. Data Collection and Analysis: Speech recognition was assessed using the 15 lists of the AzBio Sentence Test and the 10-talker babble. With the intensity of the sentences fixed at 73 dB SPL, listeners with NH were tested at 0 and −3 dB SNRs, and participants with CIs were tested at a +10 dB SNR. Repeated measures analysis of variance (ANOVA) was used to analyze the data. Results: The primary analyses revealed significant differences in performance across the 15 lists on the AzBio Sentence Test for listeners with NH and CIs. However, a follow-up analysis revealed no significant differences in performance across 10 of the 15 lists. Using the 10, equally-intelligible lists, a comparison of speech recognition performance across the two groups suggested similar performance between NH participants at a −3 dB SNR and the CI users at a +10 SNR. Several additional analyses were conducted to support the reliability and validity of the 10 equally intelligible AzBio sentence lists in noise, and preliminary normative data were provided. Conclusions: Ten lists of the commercial version of the AzBio Sentence Test may be used as a reliable and valid measure of speech recognition in noise in listeners with NH or CIs. The equivalent lists may be used for a variety of purposes including audiological evaluations, determination of CI candidacy, hearing aid and CI programming considerations, research, and recommendations for hearing assistive technology. In addition, the preliminary normative data provided in this study establishes a starting point for the creation of comprehensive normative data for the AzBio Sentence Test.

scholarly journals Assessing Information Integration Processes Using Between- or Within-Subjects Designs: Some More Evidence

2019 ◽  
Vol 18 (1) ◽  
pp. 1-9
Author(s):  
Gérard Chasseigne ◽  
Maria Teresa Muñoz Sastre ◽  
Paul CLay Sorum ◽  
Etienne Mullet
Keyword(s):  
Information Integration ◽  
Repeated Measures ◽  
Limited Range ◽  
Integration Theory ◽  
Order Effects ◽  
Repeated Measures Design ◽  
Information Integration Theory ◽  
New Findings ◽  
Valuation Process ◽  
Within Subjects

Within-subject designs (WSDs) remain unappreciated in psychology although many experimental tactics can reduce or eliminate the demand and order effects that WSDs tend to create. Comparative studies conducted in the Information Integration Theory (IIT) framework have shown that patterns of results observed using WSDs can largely be replicated using between-subject designs (BSDs). In order to add evidence to these findings, three additional studies were conducted in order to complement data obtained in previous studies. One of these studies was about health risk perception and tested the possibility to find evidence for a disjunctive rule of information integration using a BSD. The other two studies focused on the valuation process of IIT. The new findings regarding the disjunctive rule added support to the view that equivalent results can be obtained either with a highly economical repeated-measures design or with a much costlier independent factorial group arrangement. However, when the focus was on the valuation process and not on the integration process, ratings obtained in the BSD condition seemed to be restricted to a limited range of values by comparison with ratings obtained in the WSD condition. An explanation in terms of context effect is offered.

Forgiveness Reduces Anger in a School Bullying Context

2015 ◽  
Vol 32 (11) ◽  
pp. 1642-1657 ◽  
Author(s):  
Hayley Watson ◽  
Ron Rapee ◽  
Natasha Todorov
Keyword(s):  
Repeated Measures ◽  
Experimental Manipulation ◽  
School Bullying ◽  
Positive Outcomes ◽  
Coping Response ◽  
Repeated Measures Design ◽  
Study Results ◽  
Within Subjects ◽  
Verbal Bullying ◽  
Victims Of Bullying

Forgiveness has been shown to be a helpful strategy for victims of many different forms of abuse and trauma. It has also been theoretically linked to positive outcomes for victims of bullying. However, it has never been experimentally manipulated in a school bullying context. This research investigates an experimental manipulation providing children with response advice following a bullying incident. Children read hypothetical physical and verbal bullying scenarios, followed by advice from a friend to either respond with forgiveness, avoidance, or revenge, in a within-subjects repeated measures design. One hundred eighty-four children aged 11 to 15 from private schools in Sydney participated in this study. Results indicated that advice to forgive the perpetrator led to significantly less anger than advice to either avoid or exact revenge. Avoidance was the most likely advice to be followed by students and the most likely to result in ignoring the bullying and developing empathy for their abuser. However, it also resulted in interpretations of the bullying as being more serious. Forgiveness is suggested as an effective coping response for ameliorating the affective aggressive states of victimized youth, with further exploration needed regarding the interplay between the avoidance and forgiveness processes.

scholarly journals Comparing the Effects of Different Body Armour Systems on the Occupational Performance of Police Officers

2018 ◽  
Author(s):  
Ben Schram ◽  
Robin Orr ◽  
Rodney Pope ◽  
Ben Hinton ◽  
Geoff Norris
Keyword(s):  
Task Performance ◽  
Police Officers ◽  
Repeated Measures ◽  
Occupational Performance ◽  
Repeated Measures Design ◽  
Body Armour ◽  
Occupational Tasks ◽  
Within Subjects ◽  
Step Down ◽  
Occupational Task

Policing duties may inherently be dangerous due to stab, blunt trauma and ballistic threats. The addition of individual light armour vests (ILAVs) has been suggested as a means to protect officers. However, the addition of the extra load of the ILAV may affect officer ability to conduct occupational tasks. The purpose of this study was to determine if wearing any of 3 different ILAVs (ILAV A, ILAV B, & ILAV C) affected occupational task performance when compared to that in normal station wear. A prospective, within-subjects repeated measures design was employed, using a counterbalanced randomization in which each ILAV was worn for an entire day while officers completed a variety of occupationally relevant tasks. These tasks included a victim drag, car exit and 5 meter sprint, step down and marksmanship task. Results showed that performance in each task did not vary between any of the ILAV or normal station wear conditions. There was less variability in the marksmanship task with ILAV B, however. The results suggest that none of the ILAVs used in this study were heavy enough to significantly affect task performance in the assessed tasks when compared to wearing normal station wear.

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