Wideband Tympanometry Findings in School-aged Children: Effects of Age, Gender, Ear Laterality, and Ethnicity.

Objectives: Wideband tympanometry (WBT) measures middle-ear function across a range of frequencies (250 to 8000 Hz) while the ear-canal pressure is varied from +200 to -300 daPa. WBT is a suitable test to evaluate middle-ear function in children, but there is a lack of age-, ear-, gender-, or ethnicity-specific data throughout the literature. The purpose of this study was to investigate the effects of age, ear laterality, gender, and ethnicity on the WBT data retrieved from children aged 4 to 13 years determined to have normal middle-ear function.

Speech treatment improves dysarthria in multisystemic ataxia: a rater-blinded, controlled pilot-study in ARSACS.

We aimed to provide proof-of-principle evidence that intensive home-based speech treatment can improve dysarthria in complex multisystemic degenerative ataxias, exemplified by autosomal recessive spastic ataxia Charlevoix-Saguenay (ARSACS). Feasibility and piloting efficacy of speech training specifically tailored to cerebellar dysarthria was examined through a 4-week program in seven patients with rater-blinded assessment of intelligibility (primary outcome) and naturalness and acoustic measures of speech (secondary outcomes) performed 4 weeks before, immediately prior to, and directly after training (intraindividual control design). Speech intelligibility and naturalness improved post treatment.

Experimental Pain Decreases Corticomuscular Coherence in a Force- But Not a Position-Control Task.

Differences in neural drive could explain variation in adaptation to acute pain between postural and voluntary motor actions. We investigated whether cortical contributions, quantified by corticomuscular coherence, are affected differently by acute experimental pain in more posturally focused position-control tasks and voluntary focused force-control tasks. Seventeen participants performed position- and force-control contractions with matched loads (10% maximum voluntary contraction) before and during pain (injection of hypertonic saline into the infrapatellar fat pad of the knee).

Cortical activity differs between position- and force-control knee extension tasks.

Neural control differs between position- and force-control tasks as evident from divergent effects of fatigue and pain. Unlike force-control tasks, position-control tasks focus on a postural goal to maintain a joint angle. Cortical involvement is suggested to be less during postural control, but whether this differs between position- and force-control paradigms remains unclear.

Specifying peripheral aberrations in visual science.

Purpose: Investigations of foveal aberrations assume circular pupils. However, the pupil becomes increasingly elliptical with increase in visual field eccentricity. We address this and other issues concerning peripheral aberration specification.

Ocular aberrations in the peripheral visual field.

We modified a commercial Hartmann-Shack aberrometer and used it to measure ocular aberrations twice at each of 38 points across the central 42 degrees horizontal x 32 degrees vertical visual fields of five young emmetropic subjects. Some Zernike aberration coefficients show coefficient field distributions that were similar to the field dependence predicted by Seidel theory (astigmatism, oblique astigmatism, horizontal coma, vertical coma), but defocus did not demonstrate such similarity.

Measuring ocular aberrations in the peripheral visual field using Hartmann-Shack aberrometry.

We have used the Hartmann-Shack technique previously to measure ocular aberrations along the horizontal meridian of the visual field. This requires considerable modifications from the technique for measuring the aberrations corresponding to the fovea. We now further develop the technique so that it can be used for any meridian of the visual field.

Electropalatographic assessment of tongue-to-palate contact patterns and variability in children, adolescents, and adults.

Purpose: To investigate the developmental time course of tongue-to-palate contact patterns during speech from childhood to adulthood using electropalatography (EPG) and a comprehensive profile of data analysis.

Method: Tongue-to-palate contacts were recorded during productions of /t/, /l/, /s/, and /k/ in 48 children, adolescents and adults (aged 6-38 years) using the Reading Electropalatograph system.

Results: A protracted course of development for lingual control was indicated, with significant changes occurring until age 11 years; the adolescent period was in turn characterized by continual refinement of articulatory control.

Physiologic development of tongue-jaw coordination from childhood to adulthood.

Purpose: This investigation aimed to examine the development of tongue-jaw coordination during speech from childhood to adolescence.

Method: Electromagnetic articulography was used to track tongue and jaw motion in 48 children and adults (aged 6-38 years) during productions of /t/ and /k/ embedded in sentences.

Results: The coordinative organization of the tongue and jaw exhibited changes until the age of 8-11 years and continued to undergo refinement into late adolescence.

EMA assessment of tongue-jaw co-ordination during speech in dysarthria following traumatic brain injury.

Primary Objective: To investigate the spatio-timing aspects of tongue-jaw co-ordination during speech in individuals with traumatic brain injury (TBI). It was hypothesized that both timing and spatial co-ordination would be affected by TBI.

Research Design: A group comparison design wherein Mann-Whitney U-tests were used to compare non-neurologically impaired individuals with individuals with TBI.

Shape of the retinal surface in emmetropia and myopia.

Purpose: To determine and compare the shapes of the retinas of emmetropic and myopic eyes.

Methods: Nonrotationally symmetrical ellipsoids were mathematically fitted to the retinal surfaces of 21 emmetropic and 66 myopic eyes (up to -12 D) of participants aged 18 to 36 years (mean, 25.5) using transverse axial and sagittal images derived from magnetic resonance imaging.

Introducing the pressure-sensing palatograph--the next frontier in electropalatography.

Primary Objective: To extend the capabilities of current electropalatography (EPG) systems by developing a pressure-sensing EPG system. An initial trial of a prototype pressure-sensing palate will be presented.

Research Design: The processes involved in designing the pressure sensors are outlined, with Hall effect transistors being selected.

Hartmann-Shack technique and refraction across the horizontal visual field.

We compared refractions across the horizontal visual field, based on different analyses of wave aberration obtained with a Hartmann-Shack instrument. The wave aberrations had been determined for 6-mm-diameter pupils up to at least the sixth Zernike order in five normal subjects [J. Opt.

The influence of the Stiles-Crawford peak location on visual performance.

We investigated the influence of the Stiles-Crawford peak location on visual acuity, contrast sensitivity and phase transfer with 6 mm diameter pupils in two subjects. Apodising filters were used to move the peak. One subject (SM) had her natural peak 0.

Scatter and its implications for the measurement of optical image quality in human eyes.

Purpose: To investigate the effect of scatter on measurements of wavefront aberrations and point-spread functions in a model eye.

Methods: The wavefront aberrations of a model eye were measured using Hartmann-Shack wavefront sensing and crossed-cylinder aberroscope techniques and compared with its measured point-spread function in the presence of scattering media of different concentrations.

Results: The point-spread functions became broader as the concentration increased.

Theoretical analysis of peripheral imaging after excimer laser corneal refractive surgery for myopia.

Purpose: To explore theoretically the retinal point images in the peripheral fields of eyes that have had excimer laser refractive surgery. University research laboratory.

Methods: Model eyes were based on Navarro's finite schematic eye, the eyes being made myopic by an increase in axial length.

Monochromatic aberrations of human eyes in the horizontal visual field.

We measured the monochromatic aberrations of five subjects' right eyes both temporally and nasally out to 40 degrees from fixation. We used a Hartmann-Shack sensor with modifications to equipment and software to enable off-axis measurements. Results were standardized for 6-mm pupils.

Contrast sensitivity and the Stiles--Crawford effect.

We investigated the influence of the Stiles-Crawford effect (SCE) of the first kind on the contrast sensitivity function using the apodisation model of the SCE. The SCE was measured for the right eyes of two subjects using an increment threshold technique involving a two-channel Maxwellian-viewing system. Filters made of photographic film neutralised or doubled the SCE.

Influence of Stiles-Crawford apodization on visual acuity.

The Stiles-Crawford effect (SCE) of the first kind has often been considered to be important to spatial visual performance in that it ameliorates the influence of defocus and aberrations. We investigated the influence of SCE apodization on visual acuity as a function of defocus (out to +/-2 D) in four subjects. We used optical filters, conjugate with the eye's entrance pupil, that neutralized or doubled the existing SCE.

The Stiles-Crawford effect and subjective measurement of aberrations.

We considered the influence that the Stiles-Crawford effect (SCE) has on the measurement of subjective monochromatic and transverse aberration measurements. The SCE was measured with a two channel Maxwellian-viewing system. Transverse aberrations were measured using a vernier alignment technique in three subjects, with the natural SCE operating, with the SCE neutralised by filters optically conjugate with the eye's pupil, and for one subject with filters that shifted the SCE by more than 2 mm.