Ocular Vestibular Evoked Myogenic Potentials: Normative Findings in Children

To add to the limited body of literature on ocular vestibular evoked myogenic potential (oVEMP) responses in children and to assess a different montage for oVEMP recording.To evaluate the characteristics of the oVEMP response in children and compare the results with that of a group of healthy adults.Prospective descriptive study from a tertiary referral center.Twenty-two children (mean age = 6.3 yr, standard deviation = ±1.5, range = 3.5–8.9 yr) were recruited from families whose parent(s) were employed by the Cincinnati Children’s Hospital Medical Center (CCHMC). Pediatric participants were categorized by age into three groups for data analysis. The comparison adult group of ten participants were members of the employee staff at CCHMC.Audiometric assessment was completed in all participants. The latency, amplitude, and threshold of the oVEMP responses were recorded using a modified electrode montage with reference at the chin and compared between the pediatric and adult participants.All participants completed testing and had bilateral measurable oVEMP responses using a 105-dB nHL, 500-Hz tone burst stimulus. Comparison between right and left ears across all participants for each oVEMP characteristic found no statistically significant difference. oVEMP testing showed no significant differences with respect to latency, amplitude, interaural amplitude asymmetry, and threshold of response as a function of age.oVEMP responses for ages ≥3 did not differ from responses in adults.

The role of stimulus comparison in animal perceptual learning: Effects of a distractor placement

Research on perceptual learning shows that the way stimuli are presented leads to different outcomes. The intermixed/blocked (I/B) effect is one of these outcomes, and different mechanisms have been proposed to explain it. In human research, it seems that comparison between stimuli is important, and the placement of a distractor between the pre-exposed stimuli interferes with the effect. Results from animal research are usually interpreted in different terms because the type of procedure normally used in animal perceptual learning does not favour comparison. In our experiments, we explore the possibility that a distractor placed between the to-be-discriminated stimuli may interfere with the perceptual learning process in rats. In Experiment 1, two flavoured solutions are presented in an I/B fashion, with a short time lapse between them to favour comparison, showing the typical I/B effect. In Experiment 2, we introduced a distractor in between the solutions, abolishing this effect. Experiment 3 further replicates this by comparing two intermixed groups with or without distractor. The results replicate the findings from human research, suggesting that comparison also plays an important role in animal perceptual learning.