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Purpose: Prior studies (e.g., Nath & Beauchamp, 2012) report large individual variability in the extent to which participants are susceptible to the McGurk effect, a prominent audiovisual (AV) speech illusion. The current study evaluated whether susceptibility to the McGurk effect (MGS) is related to lipreading skill and whether multiple measures of MGS that have been used previously are correlated. In addition, it evaluated the test–retest reliability of individual differences in MGS. Method: Seventy-three college-age participants completed 2 tasks measuring MGS and 3 measures of lipreading skill. Fifty-eight participants returned for a 2nd session (approximately 2 months later) in which MGS was tested again. Results: The current study demonstrated that MGS shows high test–retest reliability and is correlated with some measures of lipreading skill. In addition, susceptibility measures derived from identification tasks were moderately related to the ability to detect instances of AV incongruity. Conclusions: Although MGS is often cited as a demonstration of AV integration, the results suggest that perceiving the illusion depends in part on individual differences in lipreading skill and detecting AV incongruity. Therefore, individual differences in susceptibility to the illusion are not solely attributable to individual differences in AV integration ability. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to determine whether distinct subgroups of preschool children with speech sound disorders (SSD) could be identified using a subgroup discovery algorithm (SUBgroup discovery via Alternate Random Processes, or SUBARP). Of specific interest was finding evidence of a subgroup of SSD exhibiting performance consistent with atypical speech motor control. Method: Ninety-seven preschool children with SSD completed speech and nonspeech tasks. Fifty-three kinematic, acoustic, and behavioral measures from these tasks were input to SUBARP. Results: Two distinct subgroups were identified from the larger sample. The 1st subgroup (76%; population prevalence estimate = 67.8%–84.8%) did not have characteristics that would suggest atypical speech motor control. The 2nd subgroup (10.3%; population prevalence estimate = 4.3%– 16.5%) exhibited significantly higher variability in measures of articulatory kinematics and poor ability to imitate iambic lexical stress, suggesting atypical speech motor control. Both subgroups were consistent with classes of SSD in the Speech Disorders Classification System (SDCS; Shriberg et al., 2010a). Conclusion: Characteristics of children in the larger subgroup were consistent with the proportionally large SDCS class termed speech delay; characteristics of children in the smaller subgroup were consistent with the SDCS subtype termed motor speech disorder—not otherwise specified. The authors identified candidate measures to identify children in each of these groups. [ABSTRACT FROM AUTHOR]