RESUMEN
Radiological incidental findings (IFs) are previously undetected abnormalities which are unrelated to the original indication for imaging and are unexpectedly discovered. In brain magnetic resonance imaging (MRI), the prevalence of IFs is increasing. By reviewing the literature on IFs in brain MRI performed for research purposes and discussing ethical considerations of IFs, this paper provides an overview of brain IF research results and factors contributing to inconsistencies and considers how the consent process can be improved from an ethical perspective. We found that despite extensive literature regarding IFs in research MRI of the brain, there are major inconsistencies in the reported prevalence, ranging from 1.3% to 99%. Many factors appear to contribute to this broad range: lack of standardised definition, participant demographics variance, heterogenous MRI scanner strength and sequences, reporter variation and results classification. We also found significant discrepancies in the review, consent and clinical communication processes pertaining to the ethical nature of these studies. These findings have implications for future studies, particularly those involving artificial intelligence. Further research, particularly in relation to MRI brain IFs would be useful to explore the generalisability of study results.
RESUMEN
English [É«] exhibits retracted tongue dorsum and low F2 frequencies compared to Korean [l], but is frequently asserted to be perceptually similar to Korean [l] and therefore difficult for Korean learners to acquire due to articulatory transfer. This study examines the articulatory and acoustic characteristics of Korean and English word-final laterals produced by Korean learners. Korean learners' productions of English [É«] were systematically different from Korean [l], with retracted tongue dorsum and low F2 similar to L1 English [É«]. The findings suggest Korean learners form a distinct phonetic category for English [É«] rather than modifying an existing Korean category.
RESUMEN
Kingston, Diehl, Kirk, and Castleman (Journal of Phonetics, 2008) present a sophisticated experimental design and detection theoretic analysis of the internal auditory structure of phonological contrasts. However, a potentially important aspect of multidimensional detection theory - the covariance structure of assumed underlying multivariate Gaussian perceptual densities - was left unexplored. We discuss Kingston, et al.'s approach in the context of a general definition of multidimensional d' and present a description of two distinct configurations of perceptual densities requiring fundamentally different interpretations that account equally well for the "mean-shift integrality" results reported by Kingston, et al. We end with a brief discussion of approaches to distinguishing these underlying configurations empirically.
RESUMEN
Stetson (1951) noted that repeating singleton coda consonants at fast speech rates makes them be perceived as onset consonants affiliated with a following vowel. The current study documents the perception of rate-induced resyllabification, as well as what temporal properties give rise to the perception of syllable affiliation. Stimuli were extracted from a previous study of repeated stop + vowel and vowel + stop syllables (de Jong, 2001a, 2001b). Forced-choice identification tasks show that slow repetitions are clearly distinguished. As speakers increase rate, they reach a point after which listeners disagree as to the affiliation of the stop. This pattern is found for voiced and voiceless consonants using different stimulus extraction techniques. Acoustic models of the identifications indicate that the sudden shift in syllabification occurs with the loss of an acoustic hiatus between successive syllables. Acoustic models of the fast rate identifications indicate various other qualities, such as consonant voicing, affect the probability that the consonants will be perceived as onsets. These results indicate a model of syllabic affiliation where specific juncture-marking aspects of the signal dominate parsing, and in their absence other differences provide additional, weaker cues to syllabic affiliation.