Spectral discontinuities and the vowel length effect

Perception of voicing for stop consonants in consonant-vowel syllables can be affected by the duration of the following vowel so that longer vowels lead to more “voiced” responses. On the basis of several experiments, Green, Stevens, and Kuhl (1994) concluded that continuity of fundamental frequency (f0), but not continuity of formant structure, determined the effective length of the following vowel. In an extension of those efforts, we found here that both effects were critically dependent on particular f 0s and formant values. First, discontinuity inf0 does not necessarily preclude the vowel length effect because the effect maintains whenf0 changes from 200 to 100 Hz, and 200-Hz partials extend continuously through test syllables. Second, spectral discontinuity does preclude the vowel length effect when formant changes result in a spectral peak shifting to another harmonic. The results indicate that the effectiveness of stimulus changes for sustaining or diminishing the vowel length effect depends critically on particulars of spectral composition.     

Suicidal behavior among youth with severe emotional disturbance

The purpose of this study was to replicate an investigation of risk behaviors associated with suicidal behavior in public high school students, in a population of high school age youth with severe emotional disturbance (SED). Subjects for the study were clients of the South Carolina Continuum of Care (COC) (N=83). Information on suicidal thoughts and acts, aggressive behaviors, substance use and physical recklessness was gathered using a modified version of the self-report National Youth Risk Behavior Survey. Four percent of the youth reported seriously considering suicide, 8% reported planning how they would attempt suicide, 10% reported actually attempting suicide at least once, and 6% reported attempts requiring medical treatment Of the 13 youth who reported attempting suicide, four (31%) did not report planning an attempt. All suicidal behaviors except thoughts occurred more in girls than boys with SED. Alcohol and illicit drug use were associated with suicidal behavior, with larger odds ratios for attempts than for thoughts/plans. Youth with SED who use alcohol and illicit substances are particularly at risk of suicidal behavior. A high index of suspicion is appropriate when evaluating suicidal risk in girls with SED, especially in the presence of known alcohol or substance use.Continuum of Care for Emotionally Disturbed Children Division, S. C. Office of the Governor.     

Sociodemographic Factors Associated with Types of Projects Implemented by Volunteer Lay Health Educators in Their Congregations

This study focused on the association between type of community health interventions and lay health educator variables. Lay health educators are volunteers from local faith communities who complete a healthcare training program, taught by physicians in-training. Lay health educators are instructed to implement health-related initiatives in their respective communities after graduation. Of the 72 graduates since 2011, we surveyed 55 lay health educators to gain insight into their involvement with their congregation and the type of health projects they have implemented. We dichotomized the health projects into “raising awareness” and “teaching new health skills.” Using adjusted logistic regression models, variables associated with implementing health projects aimed at teaching health skills included length of time as a member of their congregation, current employment, and age. These results may help future programs prepare lay health community educators for the type of health interventions they intend to implement in their respective communities.     

Nonword repetition stimuli for Vietnamese-speaking children

Nonword repetition (NWR) has been a widely used measure of language-learning ability in children with and without language disorders. Although NWR tasks have been created for a variety of languages, minimal attention has been given to Asian tonal languages. This study introduces a new set of NWR stimuli for Vietnamese. The stimuli include 20 items ranging in length from one to four syllables. The items consist of dialect-neutral phonemes in consonant–vowel (CV) and CVC sequences that follow the phonotactic constraints of the language. They were rated high on wordlikeness and have comparable position segments and biphone probabilities across stimulus lengths. We validated the stimuli with a sample of 59 typically developing Vietnamese–English bilingual children, ages 5 to 8. The stimuli exhibited the expected age and length effects commonly found in NWR tasks: Older children performed better on the task than younger children, and longer items were more difficult to repeat than shorter items. We also compared different scoring systems in order to examine the individual phoneme types (consonants, vowels, and tones) and composite scores (proportions of phonemes correct, with and without tone). The study demonstrates careful construction and validation of the stimuli, and future directions are discussed.     

Stress modulation of cognitive and affective processes

This review summarizes the major discussion points of a symposium on stress modulation of cognitive and affective processes, which was held during the 2010 workshop on the neurobiology of stress (Boulder, CO, USA). The four discussants addressed a number of specific cognitive and affective factors that are modulated by exposure to acute or repeated stress. Dr David Morilak discussed the effects of various repeated stress situations on cognitive flexibility, as assessed with a rodent model of attentional set-shifting task, and how performance on slightly different aspects of this test is modulated by different prefrontal regions through monoaminergic neurotransmission. Dr Serge Campeau summarized the findings of several studies exploring a number of factors and brain regions that regulate habituation of various autonomic and neuroendocrine responses to repeated audiogenic stress exposures. Dr Kerry Ressler discussed a body of work exploring the modulation and extinction of fear memories in rodents and humans, especially focusing on the role of key neurotransmitter systems including excitatory amino acids and brain-derived neurotrophic factor. Dr Israel Liberzon presented recent results on human decision-making processes in response to exogenous glucocorticoid hormone administration. Overall, these discussions are casting a wider framework on the cognitive/affective processes that are distinctly regulated by the experience of stress and some of the brain regions and neurotransmitter systems associated with these effects.     

Multisensory information boosts numerical matching abilities in young children

This study presents the first evidence that preschool children perform more accurately in a numerical matching task when given multisensory rather than unisensory information about number. Three- to 5-year-old children learned to play a numerical matching game on a touchscreen computer, which asked them to match a sample numerosity with a numerically equivalent choice numerosity. Samples consisted of a series of visual squares on some trials, a series of auditory tones on other trials, and synchronized squares and tones on still other trials. Children performed at chance on this matching task when provided with either type of unisensory sample, but improved significantly when provided with multisensory samples. There was no speed–accuracy tradeoff between unisensory and multisensory trial types. Thus, these findings suggest that intersensory redundancy may improve young children’s abilities to match numerosities.     

Age and gender comparisons of driving while sleepy: Behaviours and risk perceptions

To assist road safety professionals in developing effective strategies to combat the risk associated with driving while fatigued, a survey was administered to 1000 Australian drivers. Participants reported their past behaviours in regards to driving while sleepy and their perceptions of risk associated with driving fatigued as compared to speeding and driving under the influence of alcohol. Although participants appeared to be aware of the substantial risk associated with driving while sleepy, many drivers reported that they frequently drive when sleepy. Age and gender comparisons, revealed that risk taking behaviour in regards to driving while sleepy is occurring across all age groups and in both male and female drivers. Overall young to middle age drivers and male drivers reported the highest frequency of driving while sleepy and reported the lowest perceived personal risk in regards to driving while sleepy.