School administrators, parents, and sex education: a resolvable paradox?

The emergence of AIDS as an untreatable, lethal disease, responding to educational prevention strategies in high-risk populations, has brought the issues of sex education in the public schools to the forefront. However, administrators, teachers, and parents perceive different barriers to sex education implementation. This study, undertaken in a northeastern, multigenerational, ethnic city, characterized by adolescent pregnancy rates a third higher than the state overall, polled 42 junior and senior high school administrators regarding educational priorities, perceived barriers to expansion of sex education, and preferred methods of introducing sex education. Administrators perceive parents as a major barrier to the introduction of more formalized sex education in their schools. Paradoxically, these same administrators felt that parents were generally uncomfortable in talking to their children about human sexuality. Recommendations are offered from existing models of health education for resolution of administrators' conflicting views on parental roles.     

Infant word segmentation revisited: edge alignment facilitates target extraction

In a landmark study, Jusczyk and Aslin (1995) demonstrated that English-learning infants are able to segment words from continuous speech at 7.5 months of age. In the current study, we explored the possibility that infants segment words from the edges of utterances more readily than the middle of utterances. The same procedure was used as in Jusczyk and Aslin (1995); however, our stimuli were controlled for target word location and infants were given a shorter familiarization time to avoid ceiling effects. Infants were familiarized to one word that always occurred at the edge of an utterance (sentence-initial position for half of the infants and sentence-final position for the other half) and one word that always occurred in sentence-medial position. Our results demonstrate that infants segment words from the edges of an utterance more readily than from the middle of an utterance. In addition, infants segment words from utterance-final position just as readily as they segment words from utterance-initial position. Possible explanations for these results, as well as their implications for current models of the development of word segmentation, are discussed.     

A General Structure of Job Performance: Evidence from Two Studies

Purpose  

The purpose of this study is to test alternative models of job performance based on competing categorization criteria.     

Accommodating variability in voice and foreign accent: flexibility of early word representations

In six experiments with English‐learning infants, we examined the effects of variability in voice and foreign accent on word recognition. We found that 9‐month‐old infants successfully recognized words when two native English talkers with dissimilar voices produced test and familiarization items ( Experiment 1 ). When the domain of variability was shifted to include variability in voice as well as in accent, 13‐, but not 9‐month‐olds, recognized a word produced across talkers when only one had a Spanish accent ( Experiments 2 and 3 ). Nine‐month‐olds accommodated some variability in accent by recognizing words when the same Spanish‐accented talker produced familiarization and test items ( Experiment 4 ). However, 13‐, but not 9‐month‐olds, could do so when test and familiarization items were produced by two distinct Spanish‐accented talkers ( Experiments 5 and 6 ). These findings suggest that, although monolingual 9‐month‐olds have abstract phonological representations, these representations may not be flexible enough to accommodate the modifications found in foreign‐accented speech.     

Why the body comes first: effects of experimenter touch on infants' word finding

The lexicon of 6‐month‐olds is comprised of names and body part words. Unlike names, body part words do not often occur in isolation in the input. This presents a puzzle: How have infants been able to pull out these words from the continuous stream of speech at such a young age? We hypothesize that caregivers' interactions directed at and on the infant's body may be at the root of their early acquisition of body part words. An artificial language segmentation study shows that experimenter‐provided synchronous tactile cues help 4‐month‐olds to find words in continuous speech. A follow‐up study suggests that this facilitation cannot be reduced to the highly social situation in which the directed interaction occurs. Taken together, these studies suggest that direct caregiver–infant interaction, exemplified in this study by touch cues, may play a key role in infants' ability to find word boundaries, and suggests that early vocabulary items may consist of words often linked with caregiver touches. A video abstract of this article can be viewed at http://youtu.be/NfCj5ipatyE     

Developmental changes in the weighting of prosodic cues

Previous research has shown that the weighting of, or attention to, acoustic cues at the level of the segment changes over the course of development (Nittrouer & Miller, 1997; Nittrouer, Manning & Meyer, 1993). In this paper we examined changes over the course of development in weighting of acoustic cues at the suprasegmental level. Specifically, we tested English-learning 4-month-olds' performance on a clause segmentation task when each of three acoustic cues to clausal units was neutralized and contrasted it with performance on a Baseline condition where no cues were manipulated. Comparison with the reported performance of 6-month-olds on the same task (Seidl, 2007) reveals that 4-month-olds weight prosodic cues to clausal boundaries differently than 6-month-olds, relying more heavily on all three correlates of clausal boundaries (pause, pitch and vowel duration) than 6-month-olds do, who rely primarily on pitch. We interpret this as evidence that 4-month-olds use a holistic processing strategy, while 6-month-olds may already be able to attend separately to isolated cues in the input stream and may, furthermore, be able to exploit a language-specific cue weighting. Thus, in a way similar to that in other cognitive domains, infants begin as holistic auditory scene processors and are only later able to process individual auditory cues.     

Toddlers recognize words in an unfamiliar accent after brief exposure

Both subjective impressions and previous research with monolingual listeners suggest that a foreign accent interferes with word recognition in infants, young children, and adults. However, because being exposed to multiple accents is likely to be an everyday occurrence in many societies, it is unexpected that such non‐standard pronunciations would significantly impede language processing once the listener has experience with the relevant accent. Indeed, we report that 24‐month‐olds successfully accommodate an unfamiliar accent in rapid word learning after less than 2 minutes of accent exposure. These results underline the robustness of our speech perception mechanisms, which allow listeners to adapt even in the absence of extensive lexical knowledge and clear known‐word referents. A video abstract of this article can be viewed at http: ? ?www.youtube.com ?watch?v=bYnaZkMyKtY&feature=youtu.be     

Mechanisms underlying accent accommodation in early word learning: evidence for general expansion

Previous work reveals that toddlers can accommodate a novel accent after hearing it for only a brief period of time. A common assumption is that children, like adults, cope with nonstandard pronunciations by relying on words they know (e.g. ‘this person pronounces sock as sack, therefore by black she meant block’). In this paper, we assess whether toddlers might additionally use a general expansion strategy, whereby they simply accept non‐standard pronunciations when variability is expected. We exposed a group of 24‐month‐old English‐learning toddlers to variability in indexical cues (very diverse voices from native English talkers), and another to variability in social cues (very diverse‐looking silent actors); neither group was familiarized with the target novel accent. At test, both groups succeeded in recognizing a novel word when spoken in the novel accent. Thus, even when no lexical cues are available, variability can prepare young children for non‐standard pronunciations.     

Transfer of adaptation between ocular saccades and arm movements

Previous studies found little or no transfer of adaptation from reactive saccades to arm pointing movements, which suggests that the two motor systems rely on distinct adaptive mechanisms. However, this conclusion is based on experiments about the adaptation of response amplitudes, which is known to follow somewhat different principles than the adaptation of response directions. In the present study, we therefore investigate whether adapting the direction of reactive saccades will transfer to arm movements. We also test transfer in the opposite direction, from the arm to the eyes. Participants executed aimed saccades or arm movements from a central starting point towards visual targets in the participants' frontal plane. Targets were presented in eight possible locations along a circle of 20 cm radius about the starting point; each remained for 200 ms in one position, and was then displaced along the circle by -15 degrees . Participants from group E adapted to these double-stepped targets while executing eye movements, and were then tested for transfer while executing arm movements. The reciprocal design was used in participants from group A. Adaptive change in group A was about 14 degrees , while in group E it was only about 7 degrees . Transfer of adaptation was substantial, and was more pronounced when using the arm (i.e., eye-to-arm transfer in group E) rather than the eyes (i.e., arm-to-eye transfer in group A). Strong aftereffects were yielded in both groups. This pattern of findings implies that the adaptive change observed in our study was mainly based on recalibration rather than on cognitive strategies (strong aftereffects), that eyes and arm had access to a common adaptive mechanism (substantial transfer), and that the arm had better access than the eyes (larger adaptation and transfer when using the arm). When considering this outcome along with the available literature, it appears that arm and eyes may rely sometimes on a common and sometimes on distinct adaptive mechanisms, depending on the adapted parameter and on the nature of the motor task.