The interaction between acoustic salience and language experience in developmental speech perception: evidence from nasal place discrimination

Previous research suggests that infant speech perception reorganizes in the first year: young infants discriminate both native and non‐native phonetic contrasts, but by 10–12 months difficult non‐native contrasts are less discriminable whereas performance improves on native contrasts. In the current study, four experiments tested the hypothesis that, in addition to the influence of native language experience, acoustic salience also affects the perceptual reorganization that takes place in infancy. Using a visual habituation paradigm, two nasal place distinctions that differ in relative acoustic salience, acoustically robust labial‐alveolar [ma]–[na] and acoustically less salient alveolar‐velar [na]–[?a], were presented to infants in a cross‐language design. English‐learning infants at 6–8 and 10–12 months showed discrimination of the native and acoustically robust [ma]–[na] (Experiment 1), but not the non‐native (in initial position) and acoustically less salient [na]–[?a] (Experiment 2). Very young (4–5‐month‐old) English‐learning infants tested on the same native and non‐native contrasts also showed discrimination of only the [ma]–[na] distinction (Experiment 3). Filipino‐learning infants, whose ambient language includes the syllable‐initial alveolar (/n/)–velar (/?/) contrast, showed discrimination of native [na]–[?a] at 10–12 months, but not at 6–8 months (Experiment 4). These results support the hypothesis that acoustic salience affects speech perception in infancy, with native language experience facilitating discrimination of an acoustically similar phonetic distinction [na]–[?a]. We discuss the implications of this developmental profile for a comprehensive theory of speech perception in infancy.     

Reaching within video-capture virtual reality: using virtual reality as a motor control paradigm.

We have developed a virtual reality (VR) system that integrates a three-dimensional tracking device with a video-capture VR platform to record upper limb movements. The influence of target velocity on planning and execution of reaching movements was studied in five healthy subjects. Our initial results suggest that a target's velocity is considered when planning an interceptive action and that a hand reaching toward a moving virtual target is controlled in a similar way to how it is in the real visual environment.     

The perceptual wink model of non-switching attentional blink tasks

The attentional blink (AB) is a temporary deficit for a second target (T2) when that target appears after a first target (T1). Although sophisticated models have been developed to explain the substantial AB literature in isolation, the current study considers how the AB relates to perceptual dynamics more broadly. We show that the time-course of the AB is closely related to the time course of the transition from positive to negative repetition priming effects in perceptual identification. Many AB tasks involve a switch between a T1 defined in one manner and a T2 defined in a different manner. Other AB tasks are non-switching, with all targets belonging to the same well-known category (e.g., letter targets versus number distractors) or sharing the same perceptual feature. We propose that these non-switching AB tasks reflect perceptual habituation for the target-defining attribute; thus, a ‘perceptual wink’, with perception of one attribute (target identity) undisturbed while perception of another (target detection) is impaired. On this account, the immediate benefit following T1 (lag-1 sparing) reflects positive repetition priming and the subsequent deficit (the blink) reflects negative repetition priming for the realization that a target occurred. In developing the perceptual wink model, we extended the nROUSE model of perceptual priming to explain the results of two new experiments combining the AB and identity repetitions. This establishes important connections between non-switching AB tasks and perceptual dynamics.     

Looking for honesty: The primary role of morality (vs. sociability and competence) in information gathering

Research on the two fundamental dimensions of social judgment, namely warmth and competence, has shown that warmth has a primary and a dominant role in information gathering about others. In two studies we examined whether the sociability and morality components of warmth play distinct roles in such a process. Study 1 (N = 60) investigated which traits were mostly selected when forming impressions about others. The results showed that, regardless of the task goal, traits related to morality and sociability were differently processed. Furthermore, participants were more interested in obtaining information about morality than about sociability when asked to form a global impression about others. Study 2 (N = 98) explored the adoption of asymmetric/symmetric strategies when asking questions to make inferences on others. As predicted, participants adopted an asymmetrically disconfirming strategy on morality traits, while they looked for more symmetrical evidence on sociability or competence traits. Overall, our findings indicated a distinct and a dominant role of the moral component of warmth in the information‐gathering process. Copyright © 2010 John Wiley & Sons, Ltd.     

New knowledge for old credences: Asymmetric information search about in-group and out-group members

Three experiments examined how people gather information on in-group and out-group members. Previous studies have revealed that category-based expectancies bias the hypothesis-testing process towards confirmation through the use of asymmetric-confirming questions (which are queries where the replies supporting the prior expectancies are more informative than those falsifying them). However, to date there is no empirical investigation of the use of such a question-asking strategy in an intergroup context. In the present studies, participants were asked to produce (Study 1) or to choose (Studies 2 and 3) questions in order to investigate the presence of various traits in an in-group or an out-group member. Traits were manipulated by valence and typicality. The results revealed that category-based expectancies do not always lead to asymmetric-confirming testing: whereas participants tended to ask questions that confirmed positive in-group and negative out-group stereotypical attributes, they used a more symmetric strategy when testing for the presence of negative in-group or positive out-group traits. Moreover, Study 3 also revealed a moderation effect of in-group identification. The findings point to the role played by motivational factors associated with preserving a positive social identity. Possible consequences of these hypothesis-testing processes in preserving a positive social identity for intergroup relations are discussed.     

Cognitive vulnerability to depression during middle childhood: Stability and associations with maternal affective styles and parental depression

Theories of cognitive vulnerability to depression (CVD) imply that CVD is early-emerging and trait-like; however, little longitudinal work has tested this premise in middle childhood, or examined theoretically relevant predictors of child CVD. We examined test–retest correlations of self-referent encoding task performance and self-reported attributional styles and their associations with parental characteristics in 205 seven-year-olds. At baseline, child CVD was assessed, structured clinical interviews were conducted with parents, and ratings of observed maternal affective styles were made. Children’s CVD was re-assessed approximately one and two years later. Both measures of children’s CVD were prospectively and concurrently associated with children’s depressive symptoms and showed modest stability. Multilevel modeling indicated that maternal criticism and paternal depression were related to children’s CVD. Findings indicate that even early-emerging CVD is a valid marker of children’s depression risk.     

Individuation of visual objects over time

How does an observer decide that a particular object viewed at one time is actually the same object as one viewed at a different time? We explored this question using an experimental task in which an observer views two objects as they simultaneously approach an occluder, disappear behind the occluder, and re-emerge from behind the occluder, having switched paths. In this situation the observer either sees both objects continue straight behind the occluder (called "streaming") or sees them collide with each other and switch directions ("bouncing"). This task has been studied in the literature on motion perception, where interest has centered on manipulating spatiotemporal aspects of the motion paths (e.g. velocity, acceleration). Here we instead focus on featural properties (size, luminance, and shape) of the objects. We studied the way degrees and types of featural dissimilarity between the two objects influence the percept of bouncing vs. streaming. When there is no featural difference, the preference for straight motion paths dominates, and streaming is usually seen. But when featural differences increase, the preponderance of bounce responses increases. That is, subjects prefer the motion trajectory in which each continuously existing individual object trajectory contains minimal featural change. Under this model, the data reveal in detail exactly what magnitudes of each type of featural change subjects implicitly regard as reasonably consistent with a continuously existing object. This suggests a simple mathematical definition of "individual object:" an object is a path through feature-trajectory space that minimizes feature change, or, more succinctly, an object is a geodesic in Mahalanobis feature space.     

Suspensions and detentions in an urban,low-income school: punishment or reward?

Disciplinary records for 3rd through 8th grade students (n = 314) in an inner-city, public school were examined for one school year to assess students' variation in response to discipline. Rates of disciplinary referrals were compared for students who received no detentions or suspensions throughout the year (never group n = 117), students who received one or more detention or suspension in the fall but not in the spring (fall group n = 62), and students who received one or more detention or suspension in the fall and one or more detention or suspension in the spring (fall + spring group n = 75). Results indicated that during the fall, the fall group had nearly equivalent rates of referrals to the fall + spring group; however, the fall group exhibited significantly lower rates of referrals during winter and spring that were nearly equivalent to the never group, as would be expected for a punishment procedure. In contrast, the fall + spring group evidenced increases in referrals across the year, suggesting the possibility that detentions and suspensions were functioning as rewards for this group. The fall + spring group was rated by teachers and peers at mid-year as highly aggressive, lacking social skills, and high on hyperactivity, whereas the fall group and the never group were statistically equivalent on teacher and peer ratings. Implications for mental health programs for urban schools are discussed, especially the need for alternatives to detention and suspension for the subset of students who account for the majority of school discipline.