The social context of imitation in infancy

Infants increasingly generalize deferred imitation across environmental contexts between 6 and 18 months of age. In three experiments with 126 6-, 9-, 12-, 15-, and 18-month-olds, we examined the role of the social context in deferred imitation. One experimenter demonstrated target actions on a hand puppet, and a second experimenter tested imitation 24h later. When the second experimenter was novel, infants did not exhibit deferred imitation at any age; when infants were preexposed to the second experimenter, all of them did. Imitating immediately after the demonstration also facilitated deferred imitation in a novel social context at all ages but 6 months. Infants' pervasive failure to exhibit deferred imitation in a novel social context may reflect evolutionary selection pressures that favored conservative behavior in social animals.     

Timing variability in circle drawing and tapping: probing the relationship between event and emergent timing

R. Ivry, R. M. Spencer, H. N. Zelaznik, and J. Diedrichsen (2002) have proposed a distinction between timed movements in which a temporal representation is part of the task goal (event timing) and those in which timing properties are emergent. The issue addressed in the present experiment was how timing in conditions conducive to emergent timing becomes established. According to what the authors term the transformation hypothesis, timing initially requires an event-based representation when the temporal goal is defined externally (e.g., by a metronome), but over the first few movement cycles, control processes become established that allow timing to become emergent. Different groups of participants (N = 84) executed either 1 timed interval, 4 timed intervals, or 2 timed intervals separated by a pause. They produced the intervals by either circle drawing, a task associated with emergent timing, or tapping, a task associated with event timing. Analyses of movement variability suggested that similar timing processes were used in the 2 tasks only during the 1st interval. Those results are consistent with the transformation hypothesis and lead to the inference that the transition from event-based control to emergent timing can occur rapidly during continuous movements.     

Perception of visual speed while moving

During self-motion, the world normally appears stationary. In part, this may be due to reductions in visual motion signals during self-motion. In 8 experiments, the authors used magnitude estimation to characterize changes in visual speed perception as a result of biomechanical self-motion alone (treadmill walking), physical translation alone (passive transport), and both biomechanical self-motion and physical translation together (walking). Their results show that each factor alone produces subtractive reductions in visual speed but that subtraction is greatest with both factors together, approximating the sum of the 2 separately. The similarity of results for biomechanical and passive self-motion support H. B. Barlow's (1990) inhibition theory of sensory correlation as a mechanism for implementing H. Wallach's (1987) compensation for self-motion.     

Perceptions of Dating Violence Following a Sexualor Nonsexual Betrayal of Trust: Effects of Gender, Sexism, Acceptance of Rape Myths, and Vengeance Motivation

College womens (N = 220) and mens (N = 208) perceptions of violence following a betrayal by a romantic partner were studied in an independent groups design that varied gender of the participant, type of betrayal (sexual or nonsexual), and gender of the betrayed individual. Participants read one of four brief vignettes in which the betrayed person slapped his/her partner and made his/her lip bleed. Justification of this action was rated on 10 items. Factor analysis of these items indicated the presence of three factors for men and four for women. Both men and women indicated that hitting the partner, getting even, and being angry were more justifiable following a sexual betrayal. The hitting of a male partner by a betrayed woman was perceived as more justified than the hitting of a female partner by a betrayed man. In absolute terms, hitting and getting even by both women and men were generally viewed as unjustifiable, whereas being angry was viewed as justifiable. For both women and men, scores on the Vengeance Scale (Stuckless & Goranson, 1992) and Rape Myth Acceptance Scale (Lonsway & Fitzgerald, 1995) were related to getting even. For men, the Hostile Sexism Scale (Glick & Fiske, 2001) was related to getting even or being angry and breaking up. Results indicated that perceptions of reactions to betrayal are related to type of betrayal and to the dispositional characteristics of the perceiver.     

Letter-by-letter acquired dyslexia is due to the serial encoding of letters

Letter-by-letter acquired dyslexia (pure alexia) is assumed to be related to the serial encoding of letters, but the evidence for this assumption is somewhat indirect. Here, we demonstrate that the deficit is indeed due to serial encoding by comparing the performance of a letter-by-letter dyslexic reader with the performance of normal readers who were forced to read letter by letter; the data patterns are remarkably similar.     

Assessment of social communication skills in preschoolers

This paper orients the reader to social communication assessment and reviews methods for assessing social communication behavior in children from toddlerhood through the preschool years. Most standardized, normed tests of language in this age range focus on morpho-syntactic and semantic comprehension and production abilities. While social communication is perhaps one of the most important skills for peer acceptance, these skills are often overlooked in language evaluation with children. However, there are a number of caregiver questionnaires, interviews, or direct social-communication sampling methods that are available to assist clinicians or researchers in documenting social-communication skills or behaviors. Since assessment of social communication is essential in clinical work with children with an autism spectrum disorder, some of the tools described below are outgrowths of autism research or provide autism-related scores. While many children receiving social communication assessments do not have autism, the need to assess social communication skills in children with language impairment is highlighted by the growing literature documenting social and pragmatic difficulties in this population (Bishop 2000 Causes, Characteristics, Intervention, and Outcome. Hove, UK: Psychology press). Regardless of whether the measures presented herein were initially designed for children with autism or not, they will provide insights into the social communicative behaviors or tendencies in young children.     

The old and thee, uh, new: disfluency and reference resolution

Most research on the rapid mental processes of on-line language processing has been limited to the study of idealized, fluent utterances. Yet speakers are often disfluent, for example, saying "thee, uh, candle" instead of "the candle." By monitoring listeners' eye movements to objects in a display, we demonstrated that the fluency of an article ("thee uh" vs. "the") affects how listeners interpret the following noun. With a fluent article, listeners were biased toward an object that had been mentioned previously, but with a disfluent article, they were biased toward an object that had not been mentioned. These biases were apparent as early as lexical information became available, showing that disfluency affects the basic processes of decoding linguistic input.     

Developmental regression in autism spectrum disorders

The occurrence of developmental regression in autism is one of the more puzzling features of this disorder. Although several studies have documented the validity of parental reports of regression using home videos, accumulating data suggest that most children who demonstrate regression also demonstrated previous, subtle, developmental differences. Counter to clinical intuition, the earlier development of social, language, and attachment behaviors followed by regression does not seem to support later recovery of skills or better developmental outcomes compared to children who never had speech or typical social responsivity. In fact, this regressive group may have somewhat greater developmental impairment than the nonregressive group, though the two groups do not appear to present different behavioral phenotypes. Although autism is not the only condition in which regression occurs, it appears to be the most frequent condition. Other disorders that demonstrate an early regression with no known etiology include total blindness from birth and childhood disintegrative disorder, both of which demonstrate behavioral relations to autism. In addition, two biological conditions with known etiologies also involve regression with some behaviors resembling autism behavioral phenotype: Rett syndrome (a genetic disorder; see Glaze, this issue) and Landau-Kleffner syndrome (see McVicar and Shinnar, this issue), which involves a seizure disorder.