The Cross-Modal Coordination of Interpersonal Timing: Six-Week-Olds Infants' Gaze with Adults' Vocal Behavior

The purpose of this study was to examine the hypothesis that 6-week-old infants are capable of coordinated interpersonal timing within social interactions. Coordinated interpersonal timing refers to changes in the timing of one individual's behavior as a function of the timing of another individual's behavior. Each of 45, first-born 6-week-old infants interacted with his or her mother and a stranger for a total of 14 minutes. The interactions were videotaped and coded for the gaze behavior of the infants and the vocal behavior of the mothers and strangers. Time-series regression analyses were used to assess the extent to which the timing of each of the infants' gazes was coordinated with the timing of the adults' vocal behavior. The results revealed that (a) coordinated timing occurs between infants and their mothers and between infants and strangers as early as when infants are 6 weeks old, and (b) strangers coordinated the timing of their pauses with the infants to a greater extent than did mothers. The findings are discussed in terms of the role of temporal sensitivity in social interaction.     

The nature of regularity and irregularity: evidence from Hebrew nominal inflection

Most evidence for the role of regular inflection as a default operation comes from languages that confound the morphological properties of regular and irregular forms with their phonological characteristics. For instance, regular plurals tend to faithfully preserve the base's phonology (e.g., rat-rats), whereas irregular nouns tend to alter it (e.g., mouse-mice). The distinction between regular and irregular inflection may thus be an epiphenomenon of phonological faithfulness. In Hebrew noun inflection, however, morphological regularity and phonological faithfulness can be distinguished: Nouns whose stems change in the plural may take either a regular or an irregular suffix, and nouns whose stems are preserved in the plural may take either a regular or an irregular suffix. We use this dissociation to examine two hallmarks of default inflection: its lack of dependence on analogies from similar regular nouns, and its application to nonroots such as names. We show that these hallmarks of regularity may be found whether or not the plural form preserves the stem faithfully: People apply the regular suffix to novel nouns that do not resemble existing nouns and to names that sound like irregular nouns, regardless of whether the stem is ordinarily preserved in the plural of that family of nouns. Moreover, when they pluralize names (e.g., the Barak-Barakim), they do not apply the stem changes that are found in their homophonous nouns (e.g., barak-brakim lightning), replicating an effect found in English and German. These findings show that the distinction between regular and irregular phenomena cannot be reduced to differences in the kinds of phonological changes associated with those phenomena in English. Instead, regularity and irregularity must be distinguished in terms of the kinds of mental computations that effect them: symbolic operations versus memorized idiosyncrasies. A corollary is that complex words are not generally dichotomizable as regular or irregular different aspects of a word may be regular or irregular depending on whether they violate the rule for that aspect and hence must be stored in memory.     

What did mummy say? Dyadic interactions between young "hard to manage" children and their mothers

Thirty preschoolers rated as hard to manage on Goodman's (R. Goodman, 1997) Strengths and Difficulties Questionnaire (SDQ), and a group of matched control children were observed and recorded on audiotape at home, interacting with their mothers (Time 1). At the 18-month follow-up home visits (Time 2), the children and mothers were filmed across 4 observation settings. Mother–child interactions were rated on affect, control, responsiveness and connectedness of communication. At Time 1, mothers of the hard to manage group used more negative control and engaged in fewer connected conversations than did mothers in the control group. At Time 2, mothers of the hard to manage group displayed higher levels of negative control and lower levels of positive control. These results are discussed in terms of the importance of examining connected communication and different observation contexts when examining dyadic mother–child interactions.     

Programming of endogenous and exogenous saccades: evidence for a competitive integration model

Participants were required to make a saccade to a uniquely colored target while ignoring the presentation of an onset distractor. The results provide evidence for a competitive integration model of saccade programming that assumes endogenous and exogenous saccades are programmed in a common saccade map. The model incorporates a lateral interaction structure in which saccade-related activation at a specific location spreads to neighboring locations but inhibits distant locations. In addition, there is top-down, location-specific inhibition of locations to which the saccade should not go. The time course of exogenous and endogenous activation in the saccade map can explain a variety of eye movement data, including endpoints, latencies, and trajectories of saccades and the well-known global effect.     

Perception of pictorial eye gaze by baboons (Papio papio)

Pictorial faces looking left or right were presented to baboons (Papio papio) before the display of a target letter in the left or right hemifield of a monitor screen. Baboons had to provide go or no-go responses taking into account the identity of the target letter. The 1st 6 experiments showed no reliable effect of eye gaze on discrimination speed, using either schematic gazes or pictures of real gazes. Experiment 7 showed that eye gazes facilitated target processing when eye cues were perfect predictors of target location. Findings suggest that baboons do not spontaneously process eye-gaze direction but can learn to do so if the gaze has a predictive value. Implications of these findings on baboons' perspective-taking abilities are discussed.     

Acquired equivalence and distinctiveness of cues: I. Exploring a neural network approach

Rats were placed in 4 contexts (A, B, C, D) where they received 2 auditory stimuli (X, Y); in A and B, presentations of X were paired with food and those of Y were not, and in C and D, Y was paired with food and X was not. Rats then received combinations of contexts that had provided congruent (AB, CD) or incongruent (AD, CB) information about X and Y's relationship to food. Responding was more variable during congruent than incongruent trials (Experiment 1) and was systematically increased and decreased during congruent (relative to incongruent) trials by the presentation of food or no food, respectively (Experiment 2). These results support a connectionist approach to acquired changes in stimulus distinctiveness.     

Acquired equivalence and distinctiveness of cues: II. Neural manipulations and their implications

Neural manipulations were used to examine the mechanisms that underlie the acquired equivalence and distinctiveness of cues in rats. Control rats and those with excitotoxic lesions of either the hippocampus (HPC) or entorhinal cortex (EC) acquired the following conditional discrimination: In Contexts A and B, Stimulus X-->food and Stimulus Y-->no food, and in Contexts C and D, Y-->food and X-->no food. Rats then received many food pellets in A but not in C. After this treatment, control rats showed more magazine activity in B than in D--an acquired equivalence-distinctiveness effect. This effect was also evident in HPC rats but not in EC rats. These results indicate that changes in stimulus distinctiveness are dissociable from the process of conditional learning.     

The police officer's dilemma: using ethnicity to disambiguate potentially threatening individuals

Using a simple videogame, the effect of ethnicity on shoot/don't shoot decisions was examined. African American or White targets, holding guns or other objects, appeared in complex backgrounds. Participants were told to "shoot" armed targets and to "not shoot" unarmed targets. In Study 1, White participants made the correct decision to shoot an armed target more quickly if the target was African American than if he was White, but decided to "not shoot" an unarmed target more quickly if he was White. Study 2 used a shorter time window, forcing this effect into error rates. Study 3 replicated Study 1's effects and showed that the magnitude of bias varied with perceptions of the cultural stereotype and with levels of contact, but not with personal racial prejudice. Study 4 revealed equivalent levels of bias among both African American and White participants in a community sample. Implications and potential underlying mechanisms are discussed.     

Using the PAI with an eating disordered population: scale characteristics,factor structure,and differences among diagnostic groups

Psychometric properties of the Personality Assessment Inventory (PAI; Morey 1991) within an eating disordered sample seeking treatment (N = 238) and differences among eating disorder diagnostic groups on the PAI were examined. The PAI showed acceptable alpha coefficients, item-total correlations, and interitem correlations. The factor structure was similar to that reported by Morey (1991), with the addition of another factor related to interpersonal coolness and distance. Those with binge eating disorder (BED) reported fewer problems and less distress in general compared to other eating disordered groups. The BED and bulimia nervosa groups were different from the anorexia nervosa groups in frequency of matching on two PAI clusters. Use of the PAI with an eating disordered population and its utility in understanding eating disorder diagnostic groups is supported.