An Affordance-Based Approach to Visually Guided Overtaking

When an automobile driver overtakes a lead vehicle while avoiding oncoming traffic, does he or she do so with reference to the limits of his or her car? We investigated overtaking from the perspective of the theory of affordances. We define the overtake-ability affordance as a ratio of the minimum satisfying velocity required for safe overtaking (MSV) to the maximum velocity of the driver's car (V_max). Two groups of participants performed overtaking maneuvers, if deemed possible, by driving either a slow (V_max = 25 m/s) or a fast (V_max = 32.5 m/s) virtual car in overtaking situations constrained by 14 values of MSV. For any given MSV condition, participants in the fast car group were more likely to attempt an overtaking maneuver. However, when MSV was expressed in intrinsic units as a ratio of V_max for both groups, the frequency of overtaking was not significantly different across groups. Furthermore, overtaking frequency dropped to near 0% for both groups when MSV exceeded V_max. In accordance with the affordance-based framework (Fajen, 2007), our results suggest that participants select their overtaking maneuvers by perceiving an overtake-ability affordance.     

The role of cognitive factors in the pathogenesis of obsessive-compulsive symptoms: a prospective study

Cognitive models of obsessive-compulsive disorder (OCD) posit that specific kinds of dysfunctional beliefs (e.g., pertaining to responsibility and the significance of intrusive thoughts) underlie the development of this disorder. The present study was designed to prospectively evaluate whether dysfunctional beliefs thought to underlie OCD act as a specific vulnerability factor in the pathogenesis of obsessive-compulsive symptomatology. Eighty-five individuals were prospectively followed over a period of time thought to be associated with an increased onset of OCD symptoms -- childbirth and the postpartum. The majority of these new mothers and fathers experienced intrusive infant-related thoughts and performed neutralizing behaviors similar to, but less severe than, those observed in OCD. Scores on a measure of dysfunctional beliefs thought to underlie OCD predicted the development of obsessive-compulsive symptoms after controlling for pre-existing OCD symptoms, anxiety, and depression. Dysfunctional beliefs also predicted the severity of checking, washing, and obsessional OCD symptom dimensions, but not neutralizing, ordering, or hoarding symptom dimensions. These data provide evidence for specific dysfunctional beliefs as risk factors in the development of some types of OCD symptoms.     

Learning to control collisions: the role of perceptual attunement and action boundaries

The authors investigated the role of perceptual attunement in an emergency braking task in which participants waited until the last possible moment to slam on the brakes. Effects of the size of the approached object and initial speed on the initiation of braking were used to identify the optical variables on which participants relied at various stages of practice. In Experiments 1A and 1B, size and speed effects that were present early in practice diminished but were not eliminated as participants learned to initiate braking at a rate of optical expansion that varied with optical angle. When size and speed were manipulated together in Experiment 2, the size effect was quickly eliminated, and participants learned to use a 3rd optical variable (global optic flow rate) to nearly eliminate the speed effect. The authors conclude that perceptual attunement depends on the range of practice conditions, the availability of information, and the criteria for success.     

Targeting the probability versus cost of feared outcomes in public speaking anxiety

Cognitive-behavioral theory suggests that social phobia is maintained, in part, by overestimates of the probability and cost of negative social events. Indeed, empirically supported cognitive-behavioral treatments directly target these cognitive biases through the use of in vivo exposure or behavioral experiments. While cognitive-behavioral theories and treatment protocols emphasize the importance of targeting probability and cost biases in the reduction of social anxiety, few studies have examined specific techniques for reducing probability and cost bias, and thus the relative efficacy of exposure to the probability versus cost of negative social events is unknown. In the present study, 37 undergraduates with high public speaking anxiety were randomly assigned to a single-session intervention designed to reduce either the perceived probability or the perceived cost of negative outcomes associated with public speaking. Compared to participants in the probability treatment condition, those in the cost treatment condition demonstrated significantly greater improvement on measures of public speaking anxiety and cost estimates for negative social events. The superior efficacy of the cost treatment condition was mediated by greater treatment-related changes in social cost estimates. The clinical implications of these findings are discussed.     

Trajectories of perceived support in mother-adolescent relationships: the poor (quality) get poorer

The authors examined decreases across the early adolescent years in child reports of perceived support from mothers to determine whether the rate of decline differed as a function of the initial amount of perceived negativity in the mother-child relationship. Participants included a diverse sample of 197 girls and 116 boys who were in the 1st year of middle school (6th grade, ages 11 to 13 years) at the beginning of the study. Separate growth curve models revealed associations between the rate of change in child-reported perceived support and the initial level of both child-reported perceived negativity and mother-reported perceived negativity. Over-time declines in child-reported perceived support were larger for adolescents whose initial levels of perceived negativity were greater. The findings are consistent with the claim that mothers and children with the worst relationships at the outset of adolescence experience the greatest deterioration in relations across the early adolescent years.     

Mother and Adolescent Reports of Associations Between Child Behavior Problems and Mother-Child Relationship Qualities: Separating Shared Variance from Individual Variance

This study contrasts results from different correlational methods for examining links between mother and child (N = 72 dyads) reports of early adolescent (M = 11.5 years) behavior problems and relationship negativity and support. Simple (Pearson) correlations revealed a consistent pattern of statistically significant associations, regardless of whether scores came from the same reporter or from different reporters. When correlations between behavior problems and relationship quality differed, within-reporter correlations were always greater in magnitude than between-reporter correlations. Dyadic (common fate) analyses designed for interdependent data decomposed within-reporter correlations into variance shared across reporters (dyadic correlations) and variance unique to specific reporters (individual correlations). Dyadic correlations were responsible for most associations between adolescent behavior problems and relationship negativity; after partitioning variance shared across reporters, no individual correlations emerged as statistically significant. In contrast, adolescent behavior problems were linked to relationship support via both shared variance and variance unique to maternal perceptions. Dyadic analyses provide a parsimonious alternative to multiple contrasts in instances when identical measures have been collected from multiple reporters. Findings from these analyses indicate that same-reporter variance bias should not be assumed in the absence of dyadic statistical analyses.     

Affordance-Based Control of Visually Guided Action

The purpose of this essay is to compare and contrast existing theoretical approaches to understanding the visual guidance of action and to introduce a new approach. The focus is on tasks, such as steering, braking, and intercepting, that are (more or less) continuously guided on the basis of visual information. The prominent approach, information-based control, captures important aspects of behavior but is incompatible with the theory of affordances, a core principle of the ecological approach. Information-based control also fails to capture how actors behave in ways that take the limits of their action capabilities into account. I attempt to resolve these problems by introducing a new approach, affordance-based control, which asserts that a primary function of vision is to allow actors to see the world in terms of what they can and cannot do. Affordance-based control captures the tight coupling between information in optic flow and movement that is characteristic of visually guided action but also provides a parsimonious explanation of how actors take into account the dynamic properties of their body and the environment.     

Opportunities for Sharpening the Stereotype Inoculation Model

The purpose of this article is to offer a conceptualization of rapport that has utility for identifying the nonverbal correlates associated with rapport. We describe the nature of rapport in terms of a dynamic structure of three interrelating components: mutual attentiveness,positivity, and coordination. We propose that the relative weighting of these components in the experience of rapport changes over the course of a developing relationship between individuals. In early interactions, positivity and attentiveness are more heavily weighted than coordination, whereas in later interactions, coordination and attentiveness are the more heavily weighted components. Because of the gestalt nature of the experience of rapport, it is not easy to identify nonverbal behavioral correlates of the components. We discuss two approaches to nonverbal measurement, molecular and molar, along with recommendations for their appropriate application in the study of rapport at different stages of an interpersonal relationship. We present a meta-analytic study that demonstrates the effect of nonverbal behavior, measured at the molecular level, on the positivity component of rapport, and we conclude with an outline of hypotheses relevant to the investigation of the nonverbal correlates of rapport.     

Do young children spell words syllabically? Evidence from learners of Brazilian Portuguese

The theory that learners of alphabetic writing systems go through a period during which they treat writing as representing syllables is highly influential, especially as applied to learners of Romance languages. The results of Study 1, a 2-year longitudinal study of 76 Portuguese speakers in Brazil from 4 to 6 years of age, did not support this theory. Although most children produced some spellings of words in which the number of letters matched the number of syllables, few children produced significantly more such spellings than expected on the basis of chance. When such spellings did occur, they appeared to reflect partially successful attempts to represent phonemes rather than attempts to represent syllables. Study 2, with 68 Brazilian 4- and 5-year-olds, found similar results even when children spelled words that contained three or four syllables in which all vowels are letter names—conditions that have been thought to favor syllabic spelling. The influential theory that learners of Romance languages go through a period during which they use writing to represent the level of syllables appears to lack a solid empirical foundation.     

The language of worry: Examining linguistic elements of worry models

Despite strong evidence that worry is a verbal process, studies examining linguistic features in individuals with generalised anxiety disorder (GAD) are lacking. The aim of the present study is to investigate language use in individuals with GAD and controls based on GAD and worry theoretical models. More specifically, the degree to which linguistic elements of the avoidance and intolerance of uncertainty worry models can predict diagnostic status was analysed. Participants were 19 women diagnosed with GAD and 22 control women and their children. After participating in a diagnostic semi-structured interview, dyads engaged in a free-play interaction where mothers' language sample was collected. Overall, the findings provided evidence for distinctive linguistic features of individuals with GAD. That is, after controlling for the effect of demographic variables, present tense, future tense, prepositions and number of questions correctly classified those with GAD and controls such that a considerable amount of the variance in diagnostic status was explained uniquely by language use. Linguistic confirmation of worry models is discussed.