Perceiving affordances for joint actions

Two individuals acting together to achieve a shared goal often have an emergent set of afforded behavioral possibilities that may not easily reduce to either acting alone. In a series of experiments we examined the critical boundaries for transitions in behavior for individuals walking through an aperture alone or alongside another actor as a dyad. Results from experiment 1 indicated that an intrinsically scaled critical boundary for behavioral transitions was different in individuals than in dyads performing a similar task. Experiment 2 demonstrated that observers are perceptually sensitive to the difference in action parameters for the dyad, while still maintaining perceptual sensitivity about the boundaries of action relative to individuals. In experiment 3, we determined that observers' perception of critical action boundaries for individuals and dyads has a similar informational basis (eye-height scaling). In experiment 4, we demonstrated that observers were able to perceive critical action boundaries for other dyads independently of membership. Together, these results suggest that individuals are sensitive to the affordances related to a joint action, and that this process may not entirely reduce to the perception of the affordances for each individual.     

An information-based approach to action understanding

It has been proposed that the ability to make sense of other agents' behavior relies on the activation of internal mechanisms that map action perception onto action execution. In this study we explored the constraints on this ability introduced by eyeheight-scaled information in the optic array. Short and tall participants provided maximum overhead reaching judgments for themselves and another participant. Perceptual information was manipulated by changing the participants' optically specified eyeheight. Observers were modestly accurate in perceiving maximum overhead reach for themselves and for another actor whose action capabilities differed. Perceived maximum overhead reach increased for both self- and other-judgments when the perceiver's eyeheight was increased. The results suggest an important role of perceptual information that has gone unrecognized in existing accounts of action understanding and prediction.     

Resources for health: a primary-care-based diet and physical activity intervention targeting urban Latinos with multiple chronic conditions.

OBJECTIVE: The Resources for Health trial evaluates a social-ecologically based lifestyle (physical activity and diet) intervention targeting low-income, largely Spanish-speaking patients with multiple chronic conditions. DESIGN: A randomized controlled trial was conducted with 200 patients recruited from an urban community health center and assigned to intervention and usual care conditions. Intervention involved 2 face-to-face, self-management support and community linkage sessions with a health educator, 3 follow-up phone calls, and 3 tailored newsletters. MAIN OUTCOME MEASURES: Primary outcomes measured at 6-months were changes in dietary behavior and physical activity. Changes in multilevel support for healthy living were evaluated as a secondary outcome. RESULTS: After adjustment for age, sex, language, and number of chronic conditions, significant intervention effects were observed for dietary behavior and multilevel support for healthy lifestyles but not for physical activity. CONCLUSION: The Resources for Health intervention provides an effective and practical model for improving health behavior among low-income, Spanish-speaking patients with multiple chronic conditions.     

Rotational kinematics influence multimodal perception of heaviness

Perceived heaviness has been shown to be specific to an object’s rotational inertia (I ), its resistance to rotational acceleration. According to the kinematic specification of dynamics (KSD) principle, we hypothesized that I is optically specified by rotational kinematics. Using virtual depictions of wielded objects, we investigated whether the visually detected rotational kinematics of wielded objects would influence perceived heaviness in a manner consistent with the inertial model of heaviness perception. We scaled the virtual object’s movement so that it rotated more or less than its wielded counterpart, specifying lower and higher I, respectively. Perceived heaviness was inversely related to the rotational scaling factor, consistent with a KSD interpretation of the inertial model.     

Oral motor discoordination among children who stutter

A large body of literature describes subtle oral motor differences among people who stutter, which are not typical of other speakers. The purpose of this report was to propose that oral motor discoordination (OMD) can be assessed and treated, and that such treatment may be useful prior to targeting perceived stuttering behaviors.

Oral motor coordination (correct voicing, smooth coarticulation, proper sequencing, and age appropriate rate of production of syllables) was assessed using an Oral Motor Assessment Scale. An oral motor training program was described that improved OMD 78% after 14 hours of training in nine children. Stuttering was improved 62% by the training, although it was not specifically targeted. This report proposes that improvement in OMD and reduction of stuttering may be reciprocal (i.e., treatment of one may produce improvement in the other as a byproduct). It may be that OMD is among the physiologic features that can cause post-treatment fluency to be “tenuous.” Its inclusion in treatment programs may improve maintenance and naturalness of fluency.     

Comparatives,logical structures,and encoding in a transitive inference task

Four- to five-year-old children were asked questions on length involving single or double comparatives in a transitive inference task. The number of comparatives varied within or across pairs. The pairs of sticks were colorcoded. Initial pair-wise discrimination training on four adjacent pairs from a five-stick array with only verbal feedback was followed by tests, without feedback, on all possible pairs. When both comparatives were used, Ss learned adjacent pairs faster and more often reached criterion than when only one comparative term was used in training. In testing, Ss were successful on transitive inference tests only when the double-comparative relation was used within pairs during training. Retraining with visual feedback increased the number of Ss solving the inference test only in this condition. The findings are discussed in terms of how children may use processes other than logical operations to make transitive inferences.     

Mentoring Among Women Lawyers1

Considerable controversy exists as to both the nature and efficacy of mentoring among women professionals. As noted by Wrightsman, this controversy persists largely because researchers have failed to use a common scientific definition of the concept. In the present research a survey of existing studies was used to set a more stringent criterion of mentoring than that usually employed. Data were then gathered from a sample of women lawyers in the State of Oregon. Results indicated that those meeting the more stringent criterion perceived themselves as more successful and satisfied in their careers than those not meeting it. Those women who said that they had mentors but who did not meet the criterion reported themselves as less successful and satisfied than those who claimed to have a mentor and met the criterion. These results are seen as demonstrating the value of the more stringent criterion as well as the possible value of true mentors to women professionals.     

A multigroup confirmatory factor analysis of the Patient Health Questionnaire-9 among English- and Spanish-speaking Latinas

Depression is a significant problem for ethnic minorities that remains understudied partly due to a lack of strong measures with established psychometric properties. One screening tool, the Patient Health Questionnaire-9 (PHQ-9), which was developed for use in primary care has also gained popularity in research settings. The reliability and validity of the PHQ-9 has been well established among predominantly Caucasian samples, in addition to many minority groups. However, there is little evidence regarding its utility among Hispanic Americans, a large and growing cultural group in the United States. In this study, we investigated the reliability and structural validity of the PHQ-9 in Hispanic American women. A community sample of 479 Latina women from southern California completed the PHQ-9 in their preferred language of English or Spanish. Cronbach's alphas suggested that there was good internal consistency for both the English- and Spanish-language versions. Structural validity was investigated using multigroup confirmatory factor analysis. Results support a similar one-factor structure with equivalent response patterns and variances among English- and Spanish-speaking Latinas. These results suggest that the PHQ-9 can be used with confidence in both English and Spanish versions to screen Latinas for depression.     

Advantages of rhythmic movements at resonance: minimal active degrees of freedom, minimal noise, and maximal predictability

Using time delay embedding, the authors applied phase space reconstruction to the time series of rhythmic movements of a hand-held pendulum. Subjects (N = 6) produced the manual oscillations about the wrist at the pendulum's resonant frequency and at a higher and a lower frequency. The number of active degrees of freedom required to capture the dynamics of the rhythmic behavior was 3 for the resonant frequency and 4 for each of the nonresonant frequencies. The residual high-dimensional noise was similarly lowest for the resonant frequency. Whereas 33% and 20%, respectively, of the vectors in the phase spaces of the dynamics higher and lower than resonance were unpredictable, only 12% were unpredictable at resonance. Finally, the predictability of the evolving dynamics extended farther into the future for oscillations at the resonant frequency. At resonance, the prediction horizon was 5 times farther than the prediction horizon for the higher than resonance behavior and 2.5 times farther than that for the lower than resonance behavior. The results suggest that, in pendular oscillations of a limb or limb segment, attunement of the central nervous system to the resonant frequency minimizes the variables to be controlled and maximizes the predictability of the rhythmic movement's chaotic dynamics.