Limb and gender differences in the development of coordination in early infancy

Young infants produce a variety of spontaneous arm and leg movements in the first few months of life. Coordination of leg joints has been extensively investigated, whereas arm joint coordination has mainly been investigated in the sitting position in the context of early reaching and grasping. The current study investigated arm and leg joint coordination of movements produced in the supine position in 10 fullterm infants aged 6, 12 and 18 weeks. Longitudinal comparisons within limbs (intralimb) as well as between limbs (interlimb, ipsilateral and contralateral) were made as well as an exploration of differences in the development for boys and girls. The relationship between the joint angles was examined by measuring pair-wise cross-correlation functions for the angular displacement curves of the leg (hip, knee and ankle) and arm (shoulder, elbow and wrist) joints of both the right and left side. Both the arms and legs were found to follow a similar pattern of intralimb coordination, although the leg joints were more tightly coupled than the arm joints, particularly the proximal with the middle joint. In support of earlier findings, differences in the development of the right and left side were identified. In addition, gender differences in joint coordination were found for both intralimb and interlimb coordination. This contrasts with the view that gender differences in motor development may be primarily a result of environmental influences.     

The dynamics of threat and challenge appraisals prior to stressful achievement events

Research on cognitive appraisal of stressful achievement events has emphasized threat appraisals and anxiety. The present research also focused on challenge and positive emotion. Study 1 used hypothetical scenarios of stressful events. Study 2 explored temporal pattems of appraisal and emotion prior to an exam. Compared with threat appraisals, trait and state challenge appraisals were associated with more confident coping expectancies, lower perceptions of threat, higher positive emotion, and more beneficial perceptions of the effects of appraisal and emotion on performance. Beneficial perceptions of state appraisals were associated with higher exam performance. These findings were interpreted in the context of theoretical perspectives on the cognitive appraisal of stressful events and the adaptive functions of challenge and positive emotion.     

Extinction of conditioned odor potentiation of startle

Several recent studies with rats (Sprague-Dawley strain) have documented that an odor previously paired with shock potentiates the acoustic startle response, a phenomenon referred to as conditioned odor potentiation of startle (OPS). A surprising finding in these studies was that OPS did not extinguish even though the odor was present throughout the 25-min test session. Therefore, the present study more fully examined extinction of OPS. The results of Experiment 1, which employed both within-subject and between-group comparisons, showed that extinction of OPS occurred in adult rats only after several days of testing. Experiment 2 used the between-group procedure and found similar results with 23-day-old rats, the youngest age that exhibits the OPS effect. Experiment 2 also showed that giving rats 15 odor-shock pairings at 16 days of age, an age where they acquire the odor-shock association but cannot express it via OPS, does not increase subsequent resistance to extinction following odor-shock pairings at 23 days of age. Taken together, the results of this study show that (1) although OPS is somewhat resistant to extinction, it does extinguish with repeated tests and (2) suggests that there are no age differences in the rate of extinction of OPS.     

Screening for Depression After Stroke: Occupational Therapists' Performance to Protocols

The ability of occupational therapists to enact post-stroke depression screening protocols was considered. The medical notes of 12 patients admitted to an in-patient stroke unit over a 3-month period were consulted to assess timely, appropriate administration, interpretation, and recording of the results of administering the protocols. Post-stroke depression screening by occupational therapists occurred for 83% of patients. Of the screens conducted, all of the patients were administered the correct tool. In 100% of cases screened, the outcome was recorded and in at least 80% clinicians had provided feedback to the patient on the results of the screen.     

Relationship Commitment and Perceptions of Harm to Self

Commitment to a relationship is associated with a number of consequences, including willingness to sacrifice for the relationship, greater cognitive interdependence between partners, and increased trust in one's partner. Consistent with such consequences, we hypothesized that greater commitment is associated with decreased perceptions of one's partner as a source of harm to the self. We conducted two studies (one correlational, one experimental) to test hypotheses regarding the association between commitment level and personal harm perceptions, based on tenets from interdependence theory and balance theory. Study 1 revealed significant negative associations between commitment and personal harm perceptions. Results from Study 2 suggest that greater commitment leads to decreased perceptions of partner-based risk and increased risky behavioral tendencies.     

Conduction-electron mediated 1H nuclear spin-lattice relaxation in Ti45Zr38Ni17H x icosahedral quasicrystals

Nuclear magnetic resonance spin-lattice relaxation rates for ¹H in quasicrystalline Ti₄₅Zr₃₈Ni₁₇H _x are presented as a function of temperature and hydrogen concentration x. The temperature dependence demonstrates that the relaxation is via interaction with conduction electrons. The relaxation rate is extremely sensitive to hydrogen content, with the rate changing by a factor of as much as two for samples that differ in x     

Continuous Cognitive Tasks Improve Postural Control Compared to Discrete Cognitive Tasks

Research suggests that postural control synergies are sensitive to cognitive manipulations; however, the impact of different types of cognitive tasks on postural control remains inconclusive. The authors examined the effect of discrete and continuous tasks on postural control. Sixteen healthy young adults (M age = 22.7 ± 2.2 years) stood with feet together on a force platform while performing randomly assigned discrete and continuous cognitive tasks. Results demonstrated marked improvements in the area of 95% confidence ellipse and the standard deviation of the center of pressure in the anterior-posterior and medial-lateral directions for continuous compared to discrete tasks. This reinforces the notion that continuous tasks are sufficient in providing less opportunity to consciously attend to postural control, thereby facilitating automatic postural control.     

The relation of parenting,child temperament,and attachment security in early childhood to social competence at school entry

A wealth of research demonstrates the importance of early parent–child interactions on children's social functioning. However, less is known about the interrelations between child and parent characteristics and parent–child interactions in early childhood. Moreover, few studies have broadly examined the longitudinal relations between these constructs and social competence. This study is an examination of the relations between parent responsiveness, negativity, and emotional supportiveness, attachment security, and child temperament, and their impact on children's social competence from infancy to kindergarten entry. The sample was derived from the Early Childhood Longitudinal Study – Birth Cohort and included 6850 parent–child dyads. Observational and rating scale data were used. The proposed model was nearly fully supported by path analysis, and it provides insight into the complex relations between early parenting behaviors, child characteristics, and parent–child interactions in the development of social competence.     

Laypeople do use sample variance: The effect of embedding data in a variance-implying story

When using sample data to decide whether two populations differ, laypeople attend to the difference between group means, but largely overlook within-group variability (Obrecht, Chapman, & Gelman, 2007 Obrecht, N. A., Chapman, G. B. and Gelman, R. 2007. Intuitive t-tests: Lay use of statistical information. Psychonomic Bulletin & Review, 14: 1147–1152.  [Google Scholar]). We show, first, that laypeople know about and use story-implied variability when making pairwise comparisons. Then we demonstrate that participants’ sensitivity to variance in a dataset is boosted when presented in a context that implies consistent variance information. Statistical data were couched in stories about electrical conductivity measurements obtained from element samples (low-variability category) or body weight measurements from samples of peoples (high-variability category). We manipulated, between participants, whether the data variance matched or mismatched the story-implied variability. Participants who received data in a matching context showed high sensitivity to variance, while those in the mismatching condition did not. Laypeople use statistical data to make reasonable inferences when those data are provided in a context that makes sense.