The facets of anxiety sensitivity represented in the childhood anxiety sensitivity index: confirmatory analyses of factor models from past studies

Results of past factor analytic studies of the Childhood Anxiety Sensitivity Index and Anxiety Sensitivity Index were used to formulate hypotheses about factor models of anxiety sensitivity. Using a nonclinical sample of 767 children and adolescents and confirmatory factor analysis, hypothesized models with 2, 3, and 4 lower order factors (facets) were tested. Goodness-of-fit criteria indicated that a model with 4 facets fits these data well. Support was found for factorial invariance of the 4 facets across age and gender, using nonclinical and clinical samples. Results support a hierarchical factor model in that there was a strong general factor, explaining 71% of the variance. Findings are discussed in the context of anxiety sensitivity theory and research with children and adolescents.     

Reliability and validity of the Parent-Child Relationship Inventory (PCRI): evidence from a longitudinal cross-informant investigation

Psychometric properties of the Parent-Child Relationship Inventory (PCRI) were examined using data collected from adolescents and their parents in the Fullerton Longitudinal Study. Results revealed acceptable internal consistency for most scales and moderate to high 1-year stability for all scales. Both parents' PCRI scores correlated with their views of family climate. Cross-informant concordance was pervasive and strong between mothers' PCRI scores and adolescents' perceptions of the parent-child relationship and family climate; however, convergence was not evident between fathers' and adolescents' reports. Additionally, poor performance was observed for the Autonomy scale. In conjunction with other research on parent-adolescent relationships, concerns are raised regarding the utility of scales to contrast mother-adolescent with father-adolescent relationships.     

Age-related differences in head and trunk coordination during walking

The purpose of this study was to examine the effect of ageing on the pattern and structure of head and trunk accelerations during walking. Head and trunk accelerations of young (n=8; mean=23 years, SD=4 years) and elderly (n=8; mean=74 years, SD=3 years) individuals were measured using triaxial accelerometers while performing preferred speed walking. Accelerations were examined using power-spectral analysis and measures of signal smoothness, regularity and coupling. No differences in walking speed or signal regularity were detected between age groups. Compared to the young participants, the elderly had (1) a greater proportion of signal power above 6 Hz for the trunk, (2) a smaller difference in signal smoothness between the trunk and head, (3) less signal smoothness in the mediolateral direction, and (4) a greater degree of directional coupling for the head compared to the trunk. Overall these results suggest that the pattern of head accelerations was relatively unaffected by age, and that both age groups achieved similar levels of head stability despite differences in trunk acceleration characteristics. The manner in which head stability was achieved differed between age groups, with the elderly employing an upper body coordination strategy that enhanced coupling between acceleration directions of the head compared to the trunk. The findings of this study also suggest that an absence of age-related differences in signal complexity at one level of postural system, combined with differences at another level, may provide information about the way in which the motor system prioritises postural control during gait.     

Chromatic masking revealed by the standing wave of invisibility illusion

We have used the standing wave of invisibility illusion (Macknik and Livingstone, 1998 Nature Neuroscience 1 144-149) to examine the masking effects produced by a range of stimuli of varying chromatic and luminance contrast content. The pattern of masking was highly selective. Maximum effects were always obtained when the target and mask were identical in terms of their chromatic and/or luminance contrast composition, but were reduced as the angular separation in colour space between them was increased. Masking was of a monopolar nature, indicating the operation of rectified mechanisms selective for different combinations of colour and luminance contrast.     

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.     

Early Versus Late Onset of Spinal Cord Injury Among the Elderly

The objective of this study is to compare elderly individuals with late (60 years old) versus early (<60 years old) onset spinal cord injury (SCI) across quality of life (QOL) domains for which cross-sectional design was used. The outcome measures selected were secondary medical complications (e.g., pneumonia, autonomic dysreflexia, number of days hospitalized), Functional Independence Measure (FIM), Satisfaction With Life Scale (SWLS), and the Craig Handicap Assessment and Reporting Technique (CHART). Analyses between groups showed that individuals with SCI onset 60 years of age or older were significantly older, had a greater proportion of incomplete lesions, were more likely to have SCI resulting from medical complication, and were less likely to be working. After controlling for differences in demographic and lesion characteristics, the majority of QOL domains were similar between groups. However, overall self-reported handicap (CHART-total score) was significantly greater among elderly with late onset SCI, particularly in the areas of physical independence and social integration. Differences in QOL between elderly with late versus early onset SCI were most prominent in the area of physical independence and social integration. The importance of appropriate statistical control, theoretical implications, and future directions are discussed.     

Primate cognition: from 'what now?' to 'what if?'

The 'social brain' hypothesis has had a major impact on the study of comparative cognition. However, despite a strong sense, gained from both experimental and observational work, that monkeys and apes differ from each other, we are still no closer to understanding exactly how they differ. We hypothesize that the dispersed social systems characteristic of ape societies explains why monkeys and apes should differ cognitively. The increased cognitive control and analogical reasoning ability needed to cope with life in dispersed societies also suggests a possible route for human cognitive evolution. This hypothesis is supported by behavioural and neurobiological data, but we need more of both if we are to fully understand how our primate cousins see the world.