Rotational inertia and multimodal heaviness perception

Perceived heaviness of wielded objects has been shown to be a function of the objects’ rotational inertia—the objects’ resistance to rotational acceleration. Studies have also demonstrated that if virtual objects rotate faster than the actual wielded object (i.e., a rotational gain is applied to virtual object motion), the wielded object is perceived as systematically lighter. The present research determined whether combining those inertial and visual manipulations would influence heaviness perception in a manner consistent with an inertial model of multimodal heaviness perception. Rotational inertia and optical rotational gain of wielded objects were manipulated to specify inertia multimodally. Both visual and haptic manipulations significantly influenced perceived heaviness. The results suggest that rotational inertia is detected multimodally and that multimodal heaviness perception conforms to an inertial model.     

Atypical long-latency auditory event-related potentials in a subset of children with specific language impairment

It has been proposed that specific language impairment (SLI) is the consequence of low-level abnormalities in auditory perception. However, studies of long-latency auditory ERPs in children with SLI have generated inconsistent findings. A possible reason for this inconsistency is the heterogeneity of SLI. The intraclass correlation (ICC) has been proposed as a useful statistic for evaluating heterogeneity because it allows one to compare an individual's auditory ERP with the grand average waveform from a typically developing reference group. We used this method to reanalyse auditory ERPs from a sample previously described by Uwer, Albrecht and von Suchodoletz (2002). In a subset of children with receptive SLI, there was less correspondence (i.e. lower ICC) with the normative waveform (based on the control grand average) than for typically developing children. This poorer correspondence was seen in responses to both tone and speech stimuli for the period 100-228 ms post stimulus onset. The effect was lateralized and seen at right- but not left-sided electrodes.     

Evidence for a neuroendocrinological foundation of human affiliation: plasma oxytocin levels across pregnancy and the postpartum period predict mother-infant bonding

Although research on the neurobiological foundation of social affiliation has implicated the neuropeptide oxytocin in processes of maternal bonding in mammals, there is little evidence to support such links in humans. Plasma oxytocin and cortisol of 62 pregnant women were sampled during the first trimester, last trimester, and first postpartum month. Oxytocin was assayed using enzyme immunoassay, and free cortisol was calculated. After the infants were born, their interactions with their mothers were observed, and the mothers were interviewed regarding their infant-related thoughts and behaviors. Oxytocin was stable across time, and oxytocin levels at early pregnancy and the postpartum period were related to a clearly defined set of maternal bonding behaviors, including gaze, vocalizations, positive affect, and affectionate touch; to attachment-related thoughts; and to frequent checking of the infant. Across pregnancy and the postpartum period, oxytocin may play a role in the emergence of behaviors and mental representations typical of bonding in the human mother.     

Spousal similarity in coping and depressive symptoms over 10 years.

Following a baseline sample of 184 married couples over 10 years, the present study develops a broadened conceptualization of linkages in spouses' functioning by examining similarity in coping as well as in depressive symptoms. Consistent with hypotheses, results demonstrated (a) similarity in depressive symptoms within couples across 10 years, (b) similarity in coping within couples over 10 years, and (c) the role of coping similarity in strengthening depressive similarity between spouses. Spousal similarity in coping was evident for a composite measure of percent approach coping as well as for component measures of approach and avoidance coping. The role of coping similarity in strengthening depressive symptom similarity was observed for percent approach coping and for avoidance coping. These findings support social contextual models of psychological adjustment that emphasize the importance of dynamic interdependencies between individuals in close relationships.     

Postural stabilization of perceptual but not cognitive performance

In 2 experiments, the authors independently varied the degree of cognitive and perceptual difficulty of suprapostural tasks. Participants were 23 students in Experiment 1 and 15 in Experiment 2. Increases in perceptual difficulty tended to be correlated with decreases in the variability of postural sway, consistent with the hypothesized functional integration of postural control with suprapostural tasks. Sway variability was not influenced by changes in the cognitive difficulty of tasks when perceptual difficulty was held constant, contrary to predictions derived from the perspective that postural and suprapostural activities compete for a limited pool of central processing resources. The results underscore the need for researchers to differentiate between suprapostural tasks that require perceptual contact with the environment and those that do not.