Maternal cradling bias drives early handedness in infant monkeys: A longitudinal study of grasping lateralization in baboons

The most emblematic behavioral manifestation of human brain asymmetries is handedness. While the precise mechanisms behind the development of handedness are still widely debated, empirical evidences highlight that besides genetic factors, environmental factors may play a crucial role. As one of these factors, maternal cradling behavior may play a key role in the emergence of early handedness in the offspring. In the present study we followed 41 olive baboon (Papio anubis) infants living in different social groups with their mother for which direction (e.g., left- or right-arm) and degree of maternal cradling-side bias were available from our previous published study. We assessed hand preferences for an unimanual grasping task at 3 developmental stages: (1) 0-4, (2) 4-6 and (3) 9-10 months of age. We found that individual hand preferences for grasping exist as soon as the first months of age, with a population-level left-handedness predominance, being stable until 6 months; to wit the period during which juveniles are mainly carried by their mothers. More importantly, this early postnatal handedness is positively correlated with maternal cradling lateralization. Interestingly, hand preferences assessed later in the development, once juveniles are no longer carried (i.e., from 9 to 10 months of age), are less consistent with the earlier developmental stages and no longer dependent from the maternal cradling bias. Our findings suggest that the ontogenetic dynamics of the infant’s hand preference and its changes might ultimately rely on the degree of infant dependence from the mother across development.Research HighlightsEarly postnatal individual hand preferences are detected for unimanual food grasping within the first four months of age.Earliest measures of infant hand preference are positively correlated with measures of maternal cradling lateralization.Hand preferences assessed later in the development, from 9 to 10 months of age are less consistent with the earlier developmental stages and independent from maternal cradling bias.

Investigating Vibration Acceleration of a Segmented Piezoelectric Ciliary-Like Body Beam for a Tactile Feedback Device

A piezoelectric Ciliary-like body beam of a tactile feedback device can realize a touchpoint of different tactile sensations under simple control when the finger movement changes to the opposite direction. In a previous published study, the friction of touch sensation was shown to depend on the acceleration of forced vibration of the ciliary-like body beam. For investigating the system parameters’ effect on vibration accelerations, the dynamic model of forced vibration of the touch beam is established, and the steady-state response of the touch beam excited by piezoelectric sheets is deduced. The influence of instantaneous acceleration and average acceleration of the touch beam on skin was analyzed, and an experiment was conducted to prove the theoretical analysis. The study results show that larger excitation voltage, larger piezoelectric constants, smaller elasticity modulus, and smaller damping ratio would enhance the displacement and acceleration of the forced response of the touch beam. Through the experimental results, the working mode and frequency of the touch beam was obtained, and the correctness of the theoretical analysis was verified.

Prevalence of obesity and metabolic syndrome in a long-stay psychiatric unit

Objective:The aim of this study was to determine the prevalence of metabolic syndrome and obesity as defined by Body Mass Index (BMI) in a long-stay psychiatric unit where all care is provided by the psychiatric team.Method:All residents in this long-stay unit were screened. Their BMI was calculated. Waist circumference and blood investigations were done. Ward records were used to determine those who had been previously diagnosed with hypertension and diabetes. The ATP 111 criteria were used to determine the prevalence of metabolic syndrome.Results:We found a prevalence of 33% for BMI obesity and a prevalence of 66% for metabolic syndrome. These are higher than those of the general Irish middle aged population and the accepted estimate of a general psychiatric population. It is also higher than that of a previous published study on an Irish long-stay psychiatric ward population.Conclusion:There is high prevalence of BMI obesity and metabolic syndrome in long-stay psychiatric residents. This has the potential to impact significantly on physical morbidity and mortality. People with severe and enduring mental illness should have access to primary care and other health services on the same basis as any other citizen.

What Violent Offenders Remember of their Crime: Empirical Explorations∗

Little systematic evidence is available about how violent offenders remember and think about their violent crimes. The general aim of this article is to selectively review a range of different ‘types’ of memory disturbance and their risk factors, in an attempt to draw together different strands of research concerning memories of offending that might usefully be considered together for clinical purposes. A selective review of psychiatric or psychological studies related to amnesia, intrusive memories, posttraumatic stress disorder (PTSD), ruminations, and pleasurable memories was performed. The body of research on amnesia in relation to violent crime is relatively small and is subject to significant limitations. The empirical base of studies identifying intrusive memories arising from violent crime is also very limited, with no previous published study primarily focusing on description of the form and content of intrusive memories related to acts of violence in a population of violent offenders. A small number of studies have investigated PTSD directly arising from the commission of a violent or sexual crime, in those with mental illness. No published studies that investigated the presence of ruminations related to violent offending were identified. No systematic comparative studies were identified that described the form and content that positive memories of non-sexual violence might take. Relevant phenomenological reports from extreme populations raise concerns about selection bias. A memory-based approach to eliciting descriptions of violent offending may elicit clinical information relevant to violence risk assessment and therapeutic interventions within forensic settings.