The generative basis of natural number concepts

Number concepts must support arithmetic inference. Using this principle, it can be argued that the integer concept of exactly ONE is a necessary part of the psychological foundations of number, as is the notion of the exact equality - that is, perfect substitutability. The inability to support reasoning involving exact equality is a shortcoming in current theories about the development of numerical reasoning. A simple innate basis for the natural number concepts can be proposed that embodies the arithmetic principle, supports exact equality and also enables computational compatibility with real- or rational-valued mental magnitudes.     

The Dynamics of Visual Reweighting in Healthy and Fall-Prone Older Adults

Multisensory reweighting (MSR) is an adaptive process that prioritizes the visual, vestibular, and somatosensory inputs to provide the most reliable information for postural stability when environmental conditions change. This process is thought to degrade with increasing age and to be particularly deficient in fall-prone versus healthy older adults. In the present study, the authors investigate the dynamics of sensory reweighting, which is not well-understood at any age. Postural sway of young, healthy, and fall-prone older adults was measured in response to large changes in the visual motion stimulus amplitude within a trial. Absolute levels of gain, and the rate of adaptive gain change were examined when visual stimulus amplitude changed from high to low and from low to high. Compared with young adults, gains in both older adult groups were higher when the stimulus amplitude was high. Gains in the fall-prone elderly were higher than both other groups when the stimulus amplitude was low. Both older groups demonstrated slowed sensory reweighting over prolonged time periods when the stimulus amplitude was high. The combination of higher vision gains and slower down weighting in older adults suggest deficits that may contribute to postural instability.     

Self-efficacy as a health-protective resource in teachers? A biopsychological approach

OBJECTIVE: To examine the psychobiological correlates of self-efficacy in teachers. DESIGN: Study 1 examined associations between teacher self-efficacy and cardiac activation on a working day and Study 2 assessed the cortisol morning response in teachers with varying levels of teacher self-efficacy. MAIN OUTCOME MEASURES: Teacher self-efficacy was assessed by questionnaire. In Study 1 heart rate, heart rate variability, and locomotor activity were recorded by 22 hours ambulatory monitoring and subjective measures of stress and strain were obtained. Study 2 assessed the cortisol response to awakening to obtain a measure of HPA-axis activation and teachers filled in a questionnaire on physical complaints. RESULTS AND CONCLUSION: Study 1 found that self-efficacy proved protective for psychological well-being. Moreover, after controlling for locomotor activity, demographic, and lifestyle variables, self-efficacy was associated with elevated heart rate and attenuated heart rate variability during school and leisure time, respectively, but not during the night, thus questioning the health-implications of self-efficacy. Study 2 found that teachers high in self-efficacy exhibited an attenuated cortisol response to awakening and fewer cardiac complaints. The results of both studies are compatible with the view that teacher self-efficacy might act as a physiological toughening agent with possibly favorable health outcomes.