Strategies used by children when solving simple subtractions

Ten children, 9–11 years old, solved all subtraction problems in the form of M?N=…, where 0 ? M ? 13, 0 ? N ? 13 and M ? N. The solution times were analysed and used for the formulation of a process model for subtraction. The model involves memory processes on two different levels, called reproductive and reconstructive respectively. When M=N, N=1, and M=2N the answers were quickly retrieved in reproductive memory processes. The reconstructive processes were found to be analogous to one of two counting procedures, viz. counting up and counting down. In general, the counting process starts either on N (when M < 2N) and counts up to reach the answer, or on M (when M > 2N) and counts down to reach the answer. This may reflect an effort to minimize the number of steps to be counted. However, when M > 10 and N < 10 a problem is always solved in a decrementing counting process. When M=10 many subtractions are solved in a reproductive memory process and the number 10 is also important as a point of reference for solving subtractions when M > 10 and N < 10.     

On the role of otoliths and semicircular canals in spatial orientation: Dynamics of the visually perceived eye level during gondola centrifugation

The visually perceived eye level (VPEL) was measured during gondola centrifugation. Subjects (N = 11) were seated upright, facing motion in a swing-out gondola The head was adjusted so that Reid's baseline was tilted 10 degrees anterior end up. The subjects were requested to adjust the position of a small luminous dot so that it was perceived as gravitationally at eye level. In the 1-g environment, the VPEL was a few degrees below the true gravitational eye level (M = -1.75 degrees, SD = 1.90 degrees). After rapid acceleration of the centrifuge to 2 G (vectorial sum of the earth gravity force and the centrifugal force), there was an exponentially increasing depression of the VPEL. The initial value was -6.4 degrees +/- 5.2 degrees. During 10 min at 2 G, the VPEL approached an asymptotic value of -24.8 degrees +/- 5.4 degrees. The time constant showed a large interindividual variability, ranging from 59 to 1,000 sec (M = 261 sec, median = 147 sec). The findings are discussed, taking into consideration otolith-semicircular-canal interaction, as well as memory functions of the vestibular system.     

Cognitive bias and attitude distortion of a priority decision

Cognitive Processing - The resource saving bias is a cognitive bias describing how resource savings from improvements of high-productivity units are overestimated compared to improvements of less...     

The Swedish version of the parent-rated Junior Temperament and Character Inventory (J-TCI)

To evaluate the psychometric characteristics of the Swedish version of the Junior Temperament and Character Inventory (J-TCI), it was sent to parents of 9- and 12-yr.-old twins in Sweden. The final number of responders was 196 parents who rated 92 female and 104 male twin pairs. The inventory of one twin, randomly chosen from each pair, was included in the analyses. Reward Dependence, Persistence, and Cooperativeness were scored higher in girls; Novelty Seeking was higher in the 9-yr.-olds and Persistence in the 12-yr.-olds. Pearson's correlations showed that some dimensions were not statistically independent from each other, even if the covariance was moderate. Internal consistency (Cronbach's alpha) was satisfactory for Harm Avoidance, Novelty Seeking, Self-Directedness, and Cooperativeness (.68-.81), while it was lower in those dimensions that had fewer items. The Swedish parent version of the J-TCI shared about the same psychometric characteristics as found in international samples.