Changing Sensitivity to Duration in Human Scalar Timing: An Experiment, a Review, and Some Possible Explanations

Evidence from a number of studies of human timing, using temporal generalization and bisection tasks, suggests more sensitive behavioural adjustment to presented durations under conditions in which the timing task demands discriminations between more closely spaced stimuli. An experiment using temporal generalization demonstrated this effect, as discrimination between a 600-msec standard duration and non-standard stimuli both shorter and longer than 600 msec was better when non-standard stimuli were more closely spaced around 600 msec. A review showed similar effects in other temporal generalization tasks and in a number of bisection studies, where time discrimination improved as the ratio of the long and short standards on the bisection task decreased. A standard model of human temporal generalization explained the experimental data in terms of a decrease in the response threshold under more difficult conditions, rather than changes in the representation of the standard duration. On the other hand, data from bisection could be modelled by assuming the contrary; that representations of the short and long standards of the task were more precise under the more difficult conditions. Explanations of some of these effects in terms of attention to duration and/or arousal-induced changes in the speed of an internal clock were discussed.     

Finding Where and Saying Where: Developmental Relationships Between Place Learning and Language in the First Year

The relationship between emergent spatial understanding in different cognitive domains, including navigation and language, has rarely been studied using methods that allow for the examination of individual differences. In this study the authors explored emergent place learning and its relationship to early spatial language, namely prepositions, in 16- to 24-month-old children. Children were tested using a spatial task adapted from the Morris water maze, and the MacArthur Communicative Development Inventory. In the place-learning task, children were placed in a circular enclosure and a puzzle was hidden under the floor at one location. Before each trial, children were disoriented and placed in the maze at a different starting position. Their search types and success at finding the puzzle were coded. As expected, older children demonstrated more spatial searches and better place-learning skills (finding the goal), as well as greater overall expressive vocabulary. Place learning and language did not correlate with each other once age was partialled, with one crucial exception: a theoretically predicted correlation between prepositions and goal localization.     

Altered Cortico-Limbic Functional Connectivity During an Empathy Task in Subjects with Post-Traumatic Stress Disorder

Empathy is a multidimensional construct consisting of cognitive (inferring mental states) and emotional (empathic concern) components. Emotional empathy is severely impaired in individuals affected by Post-Traumatic Stress Disorder (PTSD). Here, we investigated the neural correlates of such an emotional empathy dysfunction to shed light on the neural circuitry responsible for the social and emotional dysfunction in PTSD. We asked a group of PTSD and a group of healthy controls to solve a Multifaceted Empathy Test, measuring both cognitive and emotional empathy, and investigated the functional connectivity of the cortical areas involved in solving the test. The results revealed that, in healthy individuals, increased neural activity in the frontal cortex modulates activity in the insula while subjects perform the emotional empathy task; whereas, in individuals affected by PTSD, increased activity in limbic regions such the insula and the amygdala modulates activity in the frontal cortex while performing the emotional empathy task. These findings suggest that the lack of cortical top-down control of the frontal cortex on the limbic system in PTSD during empathic processing may explain the emotional and social difficulties experienced by individuals suffering from PTSD.     

Manual Movement in Sign Languages: One Hand Versus Two in Communicating Shapes

In sign languages, the task of communicating a shape involves drawing in the air with one moving hand (Method One) or two (Method Two). Since the movement path is iconic, method choice might be based on the shape. In the present studies we aimed to determine whether geometric properties motivate method choice. In a study of 17 deaf signers from six countries, the strongest predictors of method choice were whether the shape has any curved edges (Method One), and whether the shape is symmetrical across the Y‐axis (Method Two), where the default was Method One. In a second study of ASL dictionary entries for which the movement path of the sign is iconic of an entity's shape, the same predictors surfaced. These tendencies are captured in the Lexical Drawing Principle, which is coherent with biological constraints on movement in general. Drawing in the air with two hands, however, is costly, both cognitively and biomechanically. Furthermore, it distinguishes signers from non‐signers, who draw shapes with only one hand. Signers assume this extra cost in the lexicon because of the enhanced iconicity the possibility of two hands offers; they assume it in drawing shapes in the air because they apply the same linguistic principle they use in the lexicon. Additionally, having a choice of methods allows the signer to benefit from over‐specification in providing redundant information about the shape, enhancing comprehensibility and resolving ambiguity.     

Ferrajoli’s Argument for Structural Entrenchment

This paper engages with Ferrajoli’s contribution to the philosophical debate on constitutional democracy and in particular his conception of ‘structural entrenchment’, or the basis upon which one can defend the normativity of the Constitution as ‘higher law’, which can trump or limit legislation, without infringing democratic principles. Ferrajoli’s own understanding of ‘structural entrenchment’ is compared to Rawls’s and Dworkin’s arguments in support of it. Ferrajoli’s position is neither grounded on a philosophy of history, as in Rawls, nor on a version of moral realism, as for Dworkin, but on a formal understanding of the nature of fundamental rights, and in a conception of democratic sovereignty as ‘joint ownership.’     

Well-Being Indicators and Convergence Across Italian Regions

This article studies convergence across Italian regions by means of two composite indicators of socio-economic progress reflecting the multidimensional nature of human well-being. The first composite indicator includes, other than household disposable income in Italy, two sub-indicators regarding health and education; the second composite indicator considers, in addition to those considered by the former, three further sub-indicators relating to the quality of the socio-institutional context, age and gender disparities in the labor market and regional competitiveness. The data base of the 17 variables or indexes used to construct the six abovementioned sub-indicators cover the period from 1998 to 2008. We assess the existence of both σ and γ- convergence; the latter computed by means of Kendall′s index. Consistent with the findings in other European countries that also use composite economic and quality of life indicators we find evidence of regional σ-convergence in well-being, but do not observe significant processes of intra-distributional mobility. In other words, while dispersion across Italian regions in terms of well-being levels declined in the period, the regional ranking remained substantially unchanged.     

Using a touch screen paradigm to assess the development of mental rotation between 3½ and 5½ years of age

Mental rotation is an important spatial skill. However, there is controversy concerning its early development and susceptibility to intervention. In the present study, we assessed individual differences in the mental rotation abilities of children between 3½ and 5½ years of age, using a touch screen paradigm to simplify task demands. A figure or its mirror image was presented in 8 different orientations, and children indicated in which of two holes the figure would fit by touching one of the holes on the screen. Task instructions were varied in three conditions, giving the children the opportunity to gather manual or observational experience with rotations of different stimuli, or giving no additional experience. Children’s error rates and response times increased linearly with increasing angular disparity between the figure and the hole by the age of 5 years, but 4-year-olds were found to respond at chance for all angular disparities, despite the use of a touch screen paradigm. Both manual and observational experience increased the response accuracy of 5-year-olds, especially for children already performing well. However, there was no effect on 4-year-olds. Results point to an emerging readiness to use mental rotation and profit from observational and manual experience at age 5.     

Probabilistic Disjoint Principal Component Analysis

One of the most relevant problems in principal component analysis and factor analysis is the interpretation of the components/factors. In this paper, disjoint principal component analysis model is extended in a maximum-likelihood framework to allow for inference on the model parameters. A coordinate ascent algorithm is proposed to estimate the model parameters. The performance of the methodology is evaluated on simulated and real data sets.