Reference frame effects on shape perception in two versus three dimensions

Three experiments are reported in which it is tested whether the Gestalt effect of configural orientation on shape perception operates on two-dimensional (2-D) or three-dimensional (3-D) representations of space. It is known that gravitationally defined squares and diamonds take longer to discriminate in diagonal arrays than in horizontal or vertical arrays. In the first experiment it is shown that this interference effect decreases dramatically in magnitude when pictorial depth information is added so that subjects perceive the target shapes in different depth planes. In the second experiment this difference is shown not to be due to relative size of the target shapes or to occlusion of a background plane. It is also shown, in the final experiment, that this difference is not due to linear perspective information or merely to perception of the target figures in a 3-D scene. The overall pattern of results supports the position that this configural reference frame effect arises primarily when the elements of the configuration are coplanar, and that the principal organization underlying it is the structure of the perceived 3-D environment rather than that of the 2-D image. In all three experiments, however, there is also a small interference effect in the noncoplanar 3-D conditions. This might be due either to some aspect of reference frame selection operating on the 2-D image representation or to the failure of subjects to see depth in the 3-D stimuli on some proportion of the trials.     

Response–reinforcer dependency and resistance to change

The effects of the response–reinforcer dependency on resistance to change were studied in three experiments with rats. In Experiment 1, lever pressing produced reinforcers at similar rates after variable interreinforcer intervals in each component of a two‐component multiple schedule. Across conditions, in the fixed component, all reinforcers were response‐dependent; in the alternative component, the percentage of response‐dependent reinforcers was 100, 50 (i.e., 50% response‐dependent and 50% response‐independent) or 10% (i.e., 10% response‐dependent and 90% response‐independent). Resistance to extinction was greater in the alternative than in the fixed component when the dependency in the former was 10%, but was similar between components when this dependency was 100 or 50%. In Experiment 2, a three‐component multiple schedule was used. The dependency was 100% in one component and 10% in the other two. The 10% components differed on how reinforcers were programmed. In one component, as in Experiment 1, a reinforcer had to be collected before the scheduling of other response‐dependent or independent reinforcers. In the other component, response‐dependent and ‐independent reinforcers were programmed by superimposing a variable‐time schedule on an independent variable‐interval schedule. Regardless of the procedure used to program the dependency, resistance to extinction was greater in the 10% components than in the 100% component. These results were replicated in Experiment 3 in which, instead of extinction, VT schedules replaced the baseline schedules in each multiple‐schedule component during the test. We argue that the relative change in dependency from Baseline to Test, which is greater when baseline dependencies are high rather than low, could account for the differential resistance to change in the present experiments. The inconsistencies in results across the present and previous experiments suggest that the effects of dependency on resistance to change are not well understood. Additional systematic analyses are important to further understand the effects of the response–reinforcer relation on resistance to change and to the development of a more comprehensive theory of behavioral persistence.     

MEDIATING ROLE OF MATERNAL SENSITIVITY: ENHANCING LANGUAGE DEVELOPMENT IN AT‐RISK FAMILIES

Home‐visiting programs have gained increasing importance in family‐centered prevention and intervention. However, few studies have examined the mechanisms underlying early intervention treatment effects. The goal of this study is to analyze the mediating role of maternal sensitivity in enhancing language development with the home‐visiting program Parents as Teachers (PAT). Data were collected and analyzed within the ongoing, long‐term ZEPPELIN study, a randomized controlled trial with 251 participating at‐risk families. Via longitudinal mediation analysis, we examined whether effects of the PAT on receptive and expressive language outcomes at 24 and 36 months were mediated by maternal sensitivity at 12 months. Within a moderated mediation framework, we investigated whether the level of family psychosocial stress affects this mediation. Results showed that intervention effects on language outcomes are mediated by maternal sensitivity—weakly and through specific pathways. Moderation and moderated mediation analyses indicated that effects of the PAT and also specific mediation effects increase with the level of psychosocial stress. Implications of the results for practice are discussed.     

Retooling Techno-Moral Scenarios. A Revisited Technique for Exploring Alternative Regimes of Responsibility for Human Enhancement

The techno-moral scenarios (TMS) approach has been developed to explore the interplay between technology, society and morality. Focused on new and emerging sciences and technologies, techno-moral scenarios can be used to inform and enhance public deliberation on the desirability of socio-technical trajectories. The article presents an attempt to hybridise this scenario tool, complementing the focus on ethics with an explicit acknowledgement of the multiple meanings of responsibility and of the plurality of its regimes, i.e. the institutional arrangements presiding over the assumption and assignment of responsibilities. We call this integrated technique ‘rTMS’ to stress the continuity with the original technique and, at the same time, to highlight the additional element we aim to develop: responsibility. The article describes this approach and illustrates a loosely standardised procedure that can be used to organise and conduct public engagement workshops based on rTMS.     

Formation of semantic associations between subliminally presented face-word pairs

Recent evidence suggests that consciousness of encoding is not necessary for the rapid formation of new semantic associations. We investigated whether unconsciously formed associations are as semantically precise as would be expected for associations formed with consciousness of encoding during episodic memory formation. Pairs of faces and written occupations were presented subliminally for unconscious associative encoding. Five minutes later, the same faces were presented suprathreshold for the cued unconscious retrieval of face-occupation associations. Retrieval instructions required participants to classify the presented individuals according to their putative (1) regularity of income, (2) length of education, and (3) creativity value of occupational activity. The three instructions yielded more classifications consistent with a person’s occupation if the person had been subliminally presented with his written occupation versus a meaningless word (control condition). This suggests that consciousness is not necessary to encode, long-term store, and retrieve semantically precise associations between primarily unrelated items.     

Aging affects attunement in perceiving length by dynamic touch

Earlier studies have revealed age-dependent differences in perception by dynamic touch. In the present study, we examined whether the capacity to learn deteriorates with aging. Adopting an ecological approach to learning, the authors examined the process of attunement--that is, the changes in what informational variable is exploited. Young and elderly adults were trained to perceive the lengths of unseen, handheld rods. It was found that the capacity to attune declines with aging: Contrary to the young adults, the elderly proved unsuccessful in learning to detect the specifying informational variables. The fact that aging affects the capacity to attune sets a new line of research in the study of perception and perceptual-motor skills of elderly. The authors discuss the implications of their findings for the ongoing discussions on the ecological approach to learning.     

Do mindsets shape intentions to help those in need? Unravelling the paradoxical effects of mindsets of poverty on helping intentions

Poverty remains a pressing problem, with social support playing a crucial role in its reduction. Drawing on previous research on health-related mindsets, we propose that a growth mindset of poverty – that is, believing poverty can be changed – can have both positive and negative effects on helping intentions through increased outcome expectancy and blame, respectively. In three experiments, we found that a growth mindset of poverty is associated with increased outcome expectancy and blame, which, in parallel, mediate the relationship between mindsets and helping intentions. However, these contrary indirect effects negate each other, yielding a total null effect. Further, manipulating the relationship between mindset and outcome expectancy (but not blame) alters the relationship between mindset and helping intentions (Studies 2 and 3). By shedding light on the circumstances under which mindsets of poverty can diminish or amplify helping intentions, our research offers valuable insights for practitioners and charities dedicated to combating poverty.     

On the dimensionality of the System Usability Scale: a test of alternative measurement models

The System Usability Scale (SUS), developed by Brooke (Usability evaluation in industry, Taylor & Francis, London, pp 189–194, 1996), had a great success among usability practitioners since it is a quick and easy to use measure for collecting users’ usability evaluation of a system. Recently, Lewis and Sauro (Proceedings of the human computer interaction international conference (HCII 2009), San Diego CA, USA, 2009) have proposed a two-factor structure—Usability (8 items) and Learnability (2 items)—suggesting that practitioners might take advantage of these new factors to extract additional information from SUS data. In order to verify the dimensionality in the SUS’ two-component structure, we estimated the parameters and tested with a structural equation model the SUS structure on a sample of 196 university users. Our data indicated that both the unidimensional model and the two-factor model with uncorrelated factors proposed by Lewis and Sauro (Proceedings of the human computer interaction international conference (HCII 2009), San Diego CA, USA, 2009) had a not satisfactory fit to the data. We thus released the hypothesis that Usability and Learnability are independent components of SUS ratings and tested a less restrictive model with correlated factors. This model not only yielded a good fit to the data, but it was also significantly more appropriate to represent the structure of SUS ratings.