Decision making, movement planning and statistical decision theory

We discuss behavioral studies directed at understanding how probability information is represented in motor and economic tasks. By formulating the behavioral tasks in the language of statistical decision theory, we can compare performance in equivalent tasks in different domains. Subjects in traditional economic decision-making tasks often misrepresent the probability of rare events and typically fail to maximize expected gain. By contrast, subjects in mathematically equivalent movement tasks often choose movement strategies that come close to maximizing expected gain. We discuss the implications of these different outcomes, noting the evident differences between the source of uncertainty and how information about uncertainty is acquired in motor and economic tasks.     

Visuotactile apparent motion

This article compares the properties of apparent motion between a light and a touch with apparent motion between either two lights or two touches. Visual and tactile stimulators were attached to the tips of the two index fingers that were held apart at different distances. Subjects rated the quality of apparent motion between each stimulus combination for a range of stimulus onset asynchronies (SOAs). Subjects reported perceiving apparent motion between all three stimulus combinations. For light—light visual apparent motion, the preferred SOA and the direction threshold SOAs increased as the distance between the stimuli increased (consistent with Korte’s third law of apparent motion). Touch—touch apparent motion also obeyed Korte’s third law, but over a smaller range of distances, showing that proprioceptive information concerning the position of the fingers is integrated into the tactile motion system. The threshold and preferred SOAs for visuotactile apparent motion did not vary with distance, suggesting a different mechanism for multimodal apparent motion.     

Young and older adults' strategies in complex arithmetic

Young and older adults solved complex addition problems such as 49 + 56. Verbal protocols, solution times, and percentage errors documented strategy repertoire and strategy selection in young and older participants and age-related differences in complex arithmetic performance. Both young and older adults used a set of 9 strategies to solve complex addition problems, although many older adults used a smaller strategy repertoire. The data also showed age-related differences in strategy execution and strategy selection. We discuss general implications of the present data to further our understanding of complex arithmetic and the role of strategic variations during aging.     

The Psychological Burden Inflicted By Multiple Cancers in Li-Fraumeni Families: Five Case Studies

To gain insight into the psychological, emotional, relational, and family problems of families afflicted by Li-Fraumeni syndrome, we interviewed members of five such families in the Pediatric Oncology Department, Gustave Roussy Institute, where at least one member of the family had been treated. These interviews showed that families were psychologically fragile, that their interactions and thinking patterns were related to a family background plagued by the repeated occurrence of cancer, and was often marked by physical or psychological violence. They had complex imaginary etiologic explanations, and showed an ambivalent willingness to learn about cancer and the risks involved. They expressed their fear of transmitting doom and death, posed questions about whether their parents would have had them had they known the test result, and about what their own attitude would be toward childbearing. Thus genetic testing awoke disconcerting and unsolved questions for them. These first results can contribute to the design of supportive interventions and future clinical research.     

A consistent way with paradox

Consideration of a paradox originally discovered by John Buridan provides a springboard for a general solution to paradoxes within the Liar family. The solution rests on a philosophical defence of truth-value-gaps and is consistent (non-dialetheist), avoids ‘revenge’ problems, imports no ad hoc assumptions, is not applicable to only a proper subset of the semantic paradoxes and implies no restriction of the expressive capacities of language.

Impact of Behavioral Inhibition and Parenting Style on Internalizing and Externalizing Problems from Early Childhood through Adolescence

Behavioral inhibition (BI) is characterized by a pattern of extreme social reticence, risk for internalizing behavior problems, and possible protection against externalizing behavior problems. Parenting style may also contribute to these associations between BI and behavior problems (BP). A sample of 113 children was assessed for BI in the laboratory at 14 and 24 months of age, self-report of maternal parenting style at 7 years of age, and maternal report of child internalizing and externalizing BP at 4, 7, and 15 years. Internalizing problems at age 4 were greatest among behaviorally inhibited children who also were exposed to permissive parenting. Furthermore, greater authoritative parenting was associated with less of an increase in internalizing behavior problems over time and greater authoritarian parenting was associated with a steeper decline in externalizing problems. Results highlight the importance of considering child and environmental factors in longitudinal patterns of BP across childhood and adolescence.     

Interpreting claims in offender profiles: the role of probability phrases,base‐rates and perceived dangerousness

Offender profilers use verbal and numerical probability expressions to convey uncertainty surrounding claims made about offender's characteristics. No previous research has examined how these expressions might affect the recipient's interpretation of the information. Seventy participants completed an online questionnaire and results showed a diverse range of interpretations of these uncertainty expressions. Moreover, characteristic base‐rates and dangerousness affected the perceived likelihood of the profiling claim, such that increased base‐rates and perceived dangerousness resulted in an increased perception of the claim being likely. Perceived likelihoods also depended on the framing of characteristics as well as the framing of the claim itself. Finally, where claims involved presenting a characteristic qualified by a low probability these claims were interpreted as more likely than not to be present. These findings have practical implications for profilers and more general theoretical implications for the study of risk perception. Copyright © 2008 John Wiley & Sons, Ltd.