Cascaded versus noncascaded models of lexical and semantic processing: the turple effect

The density of the orthographic neighborhood surrounding an item has been shown to have an inhibitory effect for nonwords in a lexical decision experiment. Four experiments are reported investigating whether a similar pattern holds for a semantic categorization task (animal vs. non-animal). In the first experiment, no effects of neighborhood density were found for nonexemplars, whether they were words or nonwords. The absence of any inhibitory effect for nonwords implies that close orthographic neighbors are ignored. However, the second experiment showed that if the nonword has a neighbor that is an animal name (eg., turple), an interference effect is observed, implying that neighbors do exert an effect if they have the right semantic properties. The same items showed no additional interference in lexical decision. These results suggest the involvement of semantic properties very early in the processing cycle. A cascaded processing system monitoring activation in semantic features can explain these results, but cannot explain the frequency effect observed for nonexemplar words or the fact that variation in density is irrelevant when one of the neighbors is an exemplar. It is argued that existing models of semantic categorization must be extended to accommodate these results.     

Stability and skill in driving

Two experiments addressed the relation between postural stability, perceptual sensitivity, and stability of driving performance. A vehicle was fitted with differential GPS for measuring position and speed, position sensors for measuring brake and accelerator depression, force transducers for measuring door, console and footrest bracing forces, and an accelerometer for measuring the 3D accelerations of the vehicle. In Experiment 1, we investigated whether the initiation of deceleration and the control of braking might be due to sensitivity to the perceptual variable tau, which specifies time-to-contact (TTC), and in particular, whether its first derivative, tau-dot, is used to maintain a constant deceleration profile. Using both untrained experienced drivers (EDs) and trained driving instructors from the Holden Performance Driving Centre (HPDC), results confirmed that, regardless of skill level, tau-dot was maintained at a value close to 0.5 and, as predicted by Lee [Perception 5 (1976) 437], braking was initiated when TTC approximately 5 s. In Experiment 2, we wished to quantify the purported differences in driving behaviour between EDs and HPDC instructors during a variety of everyday manoeuvres. Results indicated that instructors utilised a different cornering trajectory, a different emergency braking strategy, and were able to perform a high-speed swerve and recovery task more effectively than the EDs. In general, the instructors applied greater bracing forces using the door and console compared with EDs. The instructors also applied greater footrest forces during emergency braking than did the EDs. The greater use of bracing by instructor drivers to resist g-forces represents a strategy of active stabilisation that enhances both postural stability, as well as overall stability and consistency of driving performance. Results are discussed with regard to the dynamics of perceptual-motor coordination, and how increased stability might improve sensitivity to relevant perceptual information. We conclude that driver-training programmes that focus on increasing driver stability (as a pre-requisite for increased control) show great promise as a means to improving one's attention during driving, and hence have the potential to dramatically improve road safety in general.     

The Role of the Family in Childhood Obsessive–Compulsive Disorder

While obsessive–compulsive disorder is widely recognized to have a strong genetic component, psychosocial factors are also acknowledged to be important. The primary focus of this paper is on familial factors associated with OCD in children and adolescents. It explores the family context as a possible risk factor in the development and maintenance of the disorder, including parental modeling, expressed emotion, parenting style, and family accommodation of the child's symptoms. The involvement of the family in the treatment of the disorder is also reviewed. Finally, future directions for research investigating familial factors in childhood OCD are presented.     

Testing comprehension abilities in users of British Sign Language following CVA

Recent imaging (e.g., MacSweeney et al., 2002) and lesion (Hickok, Love-Geffen, & Klima, 2002) studies suggest that sign language comprehension depends primarily on left hemisphere structures. However, this may not be true of all aspects of comprehension. For example, there is evidence that the processing of topographic space in sign may be vulnerable to right hemisphere damage (e.g., Hickok, Say, Bellugi, & Klima, 1996), and the influence of iconicity on comprehension has yet to be explored. In this study, comprehension testing was conducted with 15 signers with unilateral brain damage, and with elderly Deaf controls. Four tests were administered: a test of iconic and non-iconic noun comprehension, a test of verb and sentence comprehension, a test of locative sentence comprehension, and a test of classifier comprehension. All tests were administered in British Sign Language (BSL), a language that has only recently been explored with lesioned signers (see Atkinson, Marshall, Thacker, & Woll, 2004; Marshall, Atkinson, Thacker, Woll, & Smulevitch, 2004; Marshall, Atkinson, Woll, & Thacker, in press). People with left hemisphere damage were impaired relative to controls on all tests. Those with right hemisphere damage performed well in the first two tests, but were impaired on locative sentences and classifiers. Neither group showed any effect of iconicity. The results shed further light on the laterality of sign language comprehension.     

Functional fixedness in a technologically sparse culture

Problem solving can be inefficient when the solution requires subjects to generate an atypical function for an object and the object's typical function has been primed. Subjects become "fixed" on the design function of the object, and problem solving suffers relative to control conditions in which the object's function is not demonstrated. In the current study, such functional fixedness was demonstrated in a sample of adolescents (mean age of 16 years) among the Shuar of Ecuadorian Amazonia, whose technologically sparse culture provides limited access to large numbers of artifacts with highly specialized functions. This result suggests that design function may universally be the core property of artifact concepts in human semantic memory.     

Implicit self-attitudes predict spontaneous affect in daily life

In 2 studies, the authors examined the degree to which implicit self-attitudes predicted people's spontaneous affective experiences in daily life. Across both studies, implicit attitudes toward the self (as measured by Implicit Association Tests) strongly predicted negative feeling states (as measured by computerized experience-sampling procedures), suggesting that implicit self-attitudes may be linked to changes in undifferentiated negative affect. Explicit attitudes toward the self generally did not account for these relations. Findings extend understanding of the factors that contribute to experienced affect and are the first to empirically link implicit self-attitudes with phenomenological affective experience in real-life settings over time.     

Developmental changes in facial expressions of emotions in the strange situation during the second year of life

Infants' expressions of discrete emotions were coded during the more stressful episodes (4 through 8) of the Strange Situation at 13 and 18 months. The data showed a significant decrease in full-face expressions (more complex configurations of movements) and a significant increase in component expressions (simpler and more constrained patterns of movements). The authors interpreted this trend as a developmental change toward more regulated and less intense emotions. Consistent with this view, the aggregate index of infants' full-face negative emotion expressions, interpreted as reflecting relatively unregulated intense emotions, correlated significantly with maternal ratings of difficult temperament. The authors discuss alternative interpretations of the findings in terms of changes in reactivity/arousability and the emerging capacity for self-regulation.