Development of multisensory spatial integration and perception in humans

Previous studies have shown that adults respond faster and more reliably to bimodal compared to unimodal localization cues. The current study investigated for the first time the development of audiovisual (A-V) integration in spatial localization behavior in infants between 1 and 10 months of age. We observed infants' head and eye movements in response to auditory, visual, or both kinds of stimuli presented either 25 degrees or 45 degrees to the right or left of midline. Infants under 8 months of age intermittently showed response latencies significantly faster toward audiovisual targets than toward either auditory or visual targets alone They did so, however, without exhibiting a reliable violation of the Race Model, suggesting that probability summation alone could explain the faster bimodal response. In contrast, infants between 8 and 10 months of age exhibited bimodal response latencies significantly faster than unimodal latencies for both eccentricity conditions and their latencies violated the Race Model at 25 degrees eccentricity. In addition to this main finding, we found age-dependent eccentricity and modality effects on response latencies. Together, these findings suggest that audiovisual integration emerges late in the first year of life and are consistent with neurophysiological findings from multisensory sites in the superior colliculus of infant monkeys showing that multisensory enhancement of responsiveness is not present at birth but emerges later in life.     

Deciding about decision models of remember and know judgments: a reply to Murdock (2006)

B. B. Murdock (2006) has interpreted remember-know data within a decision space defined by item and associative information, the fundamental variables in his general recognition memory model TODAM (B. B. Murdock, 1982). He has related parameters of this extended model to stimulus characteristics for several classic remember-know data sets. The authors show that this accomplishment is shared by both one- and two-dimensional signal-detection-based remember-know models (J. C. Dunn, 2004; C. M. Rotello, N. A. Macmillan, & J. A. Reeder, 2004; J. T. Wixted & V. Stretch, 2004), which can be represented in this same decision space and can be related to stimulus characteristics with similar success. Murdock claims that his model, unlike its competitors, is a process model; however, the process aspects of TODAM are not used in his application, and the decision aspects are identical to a previously proposed model. Murdock's claim that one competing model (STREAK; C. M. Rotello et al., 2004) is not fully specified is shown to be false. The new model is not superior to existing ones, but comparisons among the models to date are not definitive. The authors describe several strategies that might be applied to distinguish among them.     

Anxiety sensitivity taxonicity across gender among youth

The present investigation comparatively evaluated the latent class structure and parameters of anxiety sensitivity (AS) among female and male youth using the Childhood Anxiety Sensitivity Index. Participants were 4462 adolescents (2189 females) in grades 7-12 (M(age)=15.6 years). Consistent with prediction, taxometric analyses indicated the latent structure of AS was taxonic in both males and females, demonstrating the taxonic latent structure of AS is similarly observed across gender. Also consistent with prediction, the base rate of the AS taxon differed between genders -- higher for females (12%) compared to males (7%). These findings are discussed in terms of their implications for the study of AS and panic vulnerability among youth.     

What do two-year-olds understand about hidden-object events?

Preferential-looking studies suggest that by 2 months of age, infants may have knowledge about some object properties, such as solidity. Manual search studies of toddlers examining these same concepts, however, have failed to provide evidence for the same understanding. Investigators have recently attempted to reconcile this disparity but failed to control for the visual novelty of test outcomes. The current design corrected this problem and also tested toddlers' predictions of the object's location. The task involved the same events and apparatus that have been used in manual search tasks but used looking as the dependent measure. Children looked longer when an agent opened the correct door and found no ball than when an incorrect door was opened to reveal no ball. A 2nd experiment indicated that children's preferential-looking performance did not differ from that in manual search tasks simply because additional response time had been allowed to respond. Previous comparisons of looking versus reaching tested children's postdiction response to an object in an unexpected location, but these findings indicate that toddlers can predict where the object should be.     

Effects of part-set cuing on experienced and novice chess players' reconstruction of a typical chess midgame position

A typical midgame chess position was presented to participants for 30 sec. Participants then reconstructed the presented position on a second board from memory. Following a brief distraction phase, participants were asked to reconstruct the position a second time with 0, 6, or 12 of the original pieces present. It was hypothesized that cue presentation during second reconstruction would be more disruptive to experienced players' recall than to novices'. Recall was measured in terms of correct pieces placed, new items generated (reminiscence), and previously recalled items omitted (forgetting). Analysis indicated that cues neither facilitated nor inhibited recall: experienced players performed better than novice players across recall indices, with the exception of reminiscence at which both groups performed similarly.     

The influence of professional expertise and task complexity upon the potency of the contextual interference effect

The contextual interference (CI) effect has been investigated through practice schedule manipulations within both basic and applied studies. Despite extensive research activity there is little conclusive evidence regarding the optimal practice structure of real world manipulative tasks in professional training settings. The present study therefore assessed the efficacy of practising simple and complex knot-tying skills in professional fire-fighters training. Forty-eight participants were quasi-randomly assigned to various practice schedules along the CI continuum. Twenty-four participants were students selected for their novice knot-tying capabilities and 24 were experienced fire-fighters who were more 'experienced knot-tiers'. They were assessed for skill acquisition, retention and transfer effects having practiced tying knots classified as simple or complex. Surprisingly, high levels of CI scheduling enhance learning for novices even when practising a complex task. The findings also revealed that CI benefits are most apparent as learners engage in tasks high in transfer distality. In conclusion, complexity and experience are mediating factors influencing the potency of the CI training effect in real-world settings.     

Two Distinctive Personality Configurations: Understanding the Therapeutic Context with Suicidal Individuals

Recent theory and research have associated different levels and types of suicide risk with particular personality dimensions, focusing particularly on the distinction between introjective and anaclitic personality orientations. This distinction is discussed in relation to our general understanding of the therapeutic context with those who have attempted, or may be at risk for, suicidal behavior. Individuals characterized as predominantly introjective/self-critical or as anaclitic/dependent seem to represent relatively homogenous subgroups of suicidal individuals, with distinct concerns, vulnerabilities, and behaviors. Our conclusion is that persons in these subgroups seem to warrant different intervention and therapeutic strategies. Implications for the psychotherapeutic process are discussed.     

Derived stimulus relations, semantic priming, and event-related potentials: testing a behavioral theory of semantic networks

Derived equivalence relations, it has been argued, provide a behavioral model of semantic or symbolic meaning in natural language, and thus equivalence relations should possess properties that are typically associated with semantic relations. The present study sought to test this basic postulate using semantic priming. Across three experiments, participants were trained and tested in two 4-member equivalence relations using word-like nonsense words. Participants also were exposed to a single- or two-word lexical decision task, and both direct (Experiment 1) and mediated (Experiments 2 and 3) priming effects for reaction times and event-related potentials were observed within but not across equivalence relations. The findings support the argument that derived equivalence relations provides a useful preliminary model of semantic relations.     

Longevity, big five personality factors, and health behaviors: presidents from Washington to Nixon

In this study, the positive correlation between conscientiousness and death age discovered by H. S. Friedman et al. (1993, 1995) was replicated for 32 American presidents. Conscientiousness scores, using the Big Five variables produced by S. J. Rubenzer, T. R. Faschingbauer, and D. S. Ones (1996, 2000), were correlated with death age, r(30) = .41, p < .01, and the relationship was maintained with controls in a multiple regression framework. Smoking, drinking, and exercise, as assessed by J. R. Bumgarner (1994), were also correlated in the expected fashion with death age. Conscientiousness was correlated negatively with smoking and drinking, but openness to experience was correlated negatively with smoking and drinking to a higher degree and also was positively correlated with exercise. Openness, extraversion, neuroticism, and agreeableness were not correlated with death age, and extraversion, neuroticism, and agreeableness were not correlated with smoking, drinking or exercise.     

Simple method for predicting American presidential greatness from victory margin in popular vote (1824-1996)

The author tested the simple method (SM) for predicting presidential greatness from the winner's victory margin in the popular vote and A. M. Schlesinger Jr.'s (1986) cycles of American political history with the expert sample presidential rankings of W. J. Ridings Jr. and S. B. McIver (1997). The SM, which involves only simple calculations on minimal data available shortly after an election, predicts greatness ratings that are above average for winners with high victory margins in years of public purpose and for winners with low victory margins in years of private interest. Also, the SM predicts ratings that are below average for winners with low victory margins in public purpose years and for winners with high victory margins in private interest years. Based on the data for 42 elections from 1824 to 1996, the SM success rate was 81.0% for all elections, 85.2% for the 27 1st-term elections, 86.2% for elections after 1880, and 94.4% for 1st-term elections after 1880. Chi-square analyses showed all percentages significant at the .001 level.