Sorting between dimensions: conditions of cognitive flexibility in preschoolers

The Dimensional Change Card Sorting task frequently is used to measure extradimensional shifting abilities in preschool children. In two studies, we investigated what makes this extradimensional shifting task difficult. In Study 1 with 61 2- to 4-year-olds, we showed that extradimensional shifts from one dimension to another are more difficult than reversal shifts within a dimension (even with irrelevant variation on a second dimension). Study 2 with 77 3- and 4-year-olds further confirmed this finding using a computerized paradigm and showed that sorting instructions are critical for 3-year-olds' difficulties with extradimensional shifts. This finding is taken to suggest that 3-year-olds have particular problems with spontaneously classifying one object in two different ways.     

Let your preference be your guide? Preferences and choices are more tightly linked for North Americans than for Indians

Using experimental paradigms from economics and social psychology, the authors examined the cross-cultural applicability of 3 widely held assumptions about preference and choice: People (a) recruit or construct preferences to make choices; (b) choose according to their preferences; and (c) are motivated to express their preferences in their choices. In 6 studies, they compared how middle-class North American and Indian participants choose among consumer products. Participants in both contexts construct nonrandom preferences at similar speeds. Those in Indian contexts, however, are slower to make choices, less likely to choose according to their personal preferences, and less motivated to express their preferences in their choices. The authors infer that the strong link between preferences and choices observed among North Americans is not a universal feature of human nature. Instead, this link reflects the disjoint model of agency, which prescribes that people should choose freely on the basis of their preferences. In contrast, Indian contexts reflect and promote a conjoint model of agency, according to which agency is responsive to the desires and expectations of important others and may require restraining one's preferences. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

A nation challenged: the impact of foreign threat on America's tolerance for diversity

Three experiments investigated how perceived foreign threats to the United States can influence Americans' endorsement of assimilation and multiculturalism as models for foreign and domestic intergroup relations. The initial study, conducted during the 6-month anniversary of the September 11, 2001, terrorist attacks (9/11), discovered that a diverse group of Americans preferred assimilation as a foreign policy and multiculturalism as a domestic policy. After reading that foreigners were supporting the dominant global status of the United States, however, Americans in Experiment 2 no longer expressed this preference for assimilation as a model for foreign intergroup relations. Experiment 3 discovered that Americans primed with 9/11 (i.e., a foreign threat) revealed higher levels of national identity than did those primed with the Columbine massacre (i.e., a domestic threat); moreover, level of national identity predicted support for multiculturalism as a domestic policy and assimilation as a foreign policy.     

Cultural influences on neural substrates of attentional control

Behavioral research has shown that people from Western cultural contexts perform better on tasks emphasizing independent (absolute) dimensions than on tasks emphasizing interdependent (relative) dimensions, whereas the reverse is true for people from East Asian contexts. We assessed functional magnetic resonance imaging responses during performance of simple visuospatial tasks in which participants made absolute judgments (ignoring visual context) or relative judgments (taking visual context into account). In each group, activation in frontal and parietal brain regions known to be associated with attentional control was greater during culturally nonpreferred judgments than during culturally preferred judgments. Also, within each group, activation differences in these regions correlated strongly with scores on questionnaires measuring individual differences in culture-typical identity. Thus, the cultural background of an individual and the degree to which the individual endorses cultural values moderate activation in brain networks engaged during even simple visual and attentional tasks.     

Expertise-based differences in search and option-generation strategies

The current work builds on option-generation research using experts of various skill levels in a realistic task. We extend previous findings that relate an athlete's performance strategy to generated options and subsequent choices in handball. In a 2-year longitudinal study, we present eye-tracking data to independently verify decision strategies previously inferred from patterns of generated options. A verbal protocol identified the option-generation process for each individual prior to an allocation decision. Although athletes of varying expertise generated the same number of options on average, these options differed in quality between expert, near-expert, and nonexpert athletes for both their initial and final choices. These and other key results are formalized to elaborate a model of option generation, deliberation, and selection.     

Top-down influences on attentional capture by color changes

Previous studies have shown that a change in an existing object is not as effective in capturing attention as the appearance of a new object. This view was recently challenged by Lu and Zhou (Psychonomic Bulletin and Review 12:567–572, 2005), who found strong capture effects for an object changing its color. We suspected that this finding critically depends on a procedural particularity in Lu and Zhou’s study, namely that the color of the unique item and the color of the no-unique items randomly switched between trials. In the current study we replicate Lu and Zhou’s capture effect (Experiment 1) and show that no capture occurs when the color-to-stimuli assignment is fixed (Experiment 2). Two further experiments suggest that the capture effect in Experiment 1 is not because the unique item switched color (Experiment 3), but because all the no-unique items switched color (Experiment 4). The results are discussed considering top-down modulation and inter-trial priming effects.

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Storage and non-storage components of working memory predicting reasoning: A simultaneous examination of a wide range of ability factors

The current study examined basic cognitive abilities that are related to or included in the concept of working memory (WM): different WM components, three executive functions, simple short-term storage (STM), and sustained attention. Tasks were selected from well-established models and balanced in terms of content. The predictive power of storage and non-storage components of WM was examined. The same analyses were conducted with mental speed as an additional predictor of reasoning. Finally, we investigated whether the identified predictors of reasoning remain relevant when a general factor is considered in the analysis. The analyses revealed that short-term memory accounted for the relationship between complex span measures of WM and reasoning but not for the relationship between coordination and reasoning. These findings remained stable in the context of a mental speed and a general factor. The mental speed factor did not add an incremental contribution to the prediction of reasoning above and beyond short-term memory and coordination. The general factor was mainly built by mental speed tasks and acted as an additional predictor of reasoning besides STM and coordination. Thus, we concluded that reasoning ability can be explained by coordination, STM, and mental speed.     

Interactive effect of long-term mental stress and cardiac stress reactivity on carotid intima-media thickness: the Cardiovascular Risk in Young Finns study

The present study examined the interaction between vital exhaustion and cardiac reactivity and recovery on preclinical atherosclerosis assessed by carotid intima-media thickness (IMT) in young men and women. We measured heart rate (HR), respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to mental arithmetic and speech tasks. Vital exhaustion and carotid IMT were also measured. Significant associations were observed for men aged 28-37 years, but not for men aged 22-25 years, nor for women in these age groups. It was shown that, among highly exhausted men in the older age group, lower HR reactivity was related to greater IMT. Our results also imply that, among non-exhausted men in this age group, slow HR and RSA recovery after acute stress predicted higher IMT. These results suggest that long-term stress as assessed by vital exhaustion is a risk only if it has resulted in ineffective cardiac stress reactivity. Autonomic imbalance resulting from chronic stress may be the common mechanism linking vital exhaustion and cardiac responsiveness to an increased risk of atherosclerosis.