Contextual interference: a meta-analytic study

A meta-analysis of the contextual interference effect produced 139 estimates of effect sizes from 61 studies. The average overall effect size was .38. The effect size for basic research (.57) was significantly different from applied research (.19). Significant differences were also obtained between the effect sizes for adults (.50) and those for younger learners (.10). Power for retention and transfer scores was not significantly different. The overall mean power of the studies reviewed was .43.     

Crewmember performance before, during, and after spaceflight

The development of technologies for monitoring the welfare of crewmembers is a critical requirement for extended spaceflight. Behavior analytic methodologies provide a framework for studying the performance of individuals and groups, and brief computerized tests have been used successfully to examine the impairing effects of sleep, drug, and nutrition manipulations on human behavior. The purpose of the present study was to evaluate the feasibility and sensitivity of repeated performance testing during spaceflight. Four National Aeronautics and Space Administration crewmembers were trained to complete computerized questionnaires and performance tasks at repeated regular intervals before and after a 10-day shuttle mission and at times that interfered minimally with other mission activities during spaceflight. Two types of performance, Digit-Symbol Substitution trial completion rates and response times during the most complex Number Recognition trials, were altered slightly during spaceflight. All other dimensions of the performance tasks remained essentially unchanged over the course of the study. Verbal ratings of Fatigue increased slightly during spaceflight and decreased during the postflight test sessions. Arousal ratings increased during spaceflight and decreased postflight. No other consistent changes in rating-scale measures were observed over the course of the study. Crewmembers completed all mission requirements in an efficient manner with no indication of clinically significant behavioral impairment during the 10-day spaceflight. These results support the feasibility and utility of computerized task performances and questionnaire rating scales for repeated measurement of behavior during spaceflight.     

Different strategies for using motion-in-depth information in catching

Previous studies on ball catching have had the limitation that the catcher was restricted to lateral hand movements. The authors investigated catching behavior in the more natural situation in which hand movements were unconstrained. Movements of the hand were tracked as participants tried to "catch" an approaching ball simulated with changing size and/or changing disparity. Participants used 1 of 2 distinct interception strategies: (a) a "cutting-off" strategy where time to passage (TTP) information was used to guide movements of the hand in depth such that the ball was caught farther in front of the face when the ball was approaching more slowly and (b) a "waiting" strategy where the hand was moved along a frontoparallel plane that was constant across ball trajectories and speeds. Cue dissociation and selective adaptation manipulations demonstrated that the catcher's estimates of TTP and crossing distance were based on a combination of binocular and monocular information.     

Don't stand so close to me: the effects fo self-construal in interpersonal closeness

Abstract— Three studies investigated the effects of self-construal activation on behavior conducive to interpersonal proximity. Study 1 revealed that compared with control participants, participants who were primed with the independent (or personal) self sat further away from where they anticipated another person would sit in a waiting room. Results of Study 2 indicated that participants primed with the interdependent (or social) self sat closer to the anticipated other person than did those primed with the independent self. Finally, Study 3 used the chronic self-construal of participants to predict the seating distance in dyadic settings. Results showed that greater independence of participants' self-construals was associated with greater spatial distance during the interaction. Together, the studies provide clear evidence that self-construal activation automatically influences interpersonal behavior as reflected in the actual distance between the self and others. Results are discussed in terms of the functions and motives connected to self-construals.     

Attending to the execution of a complex sensorimotor skill: expertise differences, choking, and slumps

A simulated baseball batting task was used to compare the relative effects of attending to extraneous information (tone frequency) and attending to skill execution (direction of bat movement) on performance and swing kinematics and to evaluate how these effects differ as a function of expertise. The extraneous dual task degraded batting performance in novices but had no significant effect on experts. The skill-focused dual task increased batting errors and movement variability for experts but had no significant effect on novices. For expert batters, accuracy in the skill-focused dual task was inversely related to the current level of performance. Expert batters were significantly more accurate in the skill-focused dual task when placed under pressure. These findings indicate that the attentional focus varies substantially across and within performers with different levels of expertise.     

Impulsive choice and workplace safety: a new area of inquiry for research in occupational settings

A conceptual argument is presented for the relevance of behavior-analytic research on impulsive choice to issues of occupational safety and health. Impulsive choice is defined in terms of discounting, which is the tendency for the value of a commodity to decrease as a function of various parameters (e.g., having to wait or expend energy to receive the commodity). A high degree of discounting is often considered an index of impulsivity. We argue that for workers, possible negative consequences (e.g., injury or disease) are often disregarded, or discounted, in choices about workplace safety because such consequences are typically delayed and uncertain. Furthermore, some evidence suggests that certain environmental conditions, such as those that lead to stress or sleep deprivation, may increase discounting. Increased discounting, by extension, leads to a further devaluation of safety practices and their benefits. A call is made for research aimed at more clearly delineating the relation between impulsive choice and workplace safety.     

Ignoring famous faces: category-specific dilution of distractor interference

The extent to which famous distractor faces can be ignored was assessed in six experiments. Subjects categorized famous printed target names as those of pop stars or politicians, while attempting to ignore a flanking famous face distractor that could be congruent (e.g, a politician's name and face) or incongruent (e.g., a politician's name with a pop stars face). Congruency effects on reaction times indicated distractor intrusion. An additional, response-neutral flanker (neither pop star nor politician) could also be present. Congruency effects from the critical distractor face were reduced (diluted) by the presence of an intact anonymous face, but not by phase-shifted versions, inverted faces, or meaningful nonface objects. By contrast, congruency effects from other types of distracting objects (musical instruments, fruits), when printed names for these classes were categorized, were diluted equivalently by intact faces, phase-shifted faces, or meaningful nonface objects. Our results suggest that distractor faces act differently from other types of distractors, suffering from only face-specific capacity limits.     

Application of Herek's attitudes toward lesbians and gay men scale in The Netherlands

A national sample of 921 respondents from the Dutch population completed the translated, slightly modified version of Herek's Attitudes Toward Lesbians and Gay Men Scale, originally developed in the USA for the assessment of attitudes toward lesbians and gay men. The present study was the first attempt to test the applicability of the scale in the Netherlands. In line with previous American findings, all scale items loaded highly on one factor. The scores also correlated with another measure of attitudes toward lesbians and gay men, namely, 'denial of equal rights' (r = .76), and with 'traditional view of women' (r = .48), 'importance of traditional marriage' (r = .53), and 'authoritarianism' (r = .31). Data support the scale's acceptable reliability and construct and discriminant validity.     

Storage of verbal associations is sufficient to activate the left medial temporal lobe

Neuroimaging studies have shown that memory encoding activates the medial temporal lobe (MTL). Many believe that these activations are related to novelty but it remains unproven which is critical - novelty detection or the rich associative encoding it triggers. We examined MTL activation during verbal associative encoding using functional magnetic resonance imaging. First, associative encoding activated left posterior MTL more than single word encoding even though novelty detection was matched, indicating not only that associative encoding activates the MTL particularly strongly, but also that activation does not require novelty detection. Moreover, it remains to be convincingly shown that novelty detection alone does produce such activation. Second, repetitive associative encoding produced less MTL activation than initial associative encoding, indicating that priming of associative information reduces MTL activation. Third, re-encoding familiar associations in a well-established way had a minimal effect on both memory and MTL activation, indicating that MTL activation reflects storage of associations, not merely their initial representation.