Resolution of conflicts between internal and external information sources on a time reproduction task: the role of perceived information reliability and attributional style

Erroneous knowledge of results (KR) that conflicts with other internal or external information sources is preferentially used and misguides performance on motor and mental timing tasks. Buekers et al. [J. Motor Behavior 26 (1994) 27] hypothesized that KR is used preferentially because participants deem it to be the most reliable information source. We tested this hypothesis in two experiments. We manipulated subjective reliability of information and information content and demonstrated that both reliability and content are assessed and used. In a third experiment we examined whether attributional style affected the use of internal and external information. While KR was present, attributional style was unrelated to performance. However, when erroneous KR was withdrawn, participants who scored high in internal attributional style or high in controllability showed more accurate performance. Whereas evaluation of information quality is explicit, information provided by the KR, whether accurate or not, may influence both implicit and explicit aspects of the tasks.     

Braking reaching movements: a test of the constant tau-dot strategy under different viewing conditions

Following F. Zaal and R. J. Bootsma (1995), the authors studied whether the decelerative phase of a reaching movement could be modeled as a constant tau-dot strategy resulting in a soft collision with the object. Specifically, they investigated whether that strategy is sustained over different viewing conditions. Participants (N = 11) were required to reach for 15- and 50-mm objects at 2 different distances under 3 conditions in which visual availability of the immediate environment and of the reaching hand were varied. Tau-dot estimates and goodness-of-fit were highly similar across the 3 conditions. Only within-participant variability of tau-dot estimates was increased when environmental cues were removed. That finding suggests that the motor system uses a tau-dot strategy involving the intermodal (i.e., visual, proprioceptive, or both) specification of information to regulate the decelerative phase of reaching under restricted viewing conditions. The authors provide recommendations for improving the derivation of tau;(x) estimates and stress the need for further research on how time-to-contact information is used in the regulation of the dynamics of actions such as reaching.     

Size of the neocerebellar vermis is associated with cognition in healthy elderly men

Cerebellar volumes show small positive correlations with cognitive ability in young adults, but no studies have examined this relationship in older adults. Furthermore, no studies have examined relationships between sizes of subareas of the cerebellum and cognitive ability. We hypothesized that size of the two areas of the neocerebellar vermis would correlate with a battery of eight cognitive tests in 50 men aged 65-70. Size of the neocerebellar areas of the vermis correlated positively with several cognitive tests (r's=.29-.37, p<.05), whilst sizes of other parts of the vermis did not correlate with any cognitive tests. Total cerebellar volumes correlated significantly with a test of nonverbal reasoning (r=.030, p=.42). These findings suggest a specific association of neocerebellar vermis size with variations in cognitive ability in older adults.     

The time course and significance of cannabis withdrawal

Withdrawal symptoms following cessation of heavy cannabis (marijuana) use have been reported, yet their time course and clinical importance have not been established. A 50-day outpatient study assessed 18 marijuana users during a 5-day smoking-as-usual phase followed by a 45-day abstinence phase. Parallel assessment of 12 ex-users was obtained. A withdrawal pattern was observed for aggression, anger, anxiety, decreased appetite, decreased body weight, irritability, restlessness, shakiness, sleep problems, and stomach pain. Onset typically occurred between Days 1-3, peak effects between Days 2-6, and most effects lasted 4-14 days. The magnitude and time course of these effects appeared comparable to tobacco and other withdrawal syndromes. These effects likely contribute to the development of dependence and difficulty stopping use. Criteria for cannabis withdrawal are proposed.     

Effects of the terrorist attacks of 9/11/01 on employee attitudes

Much has been stated in the popular press about the effects of the events of 9/11/01 on employee attitudes about work. This study examined a large sample (N = 70,671) of employees of a multinational manufacturer whose annual employee survey data collection was interrupted by the events. After demonstrating measurement equivalence across time and countries, changes in attitudes pre- and post-9/11 were examined. Only negligible differences were found in Job Satisfaction, Supervisor Evaluation, Stress, and Organizational Commitment to Diversity for U.S. employees or for employees worldwide. Demographic differences in response to events were not found. Implications for understanding effects of stressful external events on employee perceptions of work are discussed.     

Does right-left prevalence occur for the Simon effect?

In four experiments, we investigated whether a right-left prevalence effect occurs for the Simon task, in which stimulus location is irrelevant, when the stimulus and the response sets vary along horizontal and vertical dimensions simultaneously. Simon effects were evident for both dimensions, and they were of similar magnitude, indicating no prevalence effect. Manipulations of the relative salience of the dimensions for the stimulus and the response sets resulted in a larger Simon effect for the more salient dimension than for the less salient one, but there was no overall prevalence effect. The results indicate that manipulations of salience affect the relative magnitudes of automatic response activation for the vertical and the horizontal dimensions but that the right-left prevalence effect is due to a coding bias in intentional response selection processes when stimulus location is relevant.     

Assumed policy similarity and voter preference

The effects of attitude similarity on voters' preferences were examined. Using secondary analyses, the authors created measures of assumed similarity across 6 issues between voters and U.S. presidential candidates (in 1972). Greater similarity was associated with greater attraction (operationalized in terms of voters' presidential preferences). In 2 independent analyses, perceived similarity resulted in predictive accuracy of 84% to 88%. In a 3rd analysis, the predictive efficiency of each of 6 similarity measures was determined and used to develop a model that accurately predicted voters' actions in a hold-out sample. Findings demonstrate the importance of perceived attitude similarity in determining voter preferences and suggest the utility of earlier similarity-attraction research for the development of models of policy choice behavior.     

Assessing the age-related effects of proactive interference on working memory tasks using the Rasch model

Inhibition-reduction theory (L. Hasher & R. Zacks, 1988) hypothesizes that the age-related decline in working memory (WM) span is a result of a decrease in the ability to inhibit irrelevant information in WM. Using the Rasch psychometric model, this study found that later trials on 2 WM span tasks were more difficult for older adults than for younger adults, consistent with inhibition-reduction theory's hypothesis that older adults are more susceptible to the effects of proactive interference (PI). Furthermore, after accounting for differential susceptibility to the effects of PI, age-related variance in WM span was reduced by about half. These results suggest that differential susceptibility to PI may account for a substantial portion, although not all, of the age-related decline in WM span.     

Scoring reliability on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III)

Nineteen psychologists and 19 graduate students scored two Wechsler Adult Intelligence Scale-Third Edition patient protocols. Mean IQs and indexes were similar across groups, but the ranges for Verbal IQ (VIQ), Performance IQ (PIQ), and Full Scale IQ (FSIQ) on one protocol were 25, 22, and 11 points, respectively. For both protocols taken together, percentages of agreement with the "actual" IQs for psychologists were only 26.3 for VIQ, 36.8 for PIQ, and 42.1 for FSIQ. For students, percentages were 15.8 for VIQ, 23.7 for PIQ, and 31.6 for FSIQ. The percentages of FSIQs that fell within +/- 1 standard error of measurement of the actual IQs were 89.5 for psychologists and 76.3 for students. Scoring error also had a negative impact on index scores. Both groups were confident about their scoring accuracy.