Learning effects in the block design task: A stimulus parameter-based approach.

Learning effects were assessed for the block design (BD) task, on the basis of variation in 2 stimulus parameters: perceptual cohesiveness (PC) and set size uncertainty (U). Thirty-one nonclinical undergraduate students (19 female) each completed 3 designs for each of 4 varied sets of the stimulus parameters (high-PC/high-U, high-PC/low-U, low-PC/high-U, and low-PC/low-U), ordered randomly within a larger set of designs with mixed stimulus characteristics. Regression analyses revealed significant, although modest, learning effects in all conditions. Negative-logarithmic learning slopes (growth factors) were greatest for high-U/high-PC designs and smallest for low-U/low-PC designs. Comparison of these slopes with known Wechsler Adult Intelligence Scale (3rd ed.; D. Wechsler, 1997; and 4th ed.; D. Wechsler, 2008) BD subtest gain scores demonstrated that presenting novel test items matched on stimulus parameters in multiple administrations reduced learning effects compared with the repeated use of the same test items. The results suggest that repeated administration of novel test items of the BD subtest, matched for PC and U, would result in more accurate assessments of changes in examinees’ abilities over time than would the use of the same items. Difficulties inherent in implementing this method are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and MMPI performance.

Evaluated the effects of age on MMPI scale scores with intelligence controlled. Data included MMPIs and Wechslers from 420 white hospitalized psychiatric patients. No sex differences were found in relationships among age, intelligence, and MMPI scale scores. Major findings were that T-scores on Scales 4, 6, 8, and 9 are affected by age, scores on Scales L and F by intelligence, and scores on only Scale F by both variables. Although Scale 2 T scores were not affected by age, peak-analysis showed that older patients more often have Scale 2 peaks. This results from decreases in T scores on the other scales, rather than increases on Scale 2. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Handwriting performance in younger and older adults: Age, familiarity, and practice effects.

The main goals of 2 experiments on the aging of handwriting skills were to investigate (1) age differences in speed of handwriting performance, (2) effects of task familiarity on age differences in performance, and (3) effects of practice on age differences in performance. Younger adults performed reliably faster than older adults on all tasks. An Age?×?Familiarity interaction in both experiments indicated that age differences were magnified for unfamiliar but attenuated for familiar tasks. In the 2nd experiment, an Age?×?Trial interaction revealed that older adults improved at a faster rate than younger adults. Regressions with initial trial data indicated that the older were slower than the younger adults by a factor of about 1.6. With practice, however, this slowing factor was only 1.02. Results suggest that familiarity and practice play a role in speed of handwriting. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age and management team performance.

180 male managers participated as age-homogeneous 4-person teams in a validated all-day decision-making simulation. 15 teams consisted of 28–35 yr old participants (young), 15 teams were in the 45–55 yrs age range (middle-aged), and 15 teams consisted of 65–75 yr old (older) persons. More than 40 objective performance measures (loading on 12–25 factors) were calculated on the basis of team decision making, planning, and other indicators. Performance by young and middle-aged teams was generally similar. Older teams made fewer decisions and were less strategic and less responsive to incoming information. Their overview of the task was less broad; action diversity and information search was reduced. However, older teams used opportunities and handled a simulated emergency as effectively as their younger and middle-aged counterparts. Alternative explanations for the obtained differences are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Similarities and differences in block design performance between older normal and brain-injured persons: A task analysis.

Developed an objective scoring system to determine whether right and left hemiplegics differ from normal controls, and from one another, in terms of competence levels, style of performance, constructional deviations, and various rates of activity while attempting to solve block designs. A microanalysis of the wais block design performances of 40 normals, 56 right hemiplegics, and 49 left hemiplegics was conducted. Results indicate that (a) brain-injured ss were inferior to normals in competence, (b) brain-injured ss did not differ from normals in style of performance and in partial competence, (c) right hemiplegic ss differed from left hemiplegic ss on all parameters of performance but competence level. Theoretical and clinical implications are discussed. (29 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age effects on executive ability.

Heterogeneity of executive tasks has made it difficult to determine whether there are age-related declines in executive functioning. To address this issue, 112 individuals, 20–79 years old, took the California Trail Making Test (CTMT) and the California Stroop Test (CST), subtests of the Delis–Kaplan Executive Function Scale (D. C. Delis, E. Kaplan, & J. H. Kramer, in press) that include measurement of component skills embedded in the executive function tasks. Multiple regression analyses revealed that after controlling for component skills, age had a significant effect on the executive requirement of the CST, namely speed on the interference condition. Age did not affect switching performance on the letter–number condition of the CTMT. Additional analyses revealed that age was significantly associated with commission of certain types of errors. This study confirms the importance of partialing out components in the assessment of multidimensional cognitive tasks, particularly when making age comparisons. It also emphasizes specificity over generalizability when examining the impact of age on cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A rotating PET scanner using BGO block detectors: design, performance and applications

Recent advances in fully three-dimensional reconstruction for multi-ring PET scanners have led us to explore the potential of a prototype scanner based on the rotation of two opposing arrays of BGO block detectors. The prototype contains only one-third of the number of detectors in the equivalent full ring scanner, resulting in reduced cost. With a lower energy threshold at 250 keV, the absolute efficiency of the scanner is 0.5% and the scatter fraction is 35% for a 20-cm cylinder. Transaxial and axial spatial resolution is about 6 mm. The maximum noise equivalent count rate estimated for a 15-cm diameter cylinder is 36,000 cps at a concentration of 26 kBq/ml. The minimum scan time for a 18F-fluoro-2-deoxyglucose (FDG) brain study is 55 sec. The camera has been validated for clinical applications using both FDG and 82Rb.     

Interpreting contradictory communications: Age and context effects.

This study examined how contradictory verbal–facial communications are understood and resolved at different ages. Preschoolers, grade school children, and adults were asked to interpret videotapes in which an actor conveyed contradictory verbal and facial expressions with and without a story context that provided a reason for the contradiction. Results showed both age and context effects: Whereas younger children were more likely to focus on the literal contents of the verbal or facial components, older subjects were more likely to relate each of the two components to an overall communicative intent. In addition, messages presented within a meaningful context were resolved in a more sophisticated manner than those presented in isolation, although younger children were limited in the extent to which they were helped by the context cues. The results are discussed in terms of the development of understanding message-referent relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age, exercise, and coding performance.

We investigated the effects of exercise on the coding performance of young and older subjects. Hypotheses were tested that exercise either facilitates spatial localization or reduces susceptibility to distraction in older subjects. In a balanced design, we administered Digit Symbol and Symbol Digit coding tasks to exercisers and nonexercisers at two age levels under conditions of low or high within-task interference. The findings showed higher performance by the exercisers than by the nonexercisers only at the older age level and only with the Symbol Digit task. These findings support the hypothesis that exercise compensates for a loss of spatial localization skills with age. We found no evidence that susceptibility to distraction either increased with age or was affected by chronic exercise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and IQ effects on stimulus and response timing.

Normal older participants (aged 60–79 yrs), with known scores on the Culture Fair Intelligence Test, were tested on 4 timing tasks (i.e., temporal generalization, bisection, differential threshold, and interval production). The data were related to the theoretical framework of scalar timing theory and ideas about information processing and aging. In general, increasing age and decreasing IQ tended to be associated with increasing variability of judgments of duration, although in all groups events could be timed on average accurately. In some cases (e.g., bisection), performance differences between the older participants and students nearly 50 years younger used in other studies were negligible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age effects on social cognition: Faces tell a different story.

The authors administered social cognition tasks to younger and older adults to investigate age-related differences in social and emotional processing. Although slower, older adults were as accurate as younger adults in identifying the emotional valence (i.e., positive, negative, or neutral) of facial expressions. However, the age difference in reaction time was largest for negative faces. Older adults were significantly less accurate at identifying specific facial expressions of fear and sadness. No age differences specific to social function were found on tasks of self-reference, identifying emotional words, or theory of mind. Performance on the social tasks in older adults was independent of performance on general cognitive tasks (e.g., working memory) but was related to personality traits and emotional awareness. Older adults also showed more intercorrelations among the social tasks than did the younger adults. These findings suggest that age differences in social cognition are limited to the processing of facial emotion. Nevertheless, with age there appears to be increasing reliance on a common resource to perform social tasks, but one that is not shared with other cognitive domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and sex effects for emotional intensity.

Examined age and sex trends in emotional intensity in 432 Ss from adopting and nonadopting biological families. It was hypothesized that younger adults and females would report greater average levels of both positive and negative affect over time, as has been demonstrated in past research. 242 Ss (parents and offspring) completed a battery of mood scales. 190 Ss completed an affect intensity measure and a general behavior inventory. In support of the hypothesis, women scored higher on measures reflecting emotional intensity and manifestation of cyclothymic symptoms, and the scores on these measures decreased through the adult life span for both males and females. Potential reasons for the differences in emotional intensity are discussed. These include biological causes, cultural expectations, and current life experiences. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Noise effects on human performance: A meta-analytic synthesis.

Noise is a pervasive and influential source of stress. Whether through the acute effects of impulse noise or the chronic influence of prolonged exposure, the challenge of noise confronts many who must accomplish vital performance duties in its presence. Although noise has diffuse effects, which are shared in common with many other chronic forms of stress, it also exerts its own specific influences on various forms of cognitive and motor response. We present a quantitative evaluation of these influences so that their harmful effects can be mitigated, their beneficial effects exploited, and any residual effects incorporated and synthesized into selection, training, and design strategies to facilitate human performance capacities. Predictions of single and joint moderator effects were made on the basis of major theories of noise and performance, specifically those explanations based on arousal, masking, or cognitive-resource mechanisms. These predictions were tested through moderator analyses of effects as a function of task type, performance measure, noise type and schedule, and the intensity and duration of exposure. Observed outcome effects (797 effect sizes derived from 242 studies) varied as a function of each of these moderators. Collective findings identified continuous versus intermittent noise, noise type, and type of task as the major distinguishing characteristics that moderated response. Mixed evidence was obtained for the traditional arousal and masking explanations for noise effects. The overall pattern of findings was most consistent with the maximal adaptability theory, a mental-resource-based explanation of stress and performance variation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age and experience effects in spatial visualization.

Three studies were conducted to investigate effects related to age and experience on measures of spatial visualization ability. All research participants were college-educated men; those in the experienced group were practicing or recently retired architects. The major results of the studies were (a) that increased age was found to be associated with lower levels of performance on several tests of spatial visualization and (b) that this was true both for unselected adults and for adults with extensive spatial visualization experience. These findings seem to suggest that age-related effects in some aspects of cognitive functioning may be independent of experiential influences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive aspects of psychomotor performance: The effects of performance goals on level of performance.

Reports an experiment stemming from Mace's work on the effects of performance standards on level of performance. It was found that Ss given specific (but difficult) standards performed at a higher level on a complex psychomotor task than Ss told to "do their best," thus replicating Mace's finding with a computation task. In contrast to Mace's study where performance goals worked by prolonging effort during the latter part of the work periods, the standards intensified effort at all stages of the work periods in the present case. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nicotine and smoking: A review of effects on human performance.

Examined the effects of nicotine administration and cigarette smoking on human performance to clarify the role of such effects in controlling smoking. The results of 101 studies (129 experiments) published in scientific journals from 1970 to 1993 were reviewed. In nonabstinent smokers and nonsmokers, nicotine enhanced finger tapping and motor responses in tests of attention; cognitive functioning was not reliably enhanced. It is unlikely that these limited performance-enhancing effects of nicotine play an important role in the initiation of cigarette smoking. In contrast, data from abstinent smokers support the conclusion that nicotine deprivation functions to maintain smoking in nicotine-dependent persons, in part, because nicotine can reverse withdrawal-induced deficits in several areas of performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in dual-task performance after practice.

This study investigated whether older adults could acquire the ability to perform 2 cognitive operations in parallel in a paradigm in which young adults had been shown to be able to do so (K. Oberauer & R. Kliegl, 2004). Twelve young and 12 older adults practiced a numerical and a visuospatial continuous memory updating task in single-task and dual-task conditions for 16 to 24 sessions. After practice, 9 young adults were able to process the 2 tasks without dual-task costs, but none of the older adults had reached the criterion of parallel processing. The results suggest a qualitative difference between young and older adults in how they approach dual-task situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus variables in the block design task.

Block-design construction tasks reliably assess cognitive deficits caused by brain injury. The important aspects of this task were examined in 4 studies with 46 undergraduates. Two problem-solving strategies were identified: (1) an analytic strategy in which Ss mentally segmented each block in the design to be constructed and (2) a synthetic strategy that involved wholistic pattern matching. Three experiments found a predominant analytic strategy. The time to place a single test block in a display decreased the greater the number of interior edges for that block in the design. Two-colored blocks requiring an orientation judgment were placed slower than solid blocks. The 4th experiment predicted overall construction times for a design from the number of solid blocks and interior edges of its blocks. Results suggest refinements in the block-design test for investigating constructional disability in brain-damaged patients. Analyses of other neuropsychological tests are recommended. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)