Assessing the validity of computer-game-like tests of processing speed and working memory.

Processing speed (Gs) and working memory (WM) tasks have received considerable interest as correlates of more complex cognitive performance measures. Gs and WM tasks are often repetitive and are often rigidly presented, however. The effects of Gs and WM may, therefore, be confounded with those of motivation and anxiety. In an effort to address this problem, we assessed the concurrent and predictive validity of computer-game-like tests of Gs (Space Code) and WM (Space Matrix) across two experiments. In Experiment 1, within a university sample (N = 70), Space Matrix exhibited concurrent validity as a WM measure, whereas Space Code appeared to be a mixed-ability measure. In Experiment 2, Space Matrix exhibited concurrent validity as well as predictive validity (as a predictor of school grades) within a school-aged sample (N = 94), but the results for Space Code were less encouraging. Relationships between computer-game-like tests and gender, handedness, and computer-game experience are also discussed.

Endogenous testosterone levels, mental rotation performance, and constituent abilities in middle-to-older aged men.

Evidence from both human and animal studies suggests that gonadal steroids, such as testosterone, exert activational effects on adult spatial behavior. Endogenous testosterone levels decline gradually but variably as men age; it remains to be shown whether these decreases are associated with age-related declines in visuo-spatial performance or constituent abilities indicative of generalized age-related cognitive decline. Ninety-six healthy, community dwelling men aged between 38 and 69 years completed the Vandenberg and Kuse Mental Rotation Test (MRT) together with a battery of tests including processing speed, executive function, perceptual discrimination, working memory, and reaction time measures. Significant main effects of tertiles of calculated free testosterone levels (cEFT) were found on composite measures of processing speed, executive function, and perceptual discrimination ability in a subset of men aged over 50 years in age and crystallized intelligence controlled analyses; higher cEFT levels were associated with poorer performance. Hierarchical multiple regression and path analyses on the whole data set showed that cEFT levels negatively moderated processing speed performance, which in turn predicted both working memory and MRT performance with aging. Together these data suggest that age-related declines in endogenous testosterone levels in healthy middle-to-older aged men are not associated with generalized age-related cognitive decline.

Perceptual learning on inspection time and motion perception.

Perceptual learning on simple perceptual tasks is interpreted as plasticity of neuronal populations in the sensory cortex (M. Fahle & T. Poggio, 2002). The authors examined individual differences on perceptual learning for 2 tasks-inspection time (IT) and a motion direction discrimination task that was instantiated as random dot kinematograms. The authors' main questions were whether individual differences in perceptual learning were consistent across the 2 tasks and whether perceptual learning correlated with cognitive abilities test scores. In all, 56 young adults completed 16 threshold estimations on 1 of 2 orthogonal versions of each task. Then, the authors made 2 further threshold estimations for the untrained, orthogonal version. Participants also completed a battery of 6 cognitive abilities tests that measured fluid ability (Gf) and perceptual speed (Gs). Perceptual learning was demonstrated for both tasks, but the degree of learning across tasks was not characteristic of the individual. Learning on IT correlated with Gs (r = .35), but learning on the motion direction discrimination task was unrelated to cognitive ability. Correlations of IT with cognitive measures were stable over the training period. IT was correlated with both the motion direction discrimination task (r = -.39) and an unmasked line length judgment task (r = -.31). The authors concluded that perceptual learning on IT correlates with cognitive abilities test scores, that correlations of IT with cognitive abilities test scores are stable as task performance improves with practice, and that the IT task is psychologically complex.

Gs invaders: assessing a computer game-like test of processing speed.

Computer games potentially offer a useful research tool for psychology but there has been little use made of them in assessing cognitive abilities. Two studies assessing the viability of a computer game-like test of cognitive processing speed are described. In Experiment 1, a computerized coding task that uses a mouse responsemethod (McPherson & Burns, 2005) was the basis for a simple computer game-like test. In Experiment 2, dynamic game-like elements were added. Validity was assessed within a factor analytic framework using standardized abilities tests as marker tests. We conclude that computer game-like tests of processing speed may provide an alternative or supplementary tool for research and assessment. There is clearly potential to develop game-like tests for other cognitive abilities.

The role of item extremity in the emergence of keying-related factors: an exploration with the life orientation test.

Keying-related factors in psychological scales are variously interpreted substantively or as products of violations of the assumptions underlying item keying. The present study investigated whether the extremity of the wording of items may contribute to the emergence of item-keying factors in a commonly used psychological scale. Respondents (N = 277) completed the Life Orientation Test (M. F. Scheier & C. S. Carver, 1985) in either its original or modified, more moderately worded form. Results indicate that the interaction of item extremity and item keying significantly affected subscale means and, more important, that the more moderately worded scale was substantially more unidimensional. Results are explained partially through the association of lesser and greater extremity with the tendency for some respondents to agree or disagree with items irrespective of keying direction. These results, although demonstrated in only 1 scale, have potential relevance to any scale comprising positive and negative items.

A speeded coding task using a computer-based mouse response.

This study assessed whether a speeded coding task that used a computer-based mouse response (CBMR) format was a measure of general processing speed (Gs). By analyzing the task within a network of tasks representing both traditional Gs tests and reaction time tasks, it was shown that a CBMR test can be used to measure the same construct as traditional paper-and-pencil (PP) tests and that this response format does not introduce variance associated with psychomotor performance. Differences between PP and CBMR formats were observed, and it is argued that these may provide information on individual differences in performance not available from traditional coding tests.