Differential age effects for case and hue mixing in visual word recognition

The authors compare older adults' lexical-decision data with younger adults' data reported in P. Allen, A. F. Smith, et al. (2002). On the basis of their work, it was proposed that consistent-case wordswould be processed by the faster holistic (magnodominated) stream, but that mixed-case words would be processed by the slower analytic (interblob-dominated or blob-dominated) steams. Hue mixing was predicted to have no effect on consistent-case performance, but mixed-hue/mixed-case words were predicted to be recognized faster than monochrome/mixed-case words. Younger adults showed the predicted results, but older adults did not. These results suggest that holistic central processes are maintained, but that older adults exhibited an analytic decrement     

Psychiatric patient- and informant-reported personality: predicting concurrent and future behavior

The authors investigated the criterion and incremental validity of personality reports from psychiatric patients and knowledgeable informants in predicting patient substance use, social and risky behaviors, and psychological distress. Patient and informant reports of patient personality and behavior were collected from an adult psychiatric sample (N = 94). Hierarchical regressions indicated that patient reports of personality accounted for significant variance in both concurrent (17%-42%) and future behavior assessed 1 year later (17%-40%). Informant reports contributed significantly to the prediction of several behaviors and most strongly to social behaviors. Behaviors were predicted equally well by self-reports and informant reports in prospective as in concurrent regressions. Thus, both patient and informant reports of personality contribute importantly to prediction of behavior, and predictive ability is stable across time.     

Courtesy stigma in mothers of children with Attention-Deficit/Hyperactivity Disorder: a preliminary investigation

Mothers of children with Attention-Deficit/Hyperactivity Disorder face an increased risk for depression, anxiety, and social isolation. In addition to stress due to children's behavior, mothers of children with ADHD may also feel stigmatized by their children's diagnosis. Fifty-one mothers participated in a study to assess attitudes toward ADHD. Although mothers of children with ADHD expected that parents of children without ADHD would hold harsh views of the disorder, this was not generally the case. This difference between perception and the actual self-reported views of mothers of children without ADHD supports the idea that mothers feel stigmatized but suggests that increased awareness might help mothers of children with ADHD feel less isolated.     

A computational account of altered error processing in older age: Dopamine and the error-related negativity

When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles’s (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects that the consequences of an action are worse than expected. To study age-related changes in error processing, we obtained performance and ERN measures of younger and high-functioning older adults. Experiment 1 demonstrated reduced ERN amplitudes in older adults in the context of otherwise intact brain potentials. This result could not be attributed to uncertainty about the required response in older adults. Experiment 2 revealed impaired performance and reduced response- and feedback-related ERNs of older adults in a probabilistic learning task. These age changes could be simulated by manipulation of a single parameter of the neurocomputational model, this manipulation corresponding to weakened phasic activity of the mesencephalic dopamine system.     

Comparison of the Trail Making and Color Trails Tests in a Chinese context: a preliminary report

The Color Trails Test developed as a culturally fair analogue of the Trail Making Test, was used to examine the relationship between the two tests with 35 undergraduate Chinese in Hong Kong recruited as the subjects. The scores on these two tests of the 12 men and 23 women were significantly correlated .71. The equivalence of the Trail Making and Color Trails Tests when applied to Chinese in Hong Kong was discussed.     

The importance of the convex hull for human performance on the traveling salesman problem: a comment on MacGregor and Ormerod (1996)

MacGregor and Ormerod (1996) have presented results purporting to show that human performance on visually presented traveling salesman problems, as indexed by a measure of response uncertainty, is strongly determined by the number of points in the stimulus array falling inside the convex hull, as distinct from the total number of points. It is argued that this conclusion is artifactually determined by their constrained procedure for stimulus construction, and, even if true, would be limited to arrays with fewer than around 50 points.     

Levels-of-processing effects on Chinese character completion: The importance of lexical processing and test cue

The levels of processing (LoP) effect was studied in Chinese character completion tasks. The same stem cue, either graphemically or semantically related to the target character, was used to generate either a perceptual or a conceptual test. Participants received either direct or indirect instructions, so that the same stem cue also produced either an explicit or an implicit test of memory. This allowed us to examine simultaneously the roles of perceptual versus conceptual test and retrieval intentionality in the LoP effect. No LoP effects were found when the memory test was implicit. LoP effects were also not found for stems and characters related graphemically (perceptually), but were found for stems and characters related semantically (conceptually) when the memory test was explicit. The results are discussed in terms of the importance of lexical processing for character completion tests and the importance of reinstatement of the study process during retrieval for explicit memory tests.