An investigation into some of the underlying associative verbal processes of the stroop colour effect

The Stroop test was examined to throw some light on the verbal basis of the test. When words are presented printed in the wrong colour it is found that the written word provides more interference with response to the colour of print than occurs the other way round (the Stroop effect). It was shown that, by allowing subjects to match the colour of the print with colour patches instead of words, the interference due to the written word can be considerably reduced. In a further experiment, associations were formed by the subjects between nonsense syllables and colours in the course of a paired-associate learning task. When nonsense syllables were presented printed in colours different from those associated with them, it was found that the interference effects depended upon the direction of the stimulus-response association in the paired-associate experiment. It is concluded that the underlying processes in the Stroop effect are primarily verbal and depend partly upon the directionality of previously established verbal associations.     

The MRCI with juvenile detainees: optimizing performance or emphasizing ecological validity?

The Miranda Rights Comprehension Instruments (MRCI) are intended to be administered to legally involved youths in a setting free from distractions and stressors with the explicit goal of assessing the examinee's best understanding. However, marked disparities have been observed between juveniles' MRCI performance and their unassisted recall of a representative Miranda warning. We hypothesized that youths' very strong MRCI performance might be partially due to prompts and clarifications used whenever incomplete or ambiguous answers are provided. In this archival study, we systematically re‐scored three MRCI instruments from 231 legally involved youths to evaluate their original responses (i.e., non‐queried scoring). This approach is viewed as more ecologically valid because actual Miranda warnings are typically provided in a routine manner without assistance following each Miranda component. For the large majority of legally involved juveniles, only small differences were noted between standard and non‐queried scoring. However, some dramatic decrements were observed, especially on the Comprehension of Miranda Rights‐II (CMR‐II). More specifically, 15.7% of CMR‐II percentiles dropped precipitously by 60% or more, when using the non‐queried scores. The results are discussed within the context of optimized performances versus ecological validity as applied to Miranda evaluations.     

An Examination of PAI Clinical Descriptors and Correlates in an Outpatient Sample: Tailoring of Interpretive Statements

The Personality Assessment Inventory (PAI; Morey 1991, 2007) was designed to evaluate patterns of psychopathology utilizing validity, clinical, treatment, and interpersonal scales. Its psychometric strengths include easily read items, gradations of responses, and extensive validation. The primary focus of the current study is to examine item-level clinical correlates to inform interpretation. For external validity, the Psychiatric Diagnostic Screening Questionnaire (PDSQ; Zimmerman 2002) was utilized by examining individual items and subscales. The investigation used archival data from 192 outpatients. The most specific and detailed clinical correlates were found for PAI mood disorder scales. Several other clinical scales, such as Schizophrenia (SCZ), had comparatively few clinical correlates. The current findings underscore the need to further validate PAI external correlates in order to augment PAI statements.     

Fast color grouping and slow color inhibition: evidence for distinct temporal windows for separate processes in preview search

The authors report 4 experiments that examined color grouping and negative carryover effects in preview search via a probe detection task (J. J. Braithwaite, G. W. Humphreys, & J. Hodsoll, 2003). In Experiment 1, there was evidence of a negative color carryover from the preview to new items, using both search and probe detection measures. There was also a negative bias against probes on old items that carried the majority color in the preview. With a short preview duration (150 ms) carryover effects to new items were greatly reduced, but probe detection remained biased against the majority color in the old items. Experiments 2 and 4 showed that the color bias effects on old items could be reduced when these items had to be prioritized relative to being ignored. Experiment 3 tested and rejected the idea that variations in the probability of whether minority or majority colors were probed were crucial. These results show that the time course of color carryover effects can be separated from effects of early color grouping in the preview display: Color grouping is fast, and inhibitory color carryover effects are slow.     

Gambling primates: reactions to a modified Iowa Gambling Task in humans,chimpanzees and capuchin monkeys

Humans will, at times, act against their own economic self-interest, for example, in gambling situations. To explore the evolutionary roots of this behavior, we modified a traditional human gambling task, the Iowa Gambling Task (IGT), for use with chimpanzees, capuchin monkeys and humans. We expanded the traditional task to include two additional payoff structures to fully elucidate the ways in which these primate species respond to differing reward distributions versus overall quantities of rewards, a component often missing in the existing literature. We found that while all three species respond as typical humans do in the standard IGT payoff structure, species and individual differences emerge in our new payoff structures. Specifically, when variance avoidance and reward maximization conflicted, roughly equivalent numbers of apes maximized their rewards and avoided variance, indicating that the traditional payoff structure of the IGT is insufficient to disentangle these competing strategies. Capuchin monkeys showed little consistency in their choices. To determine whether this was a true species difference or an effect of task presentation, we replicated the experiment but increased the intertrial interval. In this case, several capuchin monkeys followed a reward maximization strategy, while chimpanzees retained the same strategy they had used previously. This suggests that individual differences in strategies for interacting with variance and reward maximization are present in apes, but not in capuchin monkeys. The primate gambling task presented here is a useful methodology for disentangling strategies of variance avoidance and reward maximization.     

Revisiting preview search at isoluminance: new onsets are not necessary for the preview advantage

It has been argued that search performance under preview conditions relies on automatic capture by luminance onsets (Donk & Theeuwes, 2001). We present three experiments in which preview search was examined with both isoluminant and nonisoluminant items (e.g., as defined by luminance onsets). Experiment 1 provided evidence against the automatic capture of attention by onsets. Search benefited when onset previews were followed by new onset stimuli, as compared with a full-set baseline matched for the number of new onsets but in which half the distractors appeared simultaneously at isoluminance. Furthermore, both Experiments 1 and 2 established a preview advantage when isoluminant targets followed onset previews, when compared with appropriate full-set baselines. Experiment 3 replicated this result, while showing that the preview benefit was disrupted by dual-task interference. The data indicate that new onsets are not necessary to generate a preview advantage in search. We discuss the data in terms of search's benefiting from active inhibition of old onset-defined stimuli.     

Counterfactual thinking and the first instinct fallacy

Most people believe that they should avoid changing their answer when taking multiple-choice tests. Virtually all research on this topic, however, has suggested that this strategy is ill-founded: Most answer changes are from incorrect to correct, and people who change their answers usually improve their test scores. Why do people believe in this strategy if the data so strongly refute it? The authors argue that the belief is in part a product of counterfactual thinking. Changing an answer when one should have stuck with one's original answer leads to more "if only . . ." self-recriminations than does sticking with one's first instinct when one should have switched. As a consequence, instances of the former are more memorable than instances of the latter. This differential availability provides individuals with compelling (albeit illusory) personal evidence for the wisdom of always following their 1st instinct, with suboptimal test scores the result.     

When a reappearance is old news: visual marking survives occlusion

Performance in a visual search task becomes more efficient if half of the distractors are presented before the rest of the stimuli. This "preview benefit" may partly be due to inhibition of the old (previewed) items. The preview effect is abolished, however, if the old items offset briefly before reappearing (D. G. Watson & G. W. Humphreys, 1997). The authors examined whether this offset effect still occurred if the old items undergo occlusion. Results show that a preview benefit was found when the old items were occluded but not otherwise, consistent with the idea of top-down attentional inhibition being applied to the old items. The preview benefit is attenuated, however, by movement of the irrelevant stimuli in the displays.     

On the efficiency of drawing computer-generated line stimuli: Rectangles can be faster than lines

A simple method is presented for optimizing the efficiency of drawing line stimuli in Turbo Pascal. It involves the substitution of Rectangle and Bar commands for Line commands and results in time savings of up to 90%. The savings are most consistent for horizontal lines, although some savings may also be made for vertical lines. The effects of different graphics libraries, graphics modes, and hardware configurations are discussed. The method proves especially useful in improving the spatiotemporal resolution of on-line-generated motion displays.     

Use of morphology in spelling by children with dyslexia and typically developing children

In English and some other languages, spelling problems that arise at a phonological level can sometimes be solved through consideration of morphology. For example, children could infer that tuned should contain an n and that fighting should contain a t because their stems include these letters. Children could thus avoid misspellings that might otherwise occur, such as "tud" and "fiding." We used a spelling-level match design to examine the extent to which children with dyslexia and younger typical children use morphology in this way. Both groups of children benefited from morphology to some extent, but not as much as they could have given their knowledge of the stems. Our results suggest that the spellings produced by older children with dyslexia are similar to those of younger normal children in their morphological characteristics, as well as in other ways.