On the locus of redundancy effects in a letter-detection task

It takes longer to detect a target if it is the initial letter of a nonredundant letter string such as BNHTW than if it is the initial letter of a redundant letter string such as BBBBB (Johnson, 1986b; Johnson & Blum, 1988). The results of the present study reveal that the redundancy effect also occurs for mixed-case letters strings (e.g., BbbBb) and digit strings (e.g., 22222). In addition, these results suggest that the cause of the redundancy effect is not related to the visual properties of the noninitial letters per se but is instead related to the presence of the target in noninitial positions. Together, these results rule out a number of hypotheses about the cause of the redundancy effect and suggest that the locus of this effect is in processes involved in response selection and/or the read-out of information from the perceptual system.     

Sex differences in symbol-digit substitution task performance

Estes (1974) proposed that the superior performance of women over men on the Digit-Symbol Substitution subtest of the Wechsler scales was due to their greater ability to encode symbols verbally. Three forms of a symbol-digit substitution task were administered to 62 female and 96 male college students. The symbol sets of the three forms differed in the relative amount of figural and spatial orientational information. Women performed better than men on the form which used the Wechsler symbol set in which all symbols are figurally different and, presumably, most easily coded verbally. Men performed better than women on the form which had the greatest amount of spatial orientational information. Estes' hypothesis is supported by these findings.     

Some evidence for correlated separate activation in a simple letter-detection task

This study investigates the separate activation versus coactivation issue for redundant targets in a simple letter-detection paradigm with latency as the dependent variable. The results of a one-response visual-search task are reported. Since, on single-target trials, only the target was presented and no accompanying noise element, no “distraction decrement” caused by irrelevant noise elements (Grice et al., 1984) was to be expected. The data obtained showed a clear redundantsignal effect. Subsequent detailed analysis of the latency data using Miller’s (1982) procedure indicated that the results were consistent with a separate activation model and failed to provide convincing evidence in favor of coactivation models. A further analysis of the data indicated that, in the present study, the separate channels were negatively correlated for a range of fast RTs and positively correlated for intermediate and larger RTs. No evidence in favor of Grice et al.’s (1984) distraction-decrement hypothesis was found. The conclusions of this study are that (1) a separate activation model summarizes the essential features of information processing in this simple visual search task, and (2) no convincing evidence in favor of coactivation in visual search tasks has been reported in the literature up to now.     

Sex differences in smiling as measured in a picture taking task

Previous research suggests females smile more than males in a picture taking task (Mills, 1984; Morse, 1982; Ragan, 1982). Experiment 1 sought to replicate this effect and, in addition, investigate if the gender of the photographer or instructions to smile would influence smiling in females and males. Subjects were told that their picture would be used in a subsequent facial perception study. Results showed that subjects instructed to smile smiled more than subjects given no instructions. There were no main effects for subject's or photographer's gender and no interactions. In Experiment 2, graduating students from the University of New Brunswick, Saint John, completed a questionnaire which assessed how much subjects wanted to smile for their yearbook picture, whether subjects selected a picture of themselves smiling for their yearbook, and how much the photographer encouraged them to smile. Experiment 2 showed that females wished to smile significantly more than males, and females selected a picture of themselves smiling significantly more than males. Males and females did not differ in the reported degree to which the photographer encouraged them to smile. Results from Experiments 1 and 2 suggest that sex differences in smiling as measured in a picture taking task depend critically on the situation in which the picture is taken.     

Sex differences in attributions for the performance of women of a masculine task

Sex differences in the attributions of observers for the successful or unsuccessful behavior of a female actor performing a masculine task were studied. For the perceived causes of the outcome it was found that internal attributions were emphasized more for success than for failure. In addition, female observers attributed both types of outcome more to effort than did males. The nature of the outcome and the sex of the observer also affected the perceived personality traits of the actor. More positive traits were attributed to the successful than to the unsuccessful actor. The female observers attributed more instrumental traits to the actor than did the male observers. The results were discussed in terms of Jones and Davis's theory (1965) of correspondent inferences and the fact that competence was not viewed as being incompatible with femininity.     

Single landmark learning in rats: Sex differences in a navigation task

In Experiments 1 and 2, rats were trained in a Morris pool to find a hidden platform located some distance away from a single landmark. Males learned to swim to the platform faster than females, but on test trials without the platform, males, unlike females, spent less time in the platform quadrant of the pool in the second half of each test trial than in the first. They also showed greater persistence in searching in the platform quadrant over a series of extinction trials. In Experiments 3a and 3b, the problem was made easier by locating the platform closer to the solitary landmark. Now males and females learned to swim to the platform equally rapidly, and both stopped searching in the platform quadrant in the second half of each test trial. Experiment 4 ruled out the possibility that males´ shorter latencies to find the platform in Experiment 2 were due to their swimming faster than females.     

Sex differences in performance on a combined manual and decision task.

This report describes results of an experimental study of the differences in response time between 10 male and 10 female undergraduate operators performing a combined manual and decision task. Analysis indicated that the performance times of women on such tasks were shorter than those of the men as expected.     

Sex differences in dual-task interference between speaking and a manual force-production task

12 male and 12 female right-handed adults performed a unimanual force-production task alone and while sound-shadowing high frequency words. The secondary speech task disrupted right-hand performance by men and left-hand performance by women. The implications of these findings for intrahemisphere-interference models of dual-task performance are discussed.     

Sex differences in performance and hemispheric organization for a nonverbal auditory task

Musically experienced and inexperienced men and women discriminated among fundamental-frequency contours presented either binaurally (i.e., same contour to both ears) or dichotically (i.e., different contours to each ear). On two separate occasions, males made significantly fewer errors than did females in the binaural condition, but not in the dichotic condition. Subjects with prior musical experience were superior to musically naive subjects in both conditions. The dichotic pitch task produced a left-ear advantage, which was unrelated to gender or musical experience. The results suggest that the male advantage on the binaural task reflects a sex difference in the coordination of the two hemispheres during conjoint processing of the same stimuli rather than a difference in the direction or degree of hemispheric specialization for these stimuli.     

Sex differences in functional brain activation during a lexical visual field task

Functional MRI was used to investigate sex differences in brain activation during a paradigm similar to a lexical-decision task. Six males and 6 females performed two runs of the lexical visual field task (i.e., deciding which visual field a word compared with a pseudoword was presented to). A sex difference was noted behaviorally: The reaction time data showed males had a marginal right visual field advantage and women a left visual field advantage. Imaging results showed that men had a strongly left-lateralized pattern of activation, e.g., inferior frontal and fusiform gyrus, while women showed a more symmetrical pattern in language related areas with greater right-frontal and right-middle-temporal activation. The data show evidence of task-specific sex differences in the cerebral organization of language processing.     

Sex differences in processing aggression words using the Emotional Stroop task

There is a robust relationship between the salience of stimulus materials presented in the Emotional Stroop task and inhibition of response in clinical populations. Researchers have now found information‐processing biases in both forensic and non‐forensic samples presented with threatening or aggressive stimuli [Cohen et'al., 1998; Eckhardt and Cohen, 1997; Smith and Waterman, 2003; Van Honk et'al., 2001]. We sought to explore sex differences in processing words relating to acts of direct and indirect aggression using a group of undergraduates (50 males and 50 females). Participants also completed self‐report questionnaires (AQ and EXPAGG) to allow some consideration of the relationship between objective and subjective measures. We predicted that males would demonstrate delayed responses when presented with words relating to acts of direct aggression. We also predicted that high levels of physical aggression would be the best predictor of bias for direct aggression words, high levels of verbal aggression would be the best predictor of bias for indirect aggression words, physical aggression would predict bias in males, and verbal aggression would predict bias in females. Males demonstrated a perceptual bias for words relating to acts of direct aggression, taking significantly longer to correctly colour name direct aggression words. Females were slower to correctly colour name indirect aggression words, but not significantly so. Verbal aggression, as expected, predicted bias performance for indirect aggression words but anger rather than physical aggression was the best predictor of bias for direct aggression words. Gender was a predictor for bias with both sets of words. Contrary to our predictions, it was observed that a high level of physical aggression was the best predictor of bias in both males and females. These data provide further evidence to confirm the saliency of aggression words to aggressive individuals in non‐forensic populations. Aggress. Behav. 00:00–00, 2005. © 2005 Wiley‐Liss, Inc.     

Sex differences in performance and hemispheric organization for a nonverbal auditory task.

Musically experienced and inexperienced men and women discriminated among fundamental-frequency contours presented either binaurally (i.e., same contour to both ears) or dichotically (i.e., different contours to each ear). On two separate occasions, males made significantly fewer errors than did females in the binaural condition, but not in the dichotic condition. Subjects with prior musical experience were superior to musically naive subjects in both conditions. The dichotic pitch task produced a left-ear advantage, which was unrelated to gender or musical experience. The results suggest that the male advantage on the binaural task reflects a sex difference in the coordination of the two hemispheres during conjoint processing of the same stimuli rather than a difference in the direction or degree of hemispheric specialization for these stimuli.     

Sex differences in phonological processes: Speeded matching and word reading

Sex differences in phonological processing were investigated in four experiments. Two experiments required college students to decide whether two five-letter strings matched. Same-case (AA) pairs of letter strings could be matched using physical features, whereas mixed-case (Aa) pairs of letter strings required the mediation of a speech-based code (letter name) for the comparison. Women were significantly faster than men when the comparisons required the speech-based codes. In another experiment, college students read lists of words and lists of pseudohomophones to determine whether there was a sex difference in the computation of phonology for unfamiliar words (assembled phonology). In a final experiment, students read lists of words with phonologically inconsistent spelling patterns to determine whether there was a sex difference in accessing pronunciations of familiar words (addressed phonology). Women were more proficient than men under both of these conditions. Results were interpreted in terms of a female advantage in both prelexical and lexical processing, an advantage that may stem from a sex difference in the quality of the phonological representations.     

Sex differences in the effects of interest on boys' and girls' reading comprehension

This study compared the reading comprehension of groups of boys and girls (aged 10–11) on two tests, one of which was about the evacuation of children during the Second World War and the other of which was about spiders. These were the actual year 6 SATS reading tests administered in the UK in 1998 and 1999. The majority of the boys said that they would prefer to read the text about spiders, and the majority of the girls said they would prefer to read the text about leaving home in wartime. These patterns of preference were reflected in the children's performance on the actual tests. However, whereas the boys' comprehension was significantly affected by the content of the tests (they showed better performance on the test about spiders) the girls' performance was relatively little influenced by the content of the test. The implications of these results for testing reading, and for encouraging reading more generally, are discussed.     

Residual differences in language processing in compensated dyslexics revealed in simple word reading tasks

Using regional cerebral blood flow as an index of cerebral activity we studied dyslexic and control subjects during simple word reading tasks. The groups were pre-tested for reading skill and the dyslexic group had a lower reading performance but could read and comprehend standard texts. The aim was to elucidate differences in the cerebral activation pattern during reading. The tasks were simple enough that performance differences between the groups could be excluded. We found specific differences between the two groups that were dependent on the language task. When the visual route for language information was used, minor qualitative differences were found between the groups pertaining to the dominant hemisphere. Increasing the complexity of the task by using pseudowords activated the left frontal region more in the dyslexic group than in the control group. A similar effect was seen in a minor region in extrastriate lateral occipital cortex (BA 19). This finding indicates that the dyslexics used areas in these regions that the controls did not. On the other hand, the dyslexics activated less in the right angular gyrus, right dorsolateral prefrontal cortex, and in the right pallidum. Reading skill correlated with the level of activity in the right frontal cortex. We conclude, that cerebral activation pattern elicited by reading is different in dyslexics compared to controls in spite of an almost complete functional compensation.     

Individual differences in trait anxiety and goal-commitment predict updating efficiency on the reading span task

According to attentional control theory (ACT; Eysenck et al. in Emotion 7(2):336–353, 2007) anxious individuals recruit motivation on demanding tasks, which helps prevent performance shortfalls. We used a quasi-experimental design to examine the relationship between trait anxiety (operationalised using questionnaire scores), situational stress (manipulated using ego threat instructions) and motivation (indexed using a self-report goal-commitment scale) in predicting effectiveness (accuracy) and efficiency (accuracy divided by RT) on the reading span task. After controlling for depression, the variables were not related to effectiveness; however there was a significant trait anxiety × goal-commitment interaction on reading span efficiency. Higher trait anxiety predicted better efficiency at higher goal-commitment, and poorer efficiency at lower goal-commitment, and these relationships were independent of situational stress. Results are interpreted in terms of ACT.     

Sex differences in spatial task performance of patients with and without unilateral cerebral lesions

Two visuospatial tasks, the WAIS Block Design and the Street Gestalt Completion Test, were administered to men and women with and without unilateral cerebral lesions. These two tasks represent different categories of visuospatial functions. The Street test is a visual-perceptual gestalt task, requiring the closure of fragmented pictures, whereas Block Design is an analytical, manipulospatial task requiring rotation of spatial coordinates. For the non-brain-damaged group, the men showed a nonsignificant trend toward better Block Design performance relative to the women, whereas there was no sex-related difference in Street performance. For the brain-damaged groups, patients with right hemisphere lesions performed significantly worse than patients with left hemisphere lesions on both the Street test and Block Design, indicating that both tasks were more sensitive to right hemisphere functioning. There was, however, a significant sex X side of lesion interaction on Block Design only, with the men showing a more asymmetrical pattern of scores. These results suggest that sex differences in functional lateralization may underlie sex differences in visuospatial ability, and that sex differences in functional lateralization may be present for only certain visuospatial processes.     

Hemispheric differences in a letter classification task

The experiment examined hemispheric differences in same-different judgments for unilaterally presented letter pairs which could be classified as “same” on the basis of name identity (NI, e.g., Aa) or physical identity (PI, e.g., AA). Two groups of Ss were tested, a right-handed group and a predominantly left-handed group. The experiment employed a reaction time measure, and fixed the duration of brief exposures to yield an overall performance level of 90% correct. Analysis of the results focused on the difference between RTs for the NI matches and for the PI matches in each hemisphere. The method allowed differences in cognitive processing to be assessed while sensory and response factors were minimized. The right-handed group all showed a smaller mean NI-PI difference in the left hemisphere (84 msec) than in the right hemisphere (181 msec). The left-handed group showed smaller and less consistent differences, but the group as a whole had a reversed asymmetry, with a mean NI-PI difference of 128 msee in the left hemisphere and 90 msec in the right hemisphere.     

Understanding strategy differences in a fault-finding task

This article examines strategy choices for how people find faults in a simple device by using models of several strategies and new data. Diag, a model solving this task, used a single strategy that predicted the behavior of most participants in a previous study with remarkable accuracy. This article explores additional strategies used in this reasoning task that arise when less directive instructions are provided. Based on our observations, five new strategies for the task were identified and described by being modeled. These different strategies, realized in different models, predict the speed of solution while the participant is learning the task, and were validated by comparing their predictions to the observations (r² = .27 to .90). The results suggest that participants not only created different strategies for this simple fault-finding task but that some also, with practice, shifted between strategies. This research provides insights into how strategies are an important aspect of the variability in learning, illustrates the transfer of learning on a problem-by-problem level, and shows that the noisiness that most learning curves show can arise from differential transfer between problems.     

Picture-word differences in a sentence verification task

Effects of picture-word format were investigated with four problem-solving items. In Experiment 1, picture-word input was presented for 8 sec followed by a test sentence that included verbatim and inference statements. Subjects made a true/false reaction time to the test sentence. In Experiment 2, the input remained on the screen while the test sentence was presented with varied stimulus onset asynchronies from 0 to 1,000 msec. Results showed that responses to pictures were faster than responses to words, and the format effect was larger with inference than with verbatim sentences. The picture advantage seemed to be due to the nature of the input and how information is extracted from it. The findings are discussed within the context of text-processing theories (Glenberg & Langston, 1992; Larkin & Simon, 1987).