General slowing alone cannot explain age-related search effects: reply to Cerella (1991)

Cerella (1991) has argued that the performance of older adults in the Fisk and Rogers (1991) study is a linear function of the performance of younger adults that is independent of task-specific cognitive requirements. We demonstrate that this is not the case. First, we show that the scatter plot analyses used by Cerella can hide the very task-specific age-related slowing they were designed to reveal. Second, we demonstrate that the percentage of variance explained by such analyses can be misleading. Third, we show that there are reliable differences across tasks in the parameters relating younger and older adults' performance. Finally, we argue that the general, task-independent proportionate slowing that Cerella suggested explains so much of the variance in age-related performance is actually an average slowing that is a function of a relatively small task-independent and a relatively large task-dependent factor.     

Category and word search: generalizing search principles to complex processing

This research examines how the major phenomena of visual search for single characters generalize to word search and word-category search. Experiment 1 examined word and category visual search when the target and distractor sets had a varied mapping (VM) across trials. Reaction time was a linear function of the number of comparisons with a positive slope of 48 msec per word, 92 msec per category. The VM reaction time data indicated a self-terminating comparison process, and there was little or no improvement with practice. Experiment 2 examined search with a consistent mapping (CM) between targets and distractors. Category search slope dropped to 2 msec, and the function became nonlinear. Word search slope dropped to 18 msec, but the function became nonlinear. Word search slope dropped to 18 msec, but the function was still linear. Experiment 3 examined category detection carried out concurrently with serial recall of digits, allowing assessment of search performance under high workload. High workload caused a severe performance reduction in VM category search, and this decrement did not decrease with practice. High workload reduced initial performance in CM category search, but this decrement was eliminated with practice. The present category search results are similar to previous letter search results. Four principles of search are discussed in the context of a theory of automatic/control processing.     

Degree of consistent training: Improvements in search performance and automatic process development

Previous research has shown substantial improvements in detection performance when subjects consistently detect a subset of stimuli. In contrast, in conditions in which stimuli appear as both targets and distractors, there is little performance improvement with practice. The present experiments examine how varying degrees of consistency determine the improvement of detection accuracy with extended practice. The degree of consistency was varied by manipulating the frequency with which a letter was a distractor while holding the number of occurrences as a target constant. The experiments utilized a multiple-frame target-detection search paradigm in which subjects were to detect single-letter targets in a series of rapidly presented letters on four channels. Experiments showed that detection performance improvement with practice was a monotonic function of the degree of consistency, decreasing to zero as the target-to-distractor ratio increased from 10:0 to 10:20. As consistency decreased, detection performance asymptoted earlier and at a lower level. A dual-task experiment examined subjects’ ability to perform the previously trained search task as a secondary task. Results showed that the previous targetto-distractor consistency had a marked effect on resource sensitivity of the detection task. The general issues of consistency in the development of skilled performance and in the development of automatic processing are discussed.     

An individual differences analysis of ability and strategy influences: age-related differences in associative learning

The relationships among abilities, strategies, and performance on an associative learning task were investigated for young (aged 17 to 34) and older adults (aged 60 to 82). Participants received extensive practice on a noun-pair task in which they could use a visual-scanning strategy or a memory-retrieval strategy. Older adults were more likely to use the scanning strategy. Age differences were reduced when comparisons were made only for participants using a retrieval strategy. Associative memory was predictive of learning on the task, and semantic memory access speed was predictive of practiced performance. Practiced performance on a memory-search task that also required associative learning was predictive of practiced noun-pair performance. Models of ability-performance relationships for skill acquisition are discussed.     

Dyslexic students have more everyday cognitive lapses

There is a dearth of information about the everyday performance difficulties of adult dyslexic people. This study investigates the empirical support for anecdotal reports of increased vulnerability to distraction in dyslexia, using the self-report Cognitive Failures Questionnaire (CFQ). Two groups of university students, a dyslexic group and a non-dyslexic control group, were asked to complete the CFQ. The dyslexic group reported a higher frequency of everyday lapses in cognition, scoring significantly higher on a number of CFQ items. Representative problems include distractibility, over-focusing (so that relevant peripheral information is missed), and word-finding difficulties. A similar measure administered to close friends of dyslexic people, the CFQ-for-others, yielded results consistent with those of the CFQ, with major findings being that their friends considered them to be more disorganised, more distractible, and more absent-minded than normal. The results indicate clearly the continuing effects of dyslexia on cognition in adulthood and demonstrate that dyslexic impairments are not limited to "artificial" laboratory tasks or even literacy tasks but, instead, pervade everyday life.     

Valid distinctions between conscious and unconscious perception?

In this commentary, we discuss the strengths and limitations of Snodgrass, Bernat, and Shevrin's (2004) theory of unconscious perception. Our commentary centers on the value of signal detection theory (SDT) to understanding the unconscious perception controversy, a value that Snodgrass et al. for the most part agree with (i.e., that most approaches to studying unconscious perception are invalid because they have confounded the criterion for detection with the criterion for awareness). However, we believe that their model relies on a somewhat restricted application of SDT. We discuss how SDTcan be better applied to provide the necessary tests to validate their model.     

Paranormal belief and the conjunction fallacy: Controlling for temporal relatedness and potential surprise differentials in component events

Recent research suggests paranormal believers are especially prone to the ‘conjunction fallacy’. The current study extends this work by presenting believers and non‐believers with eight paranormal plus eight non‐paranormal scenarios. Participants were given either a paranormal or virtually identical non‐paranormal version of each scenario. Of these, half incorporated component events which were (virtually) co‐occurring with half including components which were temporally disjointed. Analysis of Covariance (ANCOVA; controlling for gender and maths/stats/psychology qualifications) found believers made more conjunction errors than non‐believers. Neither event type (paranormal vs. non‐paranormal) nor components' temporal relationship (co‐occurring vs. disjointed) had a significant effect on conjunction biases. Believers' tendency to produce larger conjunctive estimates was unrelated to group differences in component probability estimates (surprise values) and further, could not be attributed to group differences in the perceived functional relationship between component and conjunctive events. Possible explanations are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Women's perceptions and labeling of sexual harassment in academia before and after the Hill-Thomas hearings

Two years before the Hill—Thomas sexual harassment hearings, Jaschik and Fretz (1991) had sixty female undergraduates view videotapes of a male teaching assistant sexually harassing a female undergraduate as he evaluated her term paper. Seventy percent of subjects were Caucasian, 8% were African-American, 20% were Asian-American, and 2% were identified as of another race. Following the videos, subjects completed measures of perceptions of the teaching assistant. To explore the effects of the hearings on women's perceptions of sexual harassment, this study replicated the earlier one. In this study, 81% of subjects were Caucasian, 10% were African-American, 6% were Asian-American, and 2% were identified as of another race. Using Fisher's Exact Probability Test, results indicated that while women in 1992 were as likely as women in 1989 to label behaviors as harassment when directly asked about it (p= .16), women in 1992 were significantly more likely to spontaneously label the behaviors as harassment (p= .02), suggesting that publicity from the hearings may have increased women's sensitivity to the issue of sexual harassment, although other possible explanations for the changes are also explored.