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.     

Buffering against weight gain following dieting setbacks: An implicit theory intervention

Research on implicit theories suggests that incremental beliefs—that attributes are malleable—can help buffer people against the adverse effects of setbacks on goal achievement. We conducted a longitudinal experiment to examine whether an incremental beliefs intervention could help dieters manage their body weight in the face of severe dieting setbacks. To explore the efficacy of our incremental beliefs intervention, we randomly assigned individuals to a control, a knowledge, or an incremental beliefs condition. In addition to examining the main effect of intervention condition on weight-loss across a 12-week period, we also tested the hypothesis that although participants assigned to the control or knowledge intervention condition would gain more weight as dieting setbacks became more severe, participants assigned to the incremental beliefs condition would not. Results supported this hypothesis: Incremental beliefs protected against setback-related weight-gain. Implications for integrating implicit beliefs interventions with obesity relapse prevention programs are discussed.     

Wealth inequality and activism: Perceiving injustice galvanizes social change but perceptions depend on political ideologies

What motivates people to engage in activism against wealth inequality? The simple answer is perceiving injustice. However, the current work demonstrates that these perceptions depend on political ideologies. More specifically, for political liberals who frequently question the fairness of the economic system, messages simply describing the extent of the inequality (distributive injustice) are enough to motivate activism (Study 1). For political conservatives, who are inclined to believe that inequality results from fair procedures, messages must also detail how the system of economic forces is unjust (procedural injustice; Studies 2 and 3). Together, these studies suggest perceiving injustice can galvanize social change, but for conservatives, this means more than simply outlining the extent of the inequality.