Combining speed and accuracy to assess error-free cognitive processes

Both the speed and accuracy of responding are important measures of performance. A well-known interpretive difficulty is that participants may differ in their strategy, trading speed for accuracy, with no change in underlying competence. Another difficulty arises when participants respond slowly and inaccurately (rather than quickly but inaccurately), e.g., due to a lapse of attention. We introduce an approach that combines response time and accuracy information and addresses both situations. The modeling framework assumes two latent competing processes. The first, the error-free process, always produces correct responses. The second, the guessing process, results in all observed errors and some of the correct responses (but does so via non-specific processes, e.g., guessing in compliance with instructions to respond on each trial). Inferential summaries of the speed of the error-free process provide a principled assessment of cognitive performance reducing the influences of both fast and slow guesses. Likelihood analysis is discussed for the basic model and extensions. The approach is applied to a data set on response times in a working memory test. The authors wish to thank Roger Ratcliff, Christopher Chabris, and three anonymous referees for their helpful comments, and Aureliu Lavric for providing the data analyzed in this paper.     

Hemispheric cognitive style: a comparison of three instruments

In this study, the author tested the reliability, concurrent validity, and predictive validity of three hemispheric cognitive style instruments: (a) the Preference Test (PT; R. Zenhausern, 1978), (b) the Polarity Questionnaire (PQ; B. E. Morton, 2002), and (c) the Wagner Preference Inventory II (WAPI II; R. F. Wagner & K. A. Wells, 1985). Participants were either teachers or teachers in training. The prediction criterion was in the area of teaching licensure. Scores on the PQ had extremely low reliability, and correlations with the PT and the WAPI II were not significantly different from zero. In addition, the PQ did not correlate with the licensure area. The author found that both the PT and the WAPI II had reasonable levels of reliability, and both instruments were able to explain a small percentage of the variance in the teaching licensure area. Using factor analysis of the PT, the author found a 7-factor structure, which suggests that hemispheric cognitive style might be decomposable into separate holist analytic and visual-verbal dimensions.     

The role of coding time in estimating and interpreting growth curve models

The coding of time in growth curve models has important implications for the interpretation of the resulting model that are sometimes not transparent. The authors develop a general framework that includes predictors of growth curve components to illustrate how parameter estimates and their standard errors are exactly determined as a function of receding time in growth curve models. Linear and quadratic growth model examples are provided, and the interpretation of estimates given a particular coding of time is illustrated. How and why the precision and statistical power of predictors of lower order growth curve components changes over time is illustrated and discussed. Recommendations include coding time to produce readily interpretable estimates and graphing lower order effects across time with appropriate confidence intervals to help illustrate and understand the growth process.     

Personality over time: Methodological approaches to the study of short-term and long-term development and change

Although theories of personality emphasize the integrative, enduring, and dynamic nature of personality, the current modal research design in personality ignores the dimension of time. We consider a variety of recent methods of longitudinal data analysis to examine both short-term and long-term development and change in personality, including mean-level analyses both across and within individuals across time, variance structures across time, and cycles and dynamic models across time. These different longitudinal analyses can address classic as well as new questions in the study of personality and its development. We discuss the linkages among different longitudinal analyses, measurement issues in temporal data, the spacing of assessments, and the levels of generalization and potential insights afforded by different longitudinal analyses.     

Do intersections serve as basic features in visual search?

The status of 'intersection' as a basic feature in visual search tasks has been controversial. Under some circumstances, a target possessing this attribute (eg a plus) 'pops out' of a display of distractors that lack the attribute (eg Ls). However, those cases may be artifacts of other features such as relative size or number of line terminators. We report two sets of experiments with stimuli intended to control for these factors. Search for the presence or absence of intersections is very inefficient with these stimuli. The results suggest that intersection should not be included among the list of salient features that support efficient search through visual displays.     

Searching night and day: a dissociation of effects of circadian phase and time awake on visual selective attention and vigilance

How does sleepiness affect selective attention? We studied the effect of circadian phase and time awake on visual search. The generalized-cognitive-slowing hypothesis predicts that search rate will be slower, feature guidance less effective, and response time (RT) lengthened when observers are sleepy. Observers performed spatial-configuration (finding a 5 among 2s) and conjunction (finding red vertical among red horizontal and green vertical) search tasks during 38 hr of wakefulness under constant conditions. Adverse circadian phases and elapsed time awake did lead to increased RT (corrected for errors). However, contrary to the hypothesis, search rates (indexed by RT x Set Size slopes) were constant across the protocol. This was true for conjunction as well as for spatial-configuration search, indicating that feature guidance was also insensitive to sleepiness. The locus of sleepiness effects on search is probably downstream from the bottleneck of attentional selection. Observers did trade accuracy for speed when sleepy. This implicates decision-stage impairments.     

Structural Organization of Practice: Effects of Practicing Under Different Informational Constraints on the Acquisition of One-Handed Catching Skill

The question addressed in this study was the effects of the manipulation of the informational constraints of practice conditions on the acquisition of one-handed catching skill. Three groups of poor catchers (8 participants per group) practiced in either a normal-light, ball-only, or interspersed ball-only and normal-light condition (N = 450 trials). All groups exhibited a significant improvement in the number of catches and catching score and a reduction in the number of misses by the end of practice. The structural organization of the practice conditions had a significant effect on catching performance. Practicing in the interspersed condition had a positive residual effect on subjects' performance in normal light. Similarly, there was a positive residual effect of practicing in the ball-only and the interspersed conditions on subjects' normal-light, posttest performance. The findings are interpreted as support for the argument that practicing under varying informational constraints can benefit skill acquisition by directing the subjects' search toward relevant sources of information.     

Guided Search 2.0 A revised model of visual search

An important component of routine visual behavior is the ability to find one item in a visual world filled with other, distracting items. This ability to performvisual search has been the subject of a large body of research in the past 15 years. This paper reviews the visual search literature and presents a model of human search behavior. Built upon the work of Neisser, Treisman, Julesz, and others, the model distinguishes between a preattentive, massively parallel stage that processes information about basic visual features (color, motion, various depth cues, etc.) across large portions of the visual field and a subsequent limited-capacity stage that performs other, more complex operations (e.g., face recognition, reading, object identification) over a limited portion of the visual field. The spatial deployment of the limited-capacity process is under attentional control. The heart of the guided search model is the idea that attentional deployment of limited resources isguided by the output of the earlier parallel processes. Guided Search 2.0 (GS2) is a revision of the model in which virtually all aspects of the model have been made more explicit and/or revised in light of new data. The paper is organized into four parts: Part 1 presents the model and the details of its computer simulation. Part 2 reviews the visual search literature on preattentive processing of basic features and shows how the GS2 simulation reproduces those results. Part 3 reviews the literature on the attentional deployment of limited-capacity processes in conjunction and serial searches and shows how the simulation handles those conditions. Finally, Part 4 deals with shortcomings of the model and unresolved issues.