Divided attention and indirect memory tests

Attentional state during acquisition is an important determinant of performance on direct memory tests. In two experiments we investigated the effects of dividing attention during acquisition on conceptually driven and data-driven indirect memory tests. Subjects read a list of words with or without distraction. Memory for the words was later tested with an indirect memory test or a direct memory test that differed only in task instructions. In Experiment 1, the indirect test was categoryexemplar production (a conceptually driven task) and the direct test was category-cued recall. In Experiment 2, the indirect test was word-fragment completion (a data-driven task) and the direct test was word-fragment cued recall. Dividing attention at encoding decreased performance on both direct memory tests. Of the indirect tests, category-exemplar production but not word-fragment completion was affected. The results indicate that conceptually driven indirect memory tests, like direct memory tests, are affected by divided attention, whereas data-driven indirect tests are not. These results are interpreted within the transfer-appropriate processing framework.     

Visual attention and objects: New tests of two-object cost

Baylis and Driver (1993) proposed that the positions of object parts are coded relative to the position of the object they belong to and that parts of different objects are not directly coded relative to each other. This theory predicts that it is easier to judge a difference in height of parts belonging to a single object (one-object condition) than of parts belonging to two objects (two-object condition). This two-object cost has been reported in several articles (Baylis, 1994; Baylis & Driver, 1993, 1995). However, in all these experiments, the method that was used favored the one-object condition. In the present experiments we obtained, for the first time, evidence for the existence of two-object cost without such a bias.     

Factorial validity of imagery measures

Two correlational studies and related factor analyses (N = 70. N = 76) were addressed to four psychometric hypotheses derived from the imagery-desensitization literature. Consistent with prior research, self-ratings of imaginal vividness correlated moderately positively across sense modalities. Vividness ratings were inconsistently related to imagery control scores however. The question of the extent to which imagery scales reflect the influences of response sets and general intelligence has been raised recently in this journal Behav. Res. and Therapy 10, 137 (1972). Acquiescence tendency does not appear to influence imagery questionnaire results and there is only a small contamination effect from the social desirability response style, thus suggesting that these questionnaires are substantially free of response bias invalidation. Verbal intelligence is unrelated to researched imaginal attributes, as measured by self-report scales and several behavioral measures, including location memory and spatial visualization. These behavioral measures, in turn, do not correlate with ratings of imagery characteristics, a finding in accord with previous literature. Although self-report imagery questionnaires stand up better to psychometric scrutiny than might have been expected, and thus prior research employing them cannot be dismissed summarily, it is argued that these questionnaires may not tap the variables most relevant to desensitization outcome or mediation. The necessity of using state rather than trait measures, and of relating these to physiological indices, is highlighted.     

Factorial invariance and significance

It is shown that invariance requirements remove the indeterminacy in factor determination and lead to an integration of factorial studies with promise of considerable reduction in computational labor. The selection of significant primary factors is discussed, with special reference to Thurstone's simple structure criterion.     

Correlation between tests of attention and performance on grooved and Purdue pegboards in normal subjects

This study investigated the relation between tests of manual dexterity and attentional functions with 49 normal, right-handed medical students (26 women, 23 men, ages 19-30 years) who were assessed with a Purdue Pegboard Test, Grooved Pegboard Test, and a Test for Attentional Performance, comprising measures of tonic and phasic alertness and divided attention. Weak to moderately high partial correlations controlling for finger size were obtained between pegboard test performance of the left hand and phasic alertness (r = .31-.50). Purdue Pegboard Assembly subtest scores were weakly correlated with divided attention (r = -.39). These findings suggest that attention is an important determinant of performance for manual dexterity tests of the nondominant hand.     

Statistical Power for a Simultaneous Test of Factorial and Predictive Invariance

A common finding in studies of differential prediction across groups is that although regression slopes are the same or similar across groups, group differences exist in regression intercepts. Building on earlier work by Birnbaum (1979) Birnbaum, M. H. 1979. “Procedures for the detection and correction of salary inequities.”. In Salary equity Edited by: Pezzullo, T. R. and Brittingham, B. F. 121–144. Lexington, MA: Lexington Books..  [Google Scholar], Millsap (1998) Millsap, R. E. 1998. Group differences in regression intercepts: Implications for factorial invariance. Multivariate Behavioral Research, 33: 403–424. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] presented an invariant factor model that would explain such intercept differences as arising due to unique variance or measurement error in the predictors and criterion. The model can be tested even when only a single predictor (p = 1) and criterion are present, but Millsap (1998) Millsap, R. E. 1998. Group differences in regression intercepts: Implications for factorial invariance. Multivariate Behavioral Research, 33: 403–424. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] only illustrated the use of the test in very large samples. The present study investigates the Type I error and power performance of the test of fit across a range of sample sizes and effect sizes in simulated data, using an alternative model that includes group differences in measurement intercepts. Surprising results showed little power for the chi-square test in the p = 1 case but good power for a diagnostic indicator based on negative unique variance estimates. The p = 2 case showed better power in modest samples. A real example from an application on reading disabilities in Share and Silva (2003) Share, D. L. and Silva, P. A. 2003. Gender bias in IQ-discrepancy and post-discrepancy definitions of reading disability. Journal of Learning Disabilities, 36: 4–14. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] is given. The implications of the results for studies of differential prediction involving group differences in regression intercepts are discussed.     

Bayesian SEM for Specification Search Problems in Testing Factorial Invariance

Specification search problems refer to two important but under-addressed issues in testing for factorial invariance: how to select proper reference indicators and how to locate specific non-invariant parameters. In this study, we propose a two-step procedure to solve these issues. Step 1 is to identify a proper reference indicator using the Bayesian structural equation modeling approach. An item is selected if it is associated with the highest likelihood to be invariant across groups. Step 2 is to locate specific non-invariant parameters, given that a proper reference indicator has already been selected in Step 1. A series of simulation analyses show that the proposed method performs well under a variety of data conditions, and optimal performance is observed under conditions of large magnitude of non-invariance, low proportion of non-invariance, and large sample sizes. We also provide an empirical example to demonstrate the specific procedures to implement the proposed method in applied research. The importance and influences are discussed regarding the choices of informative priors with zero mean and small variances. Extensions and limitations are also pointed out.     

Factorial similarity of the WISC-R for Anglos and Chicanos referred for psychological services

Two- and three-factor principal factor solutions to the WISC-R (Wechsler, 1974) were compared across race for referred Anglo and Chicano children. Additional comparisons of these factor solutions were made with those for normal Anglo, Chicano, Black, and Papago students (Reschly, 1978, Note 1) and the WISC-R standardization sample (Wechsler, 1974). Substantial congruence occurred across race for both the two- and three-factor solutions, though the two-factor solution was clearly most appropriate for the present sample.     

Group Differences in Regression Intercepts: Implications for Factorial Invariance

Studies of differential prediction typically examine group differences in linear regression slopes or intercepts for predicting criterion scores from one or more test scores. When there are no group differences in slopes, what are the implications of differences in regression intercepts for the measurement equivalence of the tests or criterion across groups? Measurement equivalence is here defined as factorial invariance under a single-factor model for the tests and criterion. Two theorems are given that describe conditions under which intercept differences can exist under factorial invariance. In such cases, intercept differences do not result from measurement bias in either the tests or criterion. The conditions of the theorems are testable using multiple-group confirmatory factor analysis. These test procedures are illustrated in real data. The implications of the theorems and the test procedures for studies of differential prediction are discussed.     

Factorial analysis of Thurstone's seven primary abilities

Intercorrelation coefficients among Thurstone's seven primary mental abilities scores were obtained from scores of 170 freshmen engineering students on the experimental edition of thePrimary Mental Abilities Tests. These correlation coefficients were factored to four factors, interpreted as a general factor, a reasoning factor, a verbal factor, and, tentatively, a specific memory factor. The finding of a general factor for a college population corroborates the Thurstones' finding of a general factor for eighth-grade children.     

Evidence for a cognitive control network for goal-directed attention in simple sustained attention

The deterioration of performance over time is characteristic for sustained attention tasks. This so-called “performance decrement” is measured by the increase of reaction time (RT) over time. Some behavioural and neurobiological mechanisms of this phenomenon are not yet fully understood. Behaviourally, we examined the increase of RT over time and the inter-individual differences of this performance decrement. On the neurophysiological level, we investigated the task-relevant brain areas where neural activity was modulated by RT and searched for brain areas involved in good performance (i.e. participants with no or moderate performance decrement) as compared to poor performance (i.e. participants with a steep performance decrement). For this purpose, 20 healthy, young subjects performed a carefully designed task for simple sustained attention, namely a low-demanding version of the Rapid Visual Information Processing task. We employed a rapid event-related functional magnetic resonance imaging (fMRI) design. The behavioural results showed a significant increase of RT over time in the whole group, and also revealed that some participants were not as prone to the performance decrement as others. The latter was statistically significant comparing good versus poor performers. Moreover, high BOLD-responses were linked to longer RTs in a task-relevant bilateral fronto-cingulate-insular-parietal network. Among these regions, good performance was associated with significantly higher RT-BOLD correlations in the pre-supplementary motor area (pre-SMA). We concluded that the task-relevant bilateral fronto-cingulate-insular-parietal network was a cognitive control network responsible for goal-directed attention. The pre-SMA in particular might be associated with the performance decrement insofar that good performers could sustain activity in this brain region in order to monitor performance declines and adjust behavioural output.     

Sustained attention in children at risk for schizophrenia: Findings with two visual continuous performance tests in a new sample

In partial replication of an earlier study, 35 children at high risk for schizophrenia, 25 children at high risk for affective disorder, and 53 normal control children from a new sample of 7- to 12-year-old subjects were tested with two new visual continuous performance tests. Response levels and intrasubject variability were analyzed separately. Multivariate analyses on factor scores derived from response levels indicate that "groups" is a significant predictor for a factor reflecting discriminability (or sensitivity) for the more difficult of these tests but not for the less difficult one, and that high risk for schizophrenia is associated with lower performance. Factor scores and multiple regression analyses were used to dichotomize subjects as to whether or not they are low performance outliers. A significantly larger proportion of subjects from the high risk for schizophrenia group than from the control groups were low performance outliers. Among subjects that developed psychopathology in adolescence, subjects at high risk for schizophrenia were more likely to have contributed low performance outliers early during childhood.     

The time course of competition for attention: attention is initially labile

Competition for attention between 2 written words was investigated by presenting the words briefly in a single stream of distractors (Experiment 1) or in different streams (Experiment 2-6), using rapid serial visual presentation at 53 ms/item. Stimulus onset asynchrony (SOA) was varied from 0 to 213 ms. At all SOAs there was strong competition, but which word was more likely to be reported shifted markedly with SOA. At SOAs in the range of 13-53 ms the second word was more likely to be reported, but at 213 ms, the advantage switched to the first word, as in the attentional blink. A 2-stage competition model of attention is proposed in which attention to a detected target is labile in Stage 1. Stage 1 ends when one target is identified, initiating a serial Stage 2 process of consolidation of that target.