Analysis of the elements of attention: A neuropsychological approach

A model for conceptualizing the components or elements of attention is presented. The model substitutes for the diffuse and global concept of attention a group of four processes and links them to a putative system of cerebral structures. Data in support of the model are presented; they are derived from neuropsychological test scores obtained from two samples, the first consisting of 203 adult neuropsychiatric patients and normal control subjects, and the second, an epidemiologically-based sample of 435 elementary school children. Principal components analyses of test scores from these two populations yielded similar results: a set of independent elements of attention that are assayed by different tests. This work presents a heuristic for clinical research in which the measurement of attention is essential.     

Subgroup differences in situational judgment test scores: Evidence from large applicant samples

To promote diversity in organizations it is important to have accurate knowledge about subgroup differences associated with selection procedures. However, current estimates of subgroup differences in situational judgment tests (SJTs) are overwhelmingly based on range‐restricted incumbent samples that are downwardly biased. This study provides much‐needed applicant level estimates of SJT subgroup differences (N = 37,530). As a key finding, Black‐White differences (d = 0.66) were higher than in incumbent samples (d = 0.38). Overall, sex differences were small. Females scored higher for management jobs (d = ?0.13) and males scored higher for administrative jobs (d = 0.15). By analyzing applicant samples that do not suffer from range restriction, this study adds knowledge about subgroup differences in SJTs.     

Mapping differential responses to cognitive training using machine learning

We used two simple unsupervised machine learning techniques to identify differential trajectories of change in children who undergo intensive working memory (WM) training. We used self‐organizing maps (SOMs)—a type of simple artificial neural network—to represent multivariate cognitive training data, and then tested whether the way tasks are represented changed as a result of training. The patterns of change we observed in the SOM weight matrices implied that the processes drawn upon to perform WM tasks changed following training. This was then combined with K‐means clustering to identify distinct groups of children who respond to the training in different ways. Firstly, the K‐means clustering was applied to an independent large sample (N = 616, M_age = 9.16 years, range = 5.16–17.91 years) to identify subgroups. We then allocated children who had been through cognitive training (N = 179, M_age = 9.00 years, range = 7.08–11.50 years) to these same four subgroups, both before and after their training. In doing so, we were able to map their improvement trajectories. Scores on a separate measure of fluid intelligence were predictive of a child's improvement trajectory. This paper provides an alternative approach to analysing cognitive training data that go beyond considering changes in individual tasks. This proof‐of‐principle demonstrates a potentially powerful way of distinguishing task‐specific from domain‐general changes following training and of establishing different profiles of response to training.     

Separate and shared sources of dual-task cost in stimulus identification and response selection

There is often strong interference if a second target stimulus (T2) is presented before processing of a prior target stimulus (T1) is complete. In the "Psychological Refractory Period" (PRP) paradigm, responses are speeded and interference manifests as increased response time for T2. In the "Attentional Blink" (AB) paradigm, stimuli are masked and responses unspeeded; interference manifests as reduced T2 accuracy. While different causes have usually been considered for PRP and AB phenomena, recent evidence has supported a unified account based on a single, shared restriction on concurrent processing. Here we show that a full assessment of separate and shared resource limitations requires direct comparison of hybrid PRP/AB trials with corresponding pure PRP and AB cases. Randomizing trial types in such a comparison also brings substantial benefit in addressing possible changes in task preparation or readiness. The data from two such experiments--combining speeded auditory (SA) and unspeeded visual (UV) task events--provide clear evidence for both separate and shared resource limitations. Often interference is strongest for T1 and T2 events of the same type, reflecting predominantly different limitations in SA and UV processing. With modest increases in demand, however, interference between different event types can also be made arbitrarily large, reflecting arbitrarily important shared limitations. For even such simple tasks as these, T--T2 interference reflects a combination of relatively local and relatively global sources.     

The use of reliable digits to detect malingering in a criminal forensic pretrial population

The present research is a cross-validation of previous investigation by Greiffenstein, Baker; and Gola; Greiffenstein, Gola, and Baker; and Meyers and Volbrecht on the reliable digits (RELD) method of detecting suspected malingering on the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The results support the use of the RELD method on a criminalforensic pretrial population (N = 187). Sensitivities, specificities, and incremental hit ratesfor two cut levels of the RELD method, Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency and the Personality Assessment Inventory Negative Impression Scales, as well as multiple combined cut scores, were comparable to those observed in previous studies that used neuropsychologically evaluated participants. The selection of which cut score or combination of cut scores is appropriate on the RELD method is also discussed.     

The time course of response suppression: no evidence for a gradual release from inhibition

Most models of serial recall postulate that recalled items are suppressed and thus temporarily rendered unavailable. Response suppression can explain several results, for example the small number of erroneous repetitions and people's reluctance to report repeated items. Although it is clear that response suppression is not permanent (thus permitting renewed recall of an item on the next trial), nothing is known about its time course. We report two experiments that measured the time course of response suppression with a multiple cued-retrieval response-deadline method. Emphasis was on the extent of repetition inhibition for lists that contained a repeated item. Regardless of whether presentation was rapid (Experiment 1; 150 ms/item) or slow (Experiment 2; 500 ms/item), (a) the standard pattern of repetition inhibition and erroneous repetitions occurred and (b) repetition inhibition remained constant across increasing retrieval time. This suggests that the release from response suppression is a discrete, list-wide effect rather than a continuous, gradual wearing off. The latter conclusion is consistent with the operation of the SOB model (Farrell & Lewandowsky, 2002) but not with models that postulate complete suppression with gradual wearing off.     

Body esteem and body fat in British school children from different ethnic groups

The aim of the study was to examine the relationship between body esteem and body fat in British school children. Two hundred and seventy seven, 11–14-year-old children from central England took part in the study. Body esteem was measured using the Body Esteem Scale for children and percent body fat was determined by skin-fold measures. Results indicate that body esteem and adiposity were negatively related for the whole sample, for boys and girls and for White children, Black children and Asian children. Factorial ANOVA also indicated differences in body esteem according to gender and ethnicity. Boys and Black children had significantly higher body esteem than girls and Asian children respectively. Differences in body fat were also evident according to gender with boys being leaner than girls. No differences in body esteem or body fat were evident across school years.     

The Dimensionality of Memory Strength Between Levels of Both Serial Position and Word Frequency Category

In recognition tasks where Signal Detection Theory (SDT) is applied, a suitable decision variable is required. This variable is typically assumed to be a global assessment of memory strength. A further assumption is that factors such as old-new, serial position (SP), and word frequency (WF) simply act to change the value of strength across levels within the factor. In terms of SDT, the decision variable is assumed to be uni-dimensional. Four experiments are reported that provide a direct empirical assessment of this assumption for SP and WF. Judgements of items (JOI), recency (JOR), and primacy (JOP) were measured for SP; and subjective frequency (JOF) was measured for WF. Multiple dimensions imply non-additive effects across factor levels and different retrieval processes or the influence of an extra process. A single dimension is consistent with an additive effect of factor levels and current theorizing. The data are in fairly good agreement with the uni-dimensional assumption across all four factors with the exception of JOR and JOP. These showed less uni-dimensionality for comparisons between beginning vs. end list items. The implications of this are discussed.