Analytical Inverse Optimization in Two-Hand Prehensile Tasks

The authors explored application of analytical inverse optimization (ANIO) method to the normal finger forces in unimanual and bimanual prehensile tasks with discrete and continuously changing constraints. The subjects held an instrumented handle vertically with one or two hands. The external torque and grip force changed across trials or within a trial continuously. Principal component analysis showed similar percentages of variance accounted for by the first two principal components across tasks and conditions. Compared to unimanual tasks, bimanual tasks showed significantly more frequent inability to find a cost function leading to a stable solution. In cases of stable solutions, similar second-order polynomials were computed as cost functions across tasks and condition. The bimanual tasks, however, showed significantly worse goodness-of-fit index values. The authors show that ANIO can be used in tasks with slowly changing constraints making it an attractive tool to study optimality of performance in special populations. They also show that ANIO can fail in multifinger tasks, likely due to irreproducible behavior across trials, more likely to happen in bimanual tasks compared to unimanual tasks.     

Piagetian tasks measure intelligence and intelligence tests assess cognitive development: A reanalysis

A reanalysis of the intercorrelations of Wechsler subtests, achievements tests, and Piagetian tasks originally published by Stephens et al. (1972) has corrected errors in the original design and has used models which allow both differences and similarities to appear. Unit weighted composites of the two sets of tests were formed after first partialling chronological age out of the complete table of intercorrelations. The correlation between the composites is .876 which corrects, using split-half estimates of reliabilities, to .918. Next the matrix of partial correlations was factored and the factors rotated to a hierarchical structure. Piagetian tasks contribute almost equally to the definition of the general factor in intelligence along with the Wechsler subtests and the achievement tests. The general factor, furthermore, makes the single largest contribution to the variance of most of the measures of both sets. The smaller group factors consist of an Academic Achievement factor and three Piagetian factors. Of the latter the largest and most clearly identified is the factor called Operational Thought in the earlier analysis, but is here described simply as Conservation. It is concluded that the evidence for communality in function far outweighs the differences between intelligence tests and Piagetian tasks.     

The Measurement of Verbal Working Memory Capacity and Its Relation to Reading Comprehension

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digitrelated tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.     

Conditional reasoning and the competence-performance issue: A developmental analysis of a training task

Empirical investigations of conditional reasoning have generally found that both children and young adults perform poorly on tasks that require the selection or evaluation of those propositions that test the truth status of conditional statements (if p then q). Earlier work (D. O'Brien & W. F. Overton, Journal of Experimental Child Psychology 1980, 30, 44–60) suggested that poor performances with these tasks by young adults show improvement following the introduction of evidence that contradicts earlier faulty inferences, and this improvement generalizes to other conditional reasoning tasks. The effects of the contradiction training were not found with younger subjects. The present research is an extension of the contradiction training paradigm. Ten-, fourteen-, and eighteen-year-olds were tested to assess developmental differences in improvement with an evaluation and a conditional syllogism task. Significant improvement in performance was found for the twelfth grade students following the contradiction training, and this generalized across tasks. This effect was not found for the two younger groups. The usual poor performance of the oldest group is considered to be a false negative assessment of their conditional reasoning competency. Further, it is suggested that several correct performances of younger reasoners are false positive assessments of their conditional reasoning competency.     

Age trends in children's time-sharing performance

To investigate developmental differences in time-sharing performance, 60 boys, 20 in each of three age groups (7-, 10-, and 13-year-olds) performed an auditory matching task and a tracking task alone and concurrently, the latter under two sets of instructions. Decrements produced by concurrent performance were compared for the three age groups. When the time-shared tasks were presented as equally important, time-sharing produced significantly greater proportional decrements in the tracking performance of the younger children and for all age groups tracking task decrements were directly related to matching task difficulty. Subsequently, the children were instructed that one or the other of the tasks was more important and that they were to improve their performance on that task. All three age groups showed a significant improvement on the task emphasized by instructions. The relationship of the results to two models of information processing is discussed.     

Individual differences and interrelationships among a select set of cognitive skills

An experiment was conducted to investigate individual differences and interrelationships in performance on three short-term memory processing and visual processing tasks. Parameters of models for these tasks were correlated. High correlations (.97 and .83) were obtained for some intertask parameters. indicating that elemental component processes for different tasks can be identified that are similar or highly related. Psychometric measures (SATM and SATV) were also correlated with the information processing model parameters. High multiple correlations of SATV and SATM were obtained using model parameters as predictors. when the data were analyzed separately for female and male subjects. The results are suggestive of sex differences in the interrelationships of the cognitive processes under investigation.     

Modeling simple driving tasks with a one-boundary diffusion model

A one-boundary diffusion model was applied to the data from two experiments in which subjects were performing a simple simulated driving task. In the first experiment, the same subjects were tested on two driving tasks using a PC-based driving simulator and the psychomotor vigilance test. The diffusion model fit the response time distributions for each task and individual subject well. Model parameters were found to correlate across tasks, which suggests that common component processes were being tapped in the three tasks. The model was also fit to a distracted driving experiment of Cooper and Strayer (Human Factors, 50, 893–902, 2008). Results showed that distraction altered performance by affecting the rate of evidence accumulation (drift rate) and/or increasing the boundary settings. This provides an interpretation of cognitive distraction whereby conversing on a cell phone diverts attention from the normal accumulation of information in the driving environment.     

A comparative evaluation of factor- and component-based structural equation modelling approaches under (in)correct construct representations

Structural equation modelling (SEM) has evolved into two domains, factor-based and component-based, dependent on whether constructs are statistically represented as common factors or components. The two SEM domains are conceptually distinct, each assuming their own population models with either of the statistical construct proxies, and statistical SEM approaches should be used for estimating models whose construct representations correspond to what they assume. However, SEM approaches have often been evaluated and compared only under population factor models, providing misleading conclusions about their relative performance. This is partly because population component models and their relationships have not been clearly formulated. Also, it is of fundamental importance to examine how robust SEM approaches can be to potential misrepresentation of constructs because researchers may often lack clear theories to determine whether a factor or component is more representative of a given construct. Addressing these issues, this study begins by clarifying several population component models and their relationships and then provides a comprehensive evaluation of four SEM approaches – the maximum likelihood approach and factor score regression for factor-based SEM as well as generalized structured component analysis (GSCA) and partial least squares path modelling (PLSPM) for component-based SEM – under various experimental conditions. We confirm that the factor-based SEM approaches should be preferred for estimating factor models, whereas the component-based SEM approaches should be chosen for component models. Importantly, the component-based approaches are generally more robust to construct misrepresentation than the factor-based ones. Of the component-based approaches, GSCA should be chosen over PLSPM, regardless of whether or not constructs are misrepresented.     

A unifying model for the structure of intellectual abilities

Models of the structure of cognitive abilities suggested by Spearman, Thurstone, Guilford, Vernon and Cattell-Horn are reviewed. It is noted that some of the models include a general intellectual factor (g) while others do not. It is also noted that some models are nonhierarchical, while in others more narrow abilities are subsumed under broader abilities in a hierarchical pattern. An empirical study in which a test battery of 16 tests was administered to some 1000 subjects in the 6th grade is reported. Using the LISREL technique to test different models, good support is obtained for oblique primary factors in the Thurstone tradition as well as for the second-order factors fluid intelligence, crystallized intelligence, and general visualization hypothesized by Cattell and Horn. It is also found, however, that the second-order factor of fluid intelligence i is identical with a third-order g-factor. On the basis of these results a three-level model (the HILI-model) is suggested, with the g-factor at the top, two broad factors reflecting the ability to deal with verbal and figural information, respectively, at the second-order level, and the primary factors in the Thurstone and Guilford tradition at the lowest level. It is argued that most previously suggested models are special cases of the HILI-model.     

Social control by adult preference in operant conditioning with children

During daily sessions four institutionalized retardates and four normal, first-grade children each played a two-choice marble dropping game while an adult experimenter sat beside and watched. When one of two colored lights was presented, two tokens were dispensed as soon as the subject dropped a marble, and when the other light was on, one token was dispensed. During choice trials that were interspersed among single-colored trials the subject was required to choose one of the two different colored holes. After the subject developed a preference for the color that earned two tokens, the experimenter stated a preference for the response that earned only one token (i.e., “I like it better when you put it into the —colored hole.”) Six of the eight subjects immediately switched to the response that earned low magnitude reinforcement when the experimenter stated his preference. Only two subjects switched back to the response that earned high magnitude reinforcement when the experimenter left the room. Subjects complied with the experimenter's preference statement regardless of whether or not it also included a negative component (i.e., what the experimenter did not like). There were no systematic differences between mentally retarded and normal subjects.     

Verbal fluency and creativity: General and specific contributions of broad retrieval ability (Gr) factors to divergent thinking

The Cattell–Horn–Carroll (CHC) model of intelligence views creativity as a first-level factor within the second-level factor of broad retrieval ability (Gr), alongside other first-level abilities such as ideational fluency and word fluency. Traditional methods of measuring creativity, however, confound idea quality with idea quantity, which might exaggerate the relationship between creativity scores and verbal fluency factors. Participants (n = 131 adults) completed two divergent thinking tasks (unusual uses for a rope and a box), which were scored using newer methods that effectively separate creativity (scored via subjective ratings) and fluency (scored as number of responses). They then completed 16 verbal fluency tasks that assessed six lower-order Gr factors: word fluency, associational fluency, associative flexibility, ideational fluency, letter fluency, and dissociative ability. Viewed singly, many of the lower-order factors significantly predicted creative quality and fluency. General Gr had substantial effects on creative quality (standardized β = .443) and fluency (β = .339) in a higher-order model as well as in a bifactor model (quality β = .380, fluency β = .327). Moreover, general Gr was the only significant predictor in the bifactor model, suggesting that it, not the specific factors, was most important. All effects were essentially the same after controlling for typing speed and vocabulary knowledge. The findings thus support the CHC view of creativity/originality as a lower-order component of Gr, illuminate the relationships between creativity and first-level Gr factors, extend the study of creativity and intelligence beyond fluid intelligence, and further indicate that creativity is more closely tied to cognitive abilities than creativity research has yet recognized.     

Mathematics performance in left and right brain-lesioned children and adolescents

Children and adolescents with unilateral left- or right-hemisphere lesions were administered a standardized test of mathematics ability and a battery of experimental tests that examined the components of numerical and arithmetic processing. All lesioned groups showed at least marginally lower scores on the standardized test than the controls. More importantly, lesion-related deficits in performance were observed, especially for younger left-lesioned subjects (ages 7-12), on the verbal counting, digit matching, speeded addition, and written subtraction tasks; deficits among younger right-lesioned subjects were similar in nature, yet less pronounced than in the left-hemisphere group. Older left-lesioned subjects showed differences from their controls only on complex verbal counting and speeded addition. Correlations among the various measures indicated two further points. First, earlier onset of left-hemisphere lesion is associated with more serious disruption of mathematical processing. Second, these disruptions are not well assessed by a typical standardized test of mathematical performance, but are clearly in evidence with more precise, focused tasks.     

Mental rotation of static and dynamic figures

Previous studies comparing performance on standard (i.e., static) and dynamic spatial test items have concluded that the two item types measure different abilities. Such conclusions about the uniqueness of static and dynamic spatial abilities seem premature, however, since only a limited number of dynamic spatial tasks have been utilized in research and these have differed markedly from their static counterparts. In the present studies, tasks were designed to require a common mental operation (mental rotation) under static and dynamic conditions. Correlations between static and dynamic performance ranged from .80 to .90. This appears to suggest that the emergence of a unique dynamic ability factor depends on the utilization of certain specialized tasks (e.g., arrival time tasks) with mental operations much different than those required by conventional spatial tests. In other words, it is apparently the requirement for different cognitive processes and not the processing of stimulus motion per se that distinguishes performance onsome dynamic tasks from performance on some standard static tasks.     

The belief-bias effect in the production and evaluation of logical conclusions

In this study, we examined whether adult subjects' beliefs regarding the empirical truth of a conclusion affected their production as well as their evaluation of a logical conclusion in a reasoning task. In addition, the relation between the ability to resolve an abstract reasoning problem correctly and the effect of belief-bias was examined. The subjects were given one of four paper-and-pencil reasoning tasks, two of them using an evaluation paradigm, and two of them using a production paradigm. Each paradigm comprised either neutral problems or belief problems. The neutral problems were constructed to be as similar as possible to the belief problems, in order to control for extraneous factors. All four tasks also included an abstract reasoning problem. The results indicate a significant belief-bias effect for both the evaluation and the production tasks. Qualitative analysis indicated that the belief-bias effect was more pervasive in the production condition. In addition, the belief-bias effect was found to exist independently of the subjects' abstract reasoning ability. The results are discussed with reference to a two-stage model, in which belief is used to resolve uncertainties in inferentially produced conclusions.     

Effects of Perceptual and Conceptual Processing on Memory for Words and Voice: Different Patterns for Young and Old

In two experiments younger and older adults listened to a list of words presented auditorily by two speakers. The subjects processed each word either perceptually (voice judgements) or conceptually (pleasantness judgements), and were then given memory tasks for the words and the presenting voice. In the word-recognition task the two age groups benefited equally from conceptual as opposed to perceptual processing. In the voice memory task, however, conceptual processing improved performance relative to perceptual processing in the younger subjects (significantly so in Experiment 1), but conceptual processing was associated with decreased performance in the older group (significantly so in Experiment 2). These results suggest that whereas older subjects exhibit a trade-off in memory for item and attribute information, younger subjects exhibit a pattern of support, in which conceptual processing benefits memory for both items and their attributes.     

Response selection,sensitivity, and taste-test performance

Tasters selected the odd stimulus from among sets of three samples of party dip. Two samples came from one batch, and one sample came from another batch. The physicochemical difference between the batches consisted of the presence or absence of added salt. Two different tests of discriminability were undertaken by the same subjects with the same stimuli: the triangle test and the three-alternative forced-choice (3-AFC) method. Although different numbers of correct selections were obtained in the two tasks, an index of discriminability,d’, had the same value when the data were analyzed in accordance with the Thurstone-Ura and signal-detection models, respectively. The average data support Frijters’s (1979b) contention that different models of the discrimination process are appropriate to the results of the triangular and the 3-AFC procedures. Further analysis of the data revealed that discrimination was poorer for trios containing one physicochemically weak stimulus and two stronger stimuli than it was for trios containing one stronger stimulus and two weak stimuli. A two-signal 3-AFC task was undertaken by some subjects, andd’ estimates from this task were lower than expected on the basis of performance in the other tasks.     

CPCA: A program for principal component analysis with external information on subjects and variables

A program is described for principal component analysis with external information on subjects and variables. This method is calledconstrained principal component analysis (CPCA), in which regression analysis and principal component analysis are combined into a unified framework that allows a full exploration of data structures both within and outside known information on subjects and variables. Many existing methods are special cases of CPCA, and the program can be used for multivariate multiple regression, redundancy analysis, double redundancy analysis, dual scaling with external criteria, vector preference models, and GMANOVA (growth curve models).     

Compounds of conditioned fear stimuli

A differential conditioning procedure was used with rats to establish different levels of suppression to two different stimuli. One stimulus was paired with shock every time it was presented, while the other stimulus cued shock on only 25% of its presentations. When these two component stimuli were subsequently tested as a simultaneous compound, two different types of component-compound relationships were observed. Some subjects showed greater suppression to the compound than they did to either component stimulus, while other subjects showed an intermediate level of suppression to the compound. The difference in type of component-compound relationship appeared to be related to the degree of stability (over trials) of each subject's reaction to the probabilistic (25%) cue.When a similar discrimination was established based on the intensity of the shock, rather than its probability of occurrence, all subjects showed more suppression to the compound than to its individual component stimuli. These results are discussed in terms of their implications for choice of model for characterizing the interaction of conditioned states.     

CFA Models with a General Factor and Multiple Sets of Secondary Factors

We propose a class of confirmatory factor analysis models that include multiple sets of secondary or specific factors and a general factor. The general factor accounts for the common variance among manifest variables, whereas multiple sets of secondary factors account for the remaining source-specific dependency among subsets of manifest variables. A special case of the model is further proposed which constrains the specific factor loadings to be proportional to the general factor loadings. This proportional model substantially reduces the number of model parameters while preserving the essential structure of the general model. Furthermore, the proportional model allows for the interpretation of latent variables as the expected values of the observed manifest variables, decomposition of the variances, and the inclusion of interactions, similar to generalizability theory. We provide two applications to illustrate the utility of the proposed class of models.