Use of factor mixture modeling to capture Spearman's law of diminishing returns

Spearman's law of diminishing returns (SLODR) posits that at higher levels of general cognitive ability the general factor (g) performs less well in explaining individual differences in cognitive test performance. Research has generally supported SLODR, but previous research has required the a priori division of respondents into separate ability or IQ groups. The present study sought to obviate this limitation through the use of factor mixture modeling to investigate SLODR in the Kaufman Assessment Battery for Children-Second Edition (KABC-II). A second-order confirmatory factor model was modeled as a within-class factor structure. The fit and parameter estimates of several models with varying number of classes and factorial invariance restrictions were compared. Given SLODR, a predictable pattern of findings should emerge when factor mixture modeling is applied. Our results were consistent with these SLODR-based predictions, most notably the g factor variance was less in higher g mean classes. Use of factor mixture modeling was found to provide support for SLODR while improving the model used to investigate SLODR.     

Availability of advance visual information constrains association-football goalkeeping performance during penalty kicks

A pressing concern within the literature on anticipatory perceptual-motor behaviour is the lack of clarity on the applicability of data, observed under video-simulation task constraints, to actual performance in which actions are coupled to perception, as captured during in-situ experimental conditions. We developed an in-situ experimental paradigm which manipulated the duration of anticipatory visual information from a penalty taker's actions to examine experienced goalkeepers' vulnerability to deception for the penalty kick in association football. Irrespective of the penalty taker's kick strategy, goalkeepers initiated movement responses earlier across consecutively earlier presentation points. Overall goalkeeping performance was better in non-deception trials than in deception conditions. In deception trials, the kinematic information presented up until the penalty taker initiated his/her kicking action had a negative effect on goalkeepers' performance. It is concluded that goalkeepers are likely to benefit from not anticipating a penalty taker's performance outcome based on information from the run-up, in preference to later information that emerges just before the initiation of the penalty taker's kicking action.     

Deconstructing the tower: Parameters and predictors of problem difficulty on the Tower of London task

The Tower of London (TOL) task has been widely used in both clinical and research realms. In the current study, 104 healthy participants attempted all possible moderate- to high-difficulty TOL problems in order to determine: (1) optimal measures of problem solving performance, (2) problem characteristics, other than the minimum moves necessary to solve the problem, that determine participants’ difficulty in solving problems successfully, quickly, and efficiently, and (3) effects of increased task experience on which problem characteristics determine problem difficulty. A factor analysis of six performance measures found that, regardless of task experience, problem difficulty could be captured well either by a single factor corresponding to general quality of solution or possibly by three subordinate factors corresponding to solution efficiency, solution speed, and initial planning speed. Regression analyses predicting these performance factors revealed that in addition to a problem’s minimum moves three problem parameters were critical in determining the problem difficulty: goal position hierarchy, start position hierarchy, and number of solution paths available. The relative contributions of each of the characteristics strongly depended on which performance factor defined performance. We conclude that TOL problem performance is multifaceted, and that classifying problem difficulty using only the minimum moves necessary to solve the problem is inadequate.     

Motivation Change in Therapeutic Community Residential Treatment

Latent growth curve analysis was used to assess motivation change across 3 time points for 120 therapeutic community residents. Models included the time‐in‐variant predictor of readiness for treatment, which significantly predicted initial treatment motivation but not the rate of motivation change over time.     

Theory of mind skills 1 year after traumatic brain injury in 6- to 8-year-old children

This study examined the longer-term effects of traumatic brain injury (TBI) on theory of mind (ToM) skills of children who were between the ages of 5 and 7 years at the time of injury. Fifty-two children with orthopaedic injury, 30 children with moderate TBI, and 12 children with severe TBI were evaluated approximately 1 year post-injury (mean age=6.98 years, SD=0.59, range=6.02–8.26). Children with severe TBI did not engage in representation of first- and second-order mental states at a developmental level comparable to their peers, suggesting stagnation or lack of development, as well as regression of putatively existing ToM skills. Age, task-specific cognitive demands, and verbal abilities were strong predictors of ToM performance. However, even after taking those factors into account, children with severe TBI had poorer ToM performance than children with orthopaedic injuries.     

Immediate and delayed effects of word frequency and word length on eye movements in reading: a reversed delayed effect of word length

Three experiments examined the effects in sentence reading of varying the frequency and length of an adjective on (a) fixations on the adjective and (b) fixations on the following noun. The gaze duration on the adjective was longer for low frequency than for high frequency adjectives and longer for long adjectives than for short adjectives. This contrasted with the spillover effects: Gaze durations on the noun were longer when adjectives were low frequency but were actually shorter when the adjectives were long. The latter effect, which seems anomalous, can be explained by three mechanisms: (a) Fixations on the noun are less optimal after short adjectives because of less optimal targeting; (b) shorter adjectives are more difficult to process because they have more neighbors; and (c) prior fixations before skips are less advantageous places to extract parafoveal information. The viability of these hypotheses as explanations of this reverse length effect on the noun was examined in simulations using an updated version of the E-Z Reader model (A. Pollatsek, K. Reichle, & E. D. Rayner, 2006c; E. D. Reichle, A. Pollatsek, D. L. Fisher, & K. Rayner, 1998).     

Reading spaced and unspaced Chinese text: evidence from eye movements

Native Chinese readers' eye movements were monitored as they read text that did or did not demark word boundary information. In Experiment 1, sentences had 4 types of spacing: normal unspaced text, text with spaces between words, text with spaces between characters that yielded nonwords, and finally text with spaces between every character. The authors investigated whether the introduction of spaces into unspaced Chinese text facilitates reading and whether the word or, alternatively, the character is a unit of information that is of primary importance in Chinese reading. Global and local measures indicated that sentences with unfamiliar word spaced format were as easy to read as visually familiar unspaced text. Nonword spacing and a space between every character produced longer reading times. In Experiment 2, highlighting was used to create analogous conditions: normal Chinese text, highlighting that marked words, highlighting that yielded nonwords, and highlighting that marked each character. The data from both experiments clearly indicated that words, and not individual characters, are the unit of primary importance in Chinese reading.     

Bringing automatic stereotyping under control: implementation intentions as efficient means of thought control

The evidence for whether intentional control strategies can reduce automatic stereotyping is mixed. Therefore, the authors tested the utility of implementation intentions- specific plans linking a behavioral opportunity to a specific response-in reducing automatic bias. In three experiments, automatic stereotyping was reduced when participants made an intention to think specific counterstereotypical thoughts whenever they encountered a Black individual. The authors used two implicit tasks and process dissociation analysis, which allowed them to separate contributions of automatic and controlled thinking to task performance. Of importance, the reduction in stereotyping was driven by a change in automatic stereotyping and not controlled thinking. This benefit was acquired with little practice and generalized to novel faces. Thus, implementation intentions may be an effective and efficient means for controlling automatic aspects of thought.     

Alteration of expected hemispheric asymmetries: valence and arousal effects in neuropsychological models of emotion

The relative advantage of the left (LH) over the right hemisphere (RH) in processing of verbal material for most individuals is well established. Nevertheless, several studies have reported the ability of positively and negatively valenced stimuli to enhance and reverse, respectively, the usual LH>RH asymmetry. These studies, however, have used baseline stimuli that differed from emotional stimuli on two dimensions (i.e., valence and verbal/nonverbal nature), creating interpretive difficulties as to whether differences across these conditions are due to differences in valence or the verbal/nonverbal nature of the primes used in the baseline condition. In addition, these studies, along with many others in the literature, have failed to control for potential confounding effects of arousal. Emotional stimuli vary on dimensions of valence as well as arousal and arousal may be asymmetrically presented in the brain therefore contributing to observed asymmetries. Taken together, these considerations underscore the importance of controlling for both valence as well as arousal in any investigation of the effects of emotional stimuli. The objectives of the present study were twofold: (1) to employ an appropriate baseline condition to render emotional stimuli vs. baseline stimuli comparisons meaningful and (2) to examine the extent to which emotional verbal stimuli, equated for arousal level, alter the expected LH>RH asymmetry in a consonant trigram task. Results demonstrated that when LH lateralized consonant trigram presentations were preceded by a positive prime, an enhancement of the expected LH>RH asymmetry was observed. In contrast, when trigram presentations lateralized to the RH were preceded by a negative prime, a complete reversal of the typical asymmetry was found with RH>LH performance. These results are analogous to the pattern of relative hemispheric activations observed for various mood states. Controlling for arousal in studies investigating asymmetries associated with emotional processing may allow more clear interpretation of data intended to test predictions of neuropsychological models of emotion. Moreover, equating stimuli on the dimension of arousal as well as valence may shed more light on conflicting findings with regard to perception vs. expression of emotion.