Psychometric intelligence and visual evoked potentials: a replication

Previously we have reported significant correlations between EEG visual evoked potential (EP) parameters and scores on the Raven's Advanced Progressive Matrices (RAPM) test. This study is an attempt to replicate those findings in a new sample of 27 S s. The results provide further evidence that EP amplitude is related to intelligence-test performance. There is also confirmation that stimulus luminance levels influence the magnitude of EP amplitude/intelligence correlations. In addition, the results indicate that age may be a confounding variable.     

Auditory stimulus intensity gradients and response to methylphenidate in ADD children

Using an auditory stimulus intensity paradigm, we obtained both event related potentials (ERPs) and press and release reaction times (RT) from a large sample of children with Attention Deficit Disorder (ADD). The ERP gradients to three tone intensities were used to classify the children as augmenters (steep gradients), moderates, or reducers (shallow or negative gradients). The RT data were used to classify the children as strong or sensitive, following neo-Pavlovian guidelines. The children were then cross-classified on these two dimensions and compared on cognitive, behavioral, and performance measures. The groups were also compared in response to two dosage levels of methylphenidate. Based on prior studies, we hypothesized that: 1. ERP augmenters would respond as well to the low as high dose but that reducers would respond better to high than low dose; and II. sensitive types (RT measure) would do better on the higher dose and strong types on the low dose. The first hypothesis was confirmed on a performance task but not on behavioral ratings. At the lower dose, augmenters improved most and reducers least on a 10-minute coding task presumed to require sustained attention. There was no support for the second hypothesis either in ratings or performance. The ERP augmentation measure was significantly related to teacher rated attentiveness; i.e., reducers and moderates were rated more adversely. The RT sensitivity measure tended to be related to achievement; i.e., strong types had lower reading and spelling scores. The ERP and RT sensitivity measures were not significantly correlated.     

Strength of the nervous system and augmenting-reducing: Paradox lost

Two conflicting viewpoints were identified regarding the relationship between sensation seeking and subjective response to stimulation: (a) that sensory augmenters are high sensation seekers compared with sensory reducers (the view of Zuckerman and Buchsbaum); and (b) that it is the reducer rather than the augmenter who is the high sensation seeker (the view of Petrie and Vando). Proponents of the first approach measure Augmenting-Reducing through the use of the average cortical-evoked response, while advocates of the second position use Petrie's version of the Kinaesthetic Figural Aftereffects Test or Vando's Reducer-Augmenter Scale. It is argued that the disagreement is semantic and results from the differences in method of measurement. It is further argued that most, if not all, of the research findings may be accommodated within the framework of strength-of-the-nervous-system theory which distinguishes between two dimensions,sensitivity andfunctional endurance. The implications for future research are pointed out.     

A contextual approach on sex-related biases in pain judgements: the moderator effects of evidence of pathology and patients' distress cues on nurses' judgements of chronic low-back pain

Although women report feeling more pain than men, their pain is often underdiagnosed and undertreated. By proposing a gender-based theoretical conceptualisation, we argue that such sex-related biases may be enhanced or suppressed by contextual variables pertaining to the clinical situation, the perceiver or the patient. Consequently, we aimed to explore the moderator role of two clinically relevant variables in a chronic low-back pain (CLBP) scenario: diagnostic evidence of pathology (EP) and pain behaviours conveying distress. One-hundred and twenty-six female nurses (M?=?35.33, SD?=?7.64) participated in an experimental between-subjects design, 2 (patient's sex)?×?2 (EP: present vs. absent)?×?2 (pain behaviours: with vs. without distress). Independent variables were operationalised by vignettes depicting a patient with CLBP. Nurses judged the patient's pain on several dimensions: (1) credibility; (2) disability; (3) severity of the clinical situation; (4) psychological attributions and (5) willingness to offer support. Main findings showed that judgements of women's pain were influenced by EP, while judgements of men's pain were not. Moreover, nurses showed biases against men, but only in the presence of EP. The influence of distress cues was less consistent. Theoretical and practical implications are drawn.     

A contextual approach on sex-related biases in pain judgements: The moderator effects of evidence of pathology and patients’ distress cues on nurses’ judgements of chronic low-back pain

Although women report feeling more pain than men, their pain is often underdiagnosed and undertreated. By proposing a gender-based theoretical conceptualisation, we argue that such sex-related biases may be enhanced or suppressed by contextual variables pertaining to the clinical situation, the perceiver or the patient. Consequently, we aimed to explore the moderator role of two clinically relevant variables in a chronic low-back pain (CLBP) scenario: diagnostic evidence of pathology (EP) and pain behaviours conveying distress. One-hundred and twenty-six female nurses (M?=?35.33, SD?=?7.64) participated in an experimental between-subjects design, 2 (patient's sex)?×?2 (EP: present vs. absent)?×?2 (pain behaviours: with vs. without distress). Independent variables were operationalised by vignettes depicting a patient with CLBP. Nurses judged the patient's pain on several dimensions: (1) credibility; (2) disability; (3) severity of the clinical situation; (4) psychological attributions and (5) willingness to offer support. Main findings showed that judgements of women's pain were influenced by EP, while judgements of men's pain were not. Moreover, nurses showed biases against men, but only in the presence of EP. The influence of distress cues was less consistent. Theoretical and practical implications are drawn.     

Stimulus intensity reducers: Are they sensation seekers,extraverts, and strong nervous types?

211 university students completed Vando's (1970) Reducer-Augmenter Scale, Zuckerman's (1979) Sensation Seeking Scale, Eysenck and Eysenck's (1975) Personality Questionnaire, and Strelau's (1983) Temperament Inventory. As hypothesized, reducing was positively associated with sensation seeking, extraversion, and two of the four neo-Pavlovian dimensions of temperament: mobility and strength of excitation. Of the other two, strength of inhibition was not associated with reducing while sensitivity was negatively associated. Discriminant analysis of median-split reducing groups yielded a significant function defined by all variables except strength of inhibition. Univariate F-tests established that high reducers scored significantly more than low reducers (augmenters) on sensation seeking, strength of excitation, mobility, and extraversion, and significantly less on sensitivity. Two orthogonal dimensions consisting of reducing/sensation seeking and temperament/extraversion items defined the underlying structure. Results generalized across sex. The findings support the view that strong nervous temperament is implicated in reducing, and that reducers—not augmenters—are sensation seekers. Stimulus intensity reduction presumably creates CNS arousal deficits that require behavioural compensation. Future research linking the study variables to electrophysiological indices of reducing is necessary to further clarify the obtained relationships.     

Proactive interference and item similarity in working memory

Proactive interference (PI) may influence the predictive utility of working memory span tasks. Participants in one experiment (N=70) completed Ravens Advanced Progressive Matrices (RAPM) and multiple versions of operation span and probed recall, modified for the type of memoranda (digits or words). Changing memoranda within- or across-trials released PI, but not doing so permitted PI buildup. Scores from PI-build trials, but not PI-release trials, correlated with RAPM and accounted for as much variance in RAPM as unmodified tasks. These results are consistent with controlled attention and inhibition accounts of working memory, and they elucidate a fundamental component of working memory span tasks.     

New rule use drives the relation between working memory capacity and Raven's Advanced Progressive Matrices

The correlation between individual differences in working memory capacity and performance on the Raven's Advanced Progressive Matrices (RAPM) is well documented yet poorly understood. The present work proposes a new explanation: that the need to use a new combination of rules on RAPM problems drives the relation between performance and working memory capacity scores. Evidence for this account is supported by an item-based analysis of performance during standard administration of the RAPM and an experiment that manipulates the need to use new rule combinations across 2 subsets of RAPM items. (PsycINFO Database Record (c) 2010 APA, all rights reserved).     

Behavioural and physiological aspects of the augmenting-reducing dimension

Reducing-augmenting, sensation-seeking and extraversion-introversion are discussed in the context of strength-of-the-nervous-system theory and two experiments are reported. Experiment 1 showed that high scorers on Vando's Reducer-Augmenter Scale (RAS) (stimulus-intensity reducers) may be identified with sensation-seeking, as measured by Zuckerman's Sensation-seeking Scale, and extraversion, as measured by the Eysenck Personality Inventory. Augmenters' electrodermal responses habituate more slowly than do those of reducers to a relatively strong stimulus. Reducers prefer loud music and apparently need fewer hours of sleep. Female reducers consume relatively more stimulant drinks than female augmenters. Reducers have significantly higher resting systolic blood pressure than augmenters, a finding that was confirmed in the second experiment. However, Experiment 2 failed to find the expected relationship between augmenting-reducing as determined by the RAS and performance on the Kinaesthetic Figural Aftereffects Test.     

Developmental changes in the relations between inhibitory control and externalizing problems during early childhood

Deficits in executive function, and in particular, reduced capacity to inhibit a dominant action, are a risk factor for externalizing problems (EP). Inhibitory control (IC) develops in the later preschool and early childhood periods, such that IC might not regulate EP in toddlers and younger preschoolers. Aggression was observed during peer play for 66 girls and 49 boys, from 2.75 to 6.00 years (M=4.14, S.D.=0.78). Mothers reported on children's IC and EP concurrently and 12 months later, and concurrent teacher reports of EP were also collected. Factor analysis supported aggregation of mother and teacher‐reported EP and observed physical aggression into one measure of externalizing difficulties. Mothers reported lower IC for children with more externalizing difficulties, and the inverse relation between IC and externalizing difficulties strengthened over the toddler, preschool and kindergarten periods. Similar relations between IC and EP were observed 12 months later, and increases in IC also predicted reductions in EP over 1 year. These data demonstrate that the preschool years are a dynamic period of developmental change in the relations between IC and EP. Copyright © 2010 John Wiley & Sons, Ltd.     

Individual Differences in Reward-Based Learning Predict Fluid Reasoning Abilities

The ability to reason and problem-solve in novel situations, as measured by the Raven's Advanced Progressive Matrices (RAPM), is highly predictive of both cognitive task performance and real-world outcomes. Here we provide evidence that RAPM performance depends on the ability to reallocate attention in response to self-generated feedback about progress. We propose that such an ability is underpinned by the basal ganglia nuclei, which are critically tied to both reward processing and cognitive control. This hypothesis was implemented in a neurocomputational model of the RAPM task, which was used to derive novel predictions at the behavioral and neural levels. These predictions were then verified in one neuroimaging and two behavioral experiments. Furthermore, an effective connectivity analysis of the neuroimaging data confirmed a role for the basal ganglia in modulating attention. Taken together, these results suggest that individual differences in a neural circuit related to reward processing underpin human fluid reasoning abilities.     

EP Component Identification and Measurement by Principal Components-Analysis

Between the acquisition of Evoked Potential (EP) data and their interpretation lies a major problem: What to measure? An approach to this kind of problem is outlined here in terms of Principal Components Analysis (PCA). An important second theme is that experimental manipulation is important to functional interpretation. It would be desirable to have a system of EP measurement with the following characteristics: (1) represent the data in a concise, parsimonous way; (2) determine EP components from the data without assuming in advance any particular waveforms for the components; (3) extract components which are independent of each other; (4) measure the amounts (contributions) of various components in observed EPs; (5) use measures that have greater reliability than measures at any single time point or peak; and (6) identify and measure conponents that overlap in time. PCA has these desirable characteristics. Simulations are illustrated. PCA′s beauty also has some warts that are discussed. In addition to discussing the usual two-mode model of PCA, an extension of PCA to a three-mode model is described that provides separate parameters for (1) waveforms over time, (2) coefficients for spatial distribution, and (3) scores telling the amount of each component in each EP. PCA is compared with more traditional approaches. Some biophysical considerations are briefly discussed. Choices to be made in applying PCA are considered. Other issues include misallocation of variance, overlapping components, validation, and latency changes.     

Inspection time and IQ: Evidence for a mental speed—ability association

Two studies have tested a theory that individual differences in mental speed constitute an important component of differences in general intelligence by examining patterns of correlation between ‘inspection time’ (IT) and various ability measures assumed to reflect different kinds of speed. The first study was set within the framework of Cattell's theory about the structure of abilities. Results from 30 adult Ss whose IQs (Raven Advanced Progressive Matrices, RAPM) were in the average to above-average range suggested that IT is associated with a broad general ability variable and not with the primary abilities ‘perceptual speed’ or ‘speed of closure’. However, IT was significantly correlated with only a subgroup of those primary abilities that were significantly intercorrelated, and the outcome did not further elucidate the nature of speed as discussed within Cattell's formulation. The second study tested a relationship between IT and a measure of general ‘intellectual speed’, previously described as the major determinant of intellectual differences in a situation where two other critical variables, ‘accuracy’ and ‘continuance’ can exert no influence. It was measured for more than 40 adult Ss, whose IQs (Wechsler Adult Intelligence Scale—Revised) ranged from 81 to 138, and compared with times to produce the correct solution to individual items from the RPM. IT, IQ and solution times were all significantly intercorrelated but, nonetheless, IT and solution times appeared to be substantially reflecting different processes. It is concluded that IT can account for more than the 10% of variance in IQ commonly found to be shared with simple information-processing tasks. The present result of approx. 17% shared variance is probably an underestimate, given the restricted IQ samples used and certain procedural shortcomings. The nature of speed reflected by IT has not been determined and current measurement procedures may be confounded by internal noise.     

Intelligence and changes in regional cerebral glucose metabolic rate following learning

Positron emission tomography (PET) studies of brain glucose metabolic rate (GMR) in normal volunteers report inverse correlations between GMR and scores on the Raven's Advanced Progressive Matrices (RAPM) and verbal fluency. A new study in eight normal men reports widespread significant GMR decreases following learning a complex task (the computer game “Tetris”). The purpose of this study is to ascertain the correlations between GMR changes following learning “Tetris” and psychometric intelligence scores (RAPM and WAIS-R) to determine whether high-ability subjects show the largest GMR decreases, as predicted by a brain efficiency hypothesis. This hypothesis is supported with significant correlations between the magnitude of GMR change and intelligence scores in many brain areas that changed with learning. Some implications for the role of attention, memory, and speed of processing are discussed in view of the specific brain areas involved.     

Kinesthetic figural aftereffects in acute schizophrenia: a style of processing stimuli.

The Kinesthetic Figural Aftereffect test was administered to 106 psychiatric inpatients to assess styles of stimulus processing in schizophrenia. Three conditions were used: (1) standard stimulus conditions at the acute phase; (2) standard conditions, 7 wk. later, to evaluate stability over time; (3) reversed stimulus conditions to assess kinesthetic figural aftereffect generality under different stimulus conditions. Results indicated that: (1) schizophrenics reduced stimuli, but differences between patient groups were not significant. (2) Kinesthetic figural aftereffect stability over time was shown by nonschizophrenics (p less than .01) but not by schizophrenic and borderline patients. (3) All diagnostic groups reversed kinesthetic figural aftereffect responses under reversed stimulus conditions, e.g., former "augmenters" tended to reduce more under agumenting conditions, suggesting the importance of the specific stimulus conditions. (4) Acute schizophrenics showed a stimulus-governed style. (5) The results raise questions about kinesthetic figural aftereffects as a measure of response style.     

“Don’t you know I own the road?” The link between narcissism and aggressive driving

Aggressive drivers can make driving dangerous. Over 50% of traffic fatalities are caused by aggressive driving. This research tests whether narcissists are more aggressive drivers than other individuals. Narcissists think they are special people who deserve special treatment. When they don’t get the special treatment they think they deserve, narcissists often lash out at others in an aggressive manner. Narcissists might think they “own the road” and can drive anyway they want, and that other drivers should get out of their way. In the article, we conduct three studies to test the link between narcissism and aggressive driving. In Studies 1 (N = 139) and 2 (N = 100), Luxembourgish motorists completed a measure of narcissism and a self-report measure of aggressive driving. In Study 3 (N = 60), American university students completed a measure of narcissism and then completed a driving simulation scenario that contained a number of frustrating elements. Several measures of aggressive driving and road rage were obtained. In all three studies, narcissism was positively related to aggressive driving. A meta-analysis found an average correlation of r = 0.35 across the three studies. This research replicates previous research linking narcissism to aggression, and extends it to a driving context.     

Personality in rats and pain measures

The pain threshold of rats previously selected according to ambulation and defecation scores was assessed. Ss were 89 Sprague-Dawley rats aged 90 days. They were submitted to a low-frightening open-field (LFOF) test and 40 rats were selected on the grounds of extreme ambulation and defecation scores. The pain threshold was then assessed in 10 daily tests during 2 consecutive days. The mean of the 20 tests was used as the measure of the threshold and the mean of the two most extreme values was used as the measure for pain tolerance. The results obtained show that the pain thresholds of high-defecatory rats are significantly lower than those of low-defecatory rats. A similar relationship is found between low- and high-ambulatory rats, but the differences do not reach statistical significance. When the results of all 4 groups are compared the low-ambulatory and high-defecatory rats (introvert-neurotic) show the lowest threshold value, and the high-ambulatory and low-defecatory rats (extravert-stable) show the highest one which is significantly different from any other group. The results obtained with respect to the tolerance threshold, in spite of the lack of statistical significance, follow the same direction as those shown by the pain threshold.     

The influence of task paradigm on motor imagery ability in children with Developmental Coordination Disorder

Children with Developmental Coordination Disorder (DCD) have difficulty imagining movements such that they conform to the customary temporal constraints of real performance. We examined whether this ability is influenced by the choice of task used to elicit motor imagery (MI). Performance of typically developing (TD) (n = 30) and children with DCD (n = 30) was compared on two tasks: the Visually Guided Pointing Task (VGPT) and the Computerized Virtual Radial Fitts Task (C-VRFT). Since the VGPT places higher demands on executive functions like working memory but requires less spatial planning, we reasoned that the C-VRFT would provide a purer measure of motor imagery (or simulation). Based on our earlier work, we predicted that imagery deficits in DCD would more likely manifest on the C-VRFT. Results showed high correlations between tasks in terms of executed and imagined movement time suggest that both tasks measure MI ability. However, group differences were more pronounced in the imagined condition of the radial Fitts’ task. Taken together, the more spatially complex C-VRFT appears to be a more sensitive measure of motor imagery, better discriminating between DCD and TD. Implications for theory and practice are discussed.     

The role of processing difficulty in the predictive utility of working memory span

Storage-plus-processing working memory span tasks (e.g., operation span [OSPAN]) are strong predictors of higher order cognition, including general fluid intelligence. This is due, in part, to the difficulty of the processing component. When the processing component prevents only articulatory rehearsal, but not executive attentional control, the predictive utility is attenuated. Participants in one experiment (N = 59) completed Raven’s Advanced Progressive Matrices (RAPM) and multiple versions of OSPAN and probed recall (PR). A distractor task (high or low difficulty) was added to PR, and OSPAN’s processing component was manipulated for difficulty. OSPAN and PR correlated with RAPM when the processing component took executive attentional control. These results are suggestive of resource sharing between processing and storage.