Gray matter and intelligence factors: Is there a neuro-g?

Heterogeneous results among neuro-imaging studies using psychometric intelligence measures may result from the variety of tests used. The g-factor may provide a common metric across studies. Here we derived a g-factor from a battery of eight cognitive tests completed by 6929 young adults, 40 of whom also completed structural MRI scans. Regional gray matter (GM) was determined using voxel-based-morphometry (VBM) and correlated to g-scores. Results showed correlations distributed throughout the brain, but there was limited overlap with brain areas identified in a similar study that used a different battery of tests to derive g-scores. Comparable spatial scores (with g variance removed) also were derived from both batteries, and there was considerable overlap in brain areas where GM was correlated to the respective spatial scores. The results indicate that g-scores derived from different test batteries do not necessarily have equivalent neuro-anatomical substrates, suggesting that identifying a “neuro-g” will be difficult. The neuro-anatomical substrate of a spatial factor, however, appears more consistent and implicates a distributed network of brain areas that may be involved with spatial ability. Future imaging studies directed at identifying the neural basis of intelligence may benefit from using a psychometric test battery chosen with specific criteria.     

Hempel's Paradox, Law-likeness and Causal Relations

It is widely thought that Bayesian confirmation theory has provided a solution to Hempel's Paradox (the Ravens Paradox). I discuss one well-known example of this approach, by John Mackie, and argue that it is unconvincing. I then suggest an alternative solution, which shows that the Bayesian approach is altogether mistaken. Nicod's Condition should be rejected because a generalisation is not confirmed by any of its instances if it is not law-like. And even law-like non-basic empirical generalisations, which are expressions of assumed underlying causal regularities, are not so confirmed if they are absurd in the light of our causal background knowledge or if their instances are not also possible instances of the relevant causal claim.     

Factorial structure of traits delineating personality disorders in clinical and general population samples.

Categorical and dimensional models for classifying personality disorders were evaluated by comparing the structure of personality pathology in a clinical sample (n = 158) with the structure in a general population sample (n = 274). Subjects completed 100 personality scales. Separate factor analyses revealed similar structures in the 2 samples. An underlying structure in a combined sample showed limited agreement with the concepts of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1987). Fifteen factors were retained: Generalized Distress, Rejection, Restricted Expression, Compulsivity, Stimulus Seeking, Insecure Attachment, Diffidence, Intimacy Problems, Oppositionality, Interpersonal Disesteem, Conduct Problems, Cognitive Dysfunction, Affective Reactivity, Narcissism, and Social Apprehensiveness. The results are consistent with a dimensional representation of personality disorder.     

A microcomputer-based cardiotachometer with video display

A KIM-1 single board microcomputer implementation of a cardiotachometer that provides a low-cost versatile heart-rate data acquisition system is described. Unique features include telemetry, a composite video output signal of a video frame displaying elapsed time and heart-rate, and a TV camera signal of the behavior. Data is videotape- and/or audiotape-recorded for further analysis with a larger computer.     

Assessment of peer rejection and externalizing behavior problems in preschool boys: a short-term longitudinal study

We examined the longitudinal stability of measures of negative peer status and aggressive-disruptive behavior in preschool boys. Subjects were 53 white 4- to 5- year- old boys from low-income family backgrounds. Peer sociometric measures of rejection and behavioral deviance were assessed in the fall and spring of the preschool year. Complementary measures were also obtained from teachers at both assessment points. Half of the boys designated as rejected on the basis of peer nominations maintained this status at the end of the preschool year. Teachers and peers did not agree on their selections of socially rejected children, but had good agreement concerning the identification of children with externalizing-type behavior problems. Finally, teacher and peer classifications of aggressive-disruptive children were highly stable throughout the preschool year. These findings indicate that peer-rejected children can be identified at very young ages, and that preschoolers can be reliable informants about the social maladjustment of peers.We thank the Head Start children, parents and staff who participated, and Karen Lifgren for her help with data collection.     

Transfer of fear reduction through systematic desensitization

Systematic desensitization therapy involves the presentation of fear-provoking situations through visualization As the visualizations cease to evoke emotional responses, the fear-provoking potential of the real situations decreases. Research has clearly shown that such transfer does indeed occur with a wide variety of fears. Transfer has been demonstrated, for example, with fear of small animals (Lang and Lazovik, 1963), interpersonal performance anxiety (Paul, 1966), classic phobias (Lazarus, 1961), test anxiety (Katahn, Strenger and Cherry, 1966), impotence (Wolpe, 1958) and frigidity (Lazarus, 1963). However, the nature of transfer has received little attention. Wolpe (1963) has claimed that transfer from therapy to the real life situation is almost complete and direct: “There is almost invariably a one-to one relationship between what the patient can imagine without anxiety and what he can experience in reality without anxiety”. This claim has received support from Rachman (1966) who found that fear reduction transferred immediately to the real situation in 82 per cent of his observations. Hoenig and Reed (1966) reported that after a brief delay, transfer effects were observed in the case of words representing fearful stimuli but were inconsistent in the case of the real stimuli. Agras (1967) found transfer to be delayed in all his cases. He further reported that, though all patients improved, a direct relationship between therapeutic progress and symptom reduction was not found. Both Hain et al. (1966) and Meyer and Crisp (1966) have described the failure of therapeutic effects to transfer to real life.These somewhat inconsistent reports may stem in part from the measurement of transfer effects at different times. Another possibility is that more fearful Ss may evidence less transfer than less fearful Ss. Lang and Lazovik (1963) reported that Ss who completed less than 75 per cent of the hierarchy showed little improvement although direct transfer effects were observed for less fearful Ss (those who complete 75 per cent or more hierarchy items). The present study of transfer effects was designed to remove confoundingof level of fear with extent of progress in systematic desensitization.