Correlates of parenting on a neonatal intensive care unit: maternal characteristics and family resources

The association of maternal characteristics, family resources, and receipt of prenatal care with parenting behaviors observed in a neonatal intensive care unit (NICU; n = 383) was assessed. The parenting behavior of mothers not receiving prenatal care (n = 128) was compared to that of mothers of the preceding and subsequent admissions (n = 256) by retrospective chart review. Parenting variables included frequency of visits to the NICU and evaluative ratings of parents' involvement with their infant. Parenting of the no-prenatal-care group was significantly less favorable than the control on all comparisons. Factor analysis supported a priori grouping of parenting variables. A stepwise multiple regression of maternal and family characteristics to the factor-derived variable, parenting, showed significant contributions for prenatal drug use and father involvement. Pediatric interventions assessing maternal social and behavioral characteristics are proposed.     

An experimental analysis of impulsivity and impulse control in humans

In choosing between small, immediate and large, delayed reward, an organism behaves impulsively if it chooses the small reward and shows impulse control if it chooses the large reward. Work with nonhumans suggests that impulsivity and impulse control may be derived from gradients of delayed reinforcement. A model developed by Ainslie and by Rachlin suggests that preference for the rewards should be a function of when the choice is made: small reward with no delay may be preferred to large reward with delay X, but adding delay T to both alternatives should shift preference to the large reward. Three experiments investigated this preference reversal in humans, using termination of 90 dba white noise as the reinforcing event. Experiment 1 showed that under some instructional conditions 90-sec noise off with no delay was preferred over 120-sec noise off after a 60-sec delay, but that preference shifted to the large reward when a 15-sec delay (T) was added to both alternatives. Experiment 2 replicated this preference reversal under two conditions of large, delayed reward, and with three rather than two values of T. Experiment 3 confirmed this effect of T and showed that some humans committed themselves to the large reward when commitment could be made some time before presentation of the reward alternatives. These data support the Ainslie-Rachlin model and extend it to human choice behavior.     

A comparison of the classification capabilities of the 1-dimensional kohonen neural network with two pratitioning and three hierarchical cluster analysis algorithms

Neural Network models are commonly used for cluster analysis in engineering, computational neuroscience, and the biological sciences, although they are rarely used in the social sciences. In this study we compare the classification capabilities of the 1-dimensional Kohonen neural network with two partitioning (Hartigan and Späthk-means) and three hierarchical (Ward's, complete linkage, and average linkage) cluster methods in 2,580 data sets with known cluster structure. Overall, the performance of the Kohonen networks was similar to, or better than, the performance of the other methods.     

Student mental health: how can psychiatrists better support the work of university medical centres and university counselling services?

Student psychiatric morbidity is rising. Whilst the influence of university counselling services is widely reported, NHS involvement by psychiatrists and general practitioners is not so well described. Counselling and mental health service providers for students at the University of Leeds were approached for numerical data and a university Group on Student Mental Health discussed the findings. The Student Counselling Centre, the University Medical Practice and a dedicated student psychiatric clinic have all seen a rise in referral rates. The University Medical Practice has also seen a rise in the prescribing of psychoactive medication. Collaborative links at the University of Leeds are explored and options for the future discussed. These include self-help over the internet, a research project to assess student mental health needs and the provision of a dedicated NHS psychiatric team for the university.     

Schizotypy, taxometrics, and disconfirming theories in soft science: Comment on

Among the most consistently replicated findings in literature addressing the latent structure of psychopathology is evidence for a discrete latent class of individuals who are vulnerable to schizophrenia (schizotypes). Rawlings, Williams, Haslam, and Claridge (2008) challenge these findings by subjecting schizotypy scale scores to taxometric analysis, using a data simulation technique to accommodate variable skew. The authors conclude that schizotypy reflects a latent dimension, and that evidence for discrete latent structure from previous studies is likely an artifact of skewed variables. In this comment, we discuss (a) the philosophical implications of disconfirming well replicated findings in soft science with a single study, (b) important considerations when defining the schizotypy construct, (c) intricacies in executing and interpreting a taxometric analysis, and (d) problems with drawing strong conclusions from null results. Considerable evidence suggests that schizotypy is a discrete latent class, a conclusion that is unlikely the result of skewed variables.