Has psychology ever been a science of behavior? A comment on Skinner.

Argues that B. F. Skinner (see record 1988-00027-001) failed to recognize the role of behaviorism in the failure of psychology to become a science of behavior. The authors state that behaviorism has generated laws concerning the impact of behavior on certain environments instead of laws of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of low entropy coding in a recurrent network

In this paper we present an unsupervised neural network which exhibits competition between units via inhibitory feedback. The operation is such as to minimize reconstruction error, both for individual patterns, and over the entire training set. A key difference from networks which perform principal components analysis, or one of its variants, is the ability to converge to non-orthogonal weight values. We discuss the network's operation in relation to the twin goals of maximizing information transfer and minimizing code entropy, and show how the assignment of prior probabilities to network outputs can help to reduce entropy. We present results from two binary coding problems, and from experiments with image coding.     

Seasonal distribution of bloater (Coregonus hoyi) in the waters of Lake Huron surrounding the Bruce Peninsula

Information about bloater (Coregonus hoyi) habitat in Lake Huron was limited to correlations between commercial yield and fishing depth, despite available information from other Great Lakes. We identified seasonal patterns of bloater habitat use in hypolimnetic waters surrounding the Bruce Peninsula, Lake Huron. We applied a delta-lognormal model to fisheries-independent survey data to evaluate whether bloater catch-per-unit-effort was related to depth, temperature, and bathymetric slope. A Bayesian variable selection technique indicated that bloater distribution was most strongly related to bottom depth and water temperature. Our study also reconfirmed a previously-described pattern of seasonal inshore movement during warmer months followed by a return to deeper offshore waters during cooler months. By focusing our sampling within the hypolimnion, we characterized intra-annual patterns of bloater habitat use with respect to a temperature gradient near the minimum thermal requirements reported for this species. Bloater distribution under these thermal conditions has not been previously reported.     

Neurotoxic potential of gadodiamide after injection into the lateral cerebral ventricle of rats

PURPOSE: Results of a previous report showed that, if administered by intraventricular injection to access tissue normally protected by the blood-brain barrier, gadopentetate dimeglumine produced acute excitation, persistent ataxia, and widespread brain lesions in rats at 5-micromol/g brain but not at 3.8-micromol/g brain. The present study using gadodiamide was undertaken to see whether the effects were agent-specific. METHODS: Rats, surgically prepared with a lateral ventricular cannula, were administered a slow injection at 2 microL/min of gadodiamide into the lateral ventricle, and behavioral and neuropathologic changes were noted. RESULTS: Both gadodiamide and gadopentetate dimeglumine produced focal and generalized myoclonus over several hours. Gadodiamide did not produce the medium-term tremor or persistent ataxia seen after treatment with gadopentetate dimeglumine. Neuropathologic changes developed over 1 to 3 days and took three distinct forms: vacuolated thalamic lesions closely resembling those produced by gadopentetate dimeglumine; small but similar vacuolated symmetrical caudate lesions not produced by gadopentetate dimeglumine; and severe swelling and astrocytic hypertrophy and hyperplasia in the cerebellar vermis, again not produced by gadopentetate dimeglumine. Unlike gadopentetate dimeglumine, gadodiamide produced no spinal cord lesions. The cerebellar changes were seen at 1.25-micromol/g brain and above, behavioral changes at 2.5-micromol/g brain and above, and thalamic and caudate lesions at 10-micromol/g brain, the maximal dose used. Markedly reducing the rate of injecting the same volume over 28 hours prevented the acute excitation but did not reduce the severity of the morphologic effects. CONCLUSION: The acute excitatory effects of high intraventricular doses of gadopentetate dimeglumine and gadodiamide are similar and appear to be attributable to local action at the infusion site, but differences exist between the two agents in the character and topography of the distant morphologic changes. The cerebellum was the brain area most sensitive to gadodiamide in this experimental model. It is unlikely that gadodiamide would gain access to the brain at these tissue doses when used intravenously for conventional clinical imaging, but our experimental model suggested that it had some unexpectedly specific neuropathologic potential.     

The revised Psychopathy Checklist: Reliability and factor structure.

The revised Psychopathy Checklist (PCL) is a 20-item scale scored from interview and file information. Analyses of data from 5 prison samples (N?=?925) and 3 forensic psychiatric samples (N?=?356) indicate that the revised PCL resembles its 22-item predecessor in all important respects. It has excellent psychometric properties, and it measures 2 correlated factors that were cross-validated both within and between samples. Correlations between the original PCL and the revised version approached unity for both the factors and the full scale. We conclude that the revised PCL measures the same construct as the original and that the PCL is a reliable and valid instrument for the assessment of psychopathy in male forensic populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathy and the DSM-IV criteria for antisocial personality disorder.

The Axis II Work Group of the Task Force on Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) has expressed concern that antisocial personality disorder (APD) criteria are too long and cumbersome and that they focus on antisocial behaviors rather than personality traits central to traditional conceptions of psychopathy and to international criteria. R. D. Hare et al describe an alternative to the approach taken in the DSM-III—Revised (DSM-III—R; American Psychiatric Association, 1987), namely, the revised Psychopathy Checklist. The authors also discuss the multisite APD field trials designed to evaluate and compare 4 criteria sets: the DSM-III—R criteria, a shortened list of these criteria, the criteria for dyssocial personality disorder from the 10th edition of the International Classification of Diseases (World Health Organization, 1990), and a 10-item criteria set for psychopathic personality disorder derived from the revised Psychopathy Checklist. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigation of failure in paint films

Direct pull-off tests have been carried out on mild steel plates coated with an Alloprene-based lacquer. Several unusual features were observed on the fracture surfaces, and attempts have been made to interpret these markings, and the implications of their origin on the test methods employed. Preliminary results led to an improved testing method but new markings were produced which have been interpreted, and appear to be caused by the interaction of periodic stress waves with the fracture. This technique has the advantages of reproducibility and simplicity.     

Assessment of psychopathy as a function of age.

The assessment of psychopathy was examined as a function of age in 889 male prison inmates between the ages of 16 and 69. Ratings of psychopathy were made with the Psychopathy Checklist (PCL), which measures 2 correlated factors. Factor 1 describes a cluster of affective-interpersonal traits central to psychopathy. Factor 2 describes traits and behaviors associated with an unstable, unsocialized lifestyle, or social deviance. Cross-sectional analyses revealed that mean scores on Factor 1 were stable across the age-span; mean scores on Factor 2 declined with age. The prevalence of antisocial personality disorder, and, to a lesser extent of PCL-defined psychopathy, also declined with age. The results are consistent with a conceptualization of psychopathy as encompassing 2 correlated but distinct constructs. They also suggest that age-related differences in traits related to impulsivity, social deviance, and antisocial behavior are not necessarily paralleled by differences in the egocentric, manipulative, and callous traits fundamental to psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factor structure of the Psychopathy Checklist.

The Psychopathy Checklist (PCL) is a reliable and valid instrument for the assessment of psychopathy in criminal populations. Although it was designed to measure a unitary construct, the instrument has been shown to comprise several factors. To determine whether the PCL contains a factor structure that is stable and replicable, we factor-analyzed data from six samples of male prison inmates (N?=?1,119) in Canada, the United States, and England. Split-half cross-validation and analysis of congruence coefficients indicated that a two-factor solution could be replicated in all six samples. Factor 1 was defined by core personality traits, including superficiality; habitual lying and manipulation; callousness; and lack of affect, guilt, remorse, and empathy. Factor 2 was defined by a chronically unstable and antisocial lifestyle. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinase-negative mutants of JAK1 can sustain interferon-gamma-inducible gene expression but not an antiviral state

The receptor-associated protein tyrosine kinases JAK1 and JAK2 are both required for the interferon (IFN)-gamma response. The effects of expressing kinase-negative JAK mutant proteins on signal transduction in response to IFN-gamma in wild-type cells and in mutant cells lacking either JAK1 or JAK2 have been analysed. In cells lacking endogenous JAK1 the expression of a transfected kinase-negative JAK1 can sustain substantial IFN-gamma-inducible gene expression, consistent with a structural as well as an enzymic role for JAK1. Kinase-negative JAK2, expressed in cells lacking endogenous JAK2, cannot sustain IFN-gamma-inducible gene expression, despite low level activation of STAT1 DNA binding activity. When expressed in wild-type cells, kinase-negative JAK2 acts as a dominant-negative inhibitor of the IFN-gamma response. Further analysis of the JAK/STAT pathway suggests a model for the IFN-gamma response in which the initial phosphorylation of JAK1 and JAK2 is mediated by JAK2, whereas phosphorylation of the IFN-gamma receptor is normally carried out by JAK1. The efficient phosphorylation of STAT 1 in the receptor-JAK complex may again depend on JAK2. Interestingly, a JAK1-dependent signal, in addition to STAT1 activation, appears to be required for the expression of the antiviral state.