Dimensional complexity and power spectral measures of the EEG during functional versus predicative problem solving

Electroencephalograms were recorded in 22 men while solving tasks of visual-pattern completion and during mental relaxation. They were primed (by foregoing trials) to solve these tasks either in a predicative or functional mode of thinking. Predicative thinking required that in order to complete the pattern the subject had to get involved with the logic of the static structure of the pattern and therefore had to recognize the recurrence of certain features of the elements (e.g., shape, color, and size). Functional thinking required involvement in a dynamic reading of the logic of the pattern and therefore to search for operations and actions to be performed on the pattern elements (e.g., pushing, mirroring, and rotating). The EEG complexity during predicative thinking decreased in comparison to functional thinking and mental relaxation, with this reduction being most pronounced over the right parietal cortex. A reduction in dimensional complexity during functional thinking as compared to mental relaxation, which was concentrated over the left central cortex, although significant, was less clear. The reduced EEG complexity during predicative thought, dominant over the right hemisphere, could reflect increased competitive inhibition among respective cortical neuron assemblies in association with the visual analysis of static element features, converging upon those predicates relevant for the solution.     

Nonhomogeneous resolution of images of natural scenes

The aim of this research is to model and simulate the loss of visual resolution as a function of retinal eccentricity in the perception of natural scenes. The model of visual resolution is based on a space-variant low-pass filter, having a variable convolution kernel according to retinal eccentricity. The parameters of the model are computed from psychophysical measures of visual acuity as a function of retinal eccentricity. The implementation of the model allowed us to generate images of scenes with nonhomogeneous space-variant resolution, simulating the filtering executed by the eye. These scenes are used to test and optimise the model by means of experiments in static vision (through tachistoscopic presentations) and in dynamic vision where the resolution of the scene is computed, in real-time, as a function of the location of gaze.     

Perspectives in suicidology: families, mental illness, and suicide

The ways in which the key words "family," "mental illness," and "suicide" are interpreted in the context of research into suicide will influence the formation of theories, the interpretation of results, and the development of suicide prevention strategies. It is argued that there is no general agreement about the meaning of these words.     

Suicide: a 15-year review of the sociological literature. Part II: modernization and social integration perspectives

This article reviews the findings of 84 sociological studies published over a 15-year period. These studies deal with tests of the modernization and/or social integration perspectives on suicide. Research on modernization, religious integration, and political integration often questioned or reformulated the traditional Durkheimian perspective. A major new theoretical development, Pescosolido's religious networks perspective, gained some empirical support in the 15-year period. The strongest support for social integration theory came from research on marital integration, wherein more than three quarters of the research found a significant relationship. Finally, further research on migration, a force lowering social integration, continued to tend to find a positive link to suicide.     

Fifty Years of Prison Suicide in Austria: Does Legislation Have an Impact?

The absolute and relative frequency of suicides in jails and prisons in Austria over the 50 years from 1947 to 1996 is described. Important legislational changes regarding the criminal justice system are discussed with regard to possible consequences for the incidence of prisoners' suicides. Within the five decades a significant increase in the absolute numbers of jail and prison suicides was evident in spite of the considerable decrease in the total inmate population. Therefore, the suicide rate of inmates of correctional facilities increased significantly. Possible reasons for this phenomenon are discussed in relation to changes of the criminal law.     

Response strategies and the Simon effect

The study investigated whether the Simon effect, and its facilitation and interference components, shows up in reaction time (RT) or in movement time (MT), depending on the response strategy. Experiment 1 replicated a study by Hietanen and Rämä. Subjects had to press one of two lateralised keys in response to one of two stimuli. The stimuli were presented in the center (neutral condition) or to the left or right side (corresponding or non-corresponding conditions). To press the response key, a reaching movement was necessary, and both RT and MT were recorded. One group of subjects showed an RT facilitation effect and an MT interference effect. Another group of subjects showed both MT facilitation and MT interference effects. It was hypothesized that the two groups used different response strategies. In Exps. 2 and 3, the subjects were explicitly instructed to use the two strategies that were hypothesized for Exp. 1. The results showed that whether facilitation and interference manifest themselves in RT or MT depends on the response strategy adopted by the subjects.     

The Collaborative Longitudinal Personality Disorders Study: reliability of axis I and II diagnoses

Both the interrater and test-retest-retest reliability of axis I and axis II disorders were assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Fair-good median interrater kappa (.40-.75) were found for all axis II disorders diagnosed five times or more, except antisocial personality disorder (1.0). All of the test-retest kappa for axis II disorders, except for narcissistic personality disorder (1.0) and paranoid personality disorder (.39), were also found to be fair-good. Interrater and test-retest dimensional reliability figures for axis II were generally higher than those for their categorical counterparts; most were in the excellent range (> .75). In terms of axis I, excellent median interrater kappa were found for six of the 10 disorders diagnosed five times or more, whereas fair-good median interrater kappa were found for the other four axis I disorders. In general, test-retest reliability figures for axis I disorders were somewhat lower than the interrater reliability figures. Three test-retest kappa were in the excellent range, six were in the fair-good range, and one (for dysthymia) was in the poor range (.35). Taken together, the results of this study suggest that both axis I and axis II disorders can be diagnosed reliably when using appropriate semistructured interviews. They also suggest that the reliability of axis II disorders is roughly equivalent to that reliability found for most axis I disorders.     

Naive chimpanzees' (Pan troglodytes) observation of experienced conspecifics in a tool-using task

The authors investigated the occurrence of naive chimpanzees' (Pan troglodytes) spontaneous observation of experienced conspecifics during a tool-use task entailing honey fishing. The chimpanzees were presented with 20 kinds of "tools" of which 12 kinds were usable. Six pairs of naive and experienced chimpanzees were brought to this honey-fishing situation. A total of 40 observation episodes occurred between the naive and experienced groups, 34 of which were from naive toward experienced individuals. Naive chimpanzees never observed their partners after their own success but did so after their own failure or before their first attempts. In addition, there were 10 cases in which naive individuals used the left-over tools of the experienced ones. Two factors for the transmission of tool use were clearly evident in this study: (a) spontaneous observation of an appropriate behavioral sequence and (b) enhanced environmental cues made by skilled individuals.     

Establishing operations, cognition, and emotion

In this paper we argue that behavior analysts have tended to neglect the study of important aspects of complex human behavior, including cognition and emotion. This relative neglect has been costly in terms of mainstream psychology's perception of the field of behavior analysis and in terms of our ability to provide a more thorough account of human behavior. Observations and findings from the clinical context are offered as examples of behavior that are not readily explained by the three-term contingency, and we argue that an adequate account of these behaviors must include principles derived from recent behavior-analytic work, in particular a better understanding of the short- and long-term effects of establishing operations. The concept of the establishing operation and its implications for understanding complex human behavior are discussed.