Genetic effects explain the stability of psychopathic personality from mid- to late adolescence

This study examined the importance of genetic and environmental influence for the stability of psychopathic personality between mid- and late adolescence. The target sample consisted of all 1,480 male and female twin pairs born in Sweden between 1985 and 1986. Psychopathic personality was measured with the Youth Psychopathic Traits Inventory (YPI; H. Andershed, M. Kerr, M. Stattin, & S. Levander, 2002) when the participants were 16 and 19 years old. Results showed that the 3 psychopathic personality dimensions were stable at different levels of analysis and linked to a stable higher order general factor (i.e., psychopathic personality factor). Genetic factors contributed substantially to the stability of this general higher order factor, whereas environmental factors were of little importance. However, the authors also found specific genetic stability in the Callous/unemotional and Impulsive/irresponsible dimension. Thus, the model provides evidence for etiologic generality and etiologic specificity for the stability of psychopathic personality between mid- and late adolescence.     

Large continuous perspective transformations are necessary and sufficient for accurate perception of metric shape

We investigated the ability to perceive the metric shape of elliptical cylinders. A large number of previous studies have shown that small perspective variations (< or =10 degrees) afforded by stereovision and by head movements fail to allow accurate perception of metric shape. If space perception is affine (Koenderink & van Doom, 1991), observers are unable to compare or relate lengths in depth to frontoparallel lengths (i.e., widths). Frontoparallel lengths can be perceived correctly, whereas lengths in depth generally are not. We measured reaches to evaluate shape perception and investigated whether larger perspective variations would allow accurate perception of shape. In Experiment 1, we replicated previous results showing poor perception with small perspective variations. In Experiment 2, we found that a 90 degrees continuous change in perspective, which swapped depth and width, allowed accurate perception of the depth/width aspect ratio. In Experiment 3, we found that discrete views differing by 90 degrees were insufficient to allow accurate perception of metric shape and that perception of a continuous perspective change was required. In Experiment 4, we investigated continuous perspective changes of 30 degrees, 45 degrees, 60 degrees, and 90 degrees and discovered that a 45 degrees change or greater allowed accurate perception of the aspect ratio and that less than this did not. In conclusion, we found that perception of metric shape is possible with continuous perspective transformations somewhat larger than those investigated in the substantial number of previous studies.     

Judging Words at Face Value: Interference in a Word Processing Task Reveals Automatic Processing of Affective Facial Expressions

Earlier research has indicated that some characteristics of facial expressions may be automatically processed. This study investigated automaticity as evidenced by involuntary interference in a word evaluation task. Compound stimuli, consisting of words superimposed on pictures of affective faces, were presented to subjects who were given the task of evaluating the affective valence of the words while disregarding the faces. Results of three experiments showed that word evaluation was influenced by the concurrently shown affective faces. Overall, negative words were found to require longer latencies, indicating that more processing resources are invested in negative than in positive stimuli. This speed advantage for positive words was modified by the faces. Negative words were facilitated, relative to positive ones, when shown with a negative expression (e.g. a sad face). Correspondingly, negative words were inhibited, relative to positive ones, when shown with a positive expression (e.g. a happy face). The results are consistent with automatic, involuntary semantic processing of affective facial expressions.     

Imagery-induced negative affect,social touch and frontal EEG power band activity

Social touch seems to modulate emotions, but its brain correlates are poorly understood. Here, we investigated if frontal power band activity in the electroencephalogram (EEG) during aversive mental imagery is modulated by social touch from one’s romantic partner and a stranger. We observed the highest theta and beta power when imaging alone, next so when being touched by a stranger, with lowest theta and beta activity during holding hands with the loved one. Delta power was higher when being alone than with a stranger or a partner, with no difference between the two. Gamma power was highest during the stranger condition and lower both when being alone and with the partner, while alpha power did not change as a function of social touch. Theta power displayed a positive correlation with electrodermal activity supporting its relation to emotional arousal. Attachment style modulated the effect of touch on the EEG as only secure but not insecure partner bonding was associated with theta power reductions. Because theta power was sensitive to the experimental perturbations, mapped onto peripheral physiological arousal and reflected partner attachment style we suggest that frontal theta power might serve as an EEG derived bio-marker for social touch in emotionally significant dyads.     

CSF 5-HIAA Predicts Suicide Risk After Attempted Suicide

Suicide risk after attempted suicide, as predicted by cerebrospinal fluid (CSF) monoamine metabolite concentrations, was studied in a sample of 92 psychiatric mood disorder inpatients admitted shortly after attempting suicide. The potential of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the CSF to predict suicide risk within the first year after attempted suicide was studied by means of survival analysis after median split sub-grouping. Eleven patients (12%) committed suicide within 1 year after attempted suicide. Eight of these belonged to the below-the-median (< 87 nM) CSF 5-HIAA subgroup, that is, the suicide risk was 17% as compared with 7% among those with above-the-median CSF 5-HIAA. The cumulative number of survived patient-months during the first year after attempted suicide was significantly lower in the low CSF 5-HIAA subgroup. It was concluded that low CSF 5-HIAA predicts short-range suicide risk after attempted suicide in mood disorder psychiatric inpatients. These findings lend further support to the serotonin hypothesis of suicide risk.     

If you have a choice,you have trouble: Stimulus valence modulates presentation‐order effects in preference judgment

It is well known that the presentation order of choice options often affects decision outcomes to a significant degree. However, despite the significance and wide occurrence of the effects, they are ignored in most preference models. Furthermore, psychophysical findings of stimulus‐magnitude dependent presentation‐order effects have not been acknowledged previously in the cognitive literature on preference judgments. Thus, the potential moderating effect of the level of stimulus magnitude (here, valence) on the direction and size of order effects in preference judgment has not been investigated previously. In two experiments, participants (117 and 204, respectively) rated their preference for pairs of everyday‐type objects and phenomena (e.g., apple–pear, headache–stomachache). Stimuli were spaced horizontally, and each participant received them in one of two opposite within‐pair presentation orders. Participants also rated the stimuli's valence on a scale from very bad to very good. The results showed a positive correlation between the rated valence and the tendency to prefer the first‐mentioned (left) stimulus; that is, the effect was greatest, and opposite, for choices between the most attractive and the most unattractive options, respectively. In terms of Hellström's ( 1979 ) sensation‐weighting model, the positive correlation is caused by a higher weight (i.e., impact on the preference judgment) for the left stimulus than for the right, which is possibly due to the left stimulus being compared to the right. The results suggest that researchers may have failed previously to find important moderators of presentation‐order effects in preference judgment due to the failure to use sufficiently attractive or unattractive stimuli. Copyright © 2010 John Wiley & Sons, Ltd.     

The testing effect as a function of explicit testing instructions and judgments of learning

During study, people monitor their learning; the output of this monitoring is captured in so-called judgments of learning (JOLs). JOLs predict later recall better if they are made after a slight delay, instead of immediately after study (the delayed JOL effect). According to the self-fulfilling prophecy (SFP) hypothesis delayed JOLs are based on covert retrieval attempts from long-term memory, and successful retrieval attempts in themselves enhance learning (the testing effect). We compared memory for 40 Swahili-Swedish paired associates after a week as a function of three different learning conditions, namely study plus (i) explicitly instructed self-testing, (ii) delayed JOLs, or (iii) less self-testing. We showed that repeated delayed JOLs lead to a memory improvement that does not differ significantly from a comparable condition where the participants are explicitly testing memory, and both the latter groups performed reliably better than a group that self-tested less. The results suggest that delayed JOLs improve long-term retention as efficiently as explicit memory testing and lend support to the SFP hypothesis.     

Presentation-order effects for aesthetic stimulus preference

For preference comparisons of paired successive musical excerpts, Koh (American Journal of Psychology, 80, 171?C185, 1967) found time-order effects (TOEs) that correlated negatively with stimulus valence??the first (vs. the second) of two unpleasant (vs. two pleasant) excerpts tended to be preferred. We present three experiments designed to investigate whether valence-level-dependent order effects for aesthetic preference (a) can be accounted for using Hellstr?m??s (e.g., Journal of Experimental Psychology: Human Perception and Performance, 5, 460?C477, 1979) sensation-weighting (SW) model, (b) can be generalized to successive and to simultaneous visual stimuli, and (c) vary, in accordance with the stimulus weighting, with interstimulus interval (ISI; for successive stimuli) or stimulus duration (for simultaneous stimuli). Participants compared paired successive jingles (Exp. 1), successive color patterns (Exp. 2), and simultaneous color patterns (Exp. 3), selecting the preferred stimulus. The results were well described by the SW model, which provided a better fit than did two extended versions of the Bradley?CTerry?CLuce model. Experiments 1 and 2 revealed higher weights for the second stimulus than for the first, and negatively valence-level-dependent TOEs. In Experiment 3, there was no laterality effect on the stimulus weighting and no valence-level-dependent space-order effects (SOEs). In terms of the SW model, the valence-level-dependent TOEs can be explained as a consequence of differential stimulus weighting in combination with stimulus valence varying from low to high, and the absence of valence-level-dependent SOEs as a consequence of the absence of differential weighting. For successive stimuli, there were no important effects of ISI on weightings and TOEs, and, for simultaneous stimuli, duration had only a small effect on the weighting.     

INDIVIDUAL PERFORMANCES IN A SINGLE-CUE PROBABILITY LEARNING TASK

B jörkman , M. Individual performances in a single-cue probability learning task. Scand. J. Psychol . 1969, 10 , 113–123. —Inference behavior was studied in a 2 times 2 cue-criterion task. Fifty subjects were distributed on five conditions varying in cue validity and base rate. They were studied individually with respect to four cognitive strategies: matching, maximizing, double matching and differential maximizing. The utilization coefficients of the average subject had a tendency to 'overshoot' when the cue validity was high and to 'undershoot' when the validity was low. Double matching and differential maximizing were the most common strategies. Cognitive activity is interpreted as a compromise between various type performances.