Can computer mice be used as low-cost devices for the acquisition of planar human movement velocity signals?

The main goal of this work is to determine whether a computer mouse can be used as a low-cost device for the acquisition of two-dimensional human movement velocity signals in the context of psychophysical studies and biomedical applications. A comprehensive overview of the related literature is presented, and the problem of characterizing mouse movement acquisition is analyzed and discussed. Then, the quality of velocity signals acquired with this kind of device is measured on horizontal oscillatory movements by comparing the mouse data to the signals acquired simultaneously by a video motion tracking system and a digitizing tablet. A synthesis of the information gathered in this work indicates that the computer mouse can be used for the reliable acquisition of biosignals in the context of human movement studies, particularly for many applications dealing with the velocity of the end effector of the upper limb. This paper concludes by discussing the possibilities and limitations of such use.     

酒精对视觉加工和眼动行为控制的影响(中文)

Although moderate alcohol consumption is known to degrade performance in a variety of tasks, the exact nature and extent of such impairments is not well understood. We examined alcohol effects on different levels of visual processing and oculomotor control. On the lowest level(automatic), reflexive responses were tested using the prosaccade task. The‘automated’level, incorporating routine behavior based on implicit learning, was studied using the double step paradigm, while the highest level, representing voluntary control, was examined with antisaccade and memory guided tasks. In addition, sentence reading was included as a prototypical complex task with high ecological validity. Participant′s baseline performance was compared to alcohol conditions with intoxication levels around 70mg% of breath alcohol concentration. Functioning on the automatic level was intact, except for a substantial slowing in saccade latencies. On the automated level, deficits in the ability to adaptively reprogram saccades on the basis of new information were found. Impairments in voluntary control were apparent in hypermetric saccade amplitudes whenever a reprogramming of the initial saccade target was necessary. There was also a small but significant detrimental effect on visuospatial short term memory. Somewhat surprisingly, no alcohol related deficits emerged with regard to inhibitory functions. ‘Reading under the influence’resulted in substantially prolonged fixation durations with only a modest increase in total viewing time per word. A trade-off between increased duration and decreased number of fixations pointed to the possibility that the extra time available under alcohol can be used for linguistic processing, which in itself did not appear to be impaired. This idea is supported by the fact that there was no interaction between alcohol and word frequency. Contrary to expectation, the processing of parafoveal information during reading was not impeded. Overall, results provide a largely coherent pattern of selective effects that begin to form a comprehensive picture of alcohol related deficits.     

Watching pornographic pictures on the Internet: role of sexual arousal ratings and psychological-psychiatric symptoms for using Internet sex sites excessively

Excessive or addictive Internet use can be linked to different online activities, such as Internet gaming or cybersex. The usage of Internet pornography sites is one important facet of online sexual activity. The aim of the present work was to examine potential predictors of a tendency toward cybersex addiction in terms of subjective complaints in everyday life due to online sexual activities. We focused on the subjective evaluation of Internet pornographic material with respect to sexual arousal and emotional valence, as well as on psychological symptoms as potential predictors. We examined 89 heterosexual, male participants with an experimental task assessing subjective sexual arousal and emotional valence of Internet pornographic pictures. The Internet Addiction Test (IAT) and a modified version of the IAT for online sexual activities (IATsex), as well as several further questionnaires measuring psychological symptoms and facets of personality were also administered to the participants. Results indicate that self-reported problems in daily life linked to online sexual activities were predicted by subjective sexual arousal ratings of the pornographic material, global severity of psychological symptoms, and the number of sex applications used when being on Internet sex sites in daily life, while the time spent on Internet sex sites (minutes per day) did not significantly contribute to explanation of variance in IATsex score. Personality facets were not significantly correlated with the IATsex score. The study demonstrates the important role of subjective arousal and psychological symptoms as potential correlates of development or maintenance of excessive online sexual activity.     

Great oaks from giant acorns grow: How causal‐impact judgments depend on the strength of a cause

Causal impact is maximal when weak causes have strong effects. Do people understand this logic when they assess causal impact? In four experiments, participants judged the causal impact of strong or weak dietary treatments leading to strong or weak health effects in fictitious health studies. Rather than following the ratio of effect strength to treatment strength, judgments were influenced by three aspects of the detectability of a cause–effect relation. First, because detectability depends on the effect being strong more than on the cause being subtle, causal judgments were mainly determined by effect strength, whereas the strength of the causal treatment necessary to induce an effect was often neglected. Second, if causal input was not ignored, judgments increased when the maximal covariation between a strong causal treatment and a strong effect rendered the causal link most detectable. Or, third, causal judgments increased when a plausible causal schema facilitated detection. Consistent with sampling models of judgment and decision making, causal‐impact ratings were driven by an uncritical assessment of a detectable difference in a study sample. However, ratings were insensitive to the logical implications of the underlying causal treatment that was necessary to induce a detectable effect. Copyright © 2010 John Wiley & Sons, Ltd.     

Conceptualizing the Prospective Relationship Between Social Support,Stress, and Depressive Symptoms Among Adolescents

The goal of the current study is to examine the relationship amongst social support, stress, and depressive symptoms within a transactional and diathesis-stress framework using a multi-wave, longitudinal design. At the initial assessment, adolescents (n = 258) completed self-report measures assessing social support (peer, classmate, parent, and total), dependent interpersonal stress, anxious symptoms, and depressive symptoms. Additionally, participants reported stress and symptomology in each of the four waves spanning six months. Results of time-lagged, idiographic, multilevel modeling indicated that stress mediated the relationship between lower parental, classmate, and total social support and subsequent depressive, but not anxious, symptoms. In contrast, lower levels of peer support were not associated with higher levels of stress and subsequent depressive symptoms. Additionally, only classmate support deficits significantly moderated the relationship between stress and depressive symptoms. Overall, the results suggest that deficits in parental and classmate support may play a greater role in contributing to adolescent depression as compared to deficits in peer support.     

Increased perceptual and conceptual processing difficulty makes the immeasurable measurable: negative priming in the absence of probe distractors

Negative priming (NP) refers to the finding that people's responses to probe targets previously presented as prime distractors are usually slower and more error prone than to unrepeated stimuli. In a typical NP experiment, each probe target is accompanied by a distractor. It is an accepted, albeit puzzling, finding that the NP effect depends on the presence of these probe distractors; for, without probe distractors, NP diminishes. This phenomenon causes severe problems for the majority of theoretical accounts of NP. In the present study, we follow a simple argument, namely that without probe distractors, the difficulty of responding to the probe is so low that NP becomes irrelevant. Hence, by increasing perceptual processing difficulty, as well as by increasing conceptual processing difficulty, significant NP effects with constantly absent probe distractors can be reliably observed. In addition, our results also show that NP without probe distractors can be found by exclusively manipulating probe display processing. This finding furthers our understanding of the processes causing NP.     

Drugs as instruments: a new framework for non-addictive psychoactive drug use

Most people who are regular consumers of psychoactive drugs are not drug addicts, nor will they ever become addicts. In neurobiological theories, non-addictive drug consumption is acknowledged only as a "necessary" prerequisite for addiction, but not as a stable and widespread behavior in its own right. This target article proposes a new neurobiological framework theory for non-addictive psychoactive drug consumption, introducing the concept of "drug instrumentalization." Psychoactive drugs are consumed for their effects on mental states. Humans are able to learn that mental states can be changed on purpose by drugs, in order to facilitate other, non-drug-related behaviors. We discuss specific "instrumentalization goals" and outline neurobiological mechanisms of how major classes of psychoactive drugs change mental states and serve non-drug-related behaviors. We argue that drug instrumentalization behavior may provide a functional adaptation to modern environments based on a historical selection for learning mechanisms that allow the dynamic modification of consummatory behavior. It is assumed that in order to effectively instrumentalize psychoactive drugs, the establishment of and retrieval from a drug memory is required. Here, we propose a new classification of different drug memory subtypes and discuss how they interact during drug instrumentalization learning and retrieval. Understanding the everyday utility and the learning mechanisms of non-addictive psychotropic drug use may help to prevent abuse and the transition to drug addiction in the future.     

The genetic links between the big five personality traits and general interest domains

This is the first genetically informative study in which multiple informants were used to quantify the genetic and environmental sources of individual differences in general interests as well as the phenotypic and genetic links between general interests and Big Five personality traits. Self-reports and two peer ratings from 844 individuals, including 225 monozygotic and 113 dizygotic complete twin pairs, were collected. Multiple-rater scores (composites) revealed that the averaged levels of genetic and environmental effects on seven broad interest domains were similar to those on personality traits. Multivariate analyses showed that about 35% of the genetic and 9% of the environmental variance in interests were explained by personality domains, in particular by Openness. The findings suggest that interests cannot easily be considered as a byproduct of the interactions between personality genotypes and the environmental influences but rather as an internal regulation of behavior with an own genetic basis.     

To use or not to use: Expanding the view on non-addictive psychoactive drug consumption and its implications

Proposing a change to the view on psychoactive drug use in non-addicts touches a sensitive issue because of its potential implications to addiction prevention, therapeutic practice, and drug policy. Commentators raised nine questions that ranged from clarifications, suggested extensions of the model to supporting data previously not regarded, to assumptions on the implications of the model. Here, we take up the suggestions of the commentators to expand the model to behavioral addictions, discuss additional instrumentalization goals, and review the evidence from laboratory animal studies on drug instrumentalization. We consider further the role of sociocultural factors and individual development in the establishment in drug instrumentalization and addiction. Finally, we clarify which implications we think this model may have. We conclude that drug instrumentalization theory can be further applied to other behaviors but will require a sensitive debate when used for drug and addiction policy that directly affects prevention and treatment.     

Stereotypes as justifications of prejudice

Three experiments investigate how stereotypes form as justifications for prejudice. The authors created novel content-free prejudices toward unfamiliar social groups using either subliminal (Experiment 1, N = 79) or supraliminal (Experiment 2, N = 105; Experiment 3, N = 130) affective conditioning and measured the consequent endorsement of stereotypes about the groups. Following the stereotype content model, analyses focused on the extent to which stereotypes connoted warmth or competence. Results from all three experiments revealed effects on the warmth dimension but not on the competence dimension: Groups associated with negative affect were stereotyped as comparatively cold (but not comparatively incompetent). These results provide the first evidence that-in the absence of information, interaction, or history of behavioral discrimination-stereotypes develop to justify prejudice.