Cognitive Bias to Internal Sources of Information in Anxiety

Discrepancies between (a) self-reported psychosomatic symptoms and (b) actual fitness under non-stress (Study 1), as a function of trait anxiety, were examined, as well as discrepancies between (a) self-reported cognitive and somatic state anxiety and (b) objective measures of behavioural reactivity, physiological arousal, and performance under social-evaluative stress (Study 2). Results indicated that persons high in trait anxiety exaggerated distress in both conditions: They showed disproportionately greater self-reported concerns than actual problems. In contrast, those low in anxiety minimized distress (lower self-reported than actual problems). These discrepancy phenomena are explained in terms of biases in the processing of internal sources of information.     

Predictive inferences take time to develop

In order to determine the time course of inferences about predictable events, predicting or control contexts were presented, followed by a target word (Exps. 1A, B, and C) or a continuation sentence (Exp. 2) that confirmed or disconfirmed the predicted event. Relative to the control condition, under the predicting condition there was facilitation in naming the confirming target words 1500 ms after the onset of the last word in the context (Exp. 1C), but not after 500 ms (Exp. 1A), and only a tendency after 1000 ms (Exp. 1B). In addition, there was facilitation in reading the post-target and final regions of the continuation sentence that confirmed the predicted event, as well as inhibition when the predicted event was disconfirmed, but no effect was observed on the target word itself (Exp. 2). It is concluded that, when the predicted event is highly constrained by the context, predictive inferences are likely to be drawn on-line, but they take time to construct. Received: 14 January 1998 / Accepted: 21 April 1998     

Behavioral profile of amisulpride in agonistic encounters between male mice

Amisulpride is a substituted benzamide derivative that acts as a selective dopamine D2/D3 receptor antagonist. Although the anti‐aggressive properties of neuroleptic drugs are well known, the effects of amisulpride on agonistic interactions have not been explored, and there are no studies comparing acute and subchronic effects of this compound on aggression in rodents. In this study, we examined the action of amisulpride (5–25 mg/kg, i.p), administered acutely or subchronically for 10 days, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic "standard opponents" 30 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. After acute treatment, amisulpride (5–20 mg/kg) exhibited an ethopharmacological profile characterized by a marked decrease of offensive behaviors (threat and attack) without an impairment of motor activity. By contrast, the anti‐aggressive action of the highest dose used (25 mg/kg) was accompanied by a weak increase of immobility. Body care was also significantly enhanced after treatment with the drug (20 and 25 mg/kg), emphasizing the involvement of dopaminergic receptors in this behavior. After subchronic treatment, no tolerance to amisulpride anti‐aggressive activity was observed. Overall, this behavioral profile is similar to that observed by other atypical neuroleptics. Aggr. Behav. 25:225–232, 1999. © 1999 Wiley‐Liss, Inc.     

Impact of artificial fissioning and social networks on levels of aggression and affiliation in primates

Levels of aggression may be affected by stability of social relationships or by population density. A number of studies of nonhuman primates have indicated that spatial density influences agonistic activity levels less than does social density. Artificial fissioning of a captive troop of rhesus macaques was undertaken and the resultant differences in patterns of aggression and affiliation were examined. If population density has a major effect on levels of aggression, then fissioning will result in a decrease in aggression; if social stability has a major effect on levels of aggression, then fissioning is likely to be accompanied by an increase in aggression. An increase in rates of both aggressive and affiliative behavior resulted from artificial troop fissioning. These findings concur with other studies that have concluded that social stability is a more important determinant of primate aggression than is population density. Nonhuman primates use affiliative mechanisms to adjust their behavior when population density increases such that potentially adverse consequences of crowding are avoided.     

Transposed-letter and laterality effects in lexical decision

Two divided visual field lexical decision experiments were conducted to examine the role of the cerebral hemispheres in transposed-letter similarity effects. In Experiment 1, we created two types of nonwords: nonadjacent transposed-letter nonwords (TRADEGIA; the base word was TRAGEDIA, the Spanish for TRAGEDY) and two-letter different nonwords (orthographic controls: TRATEPIA). In Experiment 2, the controls were one-letter different nonwords (TRAGEPIA) instead of two-letter different nonwords (TRATEPIA). The effect of transposed-letter similarity was substantially greater in the right visual field (left hemisphere) than in the left visual field. Furthermore, nonwords created by transposing two letters were more competitive than the nonwords created by substituting one or two letters of a target word. We examine the implications of these findings for the models of visual word recognition.     

Do Internet‐Based Support Interventions Change Perceptions of Social Support?: An Experimental Trial of Approaches for Supporting Diabetes Self‐Management

Internet-based support groups are a rapidly growing segment of mutual aid programs for individuals with chronic illnesses and other challenges. Previous studies have informed us about the content of online exchanges between support group members, but we know little about the ability of these interventions to change participants' perceptions of support. A randomized trial of 160 adult Type 2 diabetes patients provided novice Internet users with computers and Internet access to 1 of 4 conditions: (a) diabetes information only, (b) a personal self-management coach, (c) a social support intervention, or (d) a personal self-management coach and the support intervention. After 3 months, individuals in the 2 support conditions reported significant increases in support on a diabetes-specific support measure and a general support scale. Participants' age was significantly related to change in social support, but intervention effects were still significant after accounting for this relationship. This report is a critical first step in evaluating the long-term effects of Internet-based support for diabetes self-management. The discussion identifies directions for future research.     

Effects of spatial attention on detection and identification of oriented lines

In this paper, we study the effects of spatial attention on detection and identification of oriented lines presented at near-threshold luminance. In the first experiment, we found that the cuing effect was greater when observers had to discriminate between two close orientations than when they had to discriminate between two far-apart orientations. In the second experiment, we examined the effects of peripheral cues on summation of low-contrast oriented lines. We found that the range of orientations within which summation occurred was greater when the cues were invalid than when they were valid. Our results suggest that attention to a specific location in the visual field modulates the neural channels which code orientation in at least two different ways: (a) spatial attention increases the responsivity of these channels to stimuli presented at this location, and (b) it reduces the bandwidths or ranges of orientations to which these channels are sensitive. These results suggest that the properties of the orientation-tuned channels, including those that seem to exert their effects at early stages of orientation processing (e.g., tuning function), may not be fixed, but rather vary according to the attention being paid to the spatial region within which the target stimulus is presented.     

Eye movements and processing stages in reading: relative contribution of visual,lexical, and contextual factors

The independent and the combined influence of word length, word frequency, and contextual predictability on eye movements in reading was examined across processing stages under two priming-context conditions. Length, frequency, and predictability were used as predictors in multiple regression analyses, with parafoveal, early, late, and spillover eye movement measures as the dependent variables. There were specific effects of: (a) length, both on where to look (how likely a word was fixated and in which location) and how long to fixate, across all processing stages; (b) frequency, on how long to fixate a word, but not on where to look, at an early processing stage; and (c) predictability, both on how likely a word was fixated and for how long, in late processing stages. The source of influence for predictability was related to global rather than to local contextual priming. The contribution of word length was independent of contextual source. These results are relevant to determine both the time course of the influence of visual, lexical, and contextual factors on eye movements in reading, and which main component of eye movements, that is, location or duration, is affected.