Aphasia following a right thalamic hemorrhage

A left-handed patient with a right thalamic hemorrhage and disordered speech is described. Sequential examinations and aphasia testing were done during a 1-year follow-up period and the results are reported. This case supports those authors who have described characteristics they feel are helpful in diagnosing disordered speech associated with thalamic lesions. Paucity of speech, reduced voice volume, anomia, some paraphasia, and severe dysgraphia were present, but comprehension and repetition were relatively preserved. She showed modest improvement with time. This case also confirms that thalamic involvement in speech is a dominant, rather than a specifically left hemispheric function.     

Mood and the self-reference bias in recall

Hypotheses linking a negative recall bias (or negative self-schema) with vulnerability to depression were tested using an experimental mood-induction task. Extent of bias in student subjects was found to be unstable over a 4-month period, but different measures of memory bias within one session were highly correlated. Marginally significant correlations in the expected direction were found between estimates of recall bias and mood state, whether measured at the same or at different times. Change in mood following induction did not relate to change in bias, suggesting that the observed differences in recall are not a simple function of transient mood state alone. Equally, the initial recall bias did not predict the extent of mood shift following induction, as would be expected if a negative self-schema determined ease of mood shift in a negative direction. However, significant correlations were found between negative recall bias and self-reported frequency and severity of depression, lending equivocal support to the negative self-schema model.     

The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

The Predictors of Post-Sterilization Regret in Married Women1

We interviewed a sample of 317 married women prior to a tubal sterilization (195) or a husband's vasectomy (122) and then reinterviewed them yearly for 5 years. Using these women's responses to six questions about their feelings and desires following sterilization, we fitted a latent-variable model of post-sterilization regret to the data by means of a linear structural equation analysis. The results confirmed our view that post-sterilization regret was not a simple psychological state but rather was a complex process with different, causally linked manifestations. This process began with a renewed interest in having a baby, proceeded to the development of negative feeling about the three decisions that lead to sterilization, and concluded with a desire to reverse the surgery. This sequence was affected by the negative, post-sterilization effects of the sterilization and by the Occurrence of divorce. Next, we identified the pre-sterilization predictors of six regret variables from our model by means of a series of linear regression analyses. The major pre-sterilization predictors of the regret process included being relatively young, ambivalence about future childbearing, negative attitudes toward sterilization, dominance of the decision making by the woman's husband, and conflict with her husband during decision making. Finally, we divided the sample into quintiles on the basis of their scores on a Pre-Sterilization Predictor Scale and assessed the performance of our predictor variables as indicators of risk of regret by determining the level of negative feelings toward sterilization in each quintile. The results confirm the discriminatory power of our predictors. The overall findings indicate a number of psychological and marital issues, the exploration of which might help counselors provide anticipatory and preventative services to couples seeking sterilization.     

The flanker compatibility effect as a function of visual angle, attentional focus, visual transients, and perceptual load: a search for boundary conditions

When subjects must respond to a relevant center letter and ignore irrelevant flanking letters, the identities of the flankers produce a response compatibility effect, indicating that they are processed semantically at least to some extent. Because this effect decreases as the separation between target and flankers increases, the effect appears to result from imperfect early selection (attenuation). In the present experiments, several features of the focused attention paradigm were examined, in order to determine whether they might produce the flanker compatibility effect by interfering with the operation of an early selective mechanism. Specifically, the effect might be produced because the paradigm requires subjects to (1) attend exclusively to stimuli within a very small visual angle, (2) maintain a long-term attentional focus on a constant display location, (3) focus attention on an empty display location, (4) exclude onset-transient flankers from semantic processing, or (5) ignore some of the few stimuli in an impoverished visual field. The results indicate that none of these task features is required for semantic processing of unattended stimuli to occur. In fact, visual angle is the only one of the task features that clearly has a strong influence on the size of the flanker compatibility effect. The invariance of the flanker compatibility effect across these conditions suggests that the mechanism for early selection rarely, if ever, completely excludes unattended stimuli from semantic analysis. In addition, it shows that selective mechanisms are relatively insensitive to several factors that might be expected to influence them, thereby supporting the view that spatial separation has a special status for visual selective attention.     

Effects of background anger,provocation, and methylphenidate on emotional arousal and aggressive responding in attention-deficit hyperactivity disordered boys with and without concurrent aggressiveness

We investigated the effects of background anger, provocation, and methylphenidate on emotional, physiological, and behavioral responding in children with attentiondeficit hyperactivity disorder (ADHD) with and without concurrent aggression. Our study revealed that ADHD boys showed more emotional and physiological distress when exposed to an interaction in which an administrator chastised each boy's favorite counselor, compared to a friendly interaction between the two adults. The background anger manipulation did not affect the aggressive behavior of the boys against an opponent in an aggressive game. High-aggressive (HA) ADHD boys were more likely to respond to provocation with aggression than low-aggressive (LA) ADHD boys, but only LA boys showed increased physiological reactivity with increasing provocation. Methylphenidate resulted in increased heart rates under all conditions and did not interact with any of the other findings.This project was conducted while the first author had the support of National Institute of Alcohol Abuse and Alcoholism grant AA 06267.The authors wish to thank the staff members of the 1987 Summer Day Treatment Program who assisted in conducting this project. The authors also express their appreciation to Karen Guthrie for coordinating the medication assessment and to Hart Blanton for computer programming.     

Threshold variability in subliminal perception experiments: fixed threshold estimates reduce power to detect subliminal effects.

In studies of subliminal perception, a threshold for awareness is usually estimated for each S (e.g., the stimulus duration that yields chance discrimination performance). This article shows that if the S's true threshold varies randomly from trial to trial, estimation of a fixed threshold has important consequences. Specifically, the estimated threshold approaches the minimum of the distribution of true thresholds, and the power of an experiment to detect subliminal perception is reduced. Because there is much evidence that true thresholds vary across trials, threshold variability may have seriously weakened previous experiments that tested for subliminal perception. Fortunately, it is possible to estimate the maximum power loss resulting from threshold variability and therefore to design an experiment with acceptable power even in the presence of variability.