Can semantic information be transferred between hemispheres in the split-brain?

Data from experiments with split-brain patients, who have had their left and right hemispheres disconnected, suggests a remarkable specialization of function within each hemisphere. At the same time, these patients conduct their daily lives with great proficiency. This ability suggests that some information integral to coordinated function between the hemispheres is available in the absence of the corpus callosum. Is information about the semantics of words one type of information that is shared? An experiment by suggests that it may be. Lambert reported that living/nonliving word categorization was delayed when disconnected hemispheres processed words belonging to the same category. Although other interpretations are plausible, Lambert described this effect as having a semantic source. We attempted to replicate the original effect with two additional split-brain patients, J.W. and V.P., and to extend the original design to clarify the source of the putative semantic effect. Our results indicate that any semantic interaction between the split hemispheres is not reliable. As such our study adds to the growing literature indicating that subcortical transfer of semantic information is more illusory than real.     

Body esteem and body fat in British school children from different ethnic groups

The aim of the study was to examine the relationship between body esteem and body fat in British school children. Two hundred and seventy seven, 11–14-year-old children from central England took part in the study. Body esteem was measured using the Body Esteem Scale for children and percent body fat was determined by skin-fold measures. Results indicate that body esteem and adiposity were negatively related for the whole sample, for boys and girls and for White children, Black children and Asian children. Factorial ANOVA also indicated differences in body esteem according to gender and ethnicity. Boys and Black children had significantly higher body esteem than girls and Asian children respectively. Differences in body fat were also evident according to gender with boys being leaner than girls. No differences in body esteem or body fat were evident across school years.     

Attachment categories as reflections of multiple dimensions: comment on Fraley and Spieker (2003)

Ainsworth's system of classifying patterns of attachment behavior has served the field well and will not be easily displaced--not because of a commitment by attachment researchers to the taxonomic status of these categories but rather because of difficulties lying in the way of a dimensional approach. Foremost among these is the large number of dimensions used in making classifications and the need to develop reliable scales to tap them. Other problems include the need to capture how behavior changes across age and across the episodes of the Strange Situation. Others will debate R.C. Fraley and S.J. Spieker's (2003) arguments concerning taxonomic status. However, whether taxa or not, Ainsworth's categories at the least have represented well the multidimensional space underlying attachment behavior in conditions of mild stress. Only when an alternative approach is demonstrated to predict (with equal power, in practice) the vast range of outcomes associated with Ainsworth's categories will it be a candidate for substitution.     

Alcohol intoxication and self-aggressive behavior

Nonexperimental field studies have demonstrated an association between alcohol intoxication and self-aggressive behaviors across the spectrum of lethality. Although these results are suggestive, it is not yet known whether alcohol intoxication is causally related to self-aggression. The authors therefore experimentally examined the effects of alcohol intoxication (mean blood alcohol concentration of .10) on a behavioral measure of self-aggression in men (N = 40). After consuming either an alcohol or a placebo drink, participants were provided the opportunity to self-administer shock during a task disguised as a reaction-time game, with self-aggression defined by the intensity of shock chosen. Half of the participants observed a self-aggressive model (a potential moderator of alcohol-related self-aggression). Independent alcohol and model effects were found, with alcohol accounting for over 30% of the self-aggression variance.     

The time course and significance of cannabis withdrawal

Withdrawal symptoms following cessation of heavy cannabis (marijuana) use have been reported, yet their time course and clinical importance have not been established. A 50-day outpatient study assessed 18 marijuana users during a 5-day smoking-as-usual phase followed by a 45-day abstinence phase. Parallel assessment of 12 ex-users was obtained. A withdrawal pattern was observed for aggression, anger, anxiety, decreased appetite, decreased body weight, irritability, restlessness, shakiness, sleep problems, and stomach pain. Onset typically occurred between Days 1-3, peak effects between Days 2-6, and most effects lasted 4-14 days. The magnitude and time course of these effects appeared comparable to tobacco and other withdrawal syndromes. These effects likely contribute to the development of dependence and difficulty stopping use. Criteria for cannabis withdrawal are proposed.     

Motivating operations and terms to describe them: some further refinements

Over the past decade, behavior analysts have increasingly used the term establishing operation (EO) to refer to environmental events that influence the behavioral effects of operant consequences. Nonetheless, some elements of current terminology regarding EOs may interfere with applied behavior analysts' efforts to predict, control, describe, and understand behavior. The present paper (a) describes how the current conceptualization of the EO is in need of revision, (b) suggests alternative terms, including the generic term motivating operation (MO), and (c) provides examples of MOs and their behavioral effects using articles from the applied behavior analysis literature.