A Twin and Family Study of the Association Between Immune System Dysfunction and Dyslexia Using Blood Serum Immunoassay and Survey Data

We conducted a study of the association between developmental reading disability (DRD) and immune disorders (ID) using both survey and immunoassay data in two separate samples of families. One sample was made up of twins and their parents and was ascertained through a population-based sampling scheme. The other sample was a set of extended pedigrees selected for apparent autosomal dominant transmission of DRD. We failed to find an association between DRD and ID in either sample, regardless of the method used to assess immune system function. Even though our twin sample provided evidence that both DRD and immune conditions were significantly heritable, there was no evidence for a genetic correlation between ID and DRD nor was there any clear indication that a special subgroup of individuals may be comorbid for these conditions because of genetic reasons. How these negative findings can be reconciled with the developmental hypothesis of Geschwind, Behan, Galaburda, and colleagues, and how they may relate to the gene locus influencing DRD that has been recently located in the HLA region of the short arm of chromosome 6 is discussed.     

Habitual Prospective Memory and Aging: Remembering Intentions and Forgetting Actions

Routine or habitual prospective memory tasks (e.g., taking medication) have the potential for creating confusions regarding whether or not an action has already been performed. We developed a laboratory paradigm for examining the kinds of processes thought to be operating in these kinds of tasks. Younger and older participants were asked to perform an action once and only once on each of 11 trials. The results showed that age and divided attention contributed to both omission and repetition errors. This new paradigm reveals memory failures in a habitual prospective memory task, and the results demonstrate that older adults are particularly susceptible to these memory problems.     

Dilution in legal decision making: Effect of non-diagnostic information in relation to amount of diagnostic evidence

Judgments about others are often based on information that varies in terms of its diagnosticity or usefulness in predicting a certain outcome. Previous studies have demonstrated a “dilution effect” in which the addition of nondiagnostic or irrelevant information yields less extreme judgments than those based solely on diagnostic information. Two studies investigated the dilution effect in a juror decision making context in which no midpoint of a scale was provided by researchers. Study 1 examined the inclusion of positive, negative, or neutral character information in a criminal case and found that this nondiagnostic information affected attitude toward the defendant but did not “dilute” guilt judgments. The cases in Study 1 contained a larger amount of diagnostic information than studies that demonstrated the dilution effect. Thus, the amount of diagnostic evidence provided was varied in Study 2, and the results showed “diluted” judgments only when a small amount of diagnostic information was presented. Limitations to the dilution effect were discussed.     

Reasoning ability in older adults measured through letter and number series

Letter series and number series tests, consisting of items based on identical rules, were administered in a counterbalanced design to 58 persons (46 women and 12 men) between the ages of 61 and 88 years to determine their relative efficacy (relative difficulty and acceptability) as measures of inductive/deductive reasoning ability. Results indicated that letter and number series tests, in which each item in one has a same-rule counterpart in the other, were not equivalent in regard to their relative difficulty or popularity among the elderly. The number series test was significantly (p 0001) easier and more popular than its letter series counterpart. Some of the implications of these findings for assessing reasoning ability in the elderly were specified.     

Posttraining Electrical Stimulation of Vagal Afferents with Concomitant Vagal Efferent Inactivation Enhances Memory Storage Processes in the Rat

Peripherally administered or released substances that modulate memory storage, but do not freely enter the brain, may produce their effects on memory by activating peripheral receptors that send messages centrally through the vagus nerve. Indeed, vagus nerve stimulation enhances memory performance, although it is unclear whether this effect is due to the activation of vagal afferents or efferents. To eliminate the possible influence of descending fibers on memory storage processes, rats were implanted with cuff electrode/catheter systems along the left cervical vagus. Forty-eight hours following surgery, each animal received a 3.0-μl infusion (1.0 μl/min) of either lidocaine hydrochloride (75.0 mM) or isotonic saline below the point of stimulation. Animals were then trained 10 min later on an inhibitory-avoidance task with a 0.75-mA, 1.0-s foot shock. Sham stimulation or vagus nerve stimulation (0.5-ms biphasic pulses; 20.0 Hz; 30 s; 0.2, 0.4, or 0.8 mA) was administered immediately after training. Memory, tested 24 h later, was enhanced by stimulation whether descending vagus nerve fibers were inactivated or not. Both lidocaine- and saline-infused groups showed an intensity-dependent, inverted-U-shaped pattern of retention performance, with the greatest effect observed for 0.4 mA (U= 9,p< .05, andU= 7,p< .01, respectively). Additionally, animals that received lidocaine infusions, but no vagus nerve stimulation, showed impaired memory compared to the performance of saline-infused control animals (U= 11,p< .05). Together, these findings suggest that vagal afferents carry messages about peripheral states that lead to the modulation of memory storage and that the memory-enhancing effect produced by vagus nerve stimulation is not mediated via the activation of vagal efferents.     

Sterilizations reconsidered?

Cowdin and Tuohey argue for a rethinking of Catholic bioethical principles and the Church's moral authority. Citing the Second Vatican Council for support, they argue that if the Church were to respect the proper autonomy of medicine, it would allow sterilizations. In this essay I argue against Cowdin and Tuohey's understanding that the Church has derived its moral laws independent of consultation with medicine and that it treats medicine simply as a source of technical expertise. I also argue that they misunderstand that nature of autonomy as well as the Church's position regarding the type of autonomy they request for medicine. I will especially argue against their understanding of the principles of totality and double effect as "dispensations" from the moral order. I conclude that they have provided no grounds to cause the Church to reconsider its condemnation of all sterilizations.     

REEMERGENCE AND EXTINCTION OF SELF-INJURIOUS ESCAPE BEHAVIOR DURING STIMULUS (INSTRUCTIONAL) FADING

Based on results of a functional analysis indicating that the self-injurious behavior (SIB) of 3 individuals was maintained by negative reinforcement (escape from instructional situations), the effects of stimulus (instructional) fading were evaluated in a multiple baseline design across subjects. The rate of instructions was reduced to zero at the beginning of treatment and was gradually increased (faded in) across sessions as long as SIB remained low. However, if SIB remained high for 10 consecutive sessions, extinction was implemented until SIB decreased, at which point extinction was withdrawn and fading was resumed. Treatment was completed when the rate of instructions was the same as in baseline (two per minute), and SIB remained below 0.5 responses per minute for two consecutive sessions. Results showed that instructional fading (without extinction) virtually eliminated SIB initially, but these effects were not maintained. All 3 subjects required multiple exposures to extinction and over 150 treatment sessions in order to meet the end-of-treatment criteria. Advantages and limitations of fading procedures without an extinction component, as well as extensions of both interventions to other clinical problems, are discussed.     

Electrodermal activity and extraversion: Caffeine,preparatory signal and stimulus intensity effects

The Eysenck hypothesis that introverts are more and extraverts less cortically aroused has been supported by the results of most electrodermal studies, though there is some inconsistency in the literature. Further tests of the hypothesis can be carried out using arousal-manipulation paradigms. Some studies have used caffeine or stimulus intensity to increase arousal, as was also the case in the present study. The latter, however, also introduced a preparatory signal, which may be expected under certain conditions, to reduce responses to the stimulus which follows it. Extraverts and introverts were randomly assigned to receive low, medium or high doses of caffeine or a placebo. Each S then heard two sets of tones with the tones in one set preceded by a preparatory signal. Results showed that the preparatory signal reduced phasic amplitudes only at the highest levels of stimulus intensity. Introverts had higher overall SCLs and response magnitudes. In addition, the preparatory signal had little effect on extraverts, but reversed dosage-related response patterns in introverts. Results were supportive of the basic Eysenck arousal hypothesis and also showed that the arousal difference leads to attentional variability between the two groups.