HIV counselling in the national blood transfusion service

The problems caused for the NBTS by the advent of HIV are reviewed, with particular reference to the impact on blood donor numbers, the strategies adopted to minimise the risk of HIV infection through blood transfusion, and the counselling dilemmas faced by the Service in the setting of the blood donor clinic. The notification procedure for blood donors found anti-HIV positive is described, with the importance of confirmation of such results before approach to the donor emphasised. Counselling issues arising from indeterminate and false positive lest results are explored and those arising from enquiries generated by cases of possible post-transfusion HIV infection are examined.     

Acquired distinctiveness and equivalence in human discrimination learning: Evidence for an attentional process

In a first stage of training, participants learned to associate four visual cues (two different colors and two different shapes) with verbal labels. For Group S, one label was applied to both colors and another to both shapes; for Group D, one label was applied to one color and one shape, and the other label to the other cues. When subsequently required to learn a task in which a given motor response was required to one of the colors and one of the shapes, and a different response to the other color and the other shape, Group D learned more readily than Group S. The task was designed so that the associations formed during the first stage of training could not generate differential transfer to the second stage. The results are consistent, however, with the proposal that training in which similar cues are followed by different outcomes will engage a learning process that boosts the attention paid to features that distinguish these cues.     

Amodal processing of visual speech as revealed by priming

This study investigated the linguistic processing of visual speech (video of a talker's utterance without audio) by determining if such has the capacity to prime subsequently presented word and nonword targets. The priming procedure is well suited for the investigation of whether speech perception is amodal since visual speech primes can be used with targets presented in different modalities. To this end, a series of priming experiments were conducted using several tasks. It was found that visually spoken words (for which overt identification was poor) acted as reliable primes for repeated target words in the naming, written and auditory lexical decision tasks. These visual speech primes did not produce associative or reliable form priming. The lack of form priming suggests that the repetition priming effect was constrained by lexical level processes. That priming found in all tasks is consistent with the view that similar processes operate in both visual and auditory speech processing.     

A qualitative investigation exploring the motivational climate in early career sports participants: Coach,parent and peer influences on sport motivation

ObjectivesThe objectives of this research were a) to explore the applicability of ‘motivational climate’ research to early career athletes under the age of twelve, b) to re-examine the concept of ‘motivational climate’ in the light of recent scientific developments, and c) to concurrently study the influences of coaches, parents and peers on athletic motivation.Design and MethodUsing a qualitative design, 40 participants (7–11 years of age) from various sports were interviewed in focus groups, using a semi-structured format to investigate the roles played by coaches, parents, and peers in influencing athlete motivation. An inductive content analysis was conducted to determine which behaviours among these social agents influenced key motivational outcomes.FindingsThe analysis indicated that young athletes experience a motivational climate which shows consistencies with existing models of motivation; suggesting this population is worthy of further study. The influences of coaches related most strongly to the manner in which they perform their roles of instruction and assessment, whereas parents' influences were most salient in terms of the way they support the child's participation and learning. Both parents and coaches exerted influences through their leadership styles, affective responses and pre-performance behaviours. Peers influenced participants' motivation through competitive behaviours, collaborative behaviours, evaluative communications and through their social relationships.ConclusionsThis study provides an insight into the motivational climate experienced by young athletes and helps to delineate the different roles of social agents in influencing their motivation at this early stage of development.     

Differential visual field-interhemispheric transfer: can it explain sex and handedness differences in lateralization?

104 men and women were tested for visual field-hemispheric transfer of spatial information on a dot-localization task. Right-handed subjects showed significant improvement when stimuli were presented to the left visual field of the right hemisphere (LVF-RH) after practice on the same task presented to the right visual field of the left hemisphere (RVF-LH) first. No improvement was found when the task was presented in the reverse order (LVF-RH first followed by RVF-LH). It was concluded that, for right-handers, transfer of spatial information to the right hemisphere is facilitated while transfer to the left hemisphere is inhibited. Left-handed subjects demonstrated no significant improvement in either condition, suggesting inhibition or lack of transfer of spatial information in either direction. No sex differences were found in either right-handed or left-handed subjects. The findings suggest that there may be different mechanisms underlying the similarities in functional lateralization of women and left-handers.     

Role of the area postrema in three putative measures of motion sickness in the rat

After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.     

Selective attention in human associative learning and recognition memory

Four experiments examined the role of selective attention in a new causal judgment task that allowed measurement of both causal strength and cue recognition. In Experiments 1 and 2, blocking was observed; pretraining with 1 cue (A) resulted in reduced learning about a 2nd cue (B) when those 2 cues were trained in compound (AB+). Participants also demonstrated decreased recognition performance for the causally redundant Cue B, suggesting that less attention had been paid to it in training. This is consistent with the idea that attention is preferentially allocated toward the more predictive Cue A, and away from the less predictive Cue B (e.g., N. J. Mackintosh, 1975). Contrary to this hypothesis, in Experiments 3 and 4, participants demonstrated poorer recognition for the most predictive cues, relative to control cues. A new model, which is based on N. J. Mackintosh's (1975) model, is proposed to account for the observed relationship between the extent to which each cue is attended to, learned about, and later recognized     

A Multivariate Multilevel Approach to the Modeling of Accuracy and Speed of Test Takers

Response times on test items are easily collected in modern computerized testing. When collecting both (binary) responses and (continuous) response times on test items, it is possible to measure the accuracy and speed of test takers. To study the relationships between these two constructs, the model is extended with a multivariate multilevel regression structure which allows the incorporation of covariates to explain the variance in speed and accuracy between individuals and groups of test takers. A Bayesian approach with Markov chain Monte Carlo (MCMC) computation enables straightforward estimation of all model parameters. Model-specific implementations of a Bayes factor (BF) and deviance information criterium (DIC) for model selection are proposed which are easily calculated as byproducts of the MCMC computation. Both results from simulation studies and real-data examples are given to illustrate several novel analyses possible with this modeling framework. The authors thank Steven Wise, James Madison University, and Pere Joan Ferrando, Universitat Rovira i Virgili, for generously making available their data sets for the empirical examples in this paper.