Postural change effects on infants' AB task performance: visual, postural, or spatial?

Smith and colleagues (Smith, L. B., Thelen, E., Titzer, R., & McLin, D. (1999). Knowing in the context of acting: The task dynamics of the A-not-B error. Psychological Review, 106, 235-260) demonstrated that 10-month-olds succeed on a Piagetian AB search task if they are moved from a sitting position to a standing position between A and B trials. These authors explained this result by suggesting that because the reach must be executed by different muscle forces from the standing position, an appropriate reach to B is programmed without the memory of the previous reach interfering with the current reach. In the main study reported here, the influences of postural and spatial factors are separated by adding a condition in which the table containing the hiding wells is moved up at the same time as the infant is shifted to standing, thereby allowing a postural change without a change in the spatial relations between the hand and hiding locations. Results showed that in both a standard control condition and the sitting-to-standing condition in which the table also moved up, performance was poor. Only in the sitting-to-standing condition in which the spatial relation between the hand and apparatus was altered were infants successful. These outcomes demonstrate that perseveration effects are likely to occur at the level of reach planning rather than at the level of execution, thereby narrowing the gap between explanations of improvements in AB performance with age that emphasize prefrontal maturation as opposed to improvements in reaching ability.     

"I've also experienced loss and fear": Effects of prior similar experience on empathy

Although it is frequently argued that empathy is increased by similar experiences, this idea has rarely been tested. This study investigated the relationship between empathy and prior similar experience. Participants read four different stories and rated the degree of empathy they felt. They also reported the extent to which they had prior similar experience of the events in the stories. We found that these self-reports of prior similar experience increased empathy for the persons in the stories. Similar experience may be an important situational antecedent for feeling empathy for another person. Pointing out similarities among experiences may be a fruitful means of training empathy.     

Discrimination Reversal Conditioning of an Eyeblink Response is Impaired by NMDA Receptor Blockade

In the present study we examined the effects of the specific NMDA receptor antagonist CPP on discrimination reversal learning in rabbits. We report two primary findings. First, the institution of NMDA receptor blockade had no effect on a learned discrimination. Second, after stimulus reversal, CPP treatment impaired acquisition of the discrimination reversal. This impairment manifested itself early in training as a retardation in acquisition of a CR to the new CS+ and late in training as an inability to suppress responsiveness to the new CS-. Given the comparability of the present results with previously published results for phenytoin-treated rabbits, we suggest that the effects of phenytoin on learning in this paradigm is at least in part mediated by its effects on NMDA receptors. We further suggest that these findings emphasize the need to better define the role of NMDA receptor activation and hippocampally-mediated circuits in a variety of associative learning paradigms.     

The Relationship Between Attitudinal Ambivalence and Desire to Quit Smoking Among College Smokers1

Growing evidence shows that attitudes can exist on a bivariate rather than a bipolar plane. This conceptualization provides a more dynamic approach to studying how attitudinal ambivalence (i. e., evaluating an attitude object as both positive and negative) affects smoking‐related behaviors. Based on a sample of 157 college smokers, we obtained preliminary validational support for a smoking‐specific felt attitudinal ambivalence scale. Felt attitudinal ambivalence correlated positively with potential for ambivalence, negative attitudes, and negative as well as positive outcome expectancies related to smoking. Smokers who felt more ambivalent reported a greater desire to quit and were more likely to be contemplators, as defined by the transtheoretical model of behavioral change. In multivariate analyses, felt ambivalence toward smoking predicted desire to quit after controlling for positive and negative attitudes and negative smoking consequences. These results provide promising support for the smoking‐specific felt‐ambivalence scale, and suggest that attitudinal ambivalence should be investigated further as a motivational mechanism to affect smoking cessation.     

Semantic Primitivism and Normativity

Kripke-Wittgenstein meaning scepticism appears as a serious threat to the idea that there could be meaning-constituting facts. Some people argue that the only viable response is to adopt semantic primitivism (SP). SP is the doctrine that meaning-facts are sui generis and irreducibly semantic. The idea is that by allowing such primitive semantic facts into our ontology Kripke's sceptical paradox cannot arise. I argue that SP is untenable in spite of its apparent resourcefulness. No version of SP can account for the normative and practical aspects of meaning while remaining non-reductive. A sparse, basic SP does not adequately deal with the sceptical paradox. A richer SP, with an added intuitive epistemology, can only explain the practical aspect of meaning by aligning itself with reductive use-based accounts of meaning. SP with essential relations between meanings and meaning-bearers could possibly avoid these problems, but we have no reason to think such a version of SP is really non-reductive. I conclude that Kripke-Wittgenstein meaning scepticism should not lead us to adopt SP, instead we should re-examine use-based, dispositionalist accounts of meaning.