A more complete task-set reconfiguration in random than in predictable task switch

Three experiments are presented that compare the cost found when switching from one task to another in two different conditions. In one of them, the tasks switch in predictable sequences. In the other condition, the tasks alternate at random. A smaller time cost is found in the random-switch condition when enough preparation time is allowed. Such an effect is due to the random-switch cost continuing to decrease with preparation time after the predictable-switch cost has reached an asymptote. Although the relationship between number of repetitions of one task and time cost is different in the random- and the predictable-switch conditions, only the latter shows the presence of an "exogenous" component of cost. The implications of this finding are discussed in relationship with the usual distinction between an endogenous component of switch cost that is affected by preparation time and another exogenous, residual component (e.g., Rogers & Monsell, 1995). It is proposed that a different kind of task-set preparation is at work when tasks alternate at random.     

Predictors of the International HIV–AIDS INGO Network Over Time

The HIV–AIDS epidemic is one of the most challenging and significant health crises facing the world today. In order to cope with its complexities, the United Nations and World Health Organization have increasingly relied upon the resources offered by networks of HIV–AIDS nongovernmental organizations (NGOs). The research reported here uses evolutionary theory to predict the patterns of alliances and collaborations within the HIV–AIDS International Nongovernmental Organizations (INGO) network. The hypotheses are tested using 8 years of data from the Yearbook of International Organizations. The results showed that geographic proximity and common ties with intergovernmental organizations (IGOs) predict the pattern of alliances among HIV–AIDS INGOs. The best predictor of such alliances, however, is past relationships among these organizations.     

Interaction between preexposure and overshadowing: Further analysis of the extended comparator hypothesis

Three experiments with rats used conditioned suppression of barpress to test predictions of the extended comparator hypothesis, which assumes that the effectiveness of (first-order) comparator stimuli in modulating responding to a target conditioned stimulus (CS) is itself modulated by other (second-order) comparator stimuli. Experiment 1 demonstrated that both pretraining exposure to the target CS alone (i.e., CS-preexposure effect, also known as latent inhibition) and pretraining exposure to a compound of the target CS and nontarget CS (i.e., compound-CS-preexposure effect) counteract overshadowing, and that posttraining deflation (i.e., extinction) of the overshadowing stimulus attenuates responding to the target CS when overshadowing is preceded by a CS-preexposure treatment (i.e., yields a CS-preexposure effect), but not when overshadowing is preceded by a compound-CS-preexposure treatment. Experiment 2 examined the consequences of posttraining associative inflation of the overshadowing stimulus or the preexposure companion stimulus following conjoint compound-CS-preexposure and overshadowing treatment. Experiment 3 examined the consequences of posttraining inflation of the overshadowing stimulus or the context following conjoint CS-alone preexposure and overshadowing treatment. The results support the expression-focused comparator view in contrast to recent acquisition-focused models of retrospective revaluation.     

With Fellow Travelers to Nodal Places: Reply to Dajani,Doñas,and Peltz

In this response to the useful discussions of my paper by Peltz, Dajani, and Doñas (this issue), I emphasize the complexity of the intersections that lie at juncture of the personal and the social registers of the unconscious, problematizing conventional notions of “internal” and “external.” Additionally, I draw out a distinction between the political and politics as regards psychoanalytic practice, and suggest that this practice can fruitfully occur in places beyond the consulting room.