Effects of Posttraining Intrahippocampal Injections of Platelet-Activating Factor and PAF Antagonists on Memory

The present experiments examined the effects of posttraining intrahippocampal injections of the degradative enzyme-resistant methylcarbamyl analog of the bioactive phospholipid platelet-activating factor (mc-PAF) and the platelet-activating factor (PAF) receptor antagonists BN52021 and BN 50730 on memory in male Long-Evans rats trained in a hidden platform version of the Morris water maze. Following an eight-trial training session, rats received a unilateral intrahippocampal injection of mc-PAF (0.5, 1.0, or 2.0 μg/0.5 μl), lyso-PAF (1.0 μg/0.5 μl), the cell surface PAF receptor antagonist BN 52021 (0.25, 0.5, or 1.0 μg/0.5 μl), the intracellular PAF receptor antagonist BN 50730 (2.0, 5.0, or 10.0 μg/0.5 μl), or vehicle (50% DMSO in 0.9% saline; 0.5 μl). On a retention test conducted 24 h after training, the escape latencies of rats administered mc-PAF (1.0 or 2.0 μg) were significantly lower than those of the vehicle-injected controls, demonstrating a memory-enhancing effect of mc-PAF. Injections of lyso-PAF, a structurally similar metabolite of PAF, had no influence on memory, indicating that the memory-enhancing effect of mc-PAF is not caused by membrane perturbation by the phospholipid. The retention test escape latencies of rats administered BN 52021 (0.5 μg) and BN 50730 (5.0 or 10 μg) were significantly higher than those of the controls, indicating a memory impairing effect of both PAF antagonists. When mc-PAF, BN 52021, or BN 50730 was administered 2 h posttraining, no effect on retention was observed, indicating a time-dependent effect of the neuroactive substances on memory storage. The findings suggest a role for endogenous PAF in hippocampal-dependent memory processes.     

The picture-superiority effect in category-association tests

In two experiments we examined the picture-superiority effect in the framework of the transfer-appropriate processing approach recently advocated by Roediger, Weldon, and Challis (1989). For the first time conceptual implicit-memory task is used, i.e., category association. In Experiment 1, subjects study a mixed list of pictures and words and then receive either a category-association test or a category-cued recall test, followed by a recognition test. The results show that performance on category-cued recall, recognition, and category-association tests are better when the material is studied in picture format. In Experiment 2, we show that producing a sentence with the material studied (picture or word) eliminates the picture-superiority effect in the implicit test, but does not eliminate picture superiority in the category-cued recall test. These results suggest that conceptually driven processing plays a critical role in category association and explicit tests of memory. The results are discussed in the framework of the transfer-appropriate processing approach to memory.     

The impact of illness on the family and the family's impact on illness

This paper discusses the influence that familial relationships can have on illness and the way in which illness can impact on the functioning of the family system. Developmental phases of illness, the family life cycle and chronic illness are all examined in relation to the family and it's functioning. The way in which health behaviours are adopted within families, and behavioural and genetic predispositions to illness are also discussed.     

Is human decision making under ambiguity guided by loss frequency regardless of the costs? A developmental study using the Soochow Gambling Task

Converging developmental decision-making studies have demonstrated that until late adolescence, individuals prefer options for which the risk of a loss is low regardless of the final outcome. Recent works have shown a similar inability to consider both loss frequency and final outcome among adults. The current study aimed to identify developmental changes in feedback-monitoring ability to consider both loss frequency and final outcome in decision making under ambiguity. Children, adolescents, and adults performed an adapted version of the Soochow Gambling Task. Our results showed that children and adolescents presented an exclusive preference for options associated with infrequent punishment. In contrast, only adults seemed to consider both loss frequency and the final outcome by favoring the advantageous options when the frequency of losses was low. These findings suggest that the ability to integrate both loss frequency and final outcome develops with age. Moreover, the analysis of strategic adjustments following gains and losses reveals that adults switch less often after losses compared with children and adolescents. This finding suggests that psychological tolerance to loss may facilitate learning the characteristics of each option and improve the ability to choose advantageously.     

The sweet smell of ... implicit helping: effects of pleasant ambient fragrance on spontaneous help in shopping malls

Some studies have shown that pleasant scent encourages the prosocial behavior of people requested for help. However, the effect of pleasant ambient odor on spontaneous helping has never been tested. Male and female confederates accidentally dropped a glove on the floor while walking in places with pleasant ambient odors (e.g., pastries) and in places with no odor. The confederate continued his/her walk, seemingly unaware of his/her loss. It was found that passers-by helped the confederates more favorably in the pleasant-smelling areas. Positive mood induced by ambient smell was used to explain such results.     

"Say it...near the flower shop": further evidence of the effect of flowers on mating

For millennia, flowers have been used to convey romance. In this study, 18-25-year-old women (N = 600) walking alone in a shopping mall were approached by an attractive 20-year-old male-confederate who solicited them for their phone number. The women were solicited as they were walking in the area of a flower shop, a cake shop, or a women's shoes shop. It was found that women agreed more favorably to the confederate's courtship solicitation when solicited in the area of the flower shop. Positive mood induced by exposure to flowers was used to explain these results.     

A neuroconstructivist model of past tense development and processing

We present a neural network model of learning and processing the English past tense that is based on the notion that experience-dependent cortical development is a core aspect of cognitive development. During learning the model adds and removes units and connections to develop a task-specific final architecture. The model provides an integrated account of characteristic errors during learning the past tense, adult generalization to pseudoverbs, and dissociations between verbs observed after brain damage in aphasic patients. We put forward a theory of verb inflection in which a functional processing architecture develops through interactions between experience-dependent brain development and the structure of the environment, in this case, the statistical properties of verbs in the language. The outcome of this process is a structured processing system giving rise to graded dissociations between verbs that are easy and verbs that are hard to learn and process. In contrast to dual-mechanism accounts of inflection, we argue that describing dissociations as a dichotomy between regular and irregular verbs is a post hoc abstraction and is not linked to underlying processing mechanisms. We extend current single-mechanism accounts of inflection by highlighting the role of structural adaptation in development and in the formation of the adult processing system. In contrast to some single-mechanism accounts, we argue that the link between irregular inflection and verb semantics is not causal and that existing data can be explained on the basis of phonological representations alone. This work highlights the benefit of taking brain development seriously in theories of cognitive development.     

Suspending Belief and Suspending Doubt: The Everyday and the Virtual in Practices of Factuality

From an ethnomethodological perspective, this article describes social actors?? everyday and virtual stances in terms of their practices of provisional doubt and belief for the purpose of fact-establishment. Facts are iterated, reinforced, elaborated, and transformed via phenomenal practices configuring relations of equipment, interpretation, and method organized as ??other?? than, but relevant to, the everyday. Such practices in scientific research involve forms of suspended belief; in other areas they can instead involve forms of suspended doubt. As an illuminating example of this latter class of virtual fact-establishment practices, I offer an extended analysis of the ??yes; and???? principle of information-establishment used in improvisational theatre to progressively develop the content of a performance.