Spatial behaviour of normal and septal rats on alternate route maze problems

The behaviour of normal rats and rats with lesions of the septum was compared on a variety of alternate route variations of the three-table problem. In all variations of the task, septal rats were impaired on test trial performance when they displayed stereotypic body turn responses and demonstrated a strong preference for the most direct route between tables both during exploration and testing in all conditions. Normal rats displayed a similar route choice tendency in the simplest situations but shifted route choice behaviour in the most complex configuration, when they chose the inner, but longer, path. The use of the inner path may have allowed delayed-choice, single-point reference orientation, or reduction in the number of available alternatives. It is concluded that normal rats form a cognitive representation that allows them to identify environmental factors likely to facilitate solution, whereas septal rats rely on “taxon”-type strategies that can combine guidances and orientational responses.     

The Menace of Non-Being

In the face of unremitting faith in economic progress and the attendant environmental degradation that is, increasingly, one of its ugly fruits, Jürgen Moltmann’s rich conception of God’s Sabbath peace offers a compelling reorientation. When drawn upon for its contribution toward the fostering of one’s moral imagination and for the cultivation of ethical criteria, it offers an accessible yet rigorous lens through which to view a particular situation: the attempt by Nestlé Waters to build the largest bottled water plant in North America. The author finds within Moltmann’s vision a way to critically assess the project, critique the underlying foundations of its character, and offer alternatives for seeking the flourishing of the whole of God’s creation.     

Forgotten variables in memory theory and research

Abstract

Memory research, like other scientific research, disregards many variables in order to bring the full force of the scientific method to bear on clearly important variables. The reasons why memory research attends to certain variables and disregards others emanate largely from theoretical assumptions that distinguish memory systems from other psychological systems, and that distinguish variables intrinsic to memory from those extrinsic to memory. Nevertheless, a number of these ‘forgotten’ variables affect memory performance. Regardless of past practice, it is a mistake for memory research to continue to ignore relevant variables. Doing so introduces measurement error that contaminates memory performance measures, and classification error that precludes the discovery of legitimate memory variables. It is proposed here that if forgotten memory variables are controlled, manipulated, and measured more extensively, then future memory research will have greater power and memory theories will have greater validity.     

A comparison of temperament in nonhuman apes and human infants

The adaptive behavior of primates, including humans, is often mediated by temperament. Human behavior likely differs from that of other primates in part due to temperament. In the current study we compared the reaction of bonobos, chimpanzees, orangutans, and 2.5-year-old human infants to novel objects and people - as a measure of their shyness-boldness, a key temperamental trait. Human children at the age of 2.5 years avoided novelty of all kinds far more than the other ape species. This response was most similar to that seen in bonobos and least like that of chimpanzees and orangutans. This comparison represents a first step in characterizing the temperamental profiles of species in the hominoid clade, and these findings are consistent with the hypothesis that human temperament has evolved since our lineage diverged from the other apes in ways that likely have broad effects on behavior. These findings also provide new insights into how species differences in ecology may shape differences in temperament.     

Phase-locking and amplitude modulations of EEG alpha: Two measures reflect different cognitive processes in a working memory task

It has been demonstrated in numerous experiments that oscillatory EEG responses in the alpha frequency band (8-12 Hz) increase with memory load during the retention interval in working memory tasks. However, the findings diverge with respect to which measurement of alpha activity is influenced by memory processes. Here, we differentiate between evoked and total alpha activity in order to separate effects of phase-locking and amplitude modulation. We present data from a delayed-matching-to-sample task (S1-S2 paradigm) for which we compared EEG alpha responses between a perception and a memory condition. Increased total alpha activity was found in the retention interval for the memory as compared to the perception condition. Evoked alpha activity, however, did not differentiate between memory and perception conditions but, instead, was increased for the more complex condition of processing non-Kanizsa figures as compared to Kanizsa figures. Thus, our results demonstrate a functional differentiation between evoked and total alpha activity. While alpha phase locking seemed to be influenced mainly by task complexity, alpha amplitude clearly reflected memory demands in our paradigm.     

Apes' use of iconic cues in the object-choice task

In previous studies great apes have shown little ability to locate hidden food using a physical marker placed by a human directly on the target location. In this study, we hypothesized that the perceptual similarity between an iconic cue and the hidden reward (baited container) would help apes to infer the location of the food. In the first two experiments, we found that if an iconic cue is given in addition to a spatial/indexical cue - e.g., picture or replica of a banana placed on the target location - apes (chimpanzees, bonobos, orangutans, gorillas) as a group performed above chance. However, we also found in two further experiments that when iconic cues were given on their own without spatial/indexical information (iconic cue held up by human with no diagnostic spatial/indexical information), the apes were back to chance performance. Our overall conclusion is that although iconic information helps apes in the process of searching hidden food, the poor performance found in the last two experiments is due to apes' lack of understanding of the informative (cooperative) communicative intention of the experimenter.     

Improving retrieval

The present research investigated whether ability for retrieval might be improved by practice at retrieval. Retrieval practice trials, each of 10 min duration, required subjects to attempt to recall as many examples as possible of a designated category. Two kinds of practice were investigated. Subjects given general practice attempted to recall a different category on each successive practice trial. Subjects given specific practice attempted to recall the same category on each successive practice trial. General practice had a negligible effect on recall, even when subjects practised daily for over a month. In contrast, specific practice substantially improved recall, facilitating retrieval of 50 to 100 per cent of all the example subjects known for a category.     

Axiomatization of the De Morgan type rules

In Section 1 we show that the De Morgan type rules (= sequential rules in L(, ) which remain correct if and are interchanged) are finitely based. Section 2 contains a similar result for L(). These results are essentially based on special properties of some equational theories.