A note on russell's paradox in locally cartesian closed categories

Working in the fragment of Martin-Löfs extensional type theory [12] which has products (but not sums) of dependent types, we consider two additional assumptions: firstly, that there are (strong) equality types; and secondly, that there is a type which is universal in the sense that terms of that type name all types, up to isomorphism. For such a type theory, we give a version of Russell's paradox showing that each type possesses a closed term and (hence) that all terms of each type are provably equal. We consider the kind of category theoretic structure which corresponds to this kind of type theory and obtain a categorical version of the paradox. A special case of this result is the degeneracy of a locally cartesian closed category with a morphism which is generic in the sense that every other morphism in the category can be obtained from it via pullback.The financial support of the Royal Society in London is gratefully acknowledged.     

Independence of uniphasic and biphasic audiogenic seizure progressions in mice

DBA/2J mice were monaurally or binaurally tested for susceptibility to sound-induced seizure. Two seconds following the beginning of running, one group of binaurally tested mice had acoustic stimulation interrupted for 15 s. These mice later seized when the stimulation was readministered. Their seizure progression closely resembled the behavior exhibited by noninterrupted binaurally stimulated mice and did not shift to the biphasic motor pattern of monaurally stimulated subjects. We conclude that the single burst of running of a binaurally tested mouse is qualitatively different from either of the two bursts of running exhibited by monaurally tested mice.     

Microinjections of leupeptin in the frontal cortex or dorsal hippocampus block spatial learning in the rat

Adult male Long-Evans hooded rats were given bilateral microinjections of 18 mM leupeptin or saline through cannulae implanted with tips aimed at the frontal cortex or CA1 or CA3 hippocampal cell fields. Five minutes following injections animals were allowed to complete an eight-arm radial maze. The acquisition criterion required that the animal make 7 correct choices of the first 8, and 8 correct choices of the first 10, for five consecutive sessions. Leupeptin slowed acquisition of the eight-arm radial maze task when injected into the CA1 and CA3 hippocampal fields or the frontal cortex, but did not influence spontaneous activity. These results suggest that earlier reports of the amnestic effect of leupeptin when administered into the lateral cerebral ventricle may have been due to effects within the cortex and hippocampus. The present experiment represents the first attempt to identify behaviorally those brain areas in which leupeptin acts to alter learning.     

Effects of anterior or dorsomedial thalamic ibotenic lesions on learning and memory in rats

Sprague-Dawley rats were used to study the effects of ibotenic acid lesions of the anterior (A.Th.) and the dorsomedial (MD) thalamic nuclei on learning and memory. Memory was assessed by employing a temporal alternation task in a straight alley with varying intertrial intervals. In addition, spatial orientation and response flexibility were evaluated on a radial maze and on a spatial reversal task (SSDR). The results indicated that MD rats required more trials to learn the temporal alternation task and exhibited impaired performance compared to A.Th. and control groups at the shortest delay (15 s). In contrast, compared to the control group, A.Th. subjects which required less trials to master the task and exhibited normal performance at the 15-s delay were impaired when the intertrial interval was increased to 45 s. Whatever the lesion, no impairments were found in the SSDR or the radial maze while only MD lesions were found to result in a night hyperactivity associated with greater food and water consumptions. These findings indicate that A.Th. and MD are differentially involved in learning and memory processes. It is suggested that the MD is mostly involved in registering new information while the A.Th. plays a role in the maintenance of information over time.     

Effects of attentional focusing on pain perception

Two experiments were conducted to examine the hypothesized differential effectiveness of two attentional focusing strategies in pain perception. In the first experiment, subjects (72 male college students) rated their levels of pain after being exposed to either low- or high-intensity pressure stimulation for 75 s. Subjects were instructed to use either an external or internal focus of attention during the pain induction. Results revealed that external focusing was more effective for coping than internal focusing across both levels of stimulus intensity. The second experiment was a replication of the first, and featured bolstered internal focusing and stimulus intensity manipulations. Results showed that high-intensity stimulation produced higher pain ratings than did low-intensity stimulation for subjects in the internal focusing conditions, but not for those in the external focusing conditions. The findings support the power of distraction strategies for dealing with short-term pain with a rapid onset. Theoretical implications are discussed.The authors thank Darwyn E. Linder and Daniel M. Landers for their help in development of this research. The authors are also indebted to Sarah Colley, Jona Davis, Nanci Neuberger, and Rebecca Roberts for their assistance in data collection.     

Parent attributions of emotion to their children and the cues children use in perceiving their own emotions

A number of studies have demonstrated stable individual differences in the cues that generate emotions and other feeling states. These differences are assumed to arise from the cues parents use to identify their children's emotional states. As children learn about their own emotional states, they come to rely on these same cues. To test one implication of their view, the facial expressions of children (N=41) were manipulated and their feelings assessed. Some children reported emotions consistent with their expressions, while others reported emotions appropriate to the situation. In a separate procedure, their mothers were asked to identify the emotional states of children whose expressions were inconsistent with an account of their circumstances. Mothers who paid more attention to their children's expressive behavior had children who were more responsive to their own expressive behavior. In contrast, the mothers who were more responsive to situational cues had children whose emotions arose from the situational cues as well.The authors would like to thank numerous teachers and administrators of the Worcester Public School system in Worcester, Massachusetts, for their assistance.     

Political and Nonpolitical Authority in Values Education

This article is an examination of the political (public consensus) and nonpolitical authority as a basis for values education in a democratic society. The author advocates that nonpolitical authority can be a basis for defending the teaching of values in public schools.     

Mental Health Values and Response to Alcoholism Treatment

Mental health values consist of the subset of values that refer to what constitutes good mental health. Torrey (1972) suggested that agreement between patient and therapist about such values may influence psychotherapy outcome. The authors found mixed support for this hypothesis using a sample of 100 chemical dependency inpatients. Positive treatment effects were associated with pretreatment agreement between counselor and patient about some mental health values, but with pretreatment disagreement about others. Because outcome measures assess general personality functioning, the authors suggest that attitudes about what constitutes good mental health may predict general psychotherapy effects as well as response to alcoholism treatment.