Mathematical logic: Tool and object lesson for science

The object lesson concerns the passage from the foundational aims for which various branches of modern logic were originally developed to the discovery of areas and problems for which logical methods are effective tools. The main point stressed here is that this passage did not consist of successive refinements, a gradual evolution by adaptation as it were, but required radical changes of direction, to be compared to evolution by migration. These conflicts are illustrated by reference to set theory, model theory, recursion theory, and proof theory. At the end there is a brief autobiographical note, including the touchy point to what extent the original aims of logical foundations are adequate for the broad question of the heroic tradition in the philosophy of mathematics concerned with the nature of the latter or, in modern jargon, with the architecture of mathematics and our intuitive resonances to it.     

The Ethnic Mentor Undergraduate Program: A Brief Description and Preliminary Findings

The Ethnic Mentor Undergraduate (EMU) Program targets students from traditionally underrepresented ethnic backgrounds and aims at fostering skills and attitudes necessary to persist to graduation. Findings indicate that EMU protégés perform better than the university-wide average and that drop-out rates are reduced. Implications for mentoring programs are discussed.     

The picture superiority effect in a cross-modality recognition task

Words and pictures were studied, and recognition tests were given in which each studied object was to be recognized in both word and picture format. The main dependent variable was the latency of the recognition decision. The purpose was to investigate the effects of study modality (word or picture), of congruence between study and test modalities, and of priming resulting from repeated testing. Experiments 1 and 2 used the same basic design, but the latter also varied retention interval. Experiment 3 added a manipulation of instructions to name studied objects, and Experiment 4 deviated from the others by presenting both picture and word referring to the same object together for study. The results showed that congruence between study and test modalities consistently facilitated recognition. Furthermore, items studied as pictures were more rapidly recognized than were items studied as words. With repeated testing, the second instance was affected by its predecessor, but the facilitating effect of picture-to-word priming exceeded that of word-to-picture priming. The findings suggest a two-stage recognition process, in which the first is based on perceptual familiarity and the second uses semantic links for a retrieval search. Common-code theories that grant privileged access to the semantic code for pictures or, alternatively, dual-code theories that assume mnemonic superiority for the image code are supported by the findings. Explanations of the picture superiority effect as resulting from dual encoding of pictures are not supported by the data.     

Enhanced Hippocampal CA1 LTP but Normal Spatial Learning in Inositol 1,4,5-trisphosphate 3-kinase(A)-Deficient Mice

To define the physiological role of IP₃3-kinase(A) in vivo, we have generated a mouse strain with a null mutation of the IP₃3-kinase(A) locus by gene targeting. Homozygous mutant mice were fully viable, fertile, apparently normal, and did not show any morphological anomaly in brain sections. In the mutant brain, the IP₄ level was significantly decreased whereas the IP₃ level did not change, demonstrating a major role of IP₃3-kinase(A) in the generation of IP₄. Nevertheless, no significant difference was detected in the hippocampal neuronal cells of the wild-type and the mutant mice in the kinetics of Ca²⁺ regulation after glutamate stimulation. Electrophysiological analyses carried out in hippocampal slices showed that the mutation significantly enhanced the LTP in the hippocampal CA1 region, but had no effect on the LTP in dentate gyrus (DG). No difference was noted, however, between the mutant and the wild-type mice in the Morris water maze task. Our results indicate that IP₃3-kinase(A) may play an important role in the regulation of LTP in hippocampal CA1 region through the generation of IP₄, but the enhanced LTP in the hippocampal CA1 does not affect spatial learning and memory.     

Using bifactor models to identify faking on Big Five questionnaires

To identify faking, bifactor models were applied to Big Five personality data in three studies of laboratory and applicant samples using within‐subjects designs. The models were applied to homogenous data sets from separate honest, instructed faking, applicant conditions, and to simulated applicant data sets containing random individual responses from honest and faking conditions. Factor scores from the general factor in a bifactor model were found to be most highly related to response condition in both types of data sets. Domain factor scores from the faking conditions were found less affected by faking in measurement of Big Five domains than summated scale scores across studies. We conclude that bifactor models are efficacious in assessing the Big Five domains while controlling for faking.     

Anxiety, depressed mood, self-esteem, and traumatic stress symptoms among distant witnesses of the 9/11 terrorist attacks: transitory responses and psychological resilience

Posttraumatic stress related to the September 11, 2001 terrorist attacks and general psychological distress were examined in six cohorts of college students (N=5412) enrolled at an American public university between Spring 2000 and Fall 2002 some 2,500 miles from New York. Consistent with data from Schuster et al.'s (2001) national survey, which used a very low threshold criterion, our findings revealed that 44% of women and 32% of men experienced at least one symptom of posttraumatic stress 6-17 days after the attacks. In contrast to these results, depression levels showed only small differences, and self-esteem and trait anxiety showed no changes. Findings indicate that 9/11-related stress responses among distant witnesses were very mild, transitory and focused in scope, suggesting resilience with respect to broader psychological and psychopathological reactions. Findings are discussed with respect to the role of physical and psychological proximity on the reactions to traumatic events in the general population.