Beta1-adrenoceptor or alpha1-adrenoceptor activation initiates early odor preference learning in rat pups: support for the mitral cell/cAMP model of odor preference learning

We proposed that mitral cell beta1-adrenoceptor activation mediates rat pup odor preference learning. Here we evaluate beta1-, beta2-, alpha1-, and alpha2-adrenoceptor agonists in such learning. The beta1-adrenoceptor agonist, dobutamine, and the alpha1-adrenoceptor agonist, phenylephrine, induced learning, and both exhibited an inverted U-curve dose-response relationship to odor preference learning. Phenylephrine-induced learning occurred in the presence of propranolol to prevent indirect activation of beta-adrenoceptors. Alpha1-adrenoceptor mediation may represent a novel mechanism inducing learning or may increase cAMP in mitral cells via indirect activation of GABA(B) receptors. Neither the beta2-adrenoceptor agonist, salbutamol, nor the alpha2-adrenoceptor agonist, clonidine, induced learning.     

MATLAB and graphical user interfaces: Tools for experimental management

MATLAB is a convenient platform for the development and management of psychological experiments because of its easy-to-use programming language, sophisticated graphics features, and statistics and optimization tools. Through implementation of the Brainard-Pelli Psychophysics Toolbox, the MATLAB user gains close temporal and spatial control over the CRT, while retaining the simplicity of an interpreted language conducive to rapid program development. MATLAB’s abilities can be further utilized through easily programmable graphical user interfaces (GUIs). We illustrate how a GUI can serve as a powerful and intuitive tool for organizing and controlling all aspects of a psychological experiment, including design, data collection, data analysis, and theory fitting.     

Guilty but mentally ill: An alternative verdict

Despite opposition from professional groups such as the American Psychiatric Association and the American Bar Association, “Guilty But Mentally Ill” (GBMI) statutes now exist in at least 12 states and are being considered in others. This paper reviews the development of the GBMI alternative to the insanity defense from a historical perspective, focusing especially on the reasons for its development in Michigan, the first state to pass GBMI legislation over 9 years ago. Using the Michigan experience, the GBMI statute is reviewed in terms of its perceived purpose and its success in accomplishing that purpose. Then recommendations for future changes are made.     

pCREB in the neonate rat olfactory bulb is selectively and transiently increased by odor preference-conditioned training

Early olfactory preference learning in rat pups occurs when novel odors are paired with tactile stimulation, for example stroking. cAMP-triggered phosphorylation of cAMP response element binding protein (pCREB) has been implicated as a mediator of learning and memory changes in various animals (Frank and Greenberg 1994). In the present study we investigate whether CREB is phosphorylated in response to conditioned olfactory training as might be predicted given the proposed role of the phosphorylated protein in learning. On postnatal day 6, pups were trained for 10 min using a standard conditioned olfactory learning paradigm in which a conditioned stimulus, Odor, was either used alone or paired with an unconditioned stimulus, Stroking (using a fine brush to stroke the pup). In some instances stroking only was used. The pups were sacrificed at 0, 10, 30, or 60 min after the training. Using Western blot analysis, we observed that the majority of olfactory bulbs in conditioned pups (Odor + Stroking) had a greater increase in pCREB activation at 10 min after training than pups given nonlearning training (Odor only or Stroking only). The phosphorylated protein levels were low at 0 min and at 60 min after training. This is in keeping with the slightly delayed and short-lived activation period for this protein. The localization of pCREB increases within the olfactory bulb as seen by immunocytochemistry. Naive pups were not exposed to odor or training. There was a significantly higher level of label in mitral cell nuclei within the dorsolateral quadrant of the bulb of pups undergoing odor-stroke pairing. No significant differences were observed among nonlearning groups (Naive, Odor only, or Stroking only) or among any training groups in the granule or periglomerular cells of the dorsolateral region. The localized changes in the nuclear protein are consistent with studies showing localized changes in the bulb in response to a learned familiar odor. The present study demonstrates that selective increases in pCREB occur as an early step following pairing procedures that normally lead to the development of long-term olfactory memories in rat pups. These results support the hypothesized link between pCREB and memory formation.     

Individual differences in deductive reasoning

Three studies are reported, which examined individual differences in deductive reasoning as a function of intellectual ability and thinking style. Intellectual ability was a good predictor of logical performance on syllogisms, especially where there was a conflict between logic and believability. However, in the first two experiments there was no link between ability and performance on indicative selection tasks, in sharp contrast to previous research. This correlation did, however, return in the final study. Our data are consistent with the claim that the correlation with logical accuracy on abstract selection tasks is found primarily with participants of relatively high ability. At lower levels, pragmatically cued responses are given but those of slightly higher ability divorce the rule from the scenario and respond consistently (though incorrectly) across problems. Self-report questionnaires were generally poor predictors of performance, but a measure of the ability to generate alternative representations proved an excellent predictor. These results are consistent with a mental models approach to reasoning and also have implications for the debate about human rationality.