Training intuitive decision making in a simulated real-world environment.

OBJECTIVE: We investigated whether naturalistic, intuitive (pattern recognition-based) decision making can be developed via implicit statistical learning in a simulated real-world environment. BACKGROUND: To our knowledge, no definitive studies have actually shown that implicit learning plays a causal role in the development of intuitive decision making when the latter is defined as pattern recognition of real-world, or simulated real-world, environmental situations. METHOD: The simulated environment was presented dynamically so as to induce a sense of simulated locomotion through the scene and over sequences of objects on the ground. During training, participants passively viewed the objects sequences; during test, participants made intuitive decisions about related or unrelated sequences. RESULTS: Intuitive decision making can be developed via implicit learning. Articulatory suppression, which affects working memory, exerted a significant inhibitory effect on the training of intuitive decision making. Intuitive decision making trained in the simulated environment fully transferred to a flat display (but not vice versa). CONCLUSION: Intuitive decision making is developed by an implicit learning process that is engaged by the meaning inherent in naturalistic scenes. APPLICATION: Implicit learning can be used for training intuitive decision making.

The metabolic syndrome and coronary artery disease: a structural equation modeling approach suggestive of a common underlying pathophysiology.

OBJECTIVE: The purpose of this research was to utilize a structural equation modeling (SEM) approach to simultaneously examine the relationship among the Metabolic Syndrome (MetSyn) and coronary artery calcification (CAC), a surrogate marker for sub-clinical atherosclerosis and coronary artery disease (CAD). MATERIALS/METHODS: Data were derived from the Spokane Heart Study (SHS), a prospective study designed to examine the role of traditional and non-traditional biological, psychological, and behavioral risk factors predictive of CAC. Study participants included 434 non-clinical healthy volunteers (54% female, 46% male; mean age of 56 years) who were asymptomatic for CAD at enrollment and had complete data for the primary variables of interest (MetSyn components and CAC) during the data collection period (i.e., 2002-2006). A confirmatory factor analysis (CFA) was conducted on the MetSyn factor with the following indicator variables: body mass index, fasting glucose, high-density lipoprotein cholesterol, fasting triglyceride levels, and systolic blood pressure. SEM was used to test the theoretical model that the MetSyn is associated with CAC. RESULTS: This study demonstrated that body mass index, fasting glucose, fasting triglyceride levels, HDL cholesterol, and blood pressure do cluster together under a single latent factor, and that this latent factor is associated with CAC. CONCLUSIONS: Our results highlight the possibility that there is a common pathophysiological pathway that could explain the relationship between the MetSyn and CAD. Future studies should examine these relationships in a prospective fashion for early detection and prevention of CAD and to identify ideal time points for clinical intervention.

The Hepatocyte Growth Factor/c-Met Antagonist, Divalinal-Angiotensin IV, Blocks the Acquisition of Methamphetamine Dependent Conditioned Place Preference in Rats.

The use of methamphetamine (MA) is increasing in the U.S. and elsewhere around the world. MA's capacity to cause addiction significantly exceeds other psychostimulant drugs, and its use negatively impacts learning and memory. Recently, attempts have been made to interfere with the presumed mechanism(s) underlying the establishment of drug-induced memory consolidation. The majority of these studies have employed matrix metalloproteinase (MMP) inhibitors to disrupt MMP-induced extracellular matrix molecule dependent synaptic reconfiguration, or GABA receptor agonists. The present investigation utilized an angiotensin IV (AngIV) analogue, Divalinal-AngIV (divalinal), to disrupt acquisition of MA-induced dependence in rats as measured using the conditioned place preference paradigm. Results indicate that both acute and chronic intracerebroventricular infusion of divalinal prior to each daily subcutaneous injection of MA prevented acquisition. However, divalinal was unable to prevent MA-induced reinstatement after prior acquisition followed by extinction trials. These results indicate that prevention of MA dependence can be accomplished by blockade of the brain AT4 receptor subtype. On the other hand, once MA-induced memory consolidation is in place divalinal appears to be ineffective. Mechanistic studies indicated that divalinal is a potent inhibitor of the hepatocyte growth factor (HGF)/c-Met receptor system, and thus it appears that a functional HGF/c-Met system is required for the acquisition of MA-mediated conditioned place preference.

Modeling the simulated real-world optic flow motion aftereffect.

UNLABELLED: We investigated the simulated real-world optic flow motion aftereffect (MAE) (illusory sense of moving backward following adaptation to expansive optic flow). In Experiment 1, adaptation duration was either 30, 120, 240, or 480 s. RESULTS: duration of the MAE grew with increasing adaptation duration. In Experiment 2, the MAE was measured across different combinations of values of global optical flow rate and optical edge rate. RESULTS: the aftereffect was selective for global optical flow rate, suggesting that the aftereffect reflects gain changes at processing levels where a sense of self-motion is generated. RESULTS were used in a computational model of this MAE, which was a modified framework by van de Grind et al. [Vision Res.44, 2269 (2004)].