Résumé
Background mental imagery is a multi-componential process involving different mental operations. Objective The present study investigated the subsystems of visual mental imagery processing and their interactions. Methods: Four experimental tasks were done: (1) object, the ability to generate global mental images; (2) resolution, the ability to generate vivid,high-resolution mental images; (3) transformation,the ability to mentally rotate patterns in images, and (4) spatial imagery,spatial cognition. 91 university students (77 males, 14 females) participated in this study. Results: Object task was highly correlated with resolution task, and the same the tendency was found between transformation task and spatial task. Conclusion: The results indicate there are different subsystems of visual mental imagery and corresponding operative strategies, but with strong correlation among these processes and abilities.
Résumé
Background mental imagery is a multi-componential process involving different mental operations. Objective The present study investigated the subsystems of visual mental imagery processing and their interactions. Methods: Four experimental tasks were done: (1) object, the ability to generate global mental images; (2) resolution, the ability to generate vivid,high-resolution mental images; (3) transformation,the ability to mentally rotate patterns in images, and (4) spatial imagery,spatial cognition. 91 university students (77 males, 14 females) participated in this study. Results: Object task was highly correlated with resolution task, and the same the tendency was found between transformation task and spatial task. Conclusion: The results indicate there are different subsystems of visual mental imagery and corresponding operative strategies, but with strong correlation among these processes and abilities.
Résumé
There is evidence that 5-7 d after acute seizure episodes induced by kainic acid (KA) the rats develop a long-lasting increase in the susceptibility to seizures followed by spontaneous recurrent seizures (SRS). The present study was focused on the role of hippocampal mu opioid receptors (MORs) in the susceptibility of rats to seizures with the KA model of epilepsy. The rats received a convulsant dose of KA (10 mg/kg, i.p.) were continuously infused with a selective MOR agonist PL017 (2.09, 2.59, 3.29 microg/microl), or a selective MOR antagonist beta-funaltrexamine hydrochloride (beta-FNA, 0.88, 1.10, and 1.35 microg/microl) into ventral hippocampus by means of mini-osmotic pumps. Seven days later, the susceptibility of rats to seizures was checked by a subconvulsant dose of KA (5 mg/kg, i.p.). PL017 infusion shortened the latency and increased the stage of seizures induced by subconvulsant dose of KA in a dose-dependent manner. In contrast, infusion of beta-FNA exhibited a dose-dependent effect against seizures challenged by subconvulsant dose of KA. These results indicate that hippocampal MOR may exert a promoting effect on the susceptibility of rats to KA-induced seizures.