RESUMO
OBJECTIVE: The acute nootropic potential of donepezil in young healthy volunteers has not been adequately investigated mainly because in previous studies: (1) effects were assessed before peak-plasma concentration (Tmax) was reached; (2) only a few cognitive processes were assessed. Here we investigated a myriad of cognitive effects of augmentation of acetylcholine using an acute dose of donepezil in healthy adults at theoretical Tmax. METHODS: This was a double-blind, placebo controlled, parallel group design study of cognitive effects of acute oral donepezil (5 mg). Subjects were tested twice after donepezil ingestion: 90 min (time that coincides with previous testing in the literature) and 210 min. (theoretical Tmax). The test battery included tasks that tap cognitive domains that are sensitive to acetylcholine manipulations. RESULTS: At both testing times donepezil improved long-term recall of prose, objects recall, recall of spatial locations, and integration of objects with their locations, some effects having been related to self-reported mood enhancement. However, improvement of performance in the central executive measure (backward digit span) occurred only at Tmax. CONCLUSION: Positive cognitive effects of acute donepezil can be observed in various cognitive domains including mood, but its full nootropic potential is more clearly found close to theoretical peak-plasma concentration.
Assuntos
Cognição/efeitos dos fármacos , Indanos/farmacologia , Memória/efeitos dos fármacos , Nootrópicos/farmacologia , Piperidinas/farmacologia , Adulto , Afeto/efeitos dos fármacos , Inibidores da Colinesterase/farmacocinética , Inibidores da Colinesterase/farmacologia , Donepezila , Método Duplo-Cego , Humanos , Indanos/farmacocinética , Masculino , Nootrópicos/farmacocinética , Piperidinas/farmacocinética , Fatores de Tempo , Adulto JovemRESUMO
Studies in change blindness re-enforce the suggestion that veridical, pictorial representations that survive multiple relocations of gaze are unlikely to be generated in the visual system. However, more abstract information may well be extracted and represented by the visual system. In this paper we study the types of information that are retained and the time courses over which these representations are constructed when participants view complex natural scenes. We find that such information is retained and that the resultant abstract representations encode a range of information. Different types of information are extracted and represented over different time courses. After several seconds of viewing natural scenes, our visual system is able to construct a complex information-rich representation.