Antunes, R; Moita, M
The auditory system has two parallel streams in the brain that have been implicated in auditory fear learning. The lemniscal stream has selective neurons that are tonotopically organized and is thought to be important for sound discrimination. The nonlemniscal stream has less selective neurons, which are not tonotopically organized, and is thought to be important for multimodal processing and for several forms of learning. Therefore, it has been hypothesized that the lemniscal, but not the nonlemniscal, pathway supports discriminative fear to auditory cues. To test this hypothesis we assessed the effect of electrolytic lesions to the ventral, or medial, division...
Moita, MAP; Rosis, S; Zhou, Y; LeDoux, JE; Blair, HT
We recorded hippocampal place cells in two spatial environments: a training environment in which rats underwent fear conditioning and a neutral control environment. Fear conditioning caused many place cells to alter ( or remap) their preferred firing locations in the training environment, whereas most cells remained stable in the control environment. This finding indicates that aversive reinforcement can induce place cell remapping even when the environment itself remains unchanged. Furthermore, contextual fear conditioning caused significantly more remapping of place cells than auditory fear conditioning, suggesting that place cell remapping was related to the rat's learned fear of the environment. These...
Viana, DS; Gordo, I; Sucena, E; Moita, MAP
Game theory and the Prisoner's Dilemma (PD) game in particular, which captures the paradox of cooperative interactions that lead to benefits but entail costs to the interacting individuals, have constituted a powerful tool in the study of the mechanisms of reciprocity. However, in non-human animals most tests of reciprocity in PD games have resulted in sustained defection strategies. As a consequence, it has been suggested that under such stringent conditions as the PD game humans alone have evolved the necessary cognitive abilities to engage in reciprocity, namely, numerical discrimination, memory and control of temporal discounting.
(application/pdf) - 30-jul-2010