Habituação do comportamento exploratorio a sons em pombos (Columba livia) : efeitos de lesões telencefalicas e de ordem de estimulos

AUTOR(ES)
DATA DE PUBLICAÇÃO

1994

RESUMO

Habituation refers to a process of decrement in the occurrence or magnitude of a response to a stimulus presented continuous or repeatedly. In this work, the habituation process of exploratory behavior was analysed in two experiments. The general objective was the analysis of habituation to acoustic stimulus in pigeons previously detelencephalated. In each experiment the pigeons were attributed to three distinct groups: No Lesion Learning; Sham Lesion-Learning and Telencephalic Lesion-Learning. In Experiment I (sequence AB) the pigeons had the first session with stimulus A (1.000-Hz, 83-dB, 1 sec) and, twenty-four hours later, a second session with introduction of stimulus B (500-Hz,85-dB, 1sec). In Experiment II the sequence of tests with the two stimuli was inverted (sequence BA). The sessions had presentation of stimuli every 30 sec, until the occurrence of 10 stimuli without exploratory responding or 60 trials. statistical analysis used Kruskal-Wallis for between-group comparisons. Intra-group comparisons used Friedman and wilcoxon tests. The results indicated that habituation occurred in both Experiment I and Experiment II for alI groups, independently of stimulus sequence. Comparisons between control groups did not indicate differences in number of trials to habituation (p>0,05). In both experiments, detelencephalated pigeons habituated with lower number of trials in comparison to the control groups (p<0,05). Intra-group comparisons indicate between-sessions differences in number of stimulus to habituation for control pigeons (p<0,05), but not for experimental birds (p>0,05). Analysis of the coefficient of differenciaI perception to the stimuli indicated differences only for lesioned birds. The histological analysis showed extensive ablation of the telencephalon, with remaining tissues of parahipocampal area. These data are suggestive of: (a) a facilitation of shortterm habituation of the exploratory response in detelencephalated pigeons; (b) telencephalon involvement in the long-term effect of habituation ; (c) responding to be differently affected by introduction of stimulus B following stimulus A and by introduction of stimulus A following stimulus B. These data permit a discussion about the functional role of telencephalon in the habituation process to auditory stimulus and rouse questions on the processing of accoustic information by detelencephalated pigeons

ASSUNTO(S)

pombo - comportamento pombo - fisiologia

ACESSO AO ARTIGO

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