Low-dimensional chaos maps learning in a model neuropil (olfactory bulb).
Low-dimensional chaos maps learning in a model neuropil (olfactory bulb).
复制标题
低维混沌映射模型神经细胞(嗅球)中的学习。
DOI:
10.1007/bf02691166
复制
发表时间:
1992
期刊:
影响因子:
--
通讯作者:
Skinner,JE
中科院分区:
文献类型:
--
作者:
Mitra,M;Skinner,JE
Quantification of a chaotic system can be made by calculating the correlation dimension (D2) of the data that the system generates (Packard et al., 1980). The D2 algorithm, however, requires stationarity of the generator, a feature that biological data rarely reflect (Mayer-Kress et al., 1988). So we developed the “point correlation dimension” (PD2), an algorithm that accurately tracks D2 in linked data of different dimensions (Carpeggiani et al., 1991). We now present a mathematical argument that, for stationary data, individual PD2s converge to D2 and we demonstrate that the algorithm rejects contributions made by bursts of noise. Data were obtained from the surface of the olfactory bulb of the conscious rabbit (64 electrodes, 640 Hz each, 1.3 sec epochs) before and after presentation of a novel or habituated odor. D2 could be calculated in only 1 of 10 novel-odor trials, whereas PD2 could be calculated in all. Both algorithms indicated that a novel odor evokes a spatially uniform dimensional increase. The PD2 uniquely exhibited the dimensional decreases that occur during inspiration and the gradients of mean dimension present during the nonstimulated control state. These control gradients remained unchanged without odor experience, but showed spatially specific PD2 increases following odor habituation. It is interpreted that, 1) the PD2 issensitive, accurate, and appropriatefor dimensional assessment of biological data, 2) that during analysis of unfamiliar information a singleglobal processis transiently evoked in the neuropil, and 3) after experience multiplespatially specific processestonically map the sites of learning.