RESUMO
Anticipation is the phenomenon in which the response of a system is predictive of the stimulation. The encoding of stochastic light intensity (x) into spikes is investigated in an experiment with retinas from bullfrogs to understand the mechanism of anticipation of a retina. Partial information decomposition of the mutual information between the spike rates and the joint state {x,x[over Ì]} is found to be consistent with the encoding by the linear combination of x and x[over Ì] where x[over Ì] is the rate of change of x. This spike rate encoding form indicates that a retina is capable of anticipation based on the synergistic information generation between x and x[over Ì]. Our results suggest that illusions such as the anticipation studied here during retinal perception can originate from the recombination of information extracted in the retinal network.
RESUMO
OBJECTIVE: To compare the value of dipyridamole (201)Tl Single photon emission computed tomography (SPECT) myocardial imaging and exercise myocardial (99)Tc(m)-MIBI SPECT imaging on diagnosing cardiac syndrome X. METHODS: Sixty-three patients with known cardiac syndrome X were divided into dipyridamole (201)Tl SPECT myocardial imaging group (group 1, n = 35) and exercise myocardial (99)Tc(m)-MIBI-SPECT imaging group (group 2, n = 28) and the diagnostic accuracy rates were compared. RESULTS: Thirty-one out of 35 cardiac syndrome X patients showed reverse redistribution in group 1 and the diagnostic accuracy rate was 89%. Positive test results were evidenced 24 out of 28 cardiac syndrome X patients in group 2 and the diagnostic accuracy rate was 87% (P > 0.05 vs. group 1). CONCLUSION: The diagnostic accuracy rates of these two myocardial imaging methods were satisfactory and comparable on detecting cardiac syndrome X.
