Recognizing the visual stimulus from neuronal discharges

In this article, experiments are reviewed that have a bearing on the question of how 'meaning' is related to neuronal activity in the mammalian cortex; there is evidence that the excitation time pattern plays a major role. We suggest that 'objective meaning' is related to spatiotemporal activity distributions, whereas spike counts indicate the importance of the contribution of a given neurone to that meaning. Such a 'dual-coding' principle allows the visual system to emphasize selected activity components by central messages. The feature to be noted is that the objective meaning remains largely unaltered.