A new tool that may measure certain absolute temporal properties of information processing in intact organisms is suggested by. investigations of temporal summation in single nerve cells. Two findings have led to this suggestion: One, the form of the temporal summation function (relating the intensity and duration required to evoke a criterion neural signal) depends on the analysis used by the investigator. Corresponding form variations occur in behavioral studies when the observer's task is varied. Two, the critical durations of fixed neural signals depend on the latency of the feature of the signal chosen as criterion; early features yield short critical durations and vice versa. The critical duration also varies in behavioral studies if one varies the observer's task, keeping the stimulus ensemble fixed.

These data lead to two inferences: One, the form of a behavioral temporal-summation function expresses the kind of hidden mental analysis mediating that behavior. Two, a behavioral critical duration is an indicator of the absolute timing of the hidden mental analysis mediating that behavior.

The activity of neurons was recorded extracellurayly at the junction of visual cortical areas 17, 18, 20a, and 20b in the cat. The receptive fields of these neurons were striking for their size, which ranged from a diameter of more than 40 deg of visual angle to the complete visual of the contralateral eye. It is speculated that these large receptive fields may be generated by perturbations in the individual maps as the four areas merge together.

In this paper, the 3D self-positioning problem of a mobile robot is investigated under the assumption that there are given a set of guide points along with camera vision as the detection mechanism. The minimal number of guide points is discussed to determine the position and orientation of a mobile robot via a single or multiple camera system. For practical application, a closed form 3D self-positioning algorithm is proposed using a stereo camera system with triple guide points. It is further shown that a double triangular pattern is an effective guide-mark that is robust against measurement noise in feature extraction. Then, by simulation, the sensitivity of positioning errors due to image errors are analyzed. It is experimentally shown that the proposed method with triple guide points works well for a walking robot equipped with a stereo camera in laboratory environment.