Figure 3.

Example of vector representations based on the neural activities of the decoding layer (see Figure 2E) in the path integration (PI) mechanism for a square trajectory. The agent runs for 5 m in one of the four directions (180°, 270°, 0°, 90°), thus finally returning to the starting point of its journey. The coarse encoding of heading orientations lead to a correct decoding of memory layer activities. Thus, the activities of the decoding layer in the PI mechanism (see inlay) represent the home vector (HV), where the position of the maximum firing rate is the angle and the amplitude of the maximum firing rate is the length of the vector. Note that, as the agent returns to the home position, the output activities are suppressed to zero resulting from the elimination of opposite directions.