Table 1.

Poisson fit to experimental data from a moderately large open-field environment

Apparatus	Source	Pact(1)	Fields per Cell
Cylinder	Experimental data	0.72	1.3 ± 0.03
	Poisson fit	0.731	1.326
	Relative error	0.02	0.02
Chamber floor	Experimental data	0.11	3.4 ± 0.11
	Poisson fit	0.112	3.569
	Relative error	0.02	0.05

Data are Poisson fits to experimental data from a moderately large open-field environment (Fenton et al. 2008). In addition to the statistical agreement shown in Fig. 2, the Poisson distribution [Eq. 1 with λ = 1.65m⁻² and A = 0.36 m² (cylinder) or 2.1 m² (chamber floor)] predicts the probability that an active cell (cell with at least one place field in the given apparatus) has exactly one place field within the cylinder or chamber floor [P_act(1)]. It also predicts the average number of place fields per active cell in both enclosures.