The lingering phenomenon and pattern formation in a nonlocal population model with cognitive map

TL;DR

This paper investigates how cognitive memory and forgetting influence population movement and pattern formation, revealing a lingering phenomenon where population peaks are maximized at an intermediate forgetting rate, affecting long-term space use.

Contribution

It introduces a nonlocal population model incorporating cognitive maps with learning and forgetting, analyzing pattern formation and population persistence with novel insights into lingering effects.

Findings

Finite perceptual range causes spatial heterogeneity in habitat use.

Peak population density is maximized at an intermediate forgetting rate.

Lingering persists under logistic growth, affecting total population size.

Abstract

The rates at which individuals memorize and forget environmental information strongly influence their movement paths and long-term space use. To understand how these cognitive time scales shape population-level patterns, we propose and analyze a nonlocal population model with a cognitive map. The population density moves by a Fokker--Planck type diffusion driven by a cognitive map that stores a habitat quality information nonlocally. The map is updated through local presence with learning and forgetting rates, and we consider both truncated and normalized perception kernels. We first study the movement-only system without growth. We show that finite perceptual range generates spatial heterogeneity in the cognitive map even in nearly homogeneous habitats, and we prove a lingering phenomenon on unimodal landscapes: for the fixed high learning rate, the peak density near the best location is maximized at an intermediate forgetting rate. We then couple cognitive diffusion to logistic growth. We establish local well-posedness and persistence by proving instability of the extinction equilibrium and the existence of a positive steady state, with uniqueness under an explicit condition on the motility function. Numerical simulations show that lingering persists under logistic growth and reveal a trade-off between the lingering and total population size, since near the strongest-lingering regime the total mass can fall below the total resource, in contrast to classical random diffusive--logistic models.