Corvids optimize working memory by categorizing continuous stimuli

Abstract

Working memory (WM) is a crucial element of the higher cognition of primates and corvid songbirds. Despite its importance, WM has a severely limited capacity and is vulnerable to noise. In primates, attractor dynamics mitigate the effect of noise by discretizing continuous information. Yet, it remains unclear whether similar dynamics are seen in avian brains. Here, we show jackdaws (Corvus monedula) have similar behavioral biases as humans; memories are less precise and more biased as memory demands increase. Model-based analysis reveal discrete attractors are evenly spread across the stimulus space. Altogether, our comparative approach suggests attractor dynamics in primates and corvids mitigate the effect of noise by systematically drifting towards specific attractors. By demonstrating this effect in an evolutionary distant species, our results strengthen attractor dynamics as general, adaptive biological principle to efficiently use WM.

The colorful memory

“…Indeed, increasing evidence has shown that this robust representation in higher-level cortex is useful particularly under high memory loads (Christophel et al, 2017;Linden et al, 2003;Xu & Chun, 2006), or during interference (Bettencourt & Xu, 2016). This is possibly because when storing precise, detailed information in VWM becomes (Panichello et al, 2019), but also in primates (Freedman et al, 2001, Panichello et al, 2019 and corvid (Apostel et al, 2023). The attractor dynamics model (Almeida et al, 2015;Panichello et al, 2019) suggests that as memory load increases, internal noise of memory errors (or "random diffusion") increases, while VWM is more biased towards certain nearby locations (or "attractors"), such as color prototypes (Bae et al, 2015;Zhou et al, 2021) and cardinal orientations (Bae, 2021).…”