konvergente Zahlen

Probing convergently evolved representational systems for numbers in humans, monkeys, and crows

01/03/2025 to 29/02/2028

When asked to judge the number of briefly presented items in a set, humans exhibit a behavioral dichotomy: participants respond rapidly and accurately for small numbers (up to 4), a phenomenon termed 'subitizing,' but become increasingly slower and less precise for larger numbers beyond 4, using 'estimation.' Despite over 150 years of research, the nature of this phenomenon remains unknown. Some suggest it reflects two primordial counting systems, while others argue that this apparent behavioral dichotomy can be explained by a single underlying mechanism. Previously, our single neurons identified two distinct counting systems in the human brain. However, the emergence of these two systems requires explanation in terms of evolutionary advantage, cognitive realization, and neuronal circuit implementation. It has been proposed that subitizing taps into a different system from that used for number estimation due to the differentiating role of attention in number assessments. In this proposal, we will explore the impact of voluntary attention on different representational systems for small and large numbers in humans, monkeys, and crows. Through this, we aim to continue the successful comparative approach to decipher neuronal codes and computational principles in convergently evolved brain regions of humans, nonhuman primates, and corvid songbirds.