NEURAL UNDERPINNINGS OF CATEGORICAL WORKING MEMORY IN JACKDAWS (CORVUS MONEDULA)

In complex environments, individuals must selectively focus on relevant information and maintain it for later use, relying both on attentional mechanisms and working memory (WM). Such cognitive abilities have mostly been demonstrated in primates, yet corvid songbirds show remarkably similar skills. Therefore, jackdaws were used to test their behavioral and neural implementation. Two jackdaws were trained on a delayed estimation paradigm to probe attention and WM processes. Following a memory delay one of two simultaneously presented sample colors had to be selected from a continuous color wheel of 64 colors. Visual cues indicated relevant target color either before (‘pre-cue’) or after (‘retro-cue’) sample presentation. Additionally, in load one trials the birds were shown only one color. Neural recordings were done using silicon probes implanted into NCL, the avian equivalent to the PFC, and striatum. Both birds performed well on this task. Cue type had a strong influence on overall performance. The birds consistently showed higher performance in both load one and pre-cue trials, indicating that focused attention on the cued sample color significantly improved performance by reducing WM load. This is reflected in the WM representations of the colors. Higher demands in retro-cue trials were mitigated by a more categorical representation of the colors. In the pre-cue trials, attentional resources were focused on the relevant sample, which lead to a more continuous and thus more precise representation. We expect to find these differences reflected in the neural data as well, that are yet to be analyzed.