Effects of Housing and Personality on Spatial Memory in Laying Hens

Understanding how housing conditions influence cognition and affective states is essential for improving welfare in farm animals. This experiment investigated whether moving hens into battery cages affects their spatial memory and reward-related motivation, and whether personality modulates these effects. Sixty Hy-Line Brown laying hens were reared in enriched aviary-like pens. At 18 weeks of age, half were transferred to battery cages (456 cm²/hen), while the remaining birds stayed cage-free (5333 cm²/hen) for 64 days before testing. Spatial memory was assessed using a modified holeboard task that required birds to find three baited cups among 16 locations. The dataset includes three comma-separated files: TEST.csv – Data recorded during the reward phase (from the start of the test until the hen found the three baited cups).Variables include visit order, latency, number of rewarded and unrewarded visits, and derived memory measures: working memory (WM), general working memory (GWM), and reference memory (RM). POST.csv – Data recorded during the non-reward period immediately following reward consumption.Variables include the number of empty-cup visits which was used to assess reward omission responses and motivation. BEHAVIOR_POST: Variables include the number of comfort-like behaviours (e.g., preening, wing-flapping, scratching), which were used to assess reward omission responses and motivation. The analytical workflow is implemented in two main R scripts: 01_test_metrics_models_and_figure.RThis script analyzes spatial cognition during the reward phase using data from TEST.csv.It includes: Linear mixed-effects models for each cognitive metric (WM, GWM, RM), fitted asOutcome ~ Day × Treatment + (1 | Hen) Model diagnostics (residual distribution, Q–Q plots, residuals vs fitted values) A summary figure showing mean ± SE performance across days and treatments, faceted by cognitive metric and annotated by learning and reversal phases Script 1 — 01_test_metrics_mode… 02_postreward_phase_models.RThis script analyzes reward omission responses during the post-reward phase using data from BEHAVIOR_POST.csv.It includes: A linear mixed-effects model restricted to the reversal phase:Empty-cup visits ~ Treatment × PC2 + (1 | Hen) Model diagnostics to assess normality and homoscedasticity of residuals.