Numbers Driving Space: Experience With Numerical Sequences Modulates Spatial Behavior in Newborn Chicks (Gallus...

Area of Science:

• Neuroscience
• Comparative Cognition
• Developmental Psychology

Background:

• Vertebrates exhibit right-hemisphere dominance, influencing visuospatial attention towards the left.
• This leftward bias is linked to the human mental number line (small numbers left, large numbers right).
• While human number cognition is influenced by experience, animal data on this phenomenon are scarce.

Purpose of the Study:

• To investigate if exposure to numerical sequences affects the left-to-right visuospatial exploration bias in young chicks.
• To determine if numerical sequence directionality (increasing vs. decreasing) modulates this bias.

Main Methods:

• Two experiments were conducted with 70 day-old chicks.
• Chicks were trained with either increasing (e.g., 2-5-8) or decreasing (e.g., 8-5-2) numerical sequences.
• Testing involved observing chicks' approach behavior to horizontally arranged number stimuli.

Main Results:

• Chicks exposed to increasing numerical sequences consistently approached stimuli from the left.
• This leftward bias was observed regardless of the final stimulus arrangement.
• Chicks exposed to decreasing numerical sequences did not show a directional preference.

Conclusions:

• Early experience with numerical sequences can modify innate left-to-right visuospatial biases in young animals.
• This highlights the flexibility of cognitive biases in numerical and visuospatial processing early in life.
• Findings contribute to understanding the development of numerical cognition across species.