Preference and consequences: A preliminary look at whether preference impacts oral processing in non-human primates

Area of Science:

• Primate behavior and physiology
• Comparative oral biology
• Animal feeding ecology

Background:

• Non-human primates exhibit food preferences similar to humans.
• Understanding how these preferences affect oral processing in primates is limited.
• This research explores the relationship between food preference and chewing physiology in capuchins.

Purpose of the Study:

• To investigate the impact of food preference on oral physiological variables during chewing in tufted capuchins (Cebus apella).
• To compare ranked food preferences with electromyographic (EMG) activity of jaw-closing muscles.
• To explore potential shared mechanisms underlying food preference and oral processing in primates and humans.

Main Methods:

• Assessed food preference in two capuchins across 12 diverse foods (fruits, nuts, biscuits).
• Generated a ranked preference scale by presenting randomized food pairs.
• Measured jaw-closing muscle EMG activity during chewing of preferred and non-preferred foods, controlling for food mechanical properties (FMPs).

Main Results:

• Capuchins demonstrated clear food preferences.
• Significant differences in chewing cycle length and muscle activation were observed between preferred and non-preferred foods within brittle and ductile categories.
• Chewing speed varied, with non-preferred apricots chewed faster than preferred dates and prunes.

Conclusions:

• Food preference appears to influence oral physiology in non-human primates.
• Observed differences in chewing physiology related to preference were complex and individual-specific.
• Findings suggest that the link between food preference and oral processing in humans may have evolutionary roots in non-human primates.