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Hand preferences and whole (Galago senegalensis)
C F Larson1, D L Dodson, J P Ward
1Department of Behavioral Sciences, Wilson College, Chambersburg, Pa.
Brain, Behavior and Evolution
|January 1, 1989
Summary
Lesser bushbabies show hand preferences for prey capture, with most favoring their left hand. Bipedal posture specifically enhances dominant hand use, possibly mediated by neuraxial arousal.
Area of Science:
- Primate behavior
- Comparative psychology
- Neuroscience
Background:
- Hand preference, or lateralization, is common in primates.
- Understanding the factors influencing lateralization is crucial for cognitive and behavioral studies.
Purpose of the Study:
- To investigate hand preferences in prey capture and turning biases in lesser bushbabies (Galago senegalensis).
- To examine the effects of posture, prey visibility, and reaching angle on hand use.
- To explore potential mediators of observed hand use patterns.
Main Methods:
- Assessed hand preference and turning bias in 10 lesser bushbabies across 8 experimental conditions.
- Each subject completed 480 trials, manipulating posture, prey visibility, and reaching angle.
- Recorded hand use during prey capture and whole-body turning post-capture.
Main Results:
- Seven out of ten subjects exhibited a left-hand preference for reaching; three showed right-hand preference.
- Eight subjects displayed a left whole-body turning bias; one showed a right bias, and one had no bias.
- Bipedal posture significantly facilitated dominant hand use, while other conditions had no significant effect.
- No correlation was found between hand preference and turning bias.
Conclusions:
- Lesser bushbabies demonstrate significant population-level hand preference for prey capture.
- Bipedal posture appears to be a key factor influencing hand use lateralization in this species.
- A neuraxial arousal system is proposed as a potential mechanism underlying the effect of bipedal posture on hand use.