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Chicks discriminate human gaze with their right hemisphere
Orsola Rosa Salva1, Lucia Regolin, Giorgio Vallortigara
1Department of General Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy.
Behavioural Brain Research
|December 19, 2006
Summary
Chicks show fear when gazed at, using their left eye to monitor. This innate response can be reversed with experience, highlighting the brain
Area of Science:
- Ethology
- Neuroscience
- Animal Behavior
Background:
- The gaze of others can elicit fear responses in naive animals.
- Predator detection and fear responses are often lateralized in the vertebrate brain, particularly involving the right hemisphere.
Purpose of the Study:
- To investigate the role of eye contact and gaze direction in eliciting fear responses in domestic chicks.
- To determine if chicks exhibit preferential eye use when monitoring a gaze.
- To explore the influence of prior visual experience with human gaze on these responses.
Main Methods:
- Domestic chicks were exposed to a dummy mask with varying gaze directions (feeding location vs. opposite).
- Latency to approach food and eye use (left vs. right) were recorded.
- Chicks with and without prior visual experience of human gaze were compared.
Main Results:
- Naïve chicks displayed increased fear (higher latency to feed) and preferential left-eye use when the dummy mask gazed at them.
- Chicks with prior experience showed reversed behavior: higher latency and preferential left-eye use when the mask looked away.
- Left-eye monitoring suggests right-hemisphere involvement in processing gaze and potential threats.
Conclusions:
- Gaze detection and fear responses in chicks appear to be innate and lateralized, with a predisposition for left-eye use.
- Experience with human gaze can modify these predispositions, suggesting neural plasticity.
- Findings support the hypothesis of right-hemisphere dominance in processing social cues related to fear and predation.
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