Related Experiment Videos
Light exposure of the embryo and development of behavioural lateralisation in chicks, I: olfactory responses
L J Rogers1, R J Andrew, T H Burne
1Division of Neuroscience and Animal Behaviour, School of Biological Sciences, University of New England, Armidale, NSW, Australia. lrogers@metz.une.edu.au
Insights
Chicks show lateralized olfactory responses, with the right nostril being more sensitive to odors when presented with a blue bead. Pre-hatch light exposure did not affect this olfactory lateralization in chicks.
Area of Science:
- Neuroscience
- Animal Behavior
- Sensory Physiology
Background:
- Prenatal light exposure in chicks can lead to asymmetries in visual pathways.
- The influence of sensory experience on olfactory processing and lateralization is not fully understood.
Purpose of the Study:
- To investigate olfactory lateralization in chicks using a novel test combining odor and visual stimuli.
- To determine if prenatal light exposure affects olfactory lateralization.
Main Methods:
- Chicks were incubated in light or dark conditions.
- Olfactory responses were tested using clove oil odor presented with either a blue or red bead.
- Nostril occlusion was used to assess lateralized olfactory perception.
Main Results:
- Chicks showed enhanced head shaking and pecking with the right nostril when presented with clove oil and a blue bead, indicating olfactory detection.
- With the left nostril, chicks primarily responded to the visual stimulus (blue bead), suppressing olfactory input.
- No significant lateralization was observed when a red bead was used.
- Prenatal light or dark incubation did not influence the observed lateralization patterns.
Conclusions:
- Chick olfactory processing exhibits lateralization, with the right hemisphere potentially being more involved in odor detection.
- Attention to visual stimuli can modulate olfactory responses, particularly when using the left nostril.
- Prenatal sensory environment (light/dark incubation) does not appear to impact this specific olfactory lateralization.
Abstract:
Chicks exposed to light during late foetal life experience stimulation of the right eye only and, in consequence, develop asymmetries of the crossed visual projections from thalamus to forebrain and differences in performance of some visual tasks when using the right or left eye. The present study compared dark- and light-incubated chicks in a test of olfaction in which clove oil odour was presented together with a coloured bead. When the chicks were tested with a blue bead and using the right nostril (left nostril occluded by wax), head shaking and pecking were elevated, compared to pretest responses to an unscented, white bead. No significant elevation of head shaking occurred in chicks tested with the blue bead and using the left nostril, although pecking increased, which indicates that these chicks attended to the visual parameters of the bead but not the odour. It appears that, when the left nostril is used, attention to an attractive visual stimulus suppresses responses to olfactory input to the left hemisphere. When the clove oil odour was presented together with a less attractive, red bead, no significant lateralisation emerged. Light or dark experience prior to hatching had no effect on the lateralised performance of the blue-bead test.