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A CTA is the pairing of a toxic effect with a taste, flavor, or oral somatosensory stimulus. Historically, it has been very difficult to associate the effects of a interoceptive toxin with a conditioned stimulus that works through non-oral modalities (e.g. pairing a visual, auditory, or somatic stimulus with a toxic injection of LiCl).
A CTA is the pairing of a toxic effect with a taste, flavor, or oral somatosensory stimulus. Historically, it has been very difficult to associate the effects of a interoceptive toxin with a conditioned stimulus that works through non-oral modalities (e.g. pairing a visual, auditory, or somatic stimulus with a toxic injection of LiCl).
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An important consequence of this property is that CTA learning is relatively resistant to contextual conditioning or modulation. Context is a nebulous term refering to multimodal sensory input derived from the environment of the experiment as a whole. Thus the spatial properties, visual characteristics, ambient noise, etc. of the testing situation make up the context; but for CTA learning, the context is far less important than the orosenory stimulation. Thus, if the animals rejection of a food can be attributed to a learned response to contextual, non-orosensory stimuli, then the behavior is not due to CTA.
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An important consequence of this property is that CTA learning is relatively resistant to contextual conditioning or modulation. Context is a nebulous term refering to multimodal sensory input derived from the environment of the experiment as a whole. Thus the spatial properties, visual characteristics, ambient noise, etc. of the testing situation make up the context; but for CTA learning, the context is far less important than the orosenory stimulation. Thus, if the animal's rejection of a food can be attributed to a learned response to contextual, non-orosensory stimuli, then the behavior is not due to CTA.
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(Note that other species may be more sensitive than rats to sensory modalities outside the mouth and nose. For example, birds and primates can easily associate visual cues with intereoceptive stimuli to form visual aversions. Presumably the ability to learn food aversions would evolve to take advantage of the primary senses involved in food detection.)
==3. The toxic unconditioned stimulus is an intereoceptive, not exteroceptive, stimulus.==
==3. The toxic unconditioned stimulus is an intereoceptive, not exteroceptive, stimulus.==