*Some of the work described in this paper has been supported by grants from the National Science Foundation (G2546), United States Public Health Service (C3617 and M2271), and the Rutgers University Research Council (261), to all of whom grateful acknowledgement is made.
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*With grateful acknowledgement to the Rutgers University Research Council (261), the United States Public Health Service (C3617 and M2271), and the National Science Foundation (G2546) for funding some of the work described in this paper.
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The researchers discovered that the same NCL neurons processed the information about the physical stimulus and the subsequent report; these neurons then shifted from primarily encoding the stimulus intensity at the beginning to primarily encoding the crows’ subjective experience. However, as the neurons changed their primary focus, the researchers discovered that a subset of neurons retained knowledge regarding the crows’ subjective experiences during the experiment.
In order to investigate sensory consciousness in primates, researchers observe how the subject’s brain activity varies based on whether or not they identify a stimulus. In primates, there are two stages to the development of sensory consciousness: initially, the neurons fire primarily in response to the visual stimulus (unconscious vision); later, the neurons fire primarily in response to the primate’s awareness of the stimulus.
They discovered that the neurons were primarily responding to the stimulus’s intensity during stimulus presentation. Regardless of the crow’s final report, they came to this conclusion because the neuron firing patterns were consistent across all trials with the same stimulus intensity. Stated differently, in a no-stimulus trial, the neuron responses were identical whether the crow reported a false positive or accurately indicated that there was no stimulus.
One of many recent discoveries indicating our similarities to other animals is the evidence of sensory consciousness in birds, which supports the argument that we shouldn’t be keeping them in captivity and using them in experiments. Unfortunately, anthropocentrism is ingrained in human culture, and we use it as an excuse to treat animals like less than human. As our understanding of our commonalities grows, so does our ability to justify elevating ourselves above animals.
This finding provides evidence for sensory consciousness in birds because the change in the neurons’ responses to a visual stimulus matches our understanding of how neurons perform visual consciousness. The two-stage awareness process may be how vertebrates generally acquire sensory consciousness, as it closely resembles the two-stage process observed in primates.