When you look at your pet dog or cat, have you ever wondered whether it thinks, feels, makes rational decisions and plans for events in the future? If it did, it has – liked humans –the ability to process information and behave both at the conscious and non-conscious levels.
And if such mammalian household pets have this gift, why not fish in your aquarium, ants outside or objects like an iPad or Siri – Apple’s virtual assistant that uses voice queries, gesture-based control, focus-tracking and a natural-language user interface to answer questions, make recommendations and perform actions by delegating requests to a set of Internet services.
Can we ever really know whether animals are consciously aware? A joint team of the Hebrew University of Jerusalem (HUJI) and Yale University in New Haven, Connecticut have devised a novel scientific tool to address that very question and to assess whether animals have both conscious and non-conscious minds.
The study, just published this week in the Proceedings of the National Academy of Sciences (PNAS) under the title “Disentangling Perceptual Awareness from Non-conscious Processing in Rhesus Monkeys,” is a collaboration between Prof. Laurie Santos and Prof. Steve Chang at Yale who study cognition in monkeys and dogs and Prof. Ran Hassin of HUJI’s psychology department and the Center for the Study of Rationality, whose research focuses on conscious versus non-conscious thought processes in humans. The study was initiated and performed by Dr. Shay Ben-Haim, a joint postdoctoral fellow of the two universities.
The researchers created specific tasks where the results would differ based on the thought processes recorded to effectively distinguish the two levels of perception in monkeys. “We started with humans and then performed the same test on monkeys,” recalled Ben-Haim. “Each test involved a stimulus – in this case, a star – that was either presented on the right or left of the screen. The subjects would then be rewarded with points for humans and treats for animals to look at the opposite side of the screen from where the star appeared.”
In one test condition, the star fully appeared on the screen and the subject was able to consciously process that it was there. In another condition, the star appeared and disappeared so quickly that it was processed without reaching subjects’ conscious awareness. “In other words, if you ask subjects in this condition whether they saw a star on the screen, they would say ‘no, we didn’t see anything’,” explained Hassin.
“What we were able to determine is that if the stimulus was consciously perceived, the subject – both humans and monkeys – were able to learn to look at the opposite side of the star very quickly. But when it was processed non-consciously, subjects displayed a different pattern of responses; they continued to look at the star location, consistently failing to learn to look at the required opposite location,” he continued.
The most important aspect of their discovery was that, for the first time, such a duality of conscious versus non-conscious processing was obtained in animals, a pattern that was previously observed only in humans. “The conclusion we reached was that monkeys have the same two systems that humans have: they can process information and think both consciously and non-consciously,” said Ben Haim.
“The fact that we humans engage in both conscious and non-conscious cognition is a crucial determinant of how we think, plan, and make decisions,” commented Hassin. “These findings show us that we’re not alone in the animal kingdom vis-à-vis these two systems, and it opens the way to examining consciousness and non-conscious processes in other species.”