The idea of intelligent machines has been around at least since the time of Turing’s work in the 1940s. Artificial intelligence (A.I.) has become a mature field, and is now poised on the brink of widespread application across all existing technologies. Despite this, early hopes were never realized, and today’s A.I. is not what it was once expected to be.
It became apparent early on that A.I., while being far superior to humans in doing certain specific things, could not come close to the general breadth of human intelligence. The goal of creating artificial general intelligence, or “strong A.I.,” has proven to be surprisingly difficult.
In my last blog I identified the difficulty in even defining what “intelligence” is. In fact, so many different definitions have been proposed that it is now accepted that there are many distinct facets of what could be called intelligence. ( for a small sampling, see http://en.wikipedia.org/wiki/Human_intelligence )
We can hope to replicate the functions of many of these individual facets of intelligence, as we already do with decision making, numerical analysis and the other current A.I. applications. Even then, the result will be a number is individual A.I.s working in parallel; useful, certainly, but not the strong A.I. that was the original goal. Something will still be missing, and that something is sentience. The “general” nature of human intelligence arises from a foundation of sentience.
Sentience, from the Latin “sentiēns” (feeling, perceiving), is the ability to feel, sense or experience perceptions subjectively. Sentience represents a distinct knowledge system, one that is distributed throughout the body, separate from but integrated with brain-based intelligence. Our bodies know things that we may not even be conscious of. They use this knowledge for self-maintenance and repair, for self-protection, and for many other autonomous functions. No conscious involvement is required from us. Arguably, all living creatures have some degree of sentience, as it is essential to our ability to survive and thrive.
Human sentience is complex and nuanced: through consciousness, we experience our own embodiment – we “feel” ourselves – while at the same time perceiving the world around us and our interaction with it. This body-based knowledge operates outside the realm of logic, reason and language, often even outside of our awareness, and so falls outside the traditional scope of A.I.
If we want to have a truly human-like android, we have to go beyond the limitations of machine intelligence and add machine sentience. The distinction between intelligence and sentience is crucial to understand, but in practice, they are interdependent qualities. Human-like sentience will require intelligence, and true general intelligence will require sentience.
Sentience is fundamental to human consciousness.
The foundation of human consciousness, as eloquently described by Antonio Damasio in his classic, The Feeling of What Happens, is the moment to moment orchestra of sensation arising from the biophysical activity of the body. This constant stream of data provides continuous feedback to the body’s maintenance systems, enabling the autonomic responses necessary to maintain homoeostasis, nutrient balances, and waste management. It also provides feedback as to body position and orientation, and critical information about the local environment.
The brain integrates this flow of data into a coherent model of the current bio-state of the body as a whole, and this model is what we experience as our “self.” As we experience the ongoing updating of this model, our conscious experience consists of the perception of changes occurring in the model. We have no awareness of the model per se, but we do perceive changes as they occur, and this ongoing process of change is the content of our present experience.
In order for this process to work, we need sensory and feedback data from critical functional systems, we need to compile the data from all sources into a single, coherent representational model, we need a memory system to make temporal comparisons and note changes as they occur, and we need a meta-level compiler to integrate those changes into patterns of neural stimulation that are the stuff of experience.
This is not the entirety of human consciousness, but only the prerequisite, a base level that Damasio calls “core consciousness.” I will discuss the other levels in future blogs.
Sentience is fundamental to human consciousness and human intelligence. Unless an android is sentient, it can not be conscious in the human sense, no matter how much “intelligence” is packed into it.
In my next blog I will further explain how body-based knowledge lays a critical foundation for brain-based knowledge.