An Interview with Daniel Dennett

Edited by Andy Ross

In matters of the mind, few voices today speak as boldly as that of philosopher Daniel Dennett. His best-selling works have provoked fierce debates with their rigorous arguments, eloquent polemic and witty approach to intellectual combat. He is often ranked alongside Richard Dawkins as one of the most powerful proponents of Darwinism.

Dennett says Darwinism cuts through every aspect of science, culture, religion, art and human thought. As he writes in Darwin’s Dangerous Idea, "I have tried to show that once it passes through everything, we are left with stronger, sounder versions of our most important ideas."

Consciousness has arisen from the unwilled, unordained algorithmic processes of natural selection, says Dennett. When viewed through the solvent of Darwinism, he writes, "the ‘miracles’ of life and consciousness turn out to be even better than we imagined back when we were sure they were inexplicable."

Daniel Dennett is Distinguished Arts and Sciences Professor and director of the Center for Cognitive Studies at Tufts University. Boston-born, Oxford-educated, he now divides his time between North Andover, Massachusetts, and his farm in Maine.

SS: Can you give us an overview of your ideas on consciousness?

DD: My views on consciousness are initially very counterintuitive. Those whose curiosity is piqued by what I say here are beseeched to consult the long version carefully. Aside from my books, there are dozens of articles available free on my website.

I claim that consciousness is not some extra glow or aura caused by the activities of the mature cortex. Consciousness is those various activities. One is conscious of those contents whose representations briefly monopolize certain cortical resources, in competition with many other representations. The losers quickly fade, and that’s the only difference between being a conscious content and being an unconscious content.

Consciousness is not like television, it is like fame. One’s access to these representations is simply a matter of their being influential when they are. So consciousness is fame in the brain, or cerebral celebrity. Those who claim they can imagine a being that has all these competitive activities in the cortex but is not conscious are mistaken. They can no more imagine this coherently than they can imagine a being that has all the powers of a living thing but is not alive.

There is no privileged center, no soul, no place where it all comes together, aside from the brain itself. A conscious human soul is not a thing, but a way of being organized and maintaining that organization.

SS: What are the implications of all this for the notion of free will?

DD: The implications are many. The hidden agenda for most people concerned about consciousness and the brain is a worry that unless there is a bit of us that is somehow different, and mysteriously insulated from the material world, life will have no meaning. I am returning to this subject in my next book.

SS: What then of the relationship between religion and science?

DD: There are no factual assertions that religion can reasonably claim as its own, off limits to science. Many who readily grant this have not considered its implications. You can’t consistently accept that expert scientific testimony can convict a charlatan of faking miracle cures and then deny that the same testimony counts just as conclusively against any factual claims of violations of physical law to be found in the Bible or other religious texts or traditions.

What does that leave for religion to talk about? Moral injunctions and declarations of love (and hate, unfortunately), and other ceremonial speech acts. The moral codes of all the major religions are a treasury of ethical wisdom, agreeing on core precepts, and disagreeing on others.

Centuries of ethical research and reflection have not yet achieved a consensus on any Grand Unified Theory of ethics, but there is a broad, stable consensus on how to conduct such an inquiry. Religion plays a major role as a source of possible injunctions and precepts, but it does not set the ground rules of ethical agreement and disagreement.

That leaves ceremonial speech acts as religion’s surviving domain. These play a huge role in stabilizing the attitudes and policies of those who participate in them, but ceremony without power does not appear to be a stable arrangement. Religious people will seldom acknowledge in public that their God has been reduced to a mere constitutional monarch, even while their practices and decisions presuppose that this is so.

It is seldom remarked that many people who profess belief in God do not really act the way people who believed in God would act. They act the way people would act who believed in believing in God. They manifestly think that believing in God is a state of mind to be encouraged, so they defend it. They ask for God’s help, but do not risk anything on receiving it. They thank God for their blessings, but follow the principle that God helps those who help themselves.

Once nothing follows from a belief in God that doesn’t equally follow from the presumably weaker creed that it would be good if I believed in God, God can co-exist peacefully with science. So can Santa Claus, who need not exist in order to make our yuletide season more jolly.

Science & Spirit is supported by the John Templeton Foundation.

AR I compared Dan Dennett with Santa Claus in my JCS report on the 2002 NYAS meeting
The Self: From Soul to Brain.

Flesh Made Soul

By Sandra Blakeslee
Science & Spirit

Edited by Andy Ross

A new description of how the human body and brain communicate to produce emotional states can explain how the human brain might give rise to spiritual experiences, without involving a supernatural presence, according to Dr. Martin Paulus, a psychiatrist at the University of California in San Diego who is also a Zen practitioner.

Called interoception, it offers a radically new view of human anatomy and physiology based on how information from the body reaches the brain and how that information is processed in humans.

The subjective awareness of our emotional state is based on how our brain represents our physiological state, says Dr. Arthur D. Craig, a neuroanatomist at the Barrow Neurological Institute in Phoenix and leading researcher in interoceptive processes.

The brain's centers that integrate sensory reports from the body are found to be highly active in studies of drug addiction, pain in oneself, empathy for others, humor, seeing disgust on someone's face, anticipating an electric shock, being shunned in a social setting, listening to music, sensing that time stands still, and contemplating compassion.

In this view, spirituality, a sense of timelessness, a suspension of self and dissolution of personal boundaries, can be explained in terms of brain physiology.

William James described the physical essence of emotions in 1884 when he stated that we run from a bear not because we are afraid but because we have a racing heart, tight stomach, sweaty palms, and tense muscles. But the neuroantaomical details of how such signals from the body produce feelings and motivations have only recently been worked out. It turns out that the brain exploits several pathways for knowing what the body is up to.

One involves touch. Human skin contains receptors for gentle pressure, deep pressure, sustained pressure, hair follicle bending, and vibration. When one of these touch receptors is activated, fast moving signals are sent to the brain's primary touch map, where each body part is faithfully mapped out. A touch on the arm activates the brain's arm map. A touch on the cheek activates the brain's cheek map, and so on for every inch of the human body.

According to Craig, skin, muscles, and internal organs contain other types of receptors that collect an ongoing report about the body's felt state. Thus there are receptors for heat, cold, itch, tickle, muscle ache, muscle burn, dull pain, sharp pain, cramping, air hunger, and visceral urgency. This collective interoceptive information represents the condition of the body as it strives to maintain internal balance.

Whereas touch signals for pressure and vibration are carried on fast acting fibers to the primary touch map, interoceptive information is carried up the spinal cord and into the brainstem via a wholly different network of slow acting fibers. This information about the body's felt state goes to a region of the brain called the insula.

The insula is a prune-size structure deep in the brain's upper mantle, one in each hemisphere. It is devoted to feeling interoceptive sensations from the body. It is connected to a nearby motor area, called the anterior cingulate, which produces actions responding to those feelings. Both the insula and anterior cingulate are wired to the amygdala, hypothalamus, and prefrontal cortex, which allow the brain to make sense of what the body is telling it.

Humans exploit this wiring to generate complex emotions that other animals cannot fathom. Rats, cats, and dogs, for example, have feelings from the body but they do not pass the information to the insula. It goes to simpler control centers elsewhere in the brain. This means animals cannot experience feelings from the body in the way that humans do, Craig says.

Monkeys and apes do pass interoceptive signals to the insula, but in comparison to humans, their insulas are far less developed. Their emotions are more nuanced than a dog's but more rudimentary than a human's. They do not, in all likelihood, have spiritual experiences.

We humans are anatomically unique in how we collect feelings from the body. Like our primate cousins, we gather information about ongoing physiological activity from the body and represent it in both insulas. But then we take an extra step. Our felt body senses are re-represented in the right frontal insula as social emotions. Our frontal insulas are huge compared to other primates. Social emotions are a hallmark of humankind and interoception is what allows us to feel them.

Social emotions are a mixture of positive and negative elements that activate the right and left frontal insulas differently, Craig says. In general the right insula is involved in energy expenditure and arousal whereas the left insula is associated with nourishment and love. Thus when empathy involves a challenge, the right insula is more active than the left. When empathy involves compassion, the left insula is more active. When we listen to music we don't like, the right insula is more active. When we listen to music we love, the left insula is turned on.

Of course, spiritual experiences involve more than bliss. Physical boundaries seem to dissolve. The ego vanishes. Space expands. Awareness heightens. Craving ceases. Time stands still.

Specializations in human brain circuitry can also explain these phenomena, Craig says. As the right frontal insula collects information from the body, it builds up a set of emotional moments through time. An emotional moment is the brain's image of the "self" at any point in time and is, he says, the basis for our subjective emotional awareness.

Usually, our awareness involves many simultaneous events. But sometimes, in extraordinary moments, our awareness is heightened and everything seems to unfold in slow motion. This is because heightened awareness produces a larger emotional moment, so large that it alters the perception of time.

The sensation of floating out of one's body can be traced to another brain region in the parietal lobe called the right angular gyrus, which is essential for locating ourselves in space, according to Dr. Olaf Blanke, a neurologist at University Hospital in Lausanne, Switzerland. When this area is stimulated with an electrode, essentially shutting it down, people have vivid out-of-body experiences. Such experiences naturally occur when activity in the right angular gyrus is suppressed for any reason, he says.

The right hemisphere contains circuits for recognizing and feeling the self. Imaging experiments show that the medial prefrontal cortex, precuneus, and posterior cingulate cortex light up in imaging studies when subjects think about themselves, their hopes, and aspirations and retrieve episodic memories related to their lives. Our sense of self is located in this circuit, according Dr. Marco Iacoboni, a neuroscientist at the University of California, Los Angeles. When the circuit is suppressed with a device called a transcranial magnet, people can no longer recognize themselves in a mirror.

It is possible to make predictions about the neurophysiology of a spiritual experience. The right angular gyrus or right parietal lobe should go offline, so that the body floats outside itself. Areas of the right brain should deactivate, including the anterior cingulate and frontal regions, allowing the self or ego to float free. The right frontal insula should register a huge global moment so that time appears to stop. Self-awareness will fade. Craving will cease. And the left frontal insula should become active, engendering a sense of pure bliss and love.

Recent neurological studies of religion and meditation support many of these predictions.

At the University of Wisconsin in Madison, psychologist Richard Davidson is studying Buddhist monks as they meditate. In his most recent study, the monks focused on compassion, concentrating on how to alleviate suffering. There was a dramatic increase in insula activity, Dr. Davidson says, as the monks reported a sense of love and compassion. At the same time, their anterior cingulates (the action part of the interoceptive circuit) showed less activity, suggesting the monks attained a state of awareness without motivation.

Paulus, the psychiatrist who is a Zen practitioner, says that the focus on interoceptive experiences, such as concentrating on the breath, is a central aspect of meditative practices in certain Zen schools. The physiological representation of the self in the brain and spiritual experiences that transcend the self are closely connected.

At the University of Pennsylvania, Dr. Andrew Newberg, director of the Center for Spirituality and the Mind, studies Buddhists using a brain-imaging tool called single photon emission computed tomography. The method is not suited for looking at the hard-to-reach insula, he says, but it does show decreased activity in the parietal lobe, which is involved in spatial orientation. When the monks meditate, they perceive the dissolution of personal boundaries and a feeling of being at one with the universe.

Newberg also studied Franciscan nuns while they repeated a prayer and experienced being in God's presence. He noted a similar decrease of activity in the parietal lobe, which suggests that the nuns experienced an altered body sense during prayer. The parietal lobe uses sensory information to create a sense of self and relate it spatially to the rest of the world. When they pray, they lose themselves.

At the University of Montreal, psychologist Mario Beauregard is studying the neural correlates of religious, spiritual, and mystical experiences in Carmelite nuns. When the sisters reported a sense of having touched the ultimate ground of reality, of feeling peace, joy, unconditional love, timelessness, and spacelessness, their insulas lit up, along with the caudate nucleus, parietal lobe, and portions of the frontal cortex.

Such studies do not, of course, prove or disprove the existence of God. I believe that every person is capable of achieving an equivalent state of sublimity without invoking God. There is nothing mystical about it.

Science & Spirit is supported by the John Templeton Foundation.

AR I agree with Sandra, but as a panpsychologist I naturally have more to say.