Psychology & Neuroscience

Checkerboard Illusion

Square A and square B are exactly the same shade of gray. So, scratch "objective reality" off the list of things you're personally in contact with.

Realistic AI? Not Possible Now; Science Videos say "Forget It!"

Two amazing videos recently appeared in the prestigious journal Science.

The first is an animation showing the detail in a (glutamatergic) synapse.

The second video, based on hundreds of electron micrographs stitched together, shows the impossible complex ultrastructure of the neuropil — the impenetrable forest surrounding synapses. (Even the great Cajal was blown away!)

The key question is — how much of that fine detail must be modeled to replicate the brain's performance? My confident assertion is that much more is required than is incorporated into current brain-inspired AI models. (Multi-layer convolutional neural nets are just one piece — even when combined with reinforcement learning.)

My Stanford Lecture Notes: AI and Neuroscience

Stanford Oval

These are my detailed notes on the many lectures I attend every week at Stanford: neuroscience, psychology, AI, cardiology, and molecular biology. These feature cutting edge research by our faculty, students, and visiting superstars. My WebBrain contains hundreds of archived lecture notes (last updated January, 2020).) To obtain more recent notes, contact me.

Conscious Driverless Cars!

Living in Silicon Valley, I'm used to watching Google's self-driving cars dodge me as I ride around town on my electric bike. But, are they conscious?

No (not yet!) But, here I address what it will take to make them conscious — and, why would you bother? Also, what's the difference between machine vision and mammalian visual perception? Led by advances in neuroscience, computer vision researchers are rapidly accelerating (but have quite a ways to go.)


I've been fascinated by the neurobiology of consciousness for fifty years.

How is it possible for neural circuits to produce pain, pleasure, and our entire perceived world?

Consciousness is the master illusion — the engineering product of hundreds of millions of years of evolution.

Except for career excursions into medicine and into computer science, my central interest for decades has been in two questions —

  • How does the brain produce consciousness?
  • Can it be done in silicon?

Stan Dehaene's Consciousness and the Brain

This is an outstanding work by one of the world's top researchers of consciousness. Since the death of William James and the mid-20th century ascent of Watson, Thorndike, and Skinner, consciousness all but disappeared (as a field of study) from American psychology. Europeans, especially the brilliant Stan Dehaene, are leading the current revitalization.

This is a must-read for neuroscientists and psychologists.

Consciousness - What, Who, When, and Why

In 2010 I gave a presentation at the Bay Area AI Meetup.

Here's the video (thank you, Monica!) This is for a (non-neuroscience) general audience.

In this broad overview I stress the obvious critical role played by consciousness for our survival.

I introduce comparative neuroanatomy and discuss (in broad terms) the phylogeny of consciousness

Consciousness confers a pivotal advantage in a fiercely competitive and changing world.

(See my essay: The Mystery of Consciousness: Introduction.)

Prospects for Immortality: Brain Preservation

Here's what my head-freezer friends have signed up for the minute they die. Agents from Alcor will lop off the head of the deceased and (after some prep) will drop it into a tank of liquid nitrogen for eternity (until the person can be resurrected.) I haven't signed up with Alcor, but ask me again in 2030.

But meanwhile, I'm on the Science Advisory Board of the Brain Preservation Foundation (BPF), which seeks to advance the state of the art by awarding cash prizes for best research. "But, you ask, "are you for real?" The answer is "yes (maybe!)"

Here, neuroscience MD, PhD candidate Andy McKenzie elicits my opinions. In brief: molecular whole brain preservation may be possible by 2040. Resurrection in silicon may not be possible (if ever) until well after 2100. (So, keep eating vegetables and exercising — that's my best longevity advice for now!)

By the way, we just awarded our BPF small mammal cash prize to Robert McIntyre, who spearheaded the team at 21st Century Medicine. If you want to see the state of art, look at his work Aldehyde Stabilized Cryopreservation in Cryobiology.

2018 Update: Robert McIntyre also founded Nectome, a company promoting end-of-life euthanasia to facilitate brain preservation for the purpose of future brain uploading. He had a research collaboration with MIT superstar neuroscientist Ed Boyden that MIT just terminated. Although McIntyre's brain preservation techniques are very real and "cutting edge" as is Boyden's neuroanatomical research, the notion of brain uploading to resurrect consciousness is fanciful science fiction. But, the future is not yet written.

Near Death Experiences: In the Desert with Pim Van Lommel

Out in the desert foothills of Tucson in 2010, I interviewed NDE researcher and cardiologist, Pim Van Lommel, who organized the largest study of NDEs thus far.

My view is that the patients studied by Dr. Van Lommel were genuinely conveying their experiences, but their perceptions were hallucinatory.

Dr. Van Lommel believes they were quite real and that the patients were actually seeing events outside their bodies. He believes this requires a fundamental revision of neuroscience and physics. I doubt it.

Steve Pinker in the Heart of the Amazon

In 2008 I went to the Amazon on a trip with the Center for Inquiry (CFI). (Normally, I don't go anywhere that can't be reached by bike.)

The world famous Harvard cognitive scientist, Steven Pinker, was our guest lecturer.

This is a photo essay about the trip, Steve, Paul Kurtz (CFI's Founder and leading luminary), and our traveling band of skeptics.

Brain Activity Map: Every Spike from Every Neuron

This (seemingly sci-fi) proposal to map every single spike in every neuron was batted around in mid-2012 by Kavli Foundation scientists. I got wind of it shortly thereafter and circulated it around Stanford, where it aroused considerable skepticism

But, one of the neuroscientists who took it seriously was Professor Bill Newsome, a co-chair of our Stanford Neurosciences Institute.

Roll the clock forward to January, 2013. Unbeknowst to us, this proposal had become the centerpiece of President Barack Obama's State of the Union — his ten year moonshot.

Next, roll the clock to April, 2013. Prof. Newsome gets a call from NIH Director Francis Collins asking him to co-chair the working committee to formally draft the proposal. How was I so clairvoyant? A combination of paying close attention and luck.

Why Red Doesn't Sound Like a Bell

This is my review of Kevin O'Regan's 2011 book, thus titled.

This is a beautifully written book, which, unfortunately, Oxford Press has overpriced. Similar material (by the author) is, however, freely available online.

Sensorimotor theory (SMT), while generative, has essential flaws.

Nonetheless, the book itself is a clear, delightful introduction to the problems posed by qualia, which "color" everything we know.

Consciousness as Global Cortical Resonance

In 2009 I reviewed this key paper from Stan Dehaene's group on the neural correlates of consciousness.

His research was conducted on ten human subjects using intracranial electrode arrays (ECoG.)

Electrocorticography presents a rare opportunity to track consciousness in real-time (milliseconds). MRI BOLD signal, developing over seconds, is usually too slow — although it does provide the "big picture."

The article claims that consciousness is a global reverberatory state involving all cortical lobes.

Even better than this paper is Professor Dehaene's 2014 book Consciousness and the Brain which greatly expands our knowledge of the neural mechanisms underlying consciousness.

Artificial Consciousness

This is a letter I sent to MIT's Technology Review in 2007 responding to an article by Yale computer scientist David Gelernter: Artificial Intelligence Is Lost in the Woods in TR in July/August 2007.


(In the first epoch of Bob (1965 to 1990), AI was lost in the woods. Now (thanks to the resurgence of neural nets,) it's doing much better.

Some nervous nellies are worried that AI's making too much progress — and that soon it may pose a threat.)

I say "bring it on, baby!" (Autonomous humans are the big threat!)


A brief bio I wrote a decade ago about my life-long interest in the mind/body problem.

Woody Allen would say, "which is it better to have?"

Mind and Brain: My Life Story

A chapter length autobiography of my interest in the mind/brain and software/computer relationship (downloads as a WORD document.)

I was writing this for a book. My current view is that books are almost obsolete.

Why buy a book when you can read stuff free on the web? (And, the public's attention span is at most a month. As an author, why bother?)

As an old guy, however, all my life I've enjoyed reading a book at bedtime (and actually turning the pages.) I'm now re-reading Kevin Kelly's What Technology Wants. I also love all of Steve Pinker's books.

Knowledge and Intelligence

Another chapter length essay (an early draft) on the power of knowledge.

Yes, intelligence is multi-dimensional — academic, social, emotional, motoric, spiritual , but that's later.)

TheBrain: Keep Track of Everything

This is an unsolicited, unpaid testimonial for TheBrain, a software program I use to keep track of everything. This program is so useful, it gets its on monitor in my four monitor set-up.

I've used TheBrain for a decade. A quite handy version is available for free.

By the way, I've repeatedly refused solicitations to carry ads of all sorts on my website.

I take my inspiration from philanthropists Jimmy Wales (Wikipedia founder — Jimmy gave it away!) and from Craig Newmark (Craigslist founder.)

Cafe Wall Illusion

All lines are parallel (including the horizontal ones) in the Cafe Wall Illusion.
Objective reality is out there, but it can't be experienced — ever.