Good time to remember the Ranck Symposium four years ago, Sept 7, 2016. Jim discovered head-direction cells in 1984, with full-reports in 1990 (pub 1 and pub 2). Jim’s 90th birthday last week. Remarkable set of talk, all in one day. Below is the sequence with video links. (Some messiness with the videos).
May 7, 2019, Andre Fenton and I interview Jim Ranck. The interview is quite long — 90 minutes — and is organized in a decade-by-decade manner. For each segment we discuss Jim’s personal history, his scientific accomplishments, and some major events in Neuroscience.
The interview contains lots of hippocampal minutia. Best suited for people in the field … but I think there are other gems.
The timeline is something like this:
0:00:00 1930-40s birth thru college:
0:04:50 1950s med school, Univ chicago, Public Health
0:20:10 1960s Univ Washington, Biophysics, Brain Impedance, Mich
0:31:00 1970s Hippocampal Neurons, O'Keefe & Nadel
Phil Best, place cells are real
0:48:00 1975 Move to Brooklyn, single neurons
1:08:43 1980s (part 1) computerized data collection and
1:10:40 1980s (part 2) Head-Direction cells. Ego and allocentric
1:22:55 1990s Cognitive Neuroscience, the book.
Most important segment is on discovery and description of Head-Direction Cells,
1:10:40 – 1:23:00
Since childhood I’ve been confused about my emotions. Clearly these inner feelings exist, and are strong, but what are they? Could they be controlled, or even defined? The mystery of emotion was the stimulus that drove me towards the study of the mind and, from there, neuroscience. While I have never directly studied “emotion”, I continue to read about it and think about it.
In the past decade neuroscience and psychology have reached an apparent consensus. An important feature of the consensus is that emotions are conscious feelings of the inner state of the individual. While I appreciate, and largely agree with the consensus, I’m proposing an extension: Emotion as Motivation. Continue reading →
Frequently, perhaps most of the time, I feel I drive on “autopilot”. That is, I drive without awareness of driving. This is especially true when driving along highly familiar routes, such as my 1-hour commute from NJ to Brooklyn. While driving, my clear conscious experience is typically on something else: perhaps what’s on the radio, perhaps a problem at work, or a personal relationship. Clearly, however, my sensory motor system is working. I’m steering, turning, responding to other cars, etc. Others might suggest that I’m “multitasking”, switching between 2 conscious modes, but I don’t feel that’s the case. Continue reading →
A few weeks ago the Nobel Prize Committee announced that John O’Keefe, Edvard Moser and May-Britt Moser would be the recipients of the 2014 prize for Physiology and Medicine for their work in deciphering the code of neurons in the rat hippocampal region. The work is frequently summarized as revealing the functioning of the brain’s GPS system at the level of neurons and networks of neurons. While the GPS part is true, the work is far broader, giving insights into the neural substrate of broad areas of cognition that include memory, planning, creativity and internal thought. What follows are some of my thoughts, focusing on historical roots of the discoveries. Emphasis is on the significance of John O’Keefe and Lynn Nadel’s 1978 book, “The Hippocampus as a Cognitive Map”1.
While lying in bed this Sunday morning a few thoughts on consciousness came to me. Morning insights can be useful or vapid — not sure which these are. But they’ve stuck in my head, like a tune that keeps replaying. I’d like to share them and discuss them. Three semi-awake assertions:
A conscious agent must be able to make a statement of fact
Consciousness is an act of communication
The statement of fact cannot be the state itself; it must be a symbolic representation of state
For me, there are two great guiding metaphors. The first is Plato’s “allegory of the cave“, the notion that phenomena that humans perceive through their senses are weak, distorted shadows of reality. The allegory of the cave describes, accurately, the problem of human science in deciphering underlying truths of the natural world. The second myth is my reading of the central metaphor in Herman Melville’s Moby Dick. I’ll call it the metaphor of the deep diver.Continue reading →
Every ten years the scientific study of consciousness passes a milestone. A decade ago the milestone was the publication of Chrisof Koch’s book “Quest for Consciousness” (2004). “Quest” established the groundwork for a scientific approach to the study of consciousness and described progress using techniques of neuroscience and experimental psychology1. Stenislas Dehaene’s book “Consciousness and the Brain: Deciphering how the Brain Codes our Thoughts” presents a mass of new data and along with new theory. I believe it is a major consolidation; a milestone marking the path towards the next decade.
The function of learning is clear: modifying behavior through experience. Memory, the storage of information that supports learning, is clearly necessary and valuable. Current psychology and neuroscience tell us that there are two memory systems enabled by separate neural systems. Procedural memory relies on reward circuitry and trial-and-error processes to mold efficient behaviors. Episodic memory stores specifc events in the life of the individual — but for what purpose? Continue reading →
Integrated Information Theory (IIT) is Giulio Tononi’s bold concept of the the neural underpinnings of consciousness. Roughly, IIT proposes that the subjective component of consciousness emerges when an information-processing entity has lots of informational states, is interconnected (integrated), and has certain feedback properties. “Phi” is a computed property that can measure the instantaneous amount of integrated information an information in a system. According to IIT, consciousness emerges from any system that has a proper architecture, principally, having large numbers of independent, “integrated” states. Thus, the larger the Phi, the greater the conscious experience. The human brain has large information capacity and an integrated architecture; thus, during the waking state a human brain has lots of consciousness. Continue reading →