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
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.
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 →
In 1981 I was an eager post-doctoral fellow, learning to record place cell’s in Jim Ranck’s lab and beginning to understand John O’Keefe and Lynn Nadel’s “Cognitive Map” theory of the hippocampus. One afternoon, while I had a rat in the maze and watched traces of action potentials sweep by on the oscilloscope, Jim Ranck looked over my should and said …
“This is terrific! Place cells are the gateway to understanding how the brain produces cognition.”1
Head-direction cells are neurons that fire when ever a rat’s head is pointed in a particular direction. Discovered by Jim Ranck and first reported at SfN 29 years ago today’s findings are a major update, confirming and extending the cohesive properties of head-direction cell networks.
What does the movie Memento (2000) say about memory? Personal identity? Does it get the facts straight? (mostly, yes). I’ve written a post at the BrainFacts Blog site “Memento and Personal Identity”. Leonard has amnesia; the critical clip from the movie:
(I promise to get back to posting on this site soon. I’m working on two topics)
People who study memory are familiar with the concept of a Memory Palace, a memory scheme for storing information in remembered places. The Memory Palace story is beautifully described in Joshua Foer’s book Moonwalking With Einstein (although it wasn’t clear to me if Einstein was walking on the moon or walking with Michael Jackson). For millennia, mnenonic super stars have memorized gargantuan lists by associating each list item with a location in a virtual home or palace. During learning, the mnemonicist imagines walking through the palace and placing each item in a particular location. At the time of recall, the memorizer imagines walking through the memory palace and, as if by magic, seeing each item where it had been placed. According to this notion, the ability to associate places to content is natural and fairly easy to master. So easy that Joshua Foer, who had no obvious memory potential, became a national memory champion by mastering the technique. I find the accounts impressive and extremely convincing, although I’ve failed miserably when trying to do this. Overall, the Memory Palace phenomenon suggests a strong natural link between location and memory. Some have taken this linkage to suggest that place serves as in indexing system for memory — a kind of lookup table. A point I’ll return to.