Mind reading from brain recordings? ‘Neural fingerprints’ of memory associations decoded


Mind reading from brain recordings? ‘Neural fingerprints’ of memory associations decoded.

ScienceDaily (June 26, 2012) — Researchers have long been interested in discovering the ways that human brains represent thoughts through a complex interplay of electrical signals. Recent improvements in brain recording and statistical methods have given researchers unprecedented insight into the physical processes under-lying thoughts. For example, researchers have begun to show that it is possible to use brain recordings to reconstruct aspects of an image or movie clip someone is viewing, a sound someone is hearing or even the text someone is reading.

A new study by University of Pennsylvania and Thomas Jefferson University scientists brings this work one step closer to actual mind reading by using brain recordings to infer the way people organize associations between words in their memories.

The research was conducted by professor Michael J. Kahana of the Department of Psychology in Penn’s School of Arts and Sciences and graduate student Jere-my R. Manning, then a member of the Neuroscience Graduate Group in Penn’s Perelman School of Medicine. They collaborated with other members of Kahana’s laboratory, as well as with research faculty at Thomas Jefferson University Hospital.

Their study was published in The Journal of Neuroscience.

The brain recordings necessary for the study were made possible by the fact that the participants were epilepsy patients who volunteered for the study while awaiting brain surgery. These participants had tiny electrodes implanted in their brains, which allowed researchers to precisely observe electrical signals that would not have been possible to measure outside the skull. While recording these electrical signals, the researchers asked the participants to study lists of 15 randomly chosen words and, a minute later, to repeat the words back in which-ever order they came to mind.

The researchers examined the brain recordings as the participants studied each word to home in on signals in the participant’ brains that reflected the meanings of the words. About a second before the participants recalled each word, these same “meaning signals” that were identified during the study phase were spontaneously reactivated in the participants’ brains.

Because the participants were not seeing, hearing or speaking any words at the times these patterns were reactivated, the researchers could be sure they were observing the neural signatures of the participants’ self-generated, internal thoughts.

Critically, differences across participants in the way these meaning signals were reactivated predicted the order in which the participants would recall the words. In particular, the degree to which the meaning signals were reactivated before recalling each word reflected each participant’s tendency to group similar words (like “duck” and “goose”) together in their recall sequence. Since the participants were instructed to say the words in the order they came to mind, the specific se-quence of recalls a participant makes provides insights into how the words were organized in that participant’s memory.

In an earlier study, Manning and Kahana used a similar technique to predict participants’ tendencies to organize learned information according to the time in which it was learned. Their new study adds to this research by elucidating the neural signature of organizing learned information by meaning.

“Each person’s brain patterns form a sort of ‘neural fingerprint’ that can be used to read out the ways they organize their memories through associations between words,” Manning said.

The techniques the researchers developed in this study could also be adapted to analyze many different ways of mentally organizing studied information.

“In addition to looking at memories organized by time, as in our previous study, or by meaning, as in our current study, one could use our technique to identify neural signatures of how individuals organize learned information according to appearance, size, texture, sound, taste, location or any other measurable property,” Manning said.

Such studies would paint a more complete picture of a fundamental aspect of human behavior.

“Spontaneous verbal recall is a form of memory that is both pervasive in our lives and unique to the human species,” Kahana said. “Yet, this aspect of human memory is the least well understood in terms of brain mechanisms. Our data show a direct correspondence between patterns of brain activity and the meanings of individual words and show how this neural representation of meaning predicts the way in which one item cues another during spontaneous recall.

“Given the critical role of language in human thought and communication, identifying a neural representation that reflects the meanings of words as they are spontaneously recalled brings us one step closer to the elusive goal of mapping thoughts in the human brain.”

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Topic for Tuesday Jan. 10 Discussion


I’m going to start posting the topics for the tuesday discussions ahead of time so that people can get prepared to debate. Also, if you can’t make it, you at least know what you’re missing! The discussions take place at 10amSLT at the E&S Cafe. See you there!

Topic: Consciousness and Memory Transfer
Cases have been known where children remember exact details from events they shouldn’t know anything about.
For instance, there was the boy who remembers WWII details as if he was a pilot: http://www.dailymail.co.uk/femail/article-1209795/Reincarnated-Our-son-World-War-II-pilot-come-life.html
It appears as though these children are aware of events, details, etc. that they shouldn’t know anything about. Believing that someone can be reincarnated is difficult for scientists to believe or prove.
To think that someones spirit, or consciousness, is just floating around in our world is unprovable at this point in our technology, and highly speculative.
Some people who have organ transplants claim to get the memories, emotions, etc. of the person who had the organ before them. They call it “memory transference”. http://www.namahjournal.com/doc/Actual/Memory-transference-in-organ-transplant-recipients-vol-19-iss-1.html
“…[I]t is pertinent to note that apart from miscellaneous information such as gender, age and cause of death, profiles of organ donors are traditionally concealed from their recipients for psychological reasons.”
“Neuropeptide theory
Pharmacologist Candace Pert proposed that neuropeptides which are stored in every cell act as a sort of biochemical correlate of emotion. It was previously thought that emotions resided in the limbic system in the brain.
According to Pert, neuropeptides are protein-like messenger molecules released by the brain neurons which flow through the body communicating among the
nervous, immune, endocrine, muscle, and skeletal systems via blood, interstitial fluids and the central nervous system, which are all body fluids.
At present, about 100 different peptides are known to be released by various populations of neurons in the mammalian brain.
Neuropeptides have also been found in the heart, which could explain some forms of cellular memories reported by heart transplant recipients (10).”
Here I bring you to a slightly different topic, quantum consciousness. Roger Penrose and Stuart Hameroff collaborated on a theory they call the “OR model of consciousness”. (objective reduction) http://www.quantumconsciousness.org/penrose-hameroff/consciousevents.html
“Within the OR scheme, we consider that consciousness occurs if an appropriately organized system is able to develop and maintain quantum coherent superposition until a specific “objective” criterion (a threshold related to quantum gravity) is reached; the coherent system then self-reduces.”
Cellular Automata
You know what a checkerboard looks like? A bunch of black and white squares? Well, Conway is a mathematician that basically figured out a formula stating that if a white cell has eight cells around it, then if it is given a rule saying that 3 of those cells are white then it needs to turn black.
If every cell was given that rule, it would seem as though patterns were moving across the board as they changed. They’d never settle and become still. Basically this is applied to cells, mostly seen in computer memory.
However it is found in biological cells as well; like in snails shells the patterns are due to this cellular automata. So, these “rules” have also been found in neural tissue. Penrose and Hameroff believe that this is the cause of consciousness, or self-awareness.
In that case, if these cells are moving and changing all the time, at speeds completely undefinable, then they would take time to slow down and finally stop, causing consciousness to end.
Meaning, after death, humans are still conscious. Especially since it takes a little while for the actual cells to die, and the DNA never does. It could be minutes, or hours for all we know, before consciousness stops.
Oxygen flow is what causes brain activity and from there every other kind of process in our bodies. But even after oxygen stops flowing, it takes a little while (not sure exactly how long, varies from person to person as well) for everything to suffocate.
So, these cells could continue going for a very long time before they finally die, if they do.
However, Hameroff, being an anesthesiologist, has “shown that when people are put under for surgery their tubulin dimers fall into a neutral state — instead of being black or white, they all sort of become gray.
When they do that, consciousness goes off; when they start behaving as cellular automata again, consciousness comes back on.”
Memory Transference
For the past decade, in experiments with mice, rats and even lowly flatworms, a number of researchers have claimed success in transferring learning or memory between organisms, usually by feeding or injecting one animal with the brain extract from another.
Those claims have never been completely accepted, however, because other scientists were not always able to duplicate the experiments, and no one could identify the exact nature of the so-called “memory molecules” necessary for such a transfer.
They are admitting that there would need to be some sort of physical form that the memories would need to exist in. They have not yet identified these, but that doesn’t mean they don’t exist.
What if memory could be transferred between organisms? When people die, if their bodies are left to disintegrate, they break down and get absorbed into the soil.
The plants grow from the soil, and are eaten by the animals (which could be human), and the humans eat the animals.
From this one can assume that the cells of the deceased could be absorbed into the bodies of the living.
If memory is stored in active cells or neuropeptides within the cells, they could be stored long enough, based on the cellular automata theory, to be passed on to the other human being.
This could explain why humans have the ability to learn from such a young age. It could explain why we seem to have a general set of knowledge from the time we are babies. How we know how to grow, talk, acknowledge objects, etc.
It could even describe why these children from all over the world have vivid memories of things they should know nothing about.
What do you think? I open the floor.