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A View From the Top
Thinking of causation as a "two-way street"—along which the passage of information can be inverted—could have implications for the origin of life.
Classic Article: Black Holes, Paradox Regained
In 2004, Stephen Hawking famously conceded that black holes do not devour all information when they swallow matter—seemingly resolving the "black hole information paradox" that had perplexed physicists for decades. But some argue that the paradox remains open, and we must abandon our simple picture of spacetime to unravel it.
FQXi Administrator Zeeya Merali wrote on Sep. 8, 2011 @ 18:43 GMT
To set up this post, which covers the “Memory” session of the FQXi meeting from Bergen to Copenhagen (I’m still playing catch-up on covering the sessions), take a look at the image to the right, courtesy of psychologist Henry Roediger. Both red-shaded rectangles are the same size, but we think they are not. (If you don’t believe me, Roediger created a series of images, trailing down the page, to convince you.) The illusion is meant to highlight how easily our brains can be fooled -- and why false memories are so easy to implant. But more on that in a minute.
I found the psychology talks in the Memory session particularly fascinating, although I guess that a lot what they had to say is old news (in some cases very old news going back to the 70s) to people more familiar will their fields. However, their talks created a lot of excitement amongst the physicist-heavy audience who hadn’t met them before and appreciated the slightly different questions they were asking about the nature of time in psychology. I’ve already mentioned that Kathleen McDermott spoke about “mental time travel” and the idea that imagining the future (a process she termed “pre-experiencing,” which apparently humans do every 16 minutes or so) and remembering the past are intimately related in the brain, and are highlighted in similar ways in fMRI. As some had commented on my earlier post, it’s perhaps not _that_ surprising, given that when we think about what might happen, we have to construct a picture based on events from our past. Nonetheless it was interesting to hear about the history of the development of these ideas (and you can view her slides here).
The term “mental time travel” was coined by psychologist and neuroscientist Endel Tulvig. In the 1980s, he studied the case of a man, dubbed K.C., with global amnesia, who like the protagonist of the movie Memento, could not remember anything from more than a few minutes before. When Tulvig pushed KC to try and think about what he might do tomorrow, he replied that he did not know, and when he tried to think about it, he experienced only a feeling of “a big blankness sort of thing,” or a feeling of “being in a room with nothing there and having a guy tell you to go and find a chair, and there’s nothing there” and that this was the “same kind of blankness’ he felt when he tried to think about what happened yesterday.
To see if the two processes are underlain by the same core cognitive capacity, McDermott used fMRI to scan 21 healthy young adults while they thought about a memory from their past (for example, getting lost), an imagined event involving themselves in the future (for example, going to the library) or an imagined event happening to someone else, at no particular time (the example McDermott used that apparently worked particularly well was “something involving former President Bill Clinton” -- provoking some giggling around the room). She noted that although subjectively we each know when we are thinking about the past and the future and can differentiate the two, the brain activity associated with the two was surprisingly similar.
McDermott’s next question was: “Is there anything special about time?” Further tests on 27 healthy young adults suggested no. In this set of experiments, McDermott and colleagues compared scans while people were remembering a specific memory in a familiar context, envisioning a future memory within familiar context, and envisioning a specific future episode occurring in an unfamiliar context (for instance, at a bullring). In this case, the scans for both past and future were similar if the context was familiar, but not if the future episode was imagined to be occurring in an unfamiliar setting. So it was not the time difference that caused a difference in brain activity, but the spatial difference. It was a new psychological take on the old physics’ question of which is more fundamental: time or space?
(Edited on 14 Sep 2011 to add, thanks to Ian's comment below:) One of the best questions of the session was posed by Simon Saunders' young son Ari, who asked if KC and others with global amnesia can dream, given that dreams involve memories. The answer is that nobody knows, but it's something they'd like to look into.
McDermott then touched on the idea that past “memories” are constructed just as future imaginings are, which ran nicely into Roediger’s talk on false memories that I mentioned at the start of this post. Roediger’s point was not just that it is easy to misremember the past, but that people can be extremely confident about their errors. He gave an example of how poor people typically are at assessing the uncertainties in their answers: “Ask US students what the capital of Australia is and most will say Sydney and will rate their answer with high confidence -- 3 or 4 on a confidence scale of 1-4!”
At his memory lab at Washington University, Roediger and others (including McDermott) were able to create false memories in the lab, and then compare the confidence levels of those reporting the memories with the actual accuracy of their answers. For instance he presented participants with a list of words (bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy) that were all related to another word -- sleep -- which was left off the list. Participants were fooled into thinking that the word “sleep” had appeared on the list, with high confidence, when it had not. Though that’s a highly controlled example, unfortunately the same principles lie behind false eye-witness testimony. “Police line-ups are like a multiple choice exam, where people often just go for the closest match,” said Roediger. “But it’s not emphasized enough that “none of the above” is an acceptable answer.”
(All images courtesy of Henry Roediger.)
this post has been edited by the forum administrator
Thanks for the writeup :) Regarding McDermott's talk, somewhat with delay I thought what distinguishes past memories from imagining the future is not the imagination itself, but how tightly constrained that imagination is, how it has to fit into a timeline. She should ask people to remember some event in the past, and imagine something in the future, and then ask them to change something about it. (Like, your wedding dress was red instead of white or something like that.) And see if that makes a difference.
Eckard Blumschein wrote on Sep. 9, 2011 @ 09:09 GMT
"... past “memories” are constructed just as future imaginings are,"
Of course, mental pictures are not the reality, no matter whether they construct a picture of what really was or what we expect to happen.
However, this seeming equivalence between past and future must not be mistaken as support for unrealistic physics. Hilbert, after him von Neumann and before him others denied what should be called the arrow of causality from cause to effect.
Member Ian Durham wrote on Sep. 10, 2011 @ 01:57 GMT
This was one of my favorite sessions (and that question asked by Simon's son about dreams just blew me away!). You'd think the quantization one would be my thing, given that is what I do. But maybe it was because I'd heard most of those talks before (though Scott at least is entertaining). The one on complexity was actually my favorite.
this post has been edited by the author since its original submission
Thanks for reminding me about Ari Saunders' question on dreams. I had drafted it on to the blog post, but then I wanted to check that Simon and Ari were happy for me to include it. They were, so I have edited the post to add it in. It was a great question!
Georgina Parry replied on Sep. 14, 2011 @ 00:58 GMT
Yes thank you Zeeya. It is a very interesting question.
I do not know about the specific cases discussed. I think in global amnesia there is still sense of identity, recognition of objects and older memories which maybe enough to form the basis of dreams.
Though dreams do often incorporate recent input and may have a function in analyzing/categorization it prior to storage in long term memories. Certainly sleep deprivation makes memory storage less efficient.
The plasticity of memory is interesting. Though it is not new information to me.It is useful evidence,as are the optical illusions too, of the divide between human experience and the verifiable facts independent of that individual's experience. I agree with Eckard " mental pictures are not"... [and never were] "the" [externally existent]..."reality". However as in other types of records such as history books there may be -some- characteristics of the former events included but also possible bias, subjective perspective or opinion, significant omission or substitution of facts or complete falsehood or misinterpretation.
My point of view is that we can not take the interpretation of reality formed by the observer to be the externally existing reality, even though for that observer it is experienced as the external reality. This must alter the way in which the space-time mathematical model relates to the reality that is external to the observer.
It only relates to what is experienced by the observer. This is not just a matter of human consciousness and the alterations made by processing of received data by a complex organism but is also true of simple artificial recording devices.
The output is not the whole of reality. So a complete mathematical model of the output reality is incomplete.
The source of the data is not the whole of reality either, so a complete model of a reality existing independently of observation must be incomplete.
Input data received is not the same as the source of the data or the output produced. The potential sensory data in the environment is not the whole of reality. That data (from which external reality is interpreted) can not be the whole of reality, without a source or a receiver.
Thank you for sharing the interesting information on memory Zeeya.
Wilhelmus de Wilde wrote on Sep. 10, 2011 @ 10:12 GMT
Thanks Zeeya for your adequate reports , those who could not be there still can participate in this way and even think that they have memories of the meeting in Copenhagen.
Our consciuosness is very busy administrating and especially completing the signals that we receive from our outside world, take for instance sight : in fact we "see" (in coulor and detailed) with each eye only the surface of a dime held an armlength away, the rest is completed by our mind (based on former information), this is only 5% of the total, so you see the pink elephant can be there without being "observed", it takes always 80 milliseconds before signals arrived and are being "assembled" by our consciousness, so our NOW moments are always in the past, all these processes lead to our construction of the future which is in fact the same as the construction of the past, most of it is achieved by our brains/minds/consciousnes.
Think for example about INFINITY, you may go back and forth, but in a way you understand what I mean with the word infinity , do not accept limits, but also think about ZERO, absolutely NOTHNG, you will remark it is as difficult as the infinity, but it gives us a good idea of the things we can achieve with our consciousness (especially in mathematics).
Jason Mark Wolfe wrote on Sep. 14, 2011 @ 03:23 GMT
Someone around here said that time doesn't pass for a photon. Consider this:
Photons have frequency. They cycle so many times per second. If anything, a photon acts like a clock. In fact, the electromagnetic field of a laser, whose Poynting vector is S = E X B, can sometimes be made to rotate, like the hands of a clock.
It makes more sense to interpret photons as tiny clocks.
Have read more about the talk on perception of time. It was interesting that an attempt was made to see if a timer could be better read when in a stressful situation. That it couldn't is very interesting in itself but does not surprise me.
The researcher seems to have concluded that the reported effect is not due to slowing of time but to do with memory storage. While I think memory has it part to play I do not think it can account for the mis-interpretation of duration -during- the life threatening events themselves.
I do not think time -itself- is slowing. The observer only experiences it to be slower from their perspective. It is my hypothesis that at times of -extreme- danger, difficult to simulate for experimental purposes, the subconscious mind is very active in seeking a plan of escape or minimization of injury and so sends less information to the conscious mind updating its state of awareness.
Having been in a car crash I find, upon reflection, the dramatic slowing of time between inevitable impact and the impact itself and the seemingly inappropriate sense of calm interesting. Since both occur together it seems to me likely that the brain was preoccupied with searching through former experience for solutions to the situation rather than with updating the conscious mind with lots of processed information. I doubt that it would have been possible to simultaneously read a timer. I did not experience life flash back, just quietness. I am aware that those in near death experiences do sometimes report seeing their life flash by. That I think may be trickling of the data being hurriedly analyzed by the sub conscious mind into consciousness.
Perhaps a research project could be conducted with the help of Formula 1 or Formula Ford racing drivers, stock car drivers, or stunt car drivers who have car crashes as an unfortunate occupational hazard. The roller coaster ride, while stressful, might not have been sufficiently life threatening to cause the dramatic temporal mis-interpretation that I am talking about. The sub conscious mind would have been aware of the safety of the situation.
That might also be a problem with using racing drivers. As their vehicles are designed to respond to crash situations in such a way that the vehicle sustains widespread damage but the driver remains protected within the roll cage or similar safe zone. The driver is also protected by helmet and specialized clothing. Which is quite different from a random car crash on the roads. However the suddenness and unpredictability of the crash could still have an effect on the response of the driver, unlike the response of the roller coaster rider.
From my point of view it is further evidence that the spatial and temporal reality produced and experienced by the observer is not equivalent to the external reality that exists unobserved.
FQXi Administrator Zeeya Merali wrote on Oct. 21, 2011 @ 13:52 GMT
I've just added new video to the original post. If you're interested in how false memories can be implanted in the lab, and want to see how frighteningly easy it is for eye-witnesses to mix up people in criminal cases (with genuine case studies), Henry Roediger's talk is one to watch.