Manipulation of electrons using light

"Controlling electron spins by light: Researchers of HZB manipulate the electron spin at the surface of topological insulators systematically by light" 
2014-03-27 from apl. Prof. Dr. Oliver Rader [Rader (@helmholtz-berlin.de] [https://web.archive.org/web/20140523032711/http://www.helmholtz-berlin.de/pubbin/news_seite?nid=13952;sprache=en;typoid=3228]:
Topological insulators are considered a very promising material class for the development of future electronic devices. A research team at Helmholtz-Zentrum Berlin (HZB) has discovered, how light can be used to alter the physical properties of the electrons in these materials. Their results have just been published by the renowned journal "Physical Review X".
The material class of topological insulators has been discovered a few years ago and displays amazing properties: In their inside, they behave electrically insulating but at their surface they form metallic, conducting states. The electron spin, i. e., their intrinsic angular momentum, is playing a decisive role. Their sense of rotation is directly coupled to their direction of movement. This coupling leads not only to a high stability of the metallic property but also enables a particularly lossless electrical conduction. Topological insulators are, therefore, considered interesting and promising candidates for novel devices in information technology.
A particularly innovative approach is to try and influence the electron spin at the surface in such devices by light. HZB researcher Prof. Oliver Rader and his team have discovered by which means the spin at the surface of topological insulators can be altered. To this end, the researches performed experiments with light of various energies or wavelengths.

The wavelenght counts -
At the synchrotron radiation source BESSY II they investigated the topological insulator bismuth selenide (Bi2Se3) using a method called "spin-resolved photoelectron spectroscopy" – and gained astonishing insights: They found an astonishing difference depending on whether the electrons at the surface of the material are excited with circularly polarized light in the vacuum ultraviolet (50-70 electron volts, eV) or in the ultraviolet spectral range (6 eV). They could demonstrate that they can measure the spin of the electrons without changing it at higher energies which are typically used at synchtrotron light sources. "When excited at 50 eV, the emitted electros display the typical spin texture of topological insulators", Dr. Jaime Sánchez-Barriga, who conducted the experiments, explains. "The electron spins are in the surface aligned on a circle, similarly to a traffic sign for roundabout." This is the ground state of the electrons in the surface of topological insulators."
When excited by low-energy circularly polarized photons (6 eV), the spin of the electrons moved completely out of the surface plane. Above all, they adopted the spin orientation imposed by the right- or left-circularly polarized light. This means that the spin can be systematically manipulated – depending on the light that is used. The scientists can also explain the entirely different behavior at different energies which they attribute to symmetry properties. "Our result delivers important insight how lossless currents could be induced in topological insulators", Oliver Rader explains. "This is important for the development of so-called optospintronic devices which could enormously enhance the speed at which information is stored and processed."

DFG Priority Program -
Due to the high potential promised by topological insulators, the German Research Foundation DFG initiated the Priority Program "Topological Insulators: Materials – Fundamental Properties – Devices". Prof. Rader coordinates this program which aims at an improved understanding of the physics of the surface states in topological insulators.

Publication: Photoemission of Bi2Se3 with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation? Phys. Rev. X 4, 011046 – Published 24 March 2014; J. Sánchez-Barriga, A. Varykhalov, J. Braun, S.-Y. Xu, N. Alidoust, O. Kornilov, J. Minár, K. Hummer, G. Springholz, G. Bauer, R. Schumann, L. V. Yashina, H. Ebert, M. Z. Hasan, and O. Rader.

The picture shows the characteristic spin texture (arrows) in a topological insulator (bottom) and how it is either probed by circularly polarized light (top) or manipulated by it (middle). Picture: Rader/Sachez-Barriga/HZB



"Photoemission of Bi2Se3 with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?"
Phys. Rev. X 4, 011046 – Published 24 March 2014
from: J. Sánchez-Barriga, A. Varykhalov, J. Braun, S.-Y. Xu, N. Alidoust, O. Kornilov, J. Minár, K. Hummer, G. Springholz, G. Bauer, R. Schumann, L. V. Yashina, H. Ebert, M. Z. Hasan, and O. Rader
[http://journals.aps.org/prx/abstract/10.1103/PhysRevX.4.011046]:
ABSTRACT -
Topological insulators are characterized by Dirac-cone surface states with electron spins locked perpendicular to their linear momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50–70 eV) with linear or circular polarization indeed probe the initial-state spin texture of Bi2Se3 while circularly polarized 6-eV low-energy photons flip the electron spins out of plane and reverse their spin polarization, with its sign determined by the light helicity. Our photoemission calculations, taking into account the interplay between the varying probing depth, dipole-selection rules, and spin-dependent scattering effects involving initial and final states, explain these findings and reveal proper conditions for light-induced spin manipulation. Our results pave the way for future applications of topological insulators in optospintronic devices.

POPULAR SUMMARY -
The electric conductivity at the surface of a three-dimensional topological insulator relies on spin-polarized electrons in a peculiar manner: Electrons in a left-moving current have their spins directed opposite to those in a right-moving one. For this condition to be fulfilled in all directions on a surface, the spins have to be confined to the surface plane. But how do we determine the orientation of the spins? The photoelectric effect, where electrons are excited to a higher-energy state (referred to as a “final state”) and then liberated from a solid surface by ultraviolet or x-ray light, has been used for this purpose. What is not clear is if, and how much, the light used in the measurement itself reorients the electron spins.
A recent theoretical work followed by a laser experiment using 6-eV photons reported that the use of circularly polarized light will always realign the electron spin with the direction of the incident light and control its orientation (parallel or antiparallel) through the direction of light polarization. In this combined experimental and theoretical paper, we report new findings, revealing that whether or not the spins of the photoexcited electrons are reoriented actually depends on the full symmetry properties of their final states.
We have studied the response of the spins of the photoelectrons from a prototypical topological insulator (bismuth selenide) in a wide range of photon energies. We have found that for typical photon energies employed in photoemission experiments (about 50 eV), the spins remain oriented within the surface plane. For very low photon energies, however, the photoemission process fully rotates the spin out of this plane, and its orientation is indeed controlled by the direction of circular polarization of the light.
Beyond the fundamental physics, there is also a practical question: Can light be used to manipulate the spin orientations of the surface currents of topological insulators toward the goal of light-controlled spintronic devices? The insights we have gained may prove crucial in answering this question.

Computing quantum reality, or, the limitless realm of parallel realities

"Record quantum entanglement of multiple dimensions"
2014-03-25 from UNIVERSITAT AUTÒNOMA DE BARCELONA [http://www.uab.es]
[https://web.archive.org/web/20140523031636/http://www.uab.es/servlet/Satellite/latest-news/news-detail/record-quantum-entanglement-of-multiple-dimensions-1096476786473.html?noticiaid=1345668721554]:

An international team of researchers, with participation from the UAB, has managed to create an entanglement of 103 dimensions with only two photons. The record had been established at 11 dimensions. The discovery could represent a great advance toward the construction of quantum computers with much higher processing speeds than current ones, and toward a better encryption of information.
The states in which elementary particles, such as photons, can be found have properties which are beyond common sense. Superpositions are produced, such as the possibility of being in two places at once, which defies intuition. In addition, when two particles are entangled a connection is generated: measuring the state of one (whether they are in one place or another, or spinning one way or another, for example) affects the state of the other particle instantly, no matter how far away from each other they are.
Scientists have spent years combining both properties to construct networks of entangled particles in a state of superposition. This in turn allows constructing quantum computers capable of operating at unimaginable speeds, encrypting information with total security and conducting experiments in quantum mechanics which would be impossible to carry out otherwise.
Until now, in order to increase the "computing" capacity of these particle systems, scientists have mainly turned to increasing the number of entangled particles, each of them in a two-dimensional state of superposition: a qubit (the quantum equivalent to an information bit, but with values which can be 1, 0 or an overlap of both values). Using this method, scientists managed to entangle up to 14 particles, an authentic multitude given its experimental difficulty.
The research team was directed by Anton Zeilinger and Mario Krenn from the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences. It included the participation of Marcus Huber, researcher from the Group of Quantum Information and Quantum Phenomena from the UAB Department of Physics, as well as visiting researcher at the Institute of Photonic Sciences (ICFO). The team has advanced one more step towards improving entangled quantum systems.
In an article published this week in the journal Proceedings (PNAS), scientists described how they managed to achieve a quantum entanglement with a minimum of 103 dimensions with only two particles. "We have two Schrödinger cats which could be alive, dead, or in 101 other states simultaneously", Huber jokes, “plus, they are entangled in such a way that what happens to one immediately affects the other”. The results implies a record in quantum entanglements of multiple dimensions with two particles, established until now at 11 dimensions.
Instead of entangling many particles with a qubit of information each, scientists generated one single pair of entangled photons in which each could be in more than one hundred states, or in any of the superpositions of theses states; something much easier than entangling many particles. These highly complex states correspond to different modes in which photons may find themselves in, with a distribution of their characteristic phase, angular momentum and intensity for each mode.
"This high dimension quantum entanglement offers great potential for quantum information applications. In cryptography, for example, our method would allow us to maintain the security of the information in realistic situations, with noise and interference. In addition, the discovery could facilitate the experimental development of quantum computers, since this would be an easier way of obtaining high dimensions of entanglement with few particles", explains UAB researcher Marcus Huber.
Now that the results demonstrate that obtaining high dimension entanglements is accessible, scientists conclude in the article that the next step will be to search how they can experimentally control these hundreds of spatial modes of the photons in order to conduct quantum computer operations.

Beware, Thee, of toxic chemical cocktails

“Mountain View police warn of new psychedelic drug after teen overdoses"
2014-03-12 by Mark Gomez [http://www.mercurynews.com/bay-area-news/ci_25328399/mountain-view-police-warn-new-psychedelic-drug-after%20sanfrancisco.cbslocal.com/2014/03/12/mountain-view-student-hospitalized-after-apparent-overdose-on-designer-drug-doc/]:
MOUNTAIN VIEW -- Police are warning students and their parents about a new psychedelic street drug after a high school student overdosed and was found unresponsive Tuesday on the Stevens Creek Trail.
The student -- whose age, gender and school were not released -- was rushed to a hospital. Police did not provide any immediate update on the student's medical condition.
The suspected drug used by the student is "DOC," a fairly new psychedelic street drug similar to LSD, according to police. The drug, a combination of hallucinogenic and amphetamine chemicals, has very long-lasting effects and is extremely dangerous, according to police.
Police were originally concerned a bad batch had hit the street but have since determined the overdose was an isolated incident, according to Sgt. Saul Jaeger.
"All the medical information we're getting about this particular drug, there are different reactions for different people," Jaeger said.
Mountain View police are working with Santa Clara County Public Health, the Mountain View Los Altos High School District and local hospitals to identify similar incidents and trends.
On Tuesday a letter signed by Mountain View Los Altos School District Superintendent Barry Groves and Mountain View Police Chief Scott Vermeer was sent to parents and students within the school district telling them of the incident and providing information about the drug.
"Really what it comes down to is communication with your kid," Jaeger said. "You want to talk with them about this type of thing."

Caffeine

“Caffeine” by T. R. Reid, photographs by Bob Sacha, from "National Geographic" magazine, January 2005:

Richard Wurtman knocks back at least a quart of coffee a day. The MIT medical researcher credits the 600-plus milligrams of caffeine in his daily mugs with sharpening his mind and focusing his creativity.

No fan of what he calls “the waves of sugar” in Coke, MIT graduate student Nathan Wilson mixes his own power tonic for a long night’s work in the neuroscience lab. He quarters a 200-milligram caffeine pill and dissolves 50 mg in Gatorade. Wilson is part of a huge market: Every year U.S. consumers spend 30 million dollars on caffeine tablets and an estimated 50 billion dollars on caffeinated soda.

Living on a 43-hour “day (29 hours awake, 14 asleep) during a month-long study at Brigham and Women’s Hospital in Boston, Conor O’Brien (left) and 15 other volunteers took a pill every waking hour. Some got placebos, some got caffeine. Project head Charles Czeisler and his team concluded that frequent small amounts of caffeine maintain alertness better than the classic morning jolt from a big cup of coffee – fine-tuning our understanding of the drug’s numerous physical effects.

Military studies of subjects who hadn’t slept for 48 hours showed that 600 mg of caffeine improved alertness and mood as much as 20 mg of amphetamine.
Allowed just three hours of sleep in 52 hours of running, target shooting, and vigilance excercises, weary soldiers in Canada’s Operation Nighthawk tested chewing gum with 100 milligrams of caffeine per stick as a “fatigue countermeasure.” Absorbed directly through membranes in the mouth, chewed caffeine goes to work three times faster than caffeine in drinks or pills.
 
Going without caffeine for a day and a half increases bloodflow to the brain, which may explain why people get headaches, when they first give it up.
Your Brain on Caffeine -
Feel fuzzy-headed without your morning java? When users accustomed to a daily average of 650 milligrams of caffeine (about three 12-ounce cups of coffee) went without their usual fix, visual and auditory activity in the brain (indicated by bright colors in the scans at left) was low. Giving them 250 mg of caffeine boosted activity – but only up to levels equal to those of infrequent users who’d had no caffeine. “If you regularly get a hefty dose,” says Wake Forest University researcher Paul Laurienti, “you need it for your brain to function normally.”
Paul Laurienti, Advanced Neuroscience Imaging Research Laboratory, Wake Forest University School of Medicine (All brainscan images)

Here’s what’s missing from your decaf: A shovelful of caffeine and wax residues rises from the muck as workers decaffeinate coffee beans at a plant in Trieste, Italy.

The caffeine extracted from coffee beans to make decaf is sold to drug and soft drink manufacturers. Studies at the University of Connecticut’s Human Performance Laboratory suggest that caffeine does not cause dehydration in moderate amounts. Contrary to popular belief, our bodies retain as much fluid from caffeinated liquids as they do from water. That’s good news for Finns, who drink more coffee per capita than anyone else. The average Finn ingests an estimated 145 grams of caffeine a year.

Human Evolution consciously continues...

"Scientific Proof That We Are Becoming Literal Gods", 2014-01-30 by Steven Bancarz [https://web.archive.org/web/20140330185633/http://www.spiritscienceandmetaphysics.com/scientific-proof-that-we-are-becoming-literal-gods/]: (sources numbered in parentheses)
What if I told you that in 1000 years, we will look like petty cavemen in our current physical and mental state compared to future humans?  There is an overwhelming amount of scientific evidence that proves that not only are our physical bodies evolving at an accelerated rate, our consciousness is as well.  We are indeed in the evolutionary fast lane, and perhaps we are witnessing the prophecies of apotheosis in action.   Our consciousness and bodies are evolving at a rate never seen before in the history of the earth

We can look around the world and see the signs of dramatic spiritual evolution as we continue to actualize our fullest potential.  There is an awakening happening right now, and December 21st 2012 really did mark the dawn of a new age of enlightenment.  But as this global awakening is happening, our physical vehicles and intelligence levels are also evolving as we step into the light of this new age.
In 2007, Dr. John Hawks, professor of anthropology at the University of Wisconsin-Madison, published an article in the peer-reviewed journal Proceedings of the National Academy of Sciences (PNAS) titled “Recent acceleration of human adaptive evolution”.  This article showed that positive selection within human beings has occurred at a rate 100 times higher than any other time in human history, and that this massive acceleration within evolution has happened particularly within the last 5000 years(3).
The study specifically looked for DNA sequence variation known as SNPs which are mutations at a single point on a chromosome. As indicated in Health and Medicine Week, “The researchers identify recent genetic change by finding long blocks of DNA base pairs that are connected. Because human DNA is constantly being reshuffled through recombination, a long, uninterrupted segment of LD is usually evidence of positive selection. Linkage disequilibrium decays quickly as recombination occurs across many generations, so finding these uninterrupted segments is strong evidence of recent adaptation, Hawks says” (4).
The researchers concluded that as the population of human beings continues to increase, the acceleration effect of evolution has also increased because of the amount of room there is for new mutations to occur and be passed throughout the population. According to the original journal article publication, approximately 1800 genes, or 7% of our entire genetic system, have experience recent positive selection.  They add that “To the extent that new adaptive alleles continued to reflect demographic growth, the Neolithic and later periods would have experienced a rate of adaptive evolution >100 times higher than characterized most of human evolution.”(5)
With the cultivation of agriculture, the constant changes and experimentation in diet (such as the adaptive tolerances to lactose in milk), the exposure to diseases (such as the introduction of the CCR5 gene to make people resistant to AIDS), and the massive spike in human population within the last 10,000 years, nature has been presented with the optimal breeding grounds for positive selection and new adaptive mutations in the introduction of a massive gene pool and constantly changing environments(6).
For example, in only the past few millennia, Europeans have experienced rapid changes in the gene for a protein that transfers potassium ions in and out of taste buds and nerve cells, as well as changes in genes associated with Alzheimer’s disease and even cancer.(7) John Hawks boldest of claims was recorded on the University of Wisconsin-Madison website, where Hawks says: “We are more different genetically from people living 5,000 years ago than they were different from Neanderthals.”(8) In other words, if you take a human being from 3000 BC such as an ancient Egyptian, you will find that they are more similar to Neanderthals in terms of their genetics than they are to us.
Anthropologist and geneticist Dr. Henry Harpending from the University of Utah also participated in conducting this study, and told National Geographic that “If humans had always evolved at this rate, the difference between modern humans and chimps should be 160 times greater than it really is.”(9) There is a vast body of empirical evidence that suggests that human beings have recently been the subjects of accelerated natural selection within genetic information.
There is also evidence that this recent acceleration in evolution is not only biologically physical, but is also mental in terms of intelligence. J.R. Flynn, professor of political science at the University of Otago in New Zealand, discovered that IQ scores across the globe have went up 3 points on average per decade for each decade for as long as IQ test scores have been recorded (which has been since 1910 in the United States).  This means that someone that scored in the top 10% on the IQ test 100 years ago would now been in the weakest 5%.  These increases have been occurring at a steady rate amongst both male and female genders and have been empirically verified in over 20 countries(10) (see Figure 1).
The average IQ score has always been set to 100, so if a person passes the IQ test with a score of 130, they are among the higher end of performers, and a score of 80 would deviate far from the average raw score.  What is striking is that IQ scores have had to be continuously made more difficult over the last century to keep the mean score at 100. Flynn discovered that the greatest differences were found in culturally reduced tests and fluid intelligence. Fluid intelligence is the ability to think rationality, abstractly, and find solutions to novel problems independent of acquired knowledge.
He makes adamant the fact that these are not learned-content gains through more information being accessible to people, as this would only reflect crystallized intelligence regarding the application of learned knowledge (11).  And furthermore, other environmental factors such as more education and better economic situations are impoverished when trying to adequately explain the gaps in some of the cases, such as the increase in IQ scores by a total of 20 points in 30 years by the Dutch.

As Flynn states in one of his original papers “The international data fall into the same pattern as the American data. Gains are about 18 IQ points per generation (30 years) on Ravens, somewhere between 9 and 18 points on Wechsler and Stanford–Binet tests, about 9 points on purely verbal tests, small or nil on Wechsler subtests such as arithmetic, information, and vocabulary”(12).
The Ravens test measures reasoning abilities using abstract objects independent of language, writing, and reading.  This means that these test increases are not a result of people having more access to knowledge and information, but shows that on the contrary, the most significant results were indicated in testings that involve pure problem-solving intelligence, such as identifying non-verbal patterns and relationships.(13) Environmental impacts that can explain these increases in IQ scores have yet to be identified, and are still being speculated upon.  These are some of the most important discoveries in psychology, which Flynn calls “a cultural renaissance too great to be overlooked”(14).
Contrary to some of the scientific consensus, human evolution is undergoing dramatic increase in terms of genetics and intelligence.  We now have scientific proof that evolution is not merely a matter of cultural ingenuity and social conditionings.  Nor is it exclusively reserved for physiological adaptation, but is in fact a concrete measurable phenomenon in human psychology that happening within our species right now.  Evolution can now be spoken of in something that is currently in a state of progression towards complexity, as we have seen from the evidence of geneticists and psychologists alike.
Is this accelerated state just one random hiccup that will plateau in the near future? Will we continue to evolve at this exponential rate from this point forward? Are we witnessing the physical manifestation of the ancient prophecies of human apotheosis in action?  This area remains ripe for investigation, and insofar as the conditions in which this evolution is occurring remain present (population increases, environmental changes, technological and intellectual refining) we should see this effect sufficiently sustained as we enter this new age of evolution and continue to explore this exciting frontier.
In 1000 years, we will be literal gods in comparison to our current state.  We will have technologies and abilities that we could only dream of right now, and our bodies will be so much more evolved that we will look back a millennium and wonder how ancient man lived such primitive lives with such archaic bodies.  Maybe we really are entering the Golden Age of spiritual and physical evolution that so many ancient cultures spoke of.

Sources:
1. The Guardian. “Is human evolution finally over?”. The Observer. 03 Feb. 2002. [https://web.archive.org/web/20130826001713/http://www.theguardian.com/science/2002/feb/03/genetics.research]
2.  Furness, Hannah. “Sir David Attenborough: Humans have stopped evolving”. The Telegraph. Sept 2013. [http://www.telegraph.co.uk/science/evolution/10297124/Sir-David-Attenborough-Humans-have-stopped-evolving.html]
3. “Genome study places modern humans in the evolutionary fast lane.” Health & Medicine Week. 24 Dec. 2007: 271. Academic OneFile.
4. Ibid.
5. Hawks, John. John Hawks, Eric T. Wang, Gregory M. Cochran, Henry C. Harpending, and Robert K. Moyzis. “Recent Acceleration of Human Adaptive Evolution”. PNAS, 2007 104 (52) 20753-20758; published ahead of print December 17, 2007, doi: 10.1073/pnas.0707650104
6. See 3.
7. “Darwin’s children; Human evolution.” The Economist 15 Dec. 2007: 88(US). Academic OneFile.
8. Matmiller, Brian. “Genome study places modern humans in the evolutionary fast lane”. University of Wisconsin-Madison News. 10 Dec. 2007. [http://www.news.wisc.edu/14548]
9. Roach, Joe. “Evolution is Speeding Up, Study Says”. National Geographic. 11 Dec. 2007. [http://news.nationalgeographic.com/news/2007/12/071211-human-evolution.html]
10. Passer, Michael W. Ronald E. Smith, Michael L. Atkinson, John B. Mitchell, Darwin W. Muir. Psychology: Frontiers and Applications. 4th Canadian ed. McGraw-Hill Ryerson Limited, 2011, pg. 372-373. Print.
11. Flynn, J. R. “Massive IQ gains in 14 nations: What IQ tests really measure” .Psychological Bulletin, 101(2). 1987. 171-191. doi:10.1037/0033-2909.101.2.171
12. Flynn, J. R. “Searching for justice: The discovery of IQ gains over time”. American Psychologist, 54(1). 1999. 5-20. doi:10.1037/0003-066X.54.1.5
13. See 11.
14. Bower, Bruce. “IQ’s generation gap: is intelligence reaching new heights, or is something amiss with the tests that measure it?” The Free Library 15 August 1987.

Bad skepticism

The following is an example of falsehoods presented as 'scientific skepticism', which does not address any manner of ESP, and instead provides a 'false equivalence' style of argument to explain any sort of ESP as simple awareness based on the accepted five senses.

"Australia study debunks existence of 'sixth sense' or ESP"
2014-01-14 from "United Press International (UPI)" newswire
[http://www.upi.com/Science_News/2014/01/14/Australia-study-debunks-existence-of-sixth-sense-or-ESP/UPI-88851389737536]:
MELBOURNE, Jan. 14 (UPI) -- The belief that a sixth sense, also known as extrasensory perception, exists has no foundation in science, researchers at the University of Melbourne say.
Instead, people can reliably sense when a change has occurred, even when they could not see exactly what had changed; for example, a person might notice a general change in someone's appearance but not be able to identify that the person had had a haircut.
It's not ESP, the researchers said, but rather -- as proven in their scientific study -- that people can reliably sense changes that they cannot visually identify.

"There is a common belief that observers can experience changes directly with their mind, without needing to rely on the traditional physical senses such as vision, hearing, taste, smell and touch to identify it," Piers Howe from the Melbourne School of Psychological Sciences said. "This alleged ability is sometimes referred to as a sixth sense or ESP."
"We were able to show that while observers could reliably sense changes that they could not visually identify, this ability was not due to extrasensory perception or a sixth sense," he said.
In the study, participants were presented with pairs of color photographs, both of the same female, but in some cases her appearance -- her hairstyle, for example -- would be different in the two photographs.
Results showed the participants could generally detect when a change had occurred even when they could not identify exactly what had changed, the researchers said.
They might "feel" or "sense" that a change had occurred without being able to visually identify it, the researchers said, but that could be explained without invoking an extrasensory mechanism.

"Caffeine has positive effect on memory"

2014-01-12 from Johns Hopkins University [http://hub.jhu.edu/2014/01/12/caffeine-enhances-memory]):
Whether it’s a mug full of fresh-brewed coffee, a cup of hot tea, or a can of soda, consuming caffeine is the energy boost of choice for millions who want to wake up or stay up.
Now, researchers at the Johns Hopkins University have found another use for the popular stimulant: memory enhancer.
Michael Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins, and his team of scientists found that caffeine has a positive effect on our long-term memory. Their research, published by the journal Nature Neuroscience [http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.3623.html], shows that caffeine enhances certain memories at least up to 24 hours after it is consumed.
“We’ve always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans,” said Yassa, senior author of the paper. “We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.”
The Johns Hopkins researchers conducted a double-blind trial in which participants who did not regularly eat or drink caffeinated products received either a placebo or a 200-milligram caffeine tablet five minutes after studying a series of images. Salivary samples were taken from the participants before they took the tablets to measure their caffeine levels. Samples were taken again one, three, and 24 hours afterwards.
The next day, both groups were tested on their ability to recognize images from the previous day’s study session. On the test, some of the visuals were the same as those from the day before, some were new additions, and some were similar but not the same.
More members of the caffeine group were able to correctly identify the new images as “similar” to previously viewed images rather than erroneously citing them as the same.
The brain’s ability to recognize the difference between two similar but not identical items, called pattern separation, reflects a deeper level of memory retention, the researchers said.
“If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine,” Yassa said. “However, using these items requires the brain to make a more difficult discrimination—what we call pattern separation, which seems to be the process that is enhanced by caffeine in our case.”
The memory center in the human brain is the hippocampus, a seahorse-shaped area in the medial temporal lobe of the brain. The hippocampus is the switchbox for all short- and long-term memories. Most research done on memory—the effects of concussions in athletes, of war-related head injuries, and of dementia in the aging population—focuses on this area of the brain.
Until now, caffeine’s effects on long-term memory had not been examined in detail. Of the few studies done, the general consensus was that caffeine has little or no effect on long-term memory retention.
The research is different from prior experiments because the subjects took the caffeine tablets only after they had viewed and attempted to memorize the images.
“Almost all prior studies administered caffeine before the study session, so if there is an enhancement, it’s not clear if it’s due to caffeine’s effects on attention, vigilance, focus, or other factors,” Yassa said. “By administering caffeine after the experiment, we rule out all of these effects and make sure that if there is an enhancement, it’s due to memory and nothing else.”
According to the U.S. Food and Drug Administration, 90 percent of people worldwide consume caffeine in one form or another. In the United States, 80 percent of adults consume caffeine every day. The average adult has an intake of about 200 milligrams—the same amount used in the Yassa study—or roughly one cup of strong coffee per day.
Yassa’s team completed the research at Johns Hopkins before his lab moved to the University of California, Irvine, at the start of this year.
“The next step for us is to figure out the brain mechanisms underlying this enhancement,” Yassa said. “We can use brain-imaging techniques to address these questions. We also know that caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer’s disease. These are certainly important questions for the future.”

Notes about this neuroscience and memory research -
The lead author of the paper is Daniel Borota, an undergraduate student in Yassa’s lab who received a Provost’s Undergraduate Research Award from Johns Hopkins to conduct the study.
Additional authors, all from Johns Hopkins, are: Elizabeth Murray, a research program coordinator in the Department of Psychological and Brain Sciences; John Toscano, professor in the Department of Chemistry; Gizem Kecili, a graduate student also in the Chemistry Department; and Allen Chang, Maria Ly, and Joseph Watabe, all undergraduates in the Department of Psychological and Brain Sciences.
This research was supported by grants number P50 AG05146 and R01 AG034613 from the National Institute on Aging as well as CHE-1213438 from the National Science Foundation.

Original Research: Abstract for “Post-study caffeine administration enhances memory consolidation in humans” by Daniel Borota, Elizabeth Murray, Gizem Keceli, Allen Chang, Joseph M Watabe, Maria Ly, John P Toscano and Michael A Yassa in Nature Neuroscience. Published online January 12 2014 doi:10.1038/nn.3623