HD Visual Working Memory Separates the Young and Old

Contrary to what we have always believed, when it comes to visual working memory there is in fact no neurological difference between young and old people. The elders of society remember just as much as their youthful counterparts. There is however one major difference in the memory of each age group. According to a recent study published in the journal of Attention, Perception and Psycophysics young people have high definition (HD) visual working memory. Older people, on the other hand have fuzzy, low-resolution visual working memory.

Related Article: Computers Improve and Sustain Mind and Memory of the Elderly

Visual working memory is in many senses the same as short term memory. It simply depends on which theory and definition you ascribe to. Visual working memory is used to rapidly store bits of visual information for a very short amount of time in order to compare information in our visual field. Visual working memory involves both the storage and recollection of information. It is a mechanism of memory that we entirely rely upon to go about our daily lives from day to day. It’s no wonder scientists want to learn more about it.

visual working memory brain

Visual working memory is more complex than you think. http://universe-review.ca/

The study involved 11 older adults of around 67 years of age and 13 younger adults of approximately 23 years of age. Scientists collected behavioral data as well as EEG scans from all members of the group. First, the participants were shown two, three, or four colored dots and asked to memorize their appearance.  The dots would disappear, and seconds later a single dot appeared in the garb of either a previously seen color or a new one. The participants simply stated whether the single dot contained a color that was the same or different than the dots shown initially. Additionally, all during the study the scientists took electroencephalographic (EEG) scans of each participant’s brain as it danced along with the technicolor dots.

Related Article: Memory, A Torch Pass

As we would expect, the old people didn’t perform as well on the behavioral test. They had more wrong guesses and exhibited a lower visual working memory capacity. The EEG scans painted a totally different story however. According to the scans both groups had a near equal amount of neural activity in the visual working memory centers of the brain. So although both groups stored the same amount of information, the old people still remembered less. Let’s envision this from another angle.

Let’s say that the visual working memory of the young and old can be represented by an online streaming video. While both old and young videos have the same buffer seed, the young can play at a resolution of 1080p, or maybe even 4k, while the old is stuck at a measly 480p resolution.  Although the video is being seen at the same time, and at the same speed, the quality between the two is markedly different. In this way a young and old person will have the same visual working memory speed and capacity. The quality of the memory, however, is what will differ greatly.

Related Article: Tetrachromacy: “Super Vision” Genes

The scientists are not actually positive that HD visual working memory is the reason for the young group’s superior performance, but it seems to be the most likely reason according to Philip Ko of Vanderbilt University. According to Ko, a member of the team that worked on the study,

We don’t know why older adults perform poorly when their neural activity suggests their memory capacity is intact… [However] there is emerging evidence from other labs suggesting that the quality of older adults’ memories is poorer than younger adults. In other words, while older adults might store the same number of items, their memory of each item is ‘fuzzier’ than that of younger adults.



http://link.springer.com/article/10.3758/s13414-013-0585-z via





Of Cyborg Monkeys and New Hope for Amputees


The innovative breeze of 2013 carries a particularly interesting development in the field of Neuroscience.

A joint venture funded by DARPA, composed of a group of researchers from the University of Pittsburgh and Carnegie Mellon University, revealed promising results in a recent study when monkeys were successful in moving a robotic arm using solely the power of their mind.

The practical application and climax of this study, as if it weren’t exciting enough already, finally arrived this January, when a woman was able to operate an artificial arm in a wide range of angles using her brain alone.

Related Article: Robotic Legs Controlled by Your Brain

For the past 11 years researchers have been conducting a series of experiments involving the motor-cortex, a part of the brain which facilitates movement. A tiny electrode array was implanted in the motor cortices of monkeys, enabling the scientists to read neural activity in the form of electrical spikes. Using a model based approach, the scientists were able to calculate the desired instantaneous hand and arm direction based on the activity of a few hundred neurons.

Reading brain-activity enabled the scientists to accurately move the artificial limb in the correct direction and angle, exactly the way the brain normally signals a healthy flesh and blood arm. In this way they trained the monkeys to move the arms through biofeedback.

Related Article: Robotic Sense and Feel

The monkeys were chosen as test subjects due to their similar brain structure to humans. However, it can’t be helped but to wonder: What is the secret for convincing a monkey to operate a robotic arm? The answer is simple: Marshmallows.

By hanging the treat just out of the monkey’s reach, far enough so that they would need to use the robotic arm to reach it, scientists were able to “train” the monkeys in moving the robotic arm in a space and they were able to teach the monkeys to grip their treat.

The next question that comes to mind is how many monkey-arms were removed due to the experiment? Animal rights fighters – rest assured; No monkeys were hurt in the process.

Related Article: Bionic Hand That Can Feel

After a decade of data-mining, the scientists are ready to implant a brain computer interface (BCI), an electrode array, in 53 year old Jan Scheuermann who suffers from quadriplegia; completely paralyzed from the neck down. The outcome of a not-so-simple surgery was optimistic news to all.

For many amputees, lacking an arm does not necessarily mean the brain is damaged as well. The successful experiment described above makes it very easy for a person to control a prosthetic arm, as all that needs to be done is  to ‘think’ which way the arm should move, much in the same way you are operating the arm you are using to scroll down and read this article.

Jan’s reports of headaches quickly disappeared, and no sooner did she prove to be able to feed herself, and even high-five Professor Andrew B. Schwartz, a senior figure in the research. According to Jan, feeding herself was:

One small nibble for a woman, one giant bite for BCI.

While the results of the research are certainly a breakthrough, leaving neuroscientists to fantasize about a world of possibilities opening up, major flaws cannot be ignored.

Implanting the electrode array requires invasive surgery, involving a temporary removal of part of the skull. The degree of control created by the invasive BCI (Brain Computer Interface) is limited by the number of neurons recorded, currently at a few hundred. Non-invasive methods of reading brain signals, such as EEG, offer a much lower information rate and require much more training.

Another flaw that is evident by observing Ms. Scheuermann’s arm movement is a poor eye-arm coordination. Neuroscientists are still looking for a reasonable explanation for Ms. Scheuermann inability to catch a falling object while observing it. Curiously enough, she is able to do so when not looking directly at the object.

Regardless of those facts, the sweet taste of success should not be bittered: this is still the first time a human has been able to operate a robotic arm in so many degrees of freedom, using only the power of the mind.

So what’s next? Killer-coding-ninja monkeys using telepathy? Anyone?


NYTimes: Monkeys Think, Moving Artificial Arm as Own

Lancet: Nueroprosthetic Control by Individual with Tetraplegia 

Invasive BCI UPMC: Woman with Quadraplegia Feeds Herself

Nature: Cortical Control of a Prosthetic Arm for Self-Feeding

Killer Coding Ninja Monkeys


Wondergressive: The Singularity is Nigh Upon Us

Wondergressive: Robotic Sense and Feel

Wondergressive: Bionic Hand That Can Feel

Wondergressive: Robotic Legs Controlled by Your Brain