We know exactly where an object is when we say it is “within the reach of our hand.”  But if we don’t have a hand, can we still see the object just where it is?

Apparently not, say researchers at the Hebrew University of Jerusalem and Hadassah Hospital-Mount Scopus. The space within reach of our hands — where actions such as grasping and touching occur — is known as the “action space.” .Research has shown that visual information in this area is organized in hand-centered coordinates — in other words, the representation of objects in the human brain depends on their spatial position with respect to the hand.

The team at HU sought to investigate how hand amputations affect visuospatial perception in near space. Volunteers with either left- or right-hand amputations participated in this experiment. They were instructed to look at a central cross on a screen while two white squares were briefly shown to the left and right side of the cross. The volunteers had to indicate which of the squares was farther away from the cross.

The results reveal that hand amputations affect visuospatial perception. When the right square was slightly farther away from the center, participants with right-hand amputations tended to perceive it as being at the same distance from the center as the left square; this suggests that these volunteers underestimated the distance of the right square relative to the left. Conversely, when the left square was farther away, left-hand amputees perceived both squares as being equally far away from the center — these participants underestimated the left side of near space.

Interestingly, when the volunteers were seated farther away from the screen, they were more accurate in judging the distances, indicating that hand amputations may only affect perception of the space close to the body.

The findings suggest that losing a hand may shrink the action space on the amputated side, leading to permanent distortions in spatial perception. According to the researchers, “This shows that the possibility for action in near space shapes our perception — the space near our hands is really special, and our ability to move in that space affects how we perceive it.”

The researchers note that these results have implications for spatial hemineglect — a condition (often following brain injury) in which the patient cannot perceive objects on one side of space. This condition is very often associated with paralysis of the hand in the neglected side, which, based on the current study, might exasperate the perceptual neglect.

The authors suggest that, based on their findings, “current rehabilitation approaches that emphasize action on the affected side may reverse this process.” For example, encouraging the use of the affected hand or by providing visual feedback (through prism adaptation or mirrors) may help overcome hemineglect by increasing the size of the action space on the affected side.

Published in Psychological Science, a journal of the Association for Psychological Science, amputation of the hand results in distorted visuospatial perception of the action space. The article was written by neuroscientists Dr. Tamar R. Makin, Meytal Wilf and Dr. Ehud Zohary of the Alexander Silberman Institute of Life Sciences at the Hebrew University of Jerusalem along with Dr. Isabella Schwartz of Hadassah Mount Scopus Hospital in Jerusalem

Our beloved little country, however, came in #7 with 1.385 cell phones per person. I’m trying to figure out what one does with more than one cell phone.

Why is Israel such a cell phone-crazy country? There are different theories. They include the security situation (we need to be able to reach our loved ones quickly) and, of course, we love to talk. But based on a recent study, it might be best if we love it a bit less, or at least try to use our home phones a bit more (our bank accounts wouldn’t complain, that’s for sure).

An Israeli study commissioned by the Israel Dental Association and directed by Avi Zini of the community dentistry department at the Hebrew University-Hadassah School of Dental Medicine has some bad news. They studied the incidence of oral cavity cancer from 1970 to 2006. The results?

There seems to be a rising number of cancer cases of the parotid gland. This is the gland located just where the cell phone sits on our face while we’re handsomely lining the cell phone companies’ pockets. The cancers of the other parts of the mouth, on the other hand, did not seem to be rising. Cases of this parotid gland were steady at around 25 per year from 1970 to 2002. Then, within another five years, there was a dramatic increase to 70 cases per year.

Who’s giving up their cell phone? Not I! But, the researchers were sure to mention that there is less radiation against your head if you use accessories such as a headset.

Read the whole article here.

Alzheimer’s is probably one of the most heart-breaking diseases. Anyone who has seen the affects of Alzheimer’s knows that research on this disease is extremely important for people affected directly or indirectly by it all over the world.

So, ever hear of Tau tangles? This is when certain proteins in the brain get “tangled” or folded. This is not good and has been found to be closely associated with Alzheimer’s symptoms. Recently, a bunch of researchers, including Hanna Rosenmann, Ph.D., head of the Laboratory of Molecular Neurogenetics, Department of Neurology, Hadassah University Hospital, Ein Kerem, and an investigator (Associate-Senior Lecturer) at the Hebrew University Hadassah School of Medicine, Jerusalem, Israel, did research whereby they attempted to immunize mice against the tangling.

The result? They found a major reduction in tangles without any evidence of inflammation in the brain from the therapy. The latter fact being important since other scientists had to stop their research in immunotherapy in the past because 6% of (human) participants developed brain inflammation. The chemical that these Israeli scientists are using is a different one and so far seems to be showing much better results!

Hopefully one day Alzheimer’s can enter the history book of diseases and our children can say to us when we’re 90 years old, “Mom, what was it like living in a world with Alzheimer’s?”

Click here to read the full article.