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.
According to new research 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.
They 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.
For further information: Dept. of Media Relations, the Hebrew University,
Tel: 02-588-2875. Orit Sulitzeanu, Hebrew University spokesperson, Tel: 02-5882811
Orit Sulitzeanu | Hebrew University
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy