Research tells us that human adults, toddlers, rats, chicks and even fish routinely and automatically accomplish this kind of "reorientation" by mentally visualizing the geometry of their surroundings and figuring out where they are in space. Until now, however, we haven't understood that genes may play a part in that ability.
Writing this week in the online Early Edition of the Proceedings of the National Academy of Sciences, a team led by Barbara Landau, the Dick and Lydia Todd Professor in the Department of Cognitive Science at The Johns Hopkins University, for the first time links genes to our ability to navigate the world.
"We found that people with a rare genetic disorder cannot use one of the very basic systems of navigation that is present in humans as early as 18 months and shared across a wide range of species," Landau said. "To our knowledge, this is the first evidence from human studies of a link between the missing genes and the system that we use to reorient ourselves in space."
Working with lead author Laura Lakusta of Montclair State University in New Jersey and co-author Banchiamlack Dessalegn, a postdoctoral fellow at University of Chicago (both of whom recently received their Ph.D.s at Johns Hopkins under Landau's direction and carried out the research there), Landau's study involved people with a rare genetic disorder known as Williams syndrome. Named for its discoverer, New Zealander Dr. J. C. P. Williams, the syndrome is caused when a small amount of genetic material is missing from one human chromosome. People with Williams syndrome are extremely social and verbally adept, but have difficulty with tasks such as assembling simple puzzles, copying basic patterns and navigating their bodies through the physical world. Williams syndrome occurs in one in 7,500 live births.
In the study, Landau's team challenged people with Williams syndrome to watch while someone hid an object beneath a small cloth flap in one corner of a small rectangular room with four solid black walls that had no landmarks. Subjects were then blindfolded and spun around (think "Pin the Tail on the Donkey") for about 10 seconds to disorient them. Once the blindfold was taken off, the subjects were asked to find the hidden object.
According to Landau, the people with Williams syndrome searched the four corners randomly; indicating that their ability to mentally visualize the layout of the room and quickly find which corner held the hidden object is severely impaired.
"They searched the room for the hidden object randomly, as if they had never before seen the overall geometry of the room or the lengths of the walls and their geometric – left and right – relation to each other," Landau explained. "If they could imagine the overall shape of the room's layout – that there are four walls, two of them long and two of them short and that the toy was hidden in a corner that has a short wall on the right and the long wall on the left – then they should have guessed that one of the two 'geometrically equivalent corners' was the right place. This is what typically developing humans do, as early as 18 months of age."
Control subjects (healthy college-aged students) responded more typically, searching for the object in one of the two geometrically equivalent corners, as has been found in studies by many other investigators.
According to Landau, the results of this study provides another clue to the link between how genes work, how brains develop and become specialized and what can go wrong to result in very basic cognitive system malfunctioning.
"Although we are quite far from understanding the links between the specific genes that are missing in Williams syndrome and the behavior they show, such as failure to reorient, it is clear that the missing genes ultimately have some effect on the brain," she said. "Our evidence is the first to directly show a substantial deficit in this reorientation system that is caused by missing genes in humans."
The study was underwritten by a grant from the National Institutes of Health.
Digital photos of Landau are available. Contact Lisa De Nike at Lde@jhu.edu or 443-287-9960.
For more on Landau and her work, go here:http://web.jhu.edu/cogsci/people/faculty/Landau/
Lisa Ercolano | EurekAlert!
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology