Pensei que isso era velho e comum...

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   *Getting lost -- a newly discovered developmental brain disorder***
*Feeling lost every time you leave your home? You may not be as alone as you
think. Researchers at the University of British Columbia and Vancouver
Coastal Health Research Institute recently documented the first case of a
patient who, without apparent brain damage or cognitive impairment, is
unable to orient within any environment. Researchers also believe that there
are many others in the general population who may be affected by this
developmental topographical disorder.
*

The study, published in the journal *Neuropsychologia*, and led by Giuseppe
Iaria, a UBC Faculty of Medicine and VCH postdoctoral fellow, used
functional magnetic resonance imaging (fMRI) together with behavioural
studies to assess and characterize the navigational deficiencies of the
patient, who is completely unable to orient within the environment, getting
lost even within the neighborhood where the patient lived for many years.

"Imagine not being able to do the simplest of tasks such as finding your way
home from the grocery store," says Iaria, who is affiliated with the Brain
Research Centre. "Navigating and orienting in an environment are complex
cognitive skills, involving parts of the brain used for memory, attention,
perception, and decision-making. It also requires using at least two
distinct types of memory systems."

The procedural memory system involves using landmarks, distances, or
following stereotyped movements to move between locations. The spatial
memory system is more complex. When moving through an environment – familiar
or not – a person creates a mental representation of the environment, called
a cognitive map. It is the ability to "create" and "read" these cognitive
maps that enables a person to navigate by following a route without getting
lost.

Brain malformations or lesions in parts of the brain important for
navigation are known to cause navigation difficulties. However, no such
defects or lesions in the patient's brain were detected. Moreover, a series
of behavioural tests revealed that patient's problem was due to a specific
inability to form cognitive maps.

"We suspect that this patient is not unique, and that there are others
suffering varying degrees of selective developmental topographical
disorientation," says Dr. Jason Barton, Canada Research Chair and director
of the Human Vision and Eye Movement Laboratory where the patient was
studied. "They might have a lifelong story of episodes like getting lost in
their own house or neighbourhood, at school or at work, and having to rely
on others for directions. In extreme circumstances, this can even lead to
social isolation."

Source: University of British Columbia
http://www.physorg.com/news141308823.html

Posted by
Robert Karl Stonje
 
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