Dual functions of sight demonstrated
The dissociation in the visual system between two separate theoretical functions has been demonstrated for the first time by scientists in Jerusalem.
Hebrew University researchers say the separate vision-related actions that enable humans to identify objects and to interact with them have been documented from the beginning of the 20th century in patients who suffered damage to their visual system in which one or the other function -- identification or action -- was damaged.
That dissociation suggests the existence of separate visual streams. However, despite wide research triggered by the concept, it had not been proved in subjects in whom both streams are functioning normally.
Now, using functional magnetic resonance imaging, Professor Ehud Zohary and a graduate student have been able to demonstrate dissociation between perception of objects and actions in the brains of healthy people.
An article detailing the findings appears in the journal Neuron.
Copyright 2006 by United Press International