Detour behaviour is the ability of an animal to reach a stimulus (goal) when there is an obstacle between the subject and the stimulus. Detour learning in chicks has been used as a functional test for the development of nervous system.
Since the sensitive phase for spatial memory development is around post hatch day 11, 32 chicks were exposed to 50 Hz magnetic fields before and after day 11 (for about 7 days, from day 9 until day 14 post hatch) and the detour learning task was performed (daily). 32 chicks were divided into 4 groups: 1) exposure group (20 h/day); 2) sham exposure; 3) exposure group (50 min/day); 4) sham exposure.
Exposure duration: 20 h/day or 50 min/day for 6 days
|Exposure duration||20 h/day or 50 min/day for 6 days|
|magnetic flux density||1 mT||-||-||-||-|
The data showed that 20 h/day exposure to a low frequency magnetic field induced a significant impairment in detour learning (the chicks needed more time to learn the task than the controls) but 50 min/day exposure had no effect.
The data provide the evidence of possible cognitive and biological effects of exposure to extremely low frequency magnetic fields.