What was found
DURING CRUISE, AT FL370, THE L/E SLAT ASYM MESSAGE ILLUMINATED ON EICAS FOR ABOUT 10 SEC THEN EXTINGUISHED. BOTH FLAP/SLAT INDICATOR NEEDLES MOVED FROM TO SLIGHTLY ABOVE THE UP MARK, THEN RETURNED TO UP. NO VIBRATION OR CONTROL ISSUES, FLAP HANDLE REMAIND UP AT 0. ACCOMPLISHED OPS CHECK OF FLAP SYSTEM, NO FAULTS ACCOMPLISHED FIM 27-51 AND PSEU BITE NO FAULTS TEST 40 ACCOMPLISHED AS WELL. NO TROUBLE FOUND, OK TO CONTINUE.