An E145 Captain's trim switches either failed or were operated incorrectly after takeoff. The First Officer assumed control and the flight continued to its destination.

Narrative

I was the PM for the flight and as it was the first flight of the day; I had performed all of the actions in the receiving FFOD [First Flight Of the Day] checklist prior to leaving the gate. This included checking all of the trim switches. The take-off roll and rotation were normal. After rotation I noticed that the Captain was having to push unusually hard to keep the nose at the desired 14 degrees of pitch attitude while at the same time activating the pitch trim switch on his control wheel. After about 5-8 seconds; I noticed that while he was activating the switch; the pitch trim indicator on the EICAS showed no movement. We then received an aural warning consisting of a single chime and 'Trim'; which is usually activated when the switch is depressed for more than the 3 seconds allotted. I asked the Captain if his switch was working and he said he didn't think so. I then checked my trim switch and find it to be working normally. After getting the airplane trimmed; we consulted the QRH. I remained the pilot flying and we proceeded to our destination uneventfully.To the best of my knowledge; the event occurred when the Captain unintentionally depressed only one side of the pitch trim switch on his control wheel for more than 3 seconds; blocking out the switch on his control wheel. When I tested the switch at the gate that morning; nothing abnormal was detected. After the failure was detected; appropriate action was taken.