Can ECG electrodes be used for EEG detection?
Neither the amp nor electrodes will be very useful.  

ECG pads are capacitive with large surface area and EEG must be more conductive with many probes to increase pressure points with rounded tips.  

Hair will interfere with results ( poor conduction) and you will get motion voltages from galvanic voltages and variation in pressure.  

Also the gain must be about 20dB higher  http://i.ebayimg.com/images/i/191441995702-0-1/s-l1000.jpg  http://www.pkfamily.com/users/solson/eeg/picAD.gif 

"Right Leg drive" improves the CMRR but can use a large capacitive pad on the neck or leg.

You can fit it onto a snug open top golf cap.