def compare_AlphaFz(sq_amp,sq_amp_baseline): 
    """
    Compare the baseline alpha squared amplitude with that of a single epoch.   
    
    Parameters
    ----------
    sq_amp: float
        Alpha squared amplitude (Fz) from a single epoch 
    cnt_baseline: float
        Baseline alpha squared amplitude (Fz)
        
    Returns
    -------
    feedback_val: float
        Feedback value for stimulus presentation [-1,1]
    """
    relative_error = (sq_amp-sq_amp_baseline)/sq_amp_baseline
    feedback_val = relative_error
    if feedback_val>1:
        feedback_val = 1
    elif feedback_val<-1: 
        feedback_val = -1
    return feedback_val