function[obj] = check_patterns(obj)

if isempty(obj.trial_start_pattern)
    error('No text pattern for `trial start` was provided');
end
% if isempty(obj.trial_end_pattern)
%     warning('No text pattern for `trial end` was provided : using start trial');
%     obj = obj.setPattern('trial_end', obj.trial_start_pattern);
% end

if isempty(obj.stimulus_onset_pattern)
        warning('No stimulus onset pattern was provided : using start trial');
        obj.stimulus_onset_pattern = obj.trial_start_pattern;
end

if isempty(obj.stimulus_offset_pattern)
    obj.stimulus_offset_pattern = obj.trial_end_pattern;
end

if isempty(obj.baseline_onset_pattern)
    obj.baseline_offset_pattern = obj.trial_start_pattern;
end

if isempty(obj.baseline_offset_pattern)
    obj.baseline_offset_pattern = obj.stimulus_onset_pattern;
end