KbWait 不会注册按键

我正在尝试收集键盘数据，但无法让KbWait工作。在下面的代码中，我试图等待参与者做出回应，检查他们的回应是否是两个可接受的答案之一，然后继续。只有当参与者按下"j"或"f"时，它才应该继续。

        response = [];        
        while isempty(response)&&(GetSecs - FlipTimestamp) < 10
            [keyIsDown, RTsecs, RTkeyCode, deltaSecs] = KbWait;
            if keyIsDown
                r=find(RTkeyCode);%this should be the code for the key pressed
                response=KbName(r);%Figure out what key was pressed
                rt=num2str(RTsecs-time);  %subtract off timestamp from when window was flipped
                if response == 'f'
                    match_response= false;
                end
                if response == 'j'
                    match_response= true;
                end
            end
        end

但是，KbWait永远不会返回。当我尝试从命令行运行它时，它也不起作用。它只是挂断了，拒绝返回，我不得不中断程序。