Cognitive Neuroscience Division, Taub Institute, Columbia University, New York, NY 10032, USA.
Behav Brain Res. 2010 Jul 11;210(2):229-39. doi: 10.1016/j.bbr.2010.02.036. Epub 2010 Feb 25.
Subjects performed a continuous tracking concurrently with an intermittent visual detection task to investigate the existence of competition for a capacity-limited stage (a bottleneck stage). Both perceptual and response-related processes between the two tasks were examined behaviorally and the changes in brain activity during dual-tasking relative to single-task were also assessed. Tracking error and joystick speed were analyzed for changes that were time-locked to visual detection stimuli. The associated brain activations were examined with functional magnetic resonance imaging (fMRI). These were analyzed using mixed block and event-related models to tease apart sustained neural activity and activations associated with individual events. Increased tracking error and decreased joystick speed were observed relative to the target stimuli in the dual-task condition only, which supports the existence of a bottleneck stage in response-related processes. Neuroimaging data show decreased activation to target relative to non-target stimuli in the dual-task condition in the left primary motor and somatosensory cortices controlling right-hand tracking, consistent with the tracking interference observed in behavioral data. Furthermore, the ventral attention system, rather than the dorsal attention system, was found to mediate task coordination between tracking and visual detection.
受试者同时进行连续跟踪和间歇性视觉检测任务，以研究是否存在容量有限的阶段（瓶颈阶段）的竞争。从行为上研究了两个任务之间的感知和反应相关过程，并评估了双任务相对于单任务期间大脑活动的变化。分析了与视觉检测刺激时间锁定的跟踪误差和操纵杆速度变化。使用功能磁共振成像（fMRI）检查相关脑激活。使用混合块和事件相关模型进行分析，以区分与持续神经活动和与单个事件相关的激活。仅在双任务条件下，与目标刺激相比，跟踪误差增加，操纵杆速度降低，这支持了反应相关过程中存在瓶颈阶段。神经影像学数据显示，在双任务条件下，与非目标刺激相比，控制右手跟踪的左手初级运动和躯体感觉皮层对目标的激活减少，这与行为数据中观察到的跟踪干扰一致。此外，发现腹侧注意系统而不是背侧注意系统介导了跟踪和视觉检测之间的任务协调。
