Cognitive Processing During Saccadic Eye Movements

人们为了观察周围的世界而进行快速的眼球运动，这种运动被称为扫视。扫视之间的静止期称为注视。众所周知，在扫视期间，视觉受到抑制；因此，关于世界的视觉信息只有在注视时才能获得。这项研究将调查扫视是否也会干扰特定的认知过程。初步研究结果表明，这可能是真的，但证据并不令人信服；这项研究将为一个明确的答案提供一些步骤。这些实验将检验在一只眼睛注视时启动的认知过程是否会在眼睛移动到空间中的新位置时继续运作，或者这些过程是否会在眼球移动时暂停。研究人员会向人们展示一项简单的心理任务，他们会在盯着空间中的一个位置时开始执行这项任务，然后在试图继续执行任务的同时，向空间中的另一个位置进行短扫视或长扫视。如果认知过程在眼球运动过程中受到抑制，那么长扫视（需要更长的时间来完成）应该比短扫视（需要更短的时间来完成）对表现的影响更大。在另一种眼睛不动的情况下，测试者的表现也会被衡量。如果眼动不干扰认知，在眼动条件下的表现应等同于无眼动条件下的表现。平均每个人每秒进行3次扫视（因此，每16小时工作日大约有172,800次扫视），平均扫视持续约30毫秒；因此，如果在扫视期间出现抑制，这将意味着每天大约有90分钟的认知中断。如果这种情况真的发生了，那将是非常了不起的。因此，确定这种情况是否发生对于理解人类认知，特别是对于需要许多眼球运动的活动，如阅读和场景感知，具有至关重要的意义。* * *

9615988 IRWIN People make rapid eye movements called saccades in order to examine the world around them. The still periods between saccades are called fixations. It is well known that vision is suppressed during saccades; therefore, visual information about the world is acquired only during fixations. This research will investigate whether saccades also interfere with particular cognitive processes. Preliminary findings suggest that this may be true, but the evidence is not convincing; this research will provide some steps toward a definitive answer. The experiments will examine whether cognitive processes that are set into motion during one eye fixation continue to operate while the eyes are moving to a new position in space or whether these processes pause during the eye movement. People will be presented with a simple mental task that they will begin to perform while they are fixating one position in space and will then make either a short or a long saccade to a different position in space while attempting to continue performing the task. If cognitive processing is suppressed during eye movements, then long saccades (which take longer to execute) should disrupt performance more than short saccades (which take less time to execute). Performance will also be measured in another condition, in which the eyes do not move. Performance in the eye-movement conditions should be equivalent to performance in the no-eye-movement condition if eye movements do not interfere with cognition. The average person makes about three saccades per second (hence, about 172,800 saccades per 16-hour working day), and the average saccade lasts about 30 ms; thus, if suppression occurs during saccades, it would mean that cognition is disrupted for approximately ninety minutes each day. If this happens, it is truly remarkable. Thus, determining whether this occurs is of fundamental importance to the understanding of human cognition, particularly for activities such as reading and scene perception that require many eye movements. ***