Everling S, Krappmann P, Spantekow A, Flohr H
Brain Research Institute, University of Bremen, Germany.
Exp Brain Res. 1996 Sep;111(1):139-43. doi: 10.1007/BF00229563.
When a temporal gap is introduced between the offset of the central fixation point and the appearance of a new target, saccadic reaction time is reduced (gap effect) and a special population of extremely fast saccades occurs (express saccades). It has been hypothesized that the gap triggers a readiness signal, which is responsible for the reduced saccadic reaction times. Here, we recorded event-related potentials during the gap to investigate the central processes associated with the generation of fast regular saccades and express saccades. Prior to the execution of fast regular saccades, subjects produced a slow negative shift, with a maximum at frontal and central channels that started 40 ms after fixation offset. This widespread negativity is similar to a readiness potential. Anticipatory saccades were preceded by an increased frontal and parietal negativity. Prior to express saccades, a frontal negativity was observed, which started 135 ms after the disappearance of the fixation point. It is assumed that the frontal negativity prior to express saccades corresponds to the fixation-disengagement discharge described in the frontal eye field of monkeys. Therefore, we hypothesize that fast regular saccades are the result of an increased readiness signal, while express saccades are the result of specific preparatory processes.
当在中央注视点消失与新目标出现之间引入一个时间间隔时，扫视反应时间会缩短（间隙效应），并且会出现一类特殊的极快速扫视（快速扫视）。据推测，该间隙会触发一个准备信号，这一信号导致了扫视反应时间的缩短。在此，我们在间隙期间记录了事件相关电位，以研究与快速规则扫视和快速扫视产生相关的中枢过程。在执行快速规则扫视之前，受试者会产生一个缓慢的负向偏移，在额部和中央通道达到最大值，该负向偏移在注视点消失后40毫秒开始。这种广泛的负性类似于一种准备电位。预期扫视之前会出现额部和顶叶负性增强。在快速扫视之前，会观察到一个额部负性，它在注视点消失后135毫秒开始。据推测，快速扫视之前的额部负性对应于猴子额眼区中描述的注视脱离放电。因此，我们假设快速规则扫视是准备信号增强的结果，而快速扫视是特定准备过程的结果。
