Burghardt W F, Hunt W A
Radiat Res. 1985 Jul;103(1):149-57.
Rats were trained to perform a task involving responses on two levers. Responding on an avoidance lever delayed the onset of electrical footshock for 20 sec and responding on a warning lever turned on a light for 60 sec. When the light was on, the task on the avoidance lever was changed from unsignaled shock avoidance to signaled shock avoidance by preceding the shocks with 5-sec warning tones. The animals preferred the signaled avoidance condition. After 100 Gy of 60Co irradiation, the animals were less able to avoid shock, an effect from which the animals recovered somewhat over 90 min. The response rate on the avoidance lever remained at or above control rates, while the response rate on the warning lever showed an initial increase, followed by a decrease below baseline. The increase in responding on the avoidance lever occurred in bursts just after presentation of the shocks. The data suggest that under these experimental conditions a subject will not respond appropriately to avoid shock or acquire cues that can facilitate the avoidance of shock. The effects, however, do not reflect an inability to perform the required movements but instead appear to reflect some characteristic of the task associated with a particular lever.
训练大鼠执行一项涉及在两个杠杆上做出反应的任务。在回避杠杆上做出反应可将电击足部的开始延迟20秒，而在警告杠杆上做出反应可使灯亮60秒。当灯亮时，通过在电击前发出5秒的警告音，将回避杠杆上的任务从无信号电击回避改为有信号电击回避。动物更喜欢有信号的回避条件。在接受100戈瑞的60钴照射后，动物避免电击的能力下降，这种影响在90分钟内有所恢复。回避杠杆上的反应率保持在对照率或高于对照率，而警告杠杆上的反应率最初增加，随后降至基线以下。回避杠杆上反应的增加在电击出现后立即成串出现。数据表明，在这些实验条件下，受试者不会做出适当反应以避免电击或获取有助于避免电击的线索。然而，这些影响并不反映无法执行所需动作，而是似乎反映了与特定杠杆相关的任务的某些特征。
