Nielsen E B, Appel J B
Psychopharmacology (Berl). 1983;80(1):24-8. doi: 10.1007/BF00427488.
Six pigeons were trained in a chamber with three response keys. Following an observing response on the center key, either colored or noncolored (white) lights were projected on that key. A second center key observing response provided an opportunity to respond on one of the side keys, appropriate to the stimuli presented, to obtain food; responding on the incorrect side produced a 30-s time-out. A delay period of varying duration with no stimuli followed stimulus presentation; the length of the delay was determined 'on-line', such that performance would be maintained at about 80% correct. Lysergic acid diethylamide (LSD, 0.04-0.2 mg/kg) had no significant effect on the accuracy of the discrimination (overall percent correct responses), even at doses that produced cessation of responding in some animals. Amphetamine (1-4 mg/kg) and morphine (0.5-4 mg/kg) decreased accuracy by decreasing sensitivity (A') and had little effect on reaction time. Haloperidol (0.5-2 mg/kg) had no significant effect on any measure of performance. None of the drugs altered response bias (B").
六只鸽子在一个带有三个反应键的实验箱中接受训练。在对中间键做出观察反应后，彩色或非彩色（白色）灯光会投射在该键上。对中间键的第二次观察反应提供了一个机会，让鸽子根据呈现的刺激在其中一个侧边键上做出反应以获取食物；在错误的侧边键上做出反应会导致30秒的超时。刺激呈现后会有一段不同时长且无刺激的延迟期；延迟的长度是“在线”确定的，以便使表现维持在约80%的正确率。麦角酸二乙酰胺（LSD，0.04 - 0.2毫克/千克）即使在某些动物中产生反应停止的剂量下，对辨别准确性（总体正确反应百分比）也没有显著影响。苯丙胺（1 - 4毫克/千克）和吗啡（0.5 - 4毫克/千克）通过降低敏感性（A'）降低了准确性，并且对反应时间影响很小。氟哌啶醇（0.5 - 2毫克/千克）对任何表现指标都没有显著影响。这些药物均未改变反应偏差（B"）。
