Swerdlow N R, Hartston H J, Hartman P L
Department of Psychiatry, School of Medicine, University of California, San Diego 92093-0804, USA.
Biol Psychiatry. 1999 Feb 15;45(4):482-8. doi: 10.1016/s0006-3223(98)00050-x.
Latent inhibition (LI) is the slowed acquisition of a learned response to a conditioned stimulus (CS), that occurs if that CS has previously been experienced in a noncontingent setting. This retarded acquisition is thought to occur because, due to the previous noncontingent experience, an individual must "unlearn the irrelevance" of the CS, before learning its new association to the unconditioned stimulus. A previous report using an auditory paradigm did not detect abnormal LI in obsessive-compulsive disorder (OCD) subjects; this auditory LI task included a difficult acquisition phase, which made it relatively insensitive to detecting abnormally elevated LI (i.e., slowed "unlearning").
We assessed LI using a highly sensitive computerized visual LI paradigm in 63 carefully screened control subjects and in 48 patients with OCD.
Compared to controls, OCD subjects exhibited significantly more LI; if "preexposed" to a to-be-CS, OCD subjects required significantly more trials to learn a new association to that CS, compared to control subjects. This pattern was particularly evident in unmedicated OCD subjects.
The inflated impact of preexposure on LI response acquisition in OCD subjects may be a quantitative measure of their tendency to remain "stuck in set" in this cognitive task.
潜伏抑制（LI）是指如果条件刺激（CS）先前在非关联情境中出现过，那么对该CS的习得反应的获得速度会减慢。这种习得延迟被认为是由于先前的非关联经历，个体在学习CS与无条件刺激的新关联之前，必须“消除对CS无关性的习得”。之前一项使用听觉范式的报告未在强迫症（OCD）患者中检测到异常的LI；该听觉LI任务包含一个困难的习得阶段，这使得它相对难以检测到异常升高的LI（即减慢的“消除习得”）。
我们使用高度敏感的计算机化视觉LI范式对63名经过仔细筛选的对照受试者和48名OCD患者进行了LI评估。
与对照组相比，OCD患者表现出显著更多的LI；如果对即将成为CS的刺激进行“预暴露”，与对照受试者相比，OCD患者需要显著更多的试验来学习与该CS的新关联。这种模式在未用药的OCD患者中尤为明显。
预暴露对OCD患者LI反应习得的过度影响可能是他们在这项认知任务中倾向于“固着于定势”的一种量化指标。
