Schoenbaum Geoffrey, Nugent Summer L, Saddoris Michael P, Setlow Barrry
Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, 25 Ames Hall, Baltimore, MD 21218, USA.
Neuroreport. 2002 May 7;13(6):885-90. doi: 10.1097/00001756-200205070-00030.
Recent evidence suggests that orbitofrontal cortex lesions cause an inability to withhold inappropriate responses particularly when learned behavior must be modified to reflect changes in the likely outcome or consequence of responding. By this account, orbitofrontal cortex should not be necessary for acquisition of simple discrimination problems, but should be critical for acquiring reversals of those problems. However, previous work in rats has shown orbitofrontal cortex to be critical for withholding responses even in a simple go, no-go discrimination task. Here we have reexamined the contribution of rat orbitofrontal cortex to acquisition and reversal of go, no-go odor discrimination problems. Contrary to prior reports, we found that rats with lesions of the orbitofrontal cortex acquired novel discrimination problems at the same rate as controls. Impairments were evident in lesioned rats when the response contingencies of the odors in the discrimination problem were reversed. These findings suggest that orbitofrontal cortex is not necessary for inhibiting responses unless responses must be altered to reflect changing relationships between cues and outcomes.
近期证据表明，眶额皮质损伤会导致无法抑制不适当的反应，尤其是当必须修改习得行为以反映反应可能结果或后果的变化时。据此，眶额皮质对于简单辨别问题的习得并非必需，但对于这些问题的反转习得至关重要。然而，此前对大鼠的研究表明，即使在简单的“去/不去”辨别任务中，眶额皮质对于抑制反应也至关重要。在此，我们重新审视了大鼠眶额皮质对“去/不去”气味辨别问题的习得和反转的作用。与先前的报道相反，我们发现眶额皮质损伤的大鼠习得新辨别问题的速度与对照组相同。当辨别问题中气味的反应条件反转时，损伤大鼠出现了明显的损伤。这些发现表明，除非必须改变反应以反映线索与结果之间不断变化的关系，否则眶额皮质对于抑制反应并非必需。
