Watson School of Biological Sciences, Cold Spring Harbor Laboratory Cold Spring Harbor, NY, USA.
Front Syst Neurosci. 2011 Sep 27;5:74. doi: 10.3389/fnsys.2011.00074. eCollection 2011.
We present a behavioral paradigm for the study of duration perception in the rat, and report the result of neurotoxic lesions that have the goal of identifying sites that mediate duration perception. Using a two-alternative forced-choice paradigm, rats were either trained to discriminate durations of pure tones (range = [200,500] ms; boundary = 316 ms; Weber fraction after training = 0.24 ± 0.04), or were trained to discriminate frequencies of pure tones (range = [8,16] kHz; boundary = 11.3 kHz; Weber = 0.16 ± 0.11); the latter task is a control for non-timing-specific aspects of the former. Both groups discriminate the same class of sensory stimuli, use the same motions to indicate decisions, have identical trial structures, and are trained to psychophysical threshold; the tasks are thus matched in a number of sensorimotor and cognitive demands. We made neurotoxic lesions of candidate timing-perception areas in the cerebral cortex of both groups. Following extensive bilateral lesions of the auditory cortex, the performance of the frequency discrimination group was significantly more impaired than that of the duration discrimination group. We also found that extensive bilateral lesions of the medial prefrontal cortex resulted in little to no impairment of both groups. The behavioral framework presented here provides an audition-based approach to study the neural mechanisms of time estimation and memory for durations.
我们提出了一种用于研究大鼠持续感知的行为范式，并报告了旨在确定介导持续感知的部位的神经毒性损伤的结果。使用二选一强制选择范式，训练大鼠区分纯音的持续时间（范围=[200,500]毫秒；边界=316 毫秒；训练后的韦伯分数=0.24±0.04），或区分纯音的频率（范围=[8,16]千赫兹；边界=11.3 千赫兹；韦伯=0.16±0.11）；后者任务是对前者的非定时特定方面的控制。两组都区分相同类别的感觉刺激，使用相同的动作来表示决策，具有相同的试验结构，并训练到心理物理阈值；因此，这些任务在许多感觉运动和认知需求方面是匹配的。我们对两组大脑皮层中的候选定时感知区域进行了神经毒性损伤。在广泛的听觉皮层双侧损伤后，频率辨别组的表现明显比持续时间辨别组受损更严重。我们还发现，内侧前额叶皮质的广泛双侧损伤对两组的影响很小或没有。这里提出的行为框架提供了一种基于听觉的方法来研究时间估计和持续时间记忆的神经机制。
