Damage to posterior parietal cortex impairs two forms of relational learning.
Damage to posterior parietal cortex impairs two forms of relational learning.
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DOI：
10.3389/fnint.2012.00045
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发表时间：
2012
影响因子：
3.5
通讯作者：
Bucci DJ
中科院分区：
文献类型：
--
作者：
Robinson S;Bucci DJ
后顶叶皮层（PPC）是参与关系学习的主要皮质-海马回路的组成部分，但PPC对海马依赖性学习的具体贡献尚未得到解决。为了解决这个问题，进行了两个实验来测试PPC损伤对涉及在多个感官刺激之间形成关联的任务的影响。在实验1中，假或电解损伤的PPC之前，大鼠进行了测试的三相感觉预处理任务。在第一阶段，一半的训练试验包括听觉刺激和灯光的配对。在其他试验中，第二个听觉刺激单独呈现。在下一阶段的训练中，同样的光线与食物配对，但没有听觉刺激。在手术的最后阶段，在单个测试期间，在没有强化的情况下呈现两种听觉刺激。正如在测试期间通常观察到的那样，与未配对的线索相比，对照组大鼠对先前与光配对的听觉线索表现出更大的条件反射。相比之下，PPC损伤的大鼠对两种听觉线索的反应相同。在实验2中，PPC损伤和对照大鼠进行了培训，在复合功能负歧视任务，包括加强介绍的色调单独和非加强同时介绍的轻色调复合刺激。对照组大鼠成功地学习了辨别能力，而PPC受损的大鼠则没有。总的来说，这些结果支持的想法，PPC有助于关系学习，涉及多模态的感觉刺激，也许是通过调节注意力处理的条件刺激。
The posterior parietal cortex (PPC) is a component of a major cortico-hippocampal circuit that is involved in relational learning, yet the specific contribution of PPC to hippocampal-dependent learning is unresolved. To address this, two experiments were carried out to test the effects of PPC damage on tasks that involve forming associations between multiple sensory stimuli. In Experiment 1, sham or electrolytic lesions of the PPC were made before rats were tested on a three-phase sensory preconditioning task. During the first phase, half of the training trials consisted of pairings of an auditory stimulus followed by a light. During the other trials, a second auditory stimulus was presented alone. In the next phase of training, the same light was paired with food, but no auditory stimuli were presented. During the final phase of the procedure both auditory stimuli were presented in the absence of reinforcement during a single test session. As is typically observed during the test session, control rats exhibited greater conditioned responding to the auditory cue that was previously paired with light compared to the unpaired cue. In contrast, PPC-lesioned rats responded equally to both auditory cues. In Experiment 2, PPC-lesioned and control rats were trained in a compound feature negative discrimination task consisting of reinforced presentations of a tone-alone and non-reinforced simultaneous presentations of a light-tone compound stimulus. Control rats but not rats with damage to the PPC successfully learned the discrimination. Collectively, these results support the idea that the PPC contributes to relational learning involving multimodal sensory stimuli, perhaps by regulating the attentional processing of conditioned stimuli.