Emotional Brain Institute, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
Department of Communication Sciences and Disorders, Knowles Hearing Center, Northwestern University, Evanston, IL, USA.
Chem Senses. 2019 Jan 29;44(2):135-143. doi: 10.1093/chemse/bjy083.
Perceptual learning is an enhancement in discriminability of similar stimuli following experience with those stimuli. Here, we examined the efficacy of adding additional active training following a standard training session, compared with additional stimulus exposure in the absence of associated task performance. Mice were trained daily in an odor-discrimination task, and then, several hours later each day, received 1 of 3 different manipulations: 1) a second active-training session, 2) non-task-related odor exposure in the home cage, or 3) no second session. For home-cage exposure, odorants were presented in small tubes that mice could sniff and investigate for a similar period of time as in the active discrimination task each day. The results demonstrate that daily home-cage exposure was equivalent to active odor training in supporting improved odor discrimination. Daily home-cage exposure to odorants that did not match those used in the active task did not improve learning, yielding outcomes similar to those obtained with no second session. Piriform cortical local field potential recordings revealed that both sampling in the active learning task and investigation in the home cage evoked similar beta band oscillatory activity. Together the results suggest that odor-discrimination learning can be significantly enhanced by addition of odor exposure outside of the active training task, potentially because of the robust activity evoked in the olfactory system by both exposure paradigms. They further suggest that odorant exposure alone could enhance or maintain odor-discrimination abilities in conditions associated with olfactory impairment, such as aging or dementia.
感知学习是指在经历相似刺激后，对这些刺激的可辨别性增强。在这里，我们研究了在标准训练后增加额外主动训练的效果，与在没有相关任务表现的情况下增加额外刺激暴露的效果进行了比较。小鼠每天在气味辨别任务中接受训练，然后每天在几个小时后接受 3 种不同操作中的 1 种：1）第二次主动训练，2）在其笼中进行与任务无关的气味暴露，或 3）无第二次训练。对于笼中暴露，每天将气味剂置于小管子中，使小鼠可以嗅探并探查，时间与主动辨别任务中的时间相似。结果表明，每天的笼内暴露与主动气味训练一样，可以支持改善的气味辨别。每天在笼内暴露于与主动任务中使用的气味不匹配的气味剂不会改善学习，结果与没有第二次训练相似。梨状皮层局部场电位记录显示，在主动学习任务中的采样和在笼内的探查都引起了相似的β频带振荡活动。结果共同表明，通过在主动训练任务之外增加气味暴露，可以显著增强气味辨别学习，这可能是因为这两种暴露范式都能引起嗅觉系统的强烈活动。它们进一步表明，在与嗅觉障碍相关的条件下，例如衰老或痴呆，仅暴露于气味剂就可以增强或维持气味辨别能力。
