Auditory experience and behavioral training can modify perceptual performance. However, the consequences of temporal perceptual learning for temporal and spectral neural processing remain unclear. Specifically, the attributes of neural plasticity that underlie task-generalization in behavioral performance remain uncertain. To assess the relationship between behavioral and neural plasticity, we evaluated neuronal temporal processing and spectral tuning in primary auditory cortex (AI) of anesthetized owl monkeys trained to discriminate increases in the envelope frequency (e.g., 4 Hz standard vs. >5 Hz targets) of sinusoidally amplitude-modulated (SAM) 1-kHz or 2-kHz carriers. Behavioral and neuronal performance generalization was evaluated for carriers ranging between 0.5 kHz and 8 kHz. Psychophysical thresholds revealed high SAM discrimination acuity for carriers from one octave below to ~0.6 octave above the trained carrier frequency. However, generalization of SAM discrimination learning progressively declined for carrier frequencies >0.6 octaves above the trained carrier frequency. Neural responses in AI showed that SAM discrimination training resulted in (i) increases in temporal modulation preference, especially at carriers close to the trained frequency, (ii) narrowing of spectral tuning for CFs near the trained carrier frequency, potentially limiting spectral generalization of temporal training effects, and (iii) enhancement of firing-rate contrast for rewarded versus non-rewarded SAM frequencies, providing a potential cue for behavioral temporal discrimination near the trained carrier frequency. Our findings suggest that temporal training at a specific spectral location sharpens local frequency tuning, thus, confining the training effect to a narrow frequency range and limiting generalization of temporal discrimination learning across a wider frequency range.

中文翻译：

---

猴子初级听觉皮层的频谱可塑性限制了时间辨别任务中的表现泛化

听觉经验和行为训练可以改变知觉表现。然而，时间感知学习对时间和频谱神经处理的影响仍不清楚。具体来说，作为行为表现中任务泛化基础的神经可塑性的属性仍然不确定。为了评估行为和神经可塑性之间的关系，我们评估了麻醉猫头鹰猴子的初级听觉皮层 (AI) 的神经元时间处理和频谱调谐，以区分包络频率的增加（例如，4 Hz 标准与 >5 Hz 目标）正弦调幅 (SAM) 1-kHz 或 2-kHz 载波。评估了 0.5 kHz 和 8 kHz 之间的载波的行为和神经元性能泛化。心理物理阈值显示，从低于训练载波频率 1 个八度到高于 0.6 个八度的载波具有高 SAM 辨别敏锐度。然而，对于高于训练载波频率 0.6 倍频程的载波频率，SAM 鉴别学习的泛化逐渐下降。AI 中的神经反应表明，SAM 鉴别训练导致 (i) 时间调制偏好增加，特别是在接近训练频率的载波处，(ii) 缩小训练载波频率附近 CF 的频谱调谐，可能限制时间的频谱泛化训练效果，以及 (iii) 增强奖励与非奖励 SAM 频率的发射率对比度，为训练载波频率附近的行为时间辨别提供潜在线索。