Woodry Robert, Curtis Clayton E, Winawer Jonathan
Department of Psychology, New York University, New York City, NY 10003.
Center for Neural Science, New York University, New York City, NY 10003.
bioRxiv. 2024 Dec 2:2024.04.11.589111. doi: 10.1101/2024.04.11.589111.
Perception, working memory, and long-term memory each evoke neural responses in visual cortex. While previous neuroimaging research on the role of visual cortex in memory has largely emphasized similarities between perception and memory, we hypothesized that responses in visual cortex would differ depending on the origins of the inputs. Using fMRI, we quantified spatial tuning in visual cortex while participants (both sexes) viewed, maintained in working memory, or retrieved from long-term memory a peripheral target. In each condition, BOLD responses were spatially tuned and aligned with the target's polar angle in all measured visual field maps including V1. As expected given the increasing sizes of receptive fields, polar angle tuning during perception increased in width up the visual hierarchy from V1 to V2, V3, hV4, and beyond. In stark contrast, the tuned responses were broad across the visual hierarchy during long-term memory (replicating a prior result) and during working memory. This pattern is consistent with the idea that mnemonic responses in V1 stem from top-down sources, even when the stimulus was recently viewed and is held in working memory. Moreover, in long-term memory, trial-to-trial biases in these tuned responses (clockwise or counterclockwise of target), predicted matched biases in memory, suggesting that the reinstated cortical responses influence memory guided behavior. We conclude that feedback widens spatial tuning in visual cortex during memory, where earlier visual maps inherit broader tuning from later maps thereby impacting the precision of memory.
感知、工作记忆和长期记忆均会在视觉皮层中引发神经反应。虽然先前关于视觉皮层在记忆中作用的神经成像研究主要强调了感知和记忆之间的相似性,但我们推测视觉皮层中的反应会因输入的来源不同而有所差异。我们使用功能磁共振成像(fMRI)技术,在参与者(男女皆有)观看、在工作记忆中保持或从长期记忆中提取周边目标时,对视觉皮层中的空间调谐进行了量化。在每种情况下,血氧水平依赖(BOLD)反应在包括V1在内的所有测量视野图中均进行了空间调谐,并与目标的极角对齐。正如预期的那样,鉴于感受野尺寸不断增大,从V1到V2、V3、hV4及其他区域,感知过程中的极角调谐宽度在视觉层级中逐渐增加。与之形成鲜明对比的是,在长期记忆(重复先前的结果)和工作记忆过程中,调谐反应在整个视觉层级中都很宽泛。这种模式与以下观点一致,即V1中的记忆反应源自自上而下的信号源,即使该刺激最近被观看过并保存在工作记忆中。此外,在长期记忆中,这些调谐反应中的逐次试验偏差(目标的顺时针或逆时针方向)预测了记忆中的匹配偏差,这表明恢复的皮层反应会影响记忆引导的行为。我们得出结论,在记忆过程中,反馈会拓宽视觉皮层中的空间调谐,其中早期的视觉图谱从后期图谱继承更宽泛的调谐,从而影响记忆的精度。