Schwartz T H, Haglund M M, Lettich E, Ojemann G A
University of Washington, Seattle, USA.
J Cogn Neurosci. 2000 Sep;12(5):803-12. doi: 10.1162/089892900562615.
Recordings of neuronal activity in humans have identified few correlates of the known hemispheric asymmetries of functional lateralization. Here, we examine single-unit activity recorded from both hemispheres during two delayed match-to-sample tasks that show strong hemispheric lateralization based on lesion effects; a line-matching (LM) task related to the right hemisphere, and a rhyming (RHY) task related to the left. Nineteen neuronal populations were recorded with extracellular microelectrodes from the left temporal neocortex of 11 awake patients, and 18 from the right in 9 patients during anterior temporal lobectomy for complex partial seizures under local anesthesia. All subjects were left hemisphere dominant for language. Twelve (32%) populations exhibited statistically significant changes in activity at p <.05. Although changes in firing frequency were recorded from both hemispheres during both tasks, the RHY task elicited changes in activity several hundred milliseconds earlier on the left side than on the right. The LM task, on the other hand, induced changes earlier on the right side than on the left. Both hemispheres contained units active during verbal responses regardless of which behavior elicited the response. Our results indicate that cerebral dominance is reflected in earlier neuronal activity in the anterior temporal lobe during tasks lateralized to that hemisphere.
对人类神经元活动的记录显示，已知的功能偏侧化半球不对称现象几乎没有相关性。在此，我们研究了在两项延迟匹配样本任务中从两个半球记录到的单单元活动，这两项任务基于损伤效应显示出强烈的半球偏侧化；一项与右半球相关的线条匹配（LM）任务，以及一项与左半球相关的押韵（RHY）任务。在局部麻醉下对9例复杂性部分性癫痫患者进行前颞叶切除术时，用细胞外微电极从11例清醒患者的左侧颞叶新皮质记录了19个神经元群，从9例患者的右侧记录了18个神经元群。所有受试者的语言功能均以左半球为主。12个（32%）神经元群在p<0.05时表现出具有统计学意义的活动变化。尽管在两项任务中两个半球均记录到放电频率的变化，但RHY任务在左侧比在右侧提前数百毫秒引发活动变化。另一方面，LM任务在右侧比在左侧更早诱发变化。无论哪种行为引发反应，两个半球都包含在言语反应期间活跃的单元。我们的结果表明，在向该半球侧化的任务中，脑优势反映在前颞叶更早的神经元活动中。
