条件反射の興奮並びに制止過程における大脳皮質領野の機能的役割—（II）条件反射の形成過程に及ぼす大脳皮質領野剔除の影響

FUNCTIONAL RÔLE OF CORTICAL AREAS IN THE EXCITATORY AND INHIBITORY PROCESSES IN CONDITIONED REFLEX: (II) EFFECT OF CORTICAL ABLATION ON THE FORMATION OF CONDITIONED REFLEX

　1）予め皮質聴覚領野を種々の程度に別除した犬に食餌性唾液分泌反射を土台とせる各種の聴覚条件反射の形成並びに分化実験を試み，これらの条件反射に於ける興奮・制止両過程の形成に対して皮質聴覚領野が果す役割を検討した。

　2）聴覚条件反射の興奮過程の形成に際しては聴覚領野を必ずしも必要とせぬが，これが予め剔除されている場合には，条件刺激が複雑化するにつれてその形成速度は遅延する。

　3）完全な制止過程の形成には聴覚領野が必要不可欠であり，これを欠く場合分化制止の形成は極めて困難となる。この傾向は一旦形成され且つ把持されている制止過程が別除によつて蒙る障害に比して一層著明であるが，これらは単に量的差異を示すにとどまり，本質的な相違は認められなかつた。

1) After bilateral ablation of cortical acou-stic areas, dogs were trained to establish the excitatory and inhibitory processes in the acoustic conditioned reflexes based on the salivary secretion.

2) Cortical acoustic areas were not always indispensable for the formation of the excita-tory process in the acoustic conditioned re-flex. When this area had previously been removed, however, the formation of compli-cated acoustic conditioned reflexes was reta-rded.

3) The formation of the differential inhi-bition in the acoustic conditioned reflexes was extremely difficult when the cortical acoustic areas had previously been removed. The disturbance in its postoperative forma-tion was more marked than impairment due to cortical destruction of preoperatively esta-blished differential inhibition, though no essential difference was found between them.