Interhemispheric transfer of phosphenes generated by occipital versus parietal transcranial magnetic stimulation
Interhemispheric transfer of phosphenes generated by occipital versus parietal transcranial magnetic stimulation
复制标题
枕叶与顶叶经颅磁刺激产生的光幻视的半球间转移
DOI：
10.1007/s00221-008-1496-4
复制
发表时间：
2008
影响因子：
2
通讯作者：
S. Savazzi
中科院分区：
文献类型：
--
作者：
C. Marzi;F. Mancini;S. Savazzi
磷烯代表经颅磁刺激(TMS)或视觉皮质区域电刺激的知觉效应。产生静态磷烯的一个可能的神经基础是初级视觉皮质(V1)，尽管证据存在争议。V1的一个特殊特征是，除了视野表示的中央部分外，它有稀疏的胼胝体连接。相比之下，顶叶的视觉反应皮层区域有广泛的胼胝体连接。因此，当由V1产生时，偏离中心的膦的半球间转移(IT)时间应该比视觉顶区产生的慢。要验证这一可能性，请参见Exp.1我们测量了TMS在V1和Exp中产生的磷烯的IT。2对顶叶后皮质应用TMS获得的磷烯进行IT测定。在这两个实验中，我们都得到了出现在对侧半场中的静态明亮的圆形膦。我们通过比较交叉或非交叉半手操作条件下的单手简单反应时间和磷化氢的出现来测量IT时间(Poffenberger范式)。与我们的预测一致，我们发现V1的IT时间比顶膦要长得多。此外，当参与者被要求想象先前在TMS期间经历的膦时，发现了类似于V1刺激获得的IT。综上所述，目前的结果表明，无论是由V1TMS产生的还是想象中的磷烯，其信息传递都受到慢于真实视觉刺激或顶叶磷烯通道的支持。
Phosphenes represent a perceptual effect of transcranial magnetic stimulation (TMS) or electric stimulation of visual cortical areas. One likely neural basis for the generation of static phosphenes is the primary visual cortex (V1) although evidence is controversial. A peculiar feature of V1 is that it has sparse callosal connections with the exception of a central portion of visual field representation. In contrast, visually responsive cortical areas in the parietal lobe have widespread callosal connections. Thus, interhemispheric transfer (IT) time of off-centre phosphenes should be slower when generated by V1 than by visual parietal areas. To verify this possibility, in Exp. 1 we measured IT of phosphenes generated by TMS applied to V1 and in Exp. 2 we measured IT of phosphenes obtained by TMS applied to posterior parietal cortex. In both experiments, we obtained static bright circular phosphenes appearing in the contralateral hemifield. We measured IT time behaviorally by comparing unimanual simple reaction time to the onset of a phosphene under crossed or uncrossed hemifield-hand condition (Poffenberger paradigm). In keeping with our prediction, we found a substantially longer IT time for V1 than for parietal phosphenes. Additionally, an IT similar to that obtained with V1 stimulation was found when participants were asked to imagine the phosphenes previously experienced during TMS. In conclusion, the present results suggest that IT of phosphenes either generated by V1 TMS or imagined is subserved by slower callosal channels than those of real visual stimuli or parietal phosphenes.
DOI：
10.1016/s1385-299x(02)00189-7
发表时间：
2002-10-01
期刊：
BRAIN RESEARCH PROTOCOLS
影响因子：
--
作者：
Fernandez, E;Alfaro, A;Pascual-Leone, A
通讯作者：
Pascual-Leone, A
影响因子：
2.5
作者：
Schluppeck, D;Glimcher, P;Heeger, DJ
通讯作者：
Heeger, DJ
影响因子：
2.5
作者：
Silver, MA;Ress, D;Heeger, DJ
通讯作者：
Heeger, DJ