TY - JOUR
T1 - Flow of activation from V1 to frontal cortex in humans
T2 - A framework for defining "early" visual processing
AU - Foxe, John J.
AU - Simpson, Gregory V.
N1 - Funding Information:
Acknowledgments We thank Drs. Charles Schroeder, Seppo Ahlfors, Michael Worden, and Clifford Saron for their extremely helpful comments and Dr. Martin Sliwinski for help with statistical analyses. We thank Beth Higgins and Micah Murray for technical assistance. Sincere appreciation to two anonymous reviewers for very constructive comments. This work was supported by the NIH and NIMH (MH11431-JJF, NS27900-GVS).
PY - 2002
Y1 - 2002
N2 - This study provides a time frame for the initial trajectory of activation flow along the dorsal and ventral visual processing streams and for the initial activation of prefrontal cortex in the human. We provide evidence that this widespread system of sensory, parietal, and prefrontal areas is activated in less than 30 ms, which is considerably shorter than typically assumed in the human event-related potential (ERP) literature and is consistent with recent intracranial data from macaques. We find a mean onset latency of activity over occipital cortex (C1e) at 56 ms, with dorsolateral frontal cortex subsequently active by just 80 ms. Given that activity in visual sensory areas typically continues for 100-400 ms prior to motor output, this rapid system-wide activation provides a time frame for the initiation of feedback processes onto sensory areas. There is clearly sufficient time for multiple iterations of interactive processing between sensory, parietal, and frontal areas during brief (e.g., 200 ms) periods of information processing preceding motor output. High-density electrical mapping also suggested activation in dorsal stream areas preceding ventral stream areas. Our data suggest that multiple visual generators are active in the latency range of the traditional C1 component of the ERP, which has often been taken to represent V1 activity alone. Based on the temporal pattern of activation shown in primate recordings and the evidence from these human recordings, we propose that only the initial portion of the C1 component (approximately the first 10-15 ms; C1e) is likely to represent a response that is predominated by V1 activity. These data strongly suggest that activity represented in the "early" ERP components such as P1 and N1 (and possibly even C1) is likely to reflect relatively late processing, after the initial volley of sensory afference through the visual system and involving top-down influences from parietal and frontal regions.
AB - This study provides a time frame for the initial trajectory of activation flow along the dorsal and ventral visual processing streams and for the initial activation of prefrontal cortex in the human. We provide evidence that this widespread system of sensory, parietal, and prefrontal areas is activated in less than 30 ms, which is considerably shorter than typically assumed in the human event-related potential (ERP) literature and is consistent with recent intracranial data from macaques. We find a mean onset latency of activity over occipital cortex (C1e) at 56 ms, with dorsolateral frontal cortex subsequently active by just 80 ms. Given that activity in visual sensory areas typically continues for 100-400 ms prior to motor output, this rapid system-wide activation provides a time frame for the initiation of feedback processes onto sensory areas. There is clearly sufficient time for multiple iterations of interactive processing between sensory, parietal, and frontal areas during brief (e.g., 200 ms) periods of information processing preceding motor output. High-density electrical mapping also suggested activation in dorsal stream areas preceding ventral stream areas. Our data suggest that multiple visual generators are active in the latency range of the traditional C1 component of the ERP, which has often been taken to represent V1 activity alone. Based on the temporal pattern of activation shown in primate recordings and the evidence from these human recordings, we propose that only the initial portion of the C1 component (approximately the first 10-15 ms; C1e) is likely to represent a response that is predominated by V1 activity. These data strongly suggest that activity represented in the "early" ERP components such as P1 and N1 (and possibly even C1) is likely to reflect relatively late processing, after the initial volley of sensory afference through the visual system and involving top-down influences from parietal and frontal regions.
KW - Area V1
KW - C1 component
KW - Event-related potential
KW - Frontal cortex
KW - High-density mapping
KW - Human
KW - Scalp current density
KW - Visual cortex
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U2 - 10.1007/s00221-001-0906-7
DO - 10.1007/s00221-001-0906-7
M3 - Article
C2 - 11797091
AN - SCOPUS:0036136788
SN - 0014-4819
VL - 142
SP - 139
EP - 150
JO - Experimental Brain Research
JF - Experimental Brain Research
IS - 1
ER -