Neural correlates of spatial and nonspatial attention determined using intracranial electroencephalographic signals in humans

Abstract

Few studies have directly compared the neural correlates of spatial attention (i.e., attention to a particular location) and nonspatial attention (i.e., attention to a feature in the visual scene) using well‐controlled tasks. Here, we investigated the neural correlates of spatial and nonspatial attention in humans using intracranial electroencephalography. The topography and number of electrodes showing significant event‐related desynchronization (ERD) or event‐related synchronization (ERS) in different frequency bands were studied in 13 epileptic patients. Performance was not significantly different between the two conditions. In both conditions, ERD in the low‐frequency bands and ERS in the high‐frequency bands were present bilaterally in the parietal cortex (prominently on the right hemisphere) and frontal regions. In addition to these common changes, spatial attention involved right‐lateralized activity that was maximal in the right superior parietal lobule (SPL), whereas nonspatial attention involved wider brain networks including the bilateral parietal, frontal, and temporal regions, but still had maximal activity in the right parietal lobe. Within the parietal lobe, spatial attention involved ERD or ERS in the right SPL, whereas nonspatial attention involved ERD or ERS in the right inferior parietal lobule. These findings reveal that common as well as different brain networks are engaged in spatial and nonspatial attention. Hum Brain Mapp 37:3041–3054, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Differences in theta coherence between spatial and nonspatial attention using intracranial electroencephalographic signals in humans

“…Various studies have revealed that the dorsal attention network, which consists of the FEF and SPL/IPS, is involved in top‐down visuospatial orienting attention (Corbetta & Shulman, ; Fan, McCandliss, Fossella, Flombaum, & Posner, ; Phillips et al, ). Additionally, some studies have reported the dorsal attention network has a spatial‐specific orienting function (Corbetta, Kincade, Ollinger, McAvoy, & Shulman, ; Giesbrecht et al, ; Hopfinger, Buonocore, & Mangun, ; Kastner, De Weerd, Desimone, & Ungerleider, ; Scolari et al, ; Yantis et al, ) and our previous study (Park et al, ) support these findings.…”

“…Previous studies have revealed that, while performing the tasks after cue‐onset, the right frontoparietal network is important for both tasks, and that spatial attention, when compared to nonspatial attention, is lateralized to a greater extent to the right hemisphere (Park et al, ). However, it is not entirely clear whether—and if so, to what extent—a difference in connectivity in the right frontoparietal network from the preparatory state to the cognitive state exists between the two tasks.…”

“…After finishing a video‐EEG monitoring study to localize the seizure foci with intracranial electrodes, seizures were controlled by anticonvulsant medications. The experimental paradigm for this study was conducted approximately 5–7 days after electrode implantation, by which time all of the patients had recovered sufficiently to allow them to perform these experiments (Park et al, ). All procedures of the study were approved by the Asan Medical Center, Seoul, Korea.…”

“…However, nonspatial attention involves wider brain networks, including the bilateral parietal, frontal, and temporal regions, with maximum activity occurring in the right parietal lobe. These findings suggest that the amount and pattern of networks that are involved in the right frontoparietal regions differ between spatial and nonspatial attention (Park et al, ). Regarding connectivity analysis, it has been reported that theta coherence in the frontoparietal network is engaged in attention control during the cognitive state (Brazdil et al, ; Clayton, Yeung, & Cohen Kadosh, ; Daitch et al, ; Dombrowe & Hilgetag, ).…”

“…The posterior parietal cortex contains subpopulations of neurons that are involved in the control of spatial and nonspatial feature-specific (color-specific) attention (Greenberg et al, 2010). Within the frontoparietal networks, different and common parts of the parietal lobe contribute to spatial and nonspatial attention, respectively (Husain & Nachev, 2007;Nachev & Husain, 2006;Park et al, 2016;Schenkluhn, Ruff, Heinen, & Chambers, 2008). Some subregions of the frontoparietal network are known to be specifically involved in controlling spatial attention (Giesbrecht et al, 2003).…”