Spontaneous neuronal activity distinguishes human dorsal and ventral attention systems

In the paper

“We identify a bilateral dorsal attention system and a right-lateralized ventral attention system solely on the basis of spontaneous activity.”

• Also stated in: § Quantitative Partitioning of Regions on the Basis of Spontaneous · boosted

  “Taken together, these analyses demonstrate that the four attention regions are not equally related in their spontaneous BOLD fluctuations but rather should be partitioned into two distinct systems consisting of the IPS͞FEF and the TPJ͞VFC.”

• Also stated in: § Discussion · boosted

  “Using this approach, we have shown that attentional regions can be partitioned into a bilateral dorsal attention system and a rightlateralized ventral attention system solely on the basis of spontaneous activity.”

In the paper

“The second observation is that correlations with the IPS and FEF are largely bilateral, whereas correlations with the TPJ and VFC are much more unilateral and largely limited to the right hemisphere.”

In the paper

“All map pairs were not equally correlated (F(5,45) ϭ 15.54; P Ͻ 0.0001), with the IPS͞FEF and the TPJ͞VFC correlation maps being the most similar.”

In the paper

“All region pairs were not correlated equally (F(5,45) ϭ 23.70; P Ͻ 0.0001), with the IPS͞FEF correlation and TPJ͞VFC correlation being significantly stronger than the correlation between any other region pair (P Ͻ 0.005, paired t test).”

In the paper

“First, the IPS and FEF correlation maps appear similar and the TPJ and VFC correlation maps appear similar, but the IPS͞FEF correlation maps appear quite distinct from the TPJ͞VFC correlation maps.”

In the paper

“The largest region of overlap was in the right middle frontal gyrus with additional regions in the inferior frontal gyrus and inferior parietal cortex.”

In the paper

“These factors appear to contribute to the overlap region in the inferior parietal cortex but not the other two, suggesting that the prefrontal cortex (middle and inferior frontal gyrus) may be an important locus of functional interaction between dorsal and ventral attention systems.”

In the paper

“However, in contrast to the model, the intrinsically defined dorsal attention system extends beyond IPS and FEF and includes a midline supplementary motor area (SMA)͞pre-SMA region and MTϩ.”

In the paper

“Second, we demonstrated that correlations in the dorsal system are bilateral, whereas those in the ventral system are lateralized to the right hemisphere.”

In the paper

“Our intrinsically defined dorsal system is consistent with the task-based model in that it includes IPS and FEF and is largely bilateral.”

In the paper

“It is largely right-lateralized and includes TPJ and VFC as well as other right frontal areas.”

In the paper

“The ventral system is rightlateralized and composed of the right temporal-parietal junction (TPJ) and the right ventral frontal cortex (VFC).”

What the sources say

• Not checked yetcites [4] source

In the paper

“On the basis of behavioral, neuroimaging, lesion, and electrophysiological studies, a model has been proposed that suggests that different attentional operations during sensory orienting are carried out by two separate frontoparietal systems, a dorsal attention system and a ventral attention system (for review, see ref. 4).”

What the sources say

• Not checked yetcites [4] source

In the paper

“On the basis of task-related imaging studies in normal human subjects, it has been suggested that two attention systems exist in the human brain: a bilateral dorsal attention system involved in top-down orienting of attention and a right-lateralized ventral attention system involved in reorienting attention in response to salient sensory stimuli.”

What the sources say

• Not checked yetcites [4] source

In the paper

“Activity increases also are observed in the ventral system after abrupt changes in sensory stimuli (15), at the onset and offset of task blocks (16), and at the end of a completed trial (17).”

What the sources say

• Not checked yetcites [15] source
• Not checked yetcites [16] source
• Not checked yetcites [17] source

In the paper

“It is involved in voluntary (top-down) orienting and shows activity increases after presentation of cues indicating where, when, or to what subjects should direct their attention (5)(6)(7)(8)(9)(10)(11)(12).”

What the sources say

• Not checked yetcites [5] source
• Not checked yetcites [6] source
• Not checked yetcites [7] source

In the paper

“The dorsal system is bilateral and composed of the intraparietal sulcus (IPS) and the junction of the precentral and superior frontal sulcus (frontal eye field, FEF) in each hemisphere.”

What the sources say

• Not checked yetcites [4] source

In the paper

“A functional interaction between the dorsal and ventral system has been proposed such that task-relevant signals from the dorsal system ''filter'' stimulus-driven signals in the ventral system, whereas stimulus-driven ''circuit-breaking'' signals from the ventral system provide an interrupt to the dorsal system, reorienting it toward salient stimuli (4,21).”

What the sources say

• Not checked yetcites [4] source
• Not checked yetcites [21] source

In the paper

“In addition to these positive correlations, negative or anticorrelations have been noted between regions routinely modulated in opposite directions by attention demanding tasks (28,35).”

What the sources say

• Not checked yetcites [28] source
• Not checked yetcites [35] source

In the paper

“This alternative perspective suggests that the brain is active even in the absence of task, primarily driven by internal dynamics, with external events modulating rather than determining the activity of the system (24)(25)(26)(27)(28).”

What the sources say

• Not checked yetcites [24] source
• Not checked yetcites [25] source
• Not checked yetcites [26] source

In the paper

“Correlations have been noted between regions commonly modulated together by task paradigms such as so-matomotor, visual, auditory, language, task-negative͞default, and task-positive regions including the IPS and FEF (28,(30)(31)(32)(33)(34).”

What the sources say

• Not checked yetcites [28] source
• Not checked yetcites [30] source
• Not checked yetcites [31] source

In the paper

“Correspondingly, the ventral system reacts more strongly to task-relevant than irrelevant distracters (20) and exhibits activity decreases when subjects search for a difficult target (6).”

What the sources say

• Not checked yetcites [20] source
• Not checked yetcites [6] source

In the paper

“For example, coherent spontaneous activity appears to be an important source of trial-to-trial variability in measured brain responses (42,43) and may relate to the trialto-trial variability commonly observed in human behavior (44).”

What the sources say

• Not checked yetcites [44] source

In the paper

“Third, task-evoked activity due to a specific behavior seems to be distinct from and superimposed on top of underlying spontaneous activity (40,42).”

What the sources say

• Not checked yetcites [40] source
• Not checked yetcites [42] source

In the paper

“For example, coherent spontaneous activity appears to be an important source of trial-to-trial variability in measured brain responses (42,43) and may relate to the trialto-trial variability commonly observed in human behavior (44).”

What the sources say

• Not checked yetcites [42] source
• Not checked yetcites [43] source

In the paper

“However, SMA͞pre-SMA and MTϩ typically have not been considered part of the dorsal attention system for various reasons.”

In the paper

“This extended system is consistent with previous resting-state correlation studies (28,45) and has been dubbed by us the task-positive network (28).”

What the sources say

• Not checked yetcites [28] source
• Not checked yetcites [45] source

In the paper

“The fact that IPS and FEF seem to share some functionality not present in the more extended network may relate to the stronger intrinsic correlation between these two regions (see Fig. 1).”

In the paper

“Although previous task-based studies have reported right lateralization of this network (4, 15, 16, 47), we directly test and quantify this laterality on the basis of spontaneous activity.”

What the sources say

• Not checked yetcites [4] source
• Not checked yetcites [15] source
• Not checked yetcites [16] source
• Not checked yetcites [47] source

In the paper

“Specifically, an inability of the ventral system to distinguish between relevant and irrelevant stimuli could cause increased distractibility, and an inability of the dorsal system to receive reorienting signals could cause an increase in perseveration.”

In the paper

“Although the intrinsically defined dorsal and ventral attention systems are largely segregated in their spatial topography, the original model and task-related findings suggest that there must be some mechanism of information exchange between them.”

In the paper

“Both distractibility and perseveration are hallmarks of prefrontal cortex damage (50).”

What the sources say

• Not checked yetcites [50] source

In the paper

“As noted in the introduction, the ventral system responds more strongly to task-relevant distracters than irrelevant ones (termed contingent reorienting), and the dorsal system exhibits an activity increase in addition to the ventral system when a reorientation of attention is needed.”

In the paper

“This information exchange has been hypothesized to occur between the right IPS and right TPJ (4).”

What the sources say

• Not checked yetcites [4] source

In the paper

“Consistent with this finding, recent lesion studies suggest that contingent reorienting remains intact and is even enhanced after IPS damage (S.Shomstein, personal communication), suggesting that the IPS is not required for top-down information to reach the ventral attention system.”

What the sources say

• Not checked yetcites S.Shomstein, personal communication

In the paper

“For example, regions routinely modulated together during task conditions tend to be strongly correlated in their spontaneous activity and regions modulated in opposite directions tend to be anticorrelated (28).”

What the sources say

• Not checked yetcites [28] source

In the paper

“Although the region in the parietal lobe may be due to spatial blurring, the two regions in the prefrontal cortex are not, and therefore may represent, important sites of functional interaction between the two systems.”

In the paper

“This observation is not without precedent, because the currently identified prefrontal cortex regions have been implicated in sustained attention, vigilance, and both maintaining and updating of a task set (49)(50)(51).”

What the sources say

• Not checked yetcites [49] source
• Not checked yetcites [50] source
• Not checked yetcites [51] source

In the paper

“These possibilities are not mutually exclusive, and all may be relevant to understanding why systems defined on the basis of task-related activity patterns, such as the dorsal and ventral attention systems, can be observed in patterns of spontaneous neuronal activity in the absence of task.”

In the paper

“The fact that the dorsal and ventral systems are largely segregated may be important for the flexibility observed in the task-response patterns of these two systems, allowing them to be modulated together, independently, or in opposite directions.”