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Functional specialization of the left ventral parietal cortex in working memory.

Langel J, Hakun J, Zhu DC, Ravizza SM - Front Hum Neurosci (2014)

Bottom Line: An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern.These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection.The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Program, Michigan State University East Lansing, MI, USA.

ABSTRACT
The function of the ventral parietal cortex (VPC) is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

No MeSH data available.


Related in: MedlinePlus

Time course of average (±SEM) activity for the left VPC during verbal (A) and object (B) trials of the WM task. Error (solid line) and correct (dashed line) trials are shown for each condition. A binary logistic regression indicated that higher activity averaged during the maintenance period (timepoints 14–26; shaded area) of the verbal condition was associated with a greater likelihood of making an error.
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Figure 4: Time course of average (±SEM) activity for the left VPC during verbal (A) and object (B) trials of the WM task. Error (solid line) and correct (dashed line) trials are shown for each condition. A binary logistic regression indicated that higher activity averaged during the maintenance period (timepoints 14–26; shaded area) of the verbal condition was associated with a greater likelihood of making an error.

Mentions: To assess whether activity of the left and right aVPC regions found in both oddball detection and WM retrieval was related to accuracy on a trial-to-trial basis, we performed a binary logistic regression using activity in the VPC as a predictor of accuracy on each trial (see Figure 4 for average time course for error and correct trials). For this analysis, each trial (n = 35 errors; n = 305 correct items) was treated as a separate event. Within-subject factors (subject and trial) were modeled to account for correlated observations in the data set. Note that errors were not averaged across participants. For the left aVPC, higher activity at maintenance, averaged across the entire maintenance interval timepoints 14–26, was associated with a greater likelihood of making an error in memory (β = -1.09; Wald χ2 = 5.78, p < 0.05; Figure 4). Errors were not significantly related to activity at encoding (β = -0.7; Wald χ2 = 1.15, p = 0.28) or retrieval (β = -0.15; Wald χ2 = 0.18, p = 0.67).


Functional specialization of the left ventral parietal cortex in working memory.

Langel J, Hakun J, Zhu DC, Ravizza SM - Front Hum Neurosci (2014)

Time course of average (±SEM) activity for the left VPC during verbal (A) and object (B) trials of the WM task. Error (solid line) and correct (dashed line) trials are shown for each condition. A binary logistic regression indicated that higher activity averaged during the maintenance period (timepoints 14–26; shaded area) of the verbal condition was associated with a greater likelihood of making an error.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061583&req=5

Figure 4: Time course of average (±SEM) activity for the left VPC during verbal (A) and object (B) trials of the WM task. Error (solid line) and correct (dashed line) trials are shown for each condition. A binary logistic regression indicated that higher activity averaged during the maintenance period (timepoints 14–26; shaded area) of the verbal condition was associated with a greater likelihood of making an error.
Mentions: To assess whether activity of the left and right aVPC regions found in both oddball detection and WM retrieval was related to accuracy on a trial-to-trial basis, we performed a binary logistic regression using activity in the VPC as a predictor of accuracy on each trial (see Figure 4 for average time course for error and correct trials). For this analysis, each trial (n = 35 errors; n = 305 correct items) was treated as a separate event. Within-subject factors (subject and trial) were modeled to account for correlated observations in the data set. Note that errors were not averaged across participants. For the left aVPC, higher activity at maintenance, averaged across the entire maintenance interval timepoints 14–26, was associated with a greater likelihood of making an error in memory (β = -1.09; Wald χ2 = 5.78, p < 0.05; Figure 4). Errors were not significantly related to activity at encoding (β = -0.7; Wald χ2 = 1.15, p = 0.28) or retrieval (β = -0.15; Wald χ2 = 0.18, p = 0.67).

Bottom Line: An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern.These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection.The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Program, Michigan State University East Lansing, MI, USA.

ABSTRACT
The function of the ventral parietal cortex (VPC) is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

No MeSH data available.


Related in: MedlinePlus