Is the posterior parietal lobe involved in working memory retrieval?

Berryhill, Marian E.; Olson, Ingrid R.

doi:10.1016/j.neuropsychologia.2008.03.005

Cited by 84 publications

(42 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Diwadkar et al [42] found that PA and DLPFC were activated during kinesis in spatial working memory. Berryhill and Olson [43] found that the posterior part of bilateral BA7 played an important role in maintaining visual working memory, which acted as visual-space storage in the working memory model. In our study, the bilateral DLPFC and right precuneus of the Pre-SCH group were not as activated as those in the euthyroidism group, which might suggest that the miopragia of spatial working memory of SCH patients was related to the hypofunction of DLPFC - posterior part of PA network.…”

Section: Discussionmentioning

confidence: 99%

Spatial Working Memory Impairment in Subclinical Hypothyroidism: An fMRI Study

Yin¹,

Liao

Luo³

et al. 2012

Neuroendocrinology

View full text Add to dashboard Cite

Objective: Using a block-designed BOLD-fMRI to explore the neural basis of spatial working memory impairment in patients with subclinical hypothyroidism (SCH) performing an n-back task. Methods: Sixteen patients with SCH before and after being treated with levothyroxine (LT₄) for 6 months and 16 matched euthyroid subjects were scanned by fMRI under the n-back task. Results: The fMRI scan found that a neural network consisting of bilateral dorsolateral prefrontal cortex (DLPFC), bilateral premotor area (PreMA), supplementary motor area/anterior cingulate cortex, bilateral parietal lobe (PA) and right caudate nucleus/thalamus was activated, with right hemisphere dominance. In euthyroid subjects, all these regions of interest (ROIs) showed load effect; however, only left DLPFC, left PA, bilateral PreMA and right caudate nucleus/thalamus showed the same effect in Pre-SCH patients. Furthermore, activation intensities of most ROIs (especially DLPFC and right PA) for Pre-SCH patients were lower than those in the euthyroid subjects (F <3.046, p > 0.062). Importantly, after a 6-month treatment with LT₄, the load effect in SCH patients appeared the same as in the euthyroid subjects in all the ROIs (F >13.176, p < 0.0001). Conclusion: Our previous study shows that verbal working memory of SCH patients is impaired with abnormal activity in bilateral frontal areas. In this study, the results indicated that SCH patients may also have spatial working memory impairments, and the altered activities of right DLPFC and right posterior parietal lobe may be one of the underlying neural mechanisms. Most importantly, this study shows that LT₄ replacement therapy can improve the memory impairment and reverse the altered neural activity network.

show abstract

Section: Discussionmentioning

confidence: 99%

Spatial Working Memory Impairment in Subclinical Hypothyroidism: An fMRI Study

Yin¹,

Liao

Luo³

et al. 2012

Neuroendocrinology

View full text Add to dashboard Cite

show abstract

“…Next, four shapes (randomly selected without replacement from a set of ten) were presented (1000 ms). Stimuli were bilaterally symmetrical abstract shapes (7° × 7°) generated by a computer algorithm described previously (e.g., (Berryhill & Olson, 2008; Jiang, Olson, & Chun, 2000). Each shape reversed contrast (black, white) at one of four distinct temporal frequencies: 3 Hz, 5 Hz, 12 Hz, and 20 Hz.…”

Section: Methodsmentioning

confidence: 99%

The steady-state visual evoked potential reveals neural correlates of the items encoded into visual working memory

et al. 2014

Self Cite

View full text Add to dashboard Cite

Visual working memory (VWM) capacity limitations are estimated to be ~4 items. Yet, it remains unclear why certain items from a given memory array may be successfully retrieved from VWM and others are lost. Existing measures of the neural correlates of VWM cannot address this question because they measure the aggregate processing of the entire stimulus array rather than neural signatures of individual items. Moreover, this cumulative processing is usually measured during the delay period, thereby reflecting the allocation of neural resources during VWM maintenance. Here, we use the steady-state visual evoked potential (SSVEP) to identify the neural correlates of individual stimuli at VWM encoding and test two distinct hypotheses: the focused-resource hypothesis and the diffuse-resource hypothesis, for how the allocation of neural resources during VWM encoding may contribute to VWM capacity limitations. First, we found that SSVEP amplitudes were larger for stimuli that were later remembered than for items that were subsequently forgotten. Second, this pattern generalized so that the SSVEP amplitudes were also larger for the unprobed stimuli in correct compared to incorrect trials. These data are consistent with the diffuse-resource view in which attentional resources are broadly allocated across the whole stimulus array. These results illustrate the important role encoding mechanisms play in limiting the capacity of VWM.

show abstract

“…An additional benefit of a bilateral montage is that the current flow of tDCS is more restricted to the cortical regions of interest compared to unilateral montages (Vines et al, 2008), which is important because tDCS brings about network changes even in regions that are not stimulated (Keeser et al, 2011; Lang et al, 2005), suggesting that unilateral stimulation can modulate the contralateral hemisphere and lead to behavioral effects. Bilateral tDCS can therefore oppose such modulation and, in the case of the PPC, may be a better model for mnemonic contributions because changes to memory have been primarily noted in patients with bilateral lesions (Berryhill et al, 2007; Berryhill and Olson, 2008; Drowos et al, 2010; Simons et al, 2010). Thus, in our study we used bilateral montages, placing the anode over the left hemisphere and cathode over the right hemisphere, to determine the nature of the causal role of the PPC in item and source memory retrieval.…”

Section: Introductionmentioning

confidence: 99%

Transcranial direct current stimulation over the parietal cortex alters bias in item and source memory tasks

Pergolizzi

Chua

2016

Brain and Cognition

View full text Add to dashboard Cite

Neuroimaging data has shown that activity in the lateral posterior parietal cortex (PPC) correlates with item recognition and source recollection, but there is considerable debate about its specific contributions. Performance on both item and source memory tasks were compared between participants who were given bilateral transcranial direct current stimulation (tDCS) over the parietal cortex to those given prefrontal or sham tDCS. The parietal tDCS group, but not the prefrontal group, showed decreased false recognition, and less bias in item and source discrimination tasks compared to sham stimulation. These results are consistent with a causal role of the PPC in item and source memory retrieval, likely based on attentional and decision-making biases.

show abstract

Is the posterior parietal lobe involved in working memory retrieval?

Cited by 84 publications

References 72 publications

Spatial Working Memory Impairment in Subclinical Hypothyroidism: An fMRI Study

Spatial Working Memory Impairment in Subclinical Hypothyroidism: An fMRI Study

The steady-state visual evoked potential reveals neural correlates of the items encoded into visual working memory

Transcranial direct current stimulation over the parietal cortex alters bias in item and source memory tasks

Contact Info

Product

Resources

About