Mcnab F, Klingberg T. Prefrontal cortex and basal ganglia control access to working memory. Nat Neurosci 11: 103-107

Developmental Cognitive Neuroscience, Stockholm Brain Institute, Karolinska Institutet, MR Centrum, Stockholm, Sweden.
Nature Neuroscience (Impact Factor: 16.1). 02/2008; 11(1):103-7. DOI: 10.1038/nn2024
Source: PubMed

ABSTRACT

Our capacity to store information in working memory might be determined by the degree to which only relevant information is remembered. The question remains as to how this selection of relevant items to be remembered is accomplished. Here we show that activity in the prefrontal cortex and basal ganglia preceded the filtering of irrelevant information and that activity, particularly in the globus pallidus, predicted the extent to which only relevant information is stored. The preceding frontal and basal ganglia activity were also associated with inter-individual differences in working memory capacity. These findings reveal a mechanism by which frontal and basal ganglia activity exerts attentional control over access to working memory storage in the parietal cortex in humans, and makes an important contribution to inter-individual differences in working memory capacity.

Download full-text

Full-text

Available from: Torkel Klingberg
  • Source
    • "While often considered multifactorial, poor planning for an upcoming obstacle is an important consideration. Planning requires attentional (Spiegel et al., 2013Spiegel et al., , 2014 ) and sensory processes (Buneo and Andersen, 2006 ) which may be modulated by the basal ganglia (Maschke et al., 2003; Monchi et al., 2006; McNab and Klingberg, 2008; Schendan et al., 2009 ); thus, if either process is affected by the neurodegenerative processes of Parkinson's disease, there may be a negative impact on movement planning. Understanding these planning deficits in individuals with Parkinson's disease may be critical in the prevention of falls and tripping behaviors. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Both cognitive and sensorimotor processes are needed for successful planning of footsteps during complex gait situations, but the interaction between these factors during motor planning, as well as their response to dopaminergic treatment is poorly understood in Parkinson’s disease. In the current study, we evaluated walking and gaze behaviours of Parkinson’s patients while planning an approach toward an obstacle to be stepped over. The obstacle clearance task was completed both ON and OFF dopaminergic medication by individuals with Parkinson’s disease (n=20) and compared to healthy age-matched control participants (n=19), as well as with and without an auditory digit monitoring dual task. In this novel protocol of synchronized gaze and gait data collection, each trial was split into an early and late phase prior to the obstacle, providing a unique opportunity to examine dopamine-dependent planning deficits in Parkinson’s disease. Interestingly, only patients in the OFF medication state showed greater deceleration in the late phase (i.e., just before the obstacle), as well as an increase in step time variability (also in this late phase) with the additional demands of a dual task. Although groups showed different walking behaviors, gaze behaviors were the same for all participants, in that they planned for the obstacle more so in the early phase, and fixations were reduced across participants with the presence of the dual task. Surprisingly, the gaze behavior of the PD OFF group showed no interactions with phase or condition suggesting that the deceleration and increased variability when approaching an obstacle is the result of a greater demand for online sensory feedback that cannot be compensated for with visual strategies. We conclude that dopamine influences planning by limiting sensorimotor processing capacity, especially in the presence of increased cognitive demand in Parkinson’s disease.
    Full-text · Article · Jan 2016 · Neuroscience
    • "Prefrontal cortex can bias its effective connectivity towards various posterior regions depending on the nature of the visual stimulus presented to the subject[15]. Its activation precedes the filtering of irrelevant information in visual WM tasks[11],[16]. Mental arithmetic is an experimental paradigm that triggers WM and it has been recently demonstrated that crossfrequency phase interactions correlate with the difficulty of the executed task[17]. Previous studies of mental arithmetic has also led to the hypothesis that the control processes of the WM are achieved by top-down signals from the prefrontal cortex to the posterior regions where the representations are stored[18],[19]. "

    No preview · Article · Jan 2016 · IEEE Transactions on Neural Systems and Rehabilitation Engineering
  • Source
    • "Prefrontal cortex can bias its effective connectivity towards various posterior regions depending on the nature of the visual stimulus presented to the subject[15]. Its activation precedes the filtering of irrelevant information in visual WM tasks[11],[16]. Mental arithmetic is an experimental paradigm that triggers WM and it has been recently demonstrated that crossfrequency phase interactions correlate with the difficulty of the executed task[17]. Previous studies of mental arithmetic has also led to the hypothesis that the control processes of the WM are achieved by top-down signals from the prefrontal cortex to the posterior regions where the representations are stored[18],[19]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Working memory (WM) is a distributed cognitive process that employs communication between prefrontal cortex and posterior brain regions in the form of cross-frequency coupling between theta (�) and high-alpha (�2) brain waves. A novel method for deriving causal interactions between brain waves of different frequencies is essential for a better understanding of the neural dynamics of such complex cognitive process. Here, we proposed a novel method to estimate transfer entropy (TE) through a symbolization scheme, which is based on neural-gas algorithm (NG) and encodes a bivariate time series in the form of two symbolic sequences. Given the symbolic sequences, the delay symbolic transfer entropy (dSTENG) is defined. Our approach is akin to standard symbolic transfer entropy (STE) that incorporates the ordinal pattern (OP) symbolization technique. We assessed the proposed method in a WM-invoked paradigm that included a mental arithmetic task at various levels of difficulty. Effective interactions between Frontal� (F�) and Parieto-Occipital�2 (PO�2) brain waves were detected in multichannel EEG recordings from 16 subjects. Compared with conventional methods, our technique was less sensitive to noise and demonstrated improved computational efficiency in quantifying the dominating direction of effective connectivity between brain waves of different spectral content. Moreover, we discovered an efferent F� connectivity pattern and an afferent PO�2 one, in all the levels of the task. Further statistical analysis revealed an increasing dSTENG strength following the task’s difficulty.
    Full-text · Article · Dec 2015 · IEEE Transactions on Neural Systems and Rehabilitation Engineering
Show more