Delay-period activity in frontal, parietal, and occipital cortex tracks noise and biases in visual working memory

Abstract

Working memory is imprecise, and these imprecisions can be explained by the combined influences of random diffusive error and systematic drift toward a set of stable states ("attractors"). However, the neural correlates of diffusion and drift remain unknown. Here, we investigated how delay-period activity in frontal and parietal cortex, which is known to correlate with the decline in behavioral memory precision observed with increasing memory load, might relate to diffusion and drift. We analyzed data from an existing experiment in which subjects performed delayed recall for line orientation, at different loads, during functional magnetic resonance imaging (fMRI) scanning. To quantify the influence of drift and diffusion, we modeled subjects' behavior using a discrete attractor model and calculated within-subject correlation between frontal and parietal delay-period activity and whole-trial estimates of drift and diffusion. We found that although increases in frontal and parietal activity were associated with increases in both diffusion and drift, diffusion explained the most variance in frontal and parietal delay-period activity. In comparison, a subsequent whole-brain regression analysis showed that drift, rather than diffusion, explained the most variance in delay-period activity in lateral occipital cortex. These results are consistent with a model of the differential recruitment of general frontoparietal mechanisms in response to diffusive noise and of stimulus-specific biases in occipital cortex.

Neurodynamic correlates for the cross-frequency coupled transcranial alternating current stimulation during working memory performance

“…Consistently, as frontal theta networks coordinate inter-regional communication ( Voytek et al, 2015 ), tACS might engage in network communications for better working memory performance. As shown in Figure 6 , the frontal-parietal-occipital connection of the tACS group was notably strengthened, and this result is consistent with previous studies on distributed fronto-parieto-occipital processing stages during working memory ( Halgren et al, 2002 ; Yu and Shim, 2017 ; Yu et al, 2020 ) and the parieto-frontal integration theory (P-FIT) ( Jung and Haier, 2007 ), in which human intelligence is interpreted in terms of interactions within the frontal and parietal cortical regions. For example, the central executive function of working memory is involved in the frontal area, whereas the working memory storage component is associated with the parietal area ( Sauseng et al, 2005 , 2009 , 2010 ).…”

The Spontaneous Activity Pattern of the Middle Occipital Gyrus Predicts the Clinical Efficacy of Acupuncture Treatment for Migraine Without Aura

“…The occipital cortex is the visual perception and processing center. Given the complex functional connection of the temporooccipital cortex, the occipital cortex is also responsible for multisensory integration of visual, auditory, and tactile information (50)(51)(52). Various studies have previously illustrated structural and functional alterations of the occipital cortex in patients with migraine (22,(53)(54)(55), which are generally thought to be associated with the aura phenomenon, especially visual aura (56).…”

Geometry of visual working memory information in human gaze patterns

“…However, progress in understanding the temporal dynamics of WM abstraction has thus far been limited. Few studies have examined the extent to which neural WM representations generalize (or not) across different stimulus inputs (Christophel, Allefeld, et al, 2018; Kwak & Curtis, 2022; Spitzer & Blankenburg, 2012; Vergara et al, 2016) and/or become categorically biased (e.g., Bae, 2021; Wolff et al, 2020; Yu et al, 2020). In humans, these studies used functional imaging (fMRI), which lacks the temporal resolution to disclose rapid format changes, or EEG/MEG, which often can decode the task-relevant stimulus information only during the first 1-2 seconds of unfilled WM delays (Bae, 2021; Barbosa et al, 2021; King et al, 2016; Spitzer & Blankenburg, 2011; Wolff et al, 2017).…”