Article
Neurosciences
Megan Roussy, Benjamin Corrigan, Rogelio Luna, Roberto A. Gulli, Adam J. Sachs, Lena Palaniyappan, Julio C. Martinez-Trujilio
Summary: The study found that LPFC neurons maintain robust and distinct neural codes for mnemonic and perceptual visuospatial representations during naturalistic vision, with animals using different behavioral strategies for working memory and perception tasks.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Neurosciences
Rose Nasrawi, Sage E. P. Boettcher, Freek van Ede
Summary: In order for visual working memory to serve future behavior, it is important to prepare for the potential use of working memory contents ahead of time. Recent studies show that the planning for upcoming manual actions starts early after visual encoding and occurs alongside visual retention. This study explores whether such output planning in visual working memory can flexibly adapt to different visual-motor mappings, and if it occurs even for actions that may only potentially become relevant for behavior.
JOURNAL OF NEUROSCIENCE
(2023)
Article
Multidisciplinary Sciences
Ivan Voitov, Thomas D. Mrsic-Flogel
Summary: Working memory is an essential component of cognition, but the mechanisms by which neural populations represent and maintain working memory are still unclear. In this study using mice, researchers found that distributed areas of the neocortex were selectively involved in the maintenance of working memory during a visual task. They also discovered that working memory representations were embedded in high-dimensional population activity in visual area AM and premotor area M2, persisting throughout the inter-stimulus delay period.
Article
Neurosciences
Krithika Mohan, Ou Zhu, David J. Freedman
Summary: The study found that primates' category encoding can generalize across different cognitive and motor tasks, with differences in binary-like encoding in the DMC task and graded encoding in the OIC task. Furthermore, analysis of trained RNNs suggests that the binary-like encoding in the DMC task may arise through compression of graded feature encoding by attractor dynamics supporting stimulus maintenance and/or comparison in working memory.
Article
Multidisciplinary Sciences
Shinichiro Kira, Houman Safaai, Ari S. Morcos, Stefano Panzeri, Christopher D. Harvey
Summary: Decision-making relies on flexibility to respond rapidly to sensory stimuli based on stored memory information. The study identifies cortical areas and neural patterns that underlie this flexibility during virtual navigation in mice. The authors find that neurons in posterior cortex mix sensory and memory information, allowing for flexible navigation decisions within the visual-parietal-retrosplenial network. The findings highlight the importance of adaptability in navigation routes.
NATURE COMMUNICATIONS
(2023)
Article
Neurosciences
Yi-Jie Zhao, Kendrick N. Kay, Yonghong Tian, Yixuan Ku
Summary: This study measured brain activity using fMRI and found encoding and tuning characteristics of visual working memory in the visual cortex. The results support the sensory recruitment hypothesis and extend it to the ipsilateral sensory areas.
Article
Neurosciences
Garikoitz Lerma-Usabiaga, Jonathan Winawer, Brian A. Wandell
Summary: The study investigates accurate estimation of the RF of neuronal populations and its shape, finding that elliptical pRFs are common in the early visual cortex. Researchers also found discrepancies in estimation results using different software packages.
JOURNAL OF NEUROSCIENCE
(2021)
Article
Neurosciences
Aspen H. Yoo, Alfredo Bolanos, Grace E. Hallenbeck, Masih Rahmati, Thomas C. Sprague, Clayton E. Curtis
Summary: Humans allocate visual working memory resources according to behavioral relevance, resulting in more precise memories for more important items. In the early visual cortex, the amplitude of brain activity corresponding to the retinotopic location of visual working memory items increases with the priority of the item.
JOURNAL OF COGNITIVE NEUROSCIENCE
(2022)
Article
Neurosciences
Zhu Lin, Feng You, Ting Li, Yijia Feng, Xinyue Zhao, Jingjing Yang, Zhimo Yao, Ying Gao, Jiang-Fan Chen
Summary: Recent studies have shown that astrocytes in the hippocampus exhibit calcium dynamics regulated by sensory inputs and reward delivery, with synchronized but phase-differing dynamics compared to neurons. Additionally, robust synchronization of astrocytic calcium dynamics at the population level was observed among the hippocampus, medial prefrontal cortex, and striatum. The inter-locked, bidirectional communication between astrocytes and neurons may play a role in modulating information processing in working memory.
NEUROSCIENCE BULLETIN
(2022)
Article
Neurosciences
Jacqueline M. Fulvio, Qing Yu, Bradley R. Postle
Summary: Working memory requires encoding stimulus identity and context. The posterior parietal cortex (PPC) plays a crucial role in controlling the representation of stimulus context in visual working memory (WM), showing sensitivity to context binding requirements and domain.
Article
Biochemistry & Molecular Biology
Hsin-Hung Li, Clayton E. Curtis
Summary: The activity of neurons in the prefrontal cortex during working memory delays is dynamic, and the dynamics vary across different cortical visual field maps. Using fMRI responses, researchers found that the early visual cortex exhibited stronger dynamics compared to the high-level visual and frontoparietal cortex. By leveraging population receptive field models, they visualized and interpreted the neural dynamics. Specifically, during working memory delays, the V1 population encoded a narrow bump of activation centered on the peripheral memory target, which then spread inward along the trajectory of the forthcoming memory-guided saccade.
Article
Multidisciplinary Sciences
Nareg Berberian, Matt Ross, Sylvain Chartier
Summary: Studies have shown that animals can rely on internal representations to maintain memory for a period of time in the absence of external inputs. This working memory capacity is associated with neural activity.
Article
Neurosciences
Erin Goddard, Erika W. Contini, Muireann Irish
Summary: This study used MEG to measure the activity of the posteromedial cortex (PMC) in healthy human participants during a visuospatial working memory task. The findings suggest that the PMC plays a role in shaping object representations in other cortical regions and influences the retrieval process.
JOURNAL OF NEUROSCIENCE
(2022)
Review
Neurosciences
Clayton E. Curtis, Thomas C. Sprague
Summary: This article reviews two major research directions on the neural mechanisms of WM, discussing the relationship between classic theories and emerging neuroimaging studies, and pointing out the importance of these studies for WM theory as well as the challenges they pose.
FRONTIERS IN NEURAL CIRCUITS
(2021)
Article
Multidisciplinary Sciences
Panagiotis Sapountzis, Sofia Paneri, Sotirios Papadopoulos, Georgia G. Gregoriou
Summary: Recent work has shown that neural representations in the prefrontal cortex (PFC) are changing to adapt to task demands, but it is still unclear how this dynamic coding depends on the encoded variable and anatomical constraints. In this study, using a cued attention task and multivariate classification methods, the researchers found that neuronal ensembles in the PFC encode and retain spatial and color attentional instructions in a specific manner. Spatial instructions were decoded from both the frontal eye field (FEF) and the ventrolateral PFC (vlPFC) populations, while color instructions were decoded more robustly from vlPFC. The results suggest that dynamic population coding of attentional instructions in the PFC is influenced by anatomical constraints and can coexist with stable subspace coding.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)