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Item-specific delay activity demonstrates concurrent storage of multiple active neural representations in working memory
- Source :
- PLoS Biology, PLoS Biology, Vol 17, Iss 4, p e3000239 (2019)
- Publication Year :
- 2019
- Publisher :
- Public Library of Science (PLoS), 2019.
-
Abstract
- Persistent neural activity that encodes online mental representations plays a central role in working memory (WM). However, there has been debate regarding the number of items that can be concurrently represented in this active neural state, which is often called the “focus of attention.” Some models propose a strict single-item limit, such that just 1 item can be neurally active at once while other items are relegated to an activity-silent state. Although past studies have decoded multiple items stored in WM, these studies cannot rule out a switching account in which only a single item is actively represented at a time. Here, we directly tested whether multiple representations can be held concurrently in an active state. We tracked spatial representations in WM using alpha-band (8–12 Hz) activity, which encodes spatial positions held in WM. Human observers remembered 1 or 2 positions over a short delay while we recorded electroencephalography (EEG) data. Using a spatial encoding model, we reconstructed active stimulus-specific representations (channel-tuning functions [CTFs]) from the scalp distribution of alpha-band power. Consistent with past work, we found that the selectivity of spatial CTFs was lower when 2 items were stored than when 1 item was stored. Critically, data-driven simulations revealed that the selectivity of spatial representations in the two-item condition could not be explained by models that propose that only a single item can exist in an active state at once. Thus, our findings demonstrate that multiple items can be concurrently represented in an active neural state.<br />An electroencephalography-based study shows that working memory delay activity concurrently represents two items, posing a challenge for models which propose that only one item can be actively represented at a time.
- Subjects :
- Male
0301 basic medicine
Physiology
Vision
Speech recognition
Test Statistics
Social Sciences
Electroencephalography
Cognition
Learning and Memory
Mathematical and Statistical Techniques
0302 clinical medicine
Medicine and Health Sciences
Psychology
Attention
Biology (General)
Clinical Neurophysiology
Brain Mapping
medicine.diagnostic_test
Simulation and Modeling
General Neuroscience
Statistics
Brain
Healthy Volunteers
Electrophysiology
Alpha Rhythm
Bioassays and Physiological Analysis
Memory, Short-Term
Brain Electrophysiology
Physical Sciences
Sensory Perception
Female
Anatomy
General Agricultural and Biological Sciences
Neuronal Tuning
Research Article
Adult
Adolescent
QH301-705.5
Imaging Techniques
Permutation
Neurophysiology
Neuroimaging
Biology
Research and Analysis Methods
General Biochemistry, Genetics and Molecular Biology
03 medical and health sciences
Memory
Neuronal tuning
medicine
Humans
Statistical Methods
Statistical hypothesis testing
Focus (computing)
Scalp
General Immunology and Microbiology
Discrete Mathematics
Working memory
Electrophysiological Techniques
Biology and Life Sciences
030104 developmental biology
Combinatorics
Mental representation
Cognitive Science
State (computer science)
Clinical Medicine
Head
Mathematics
Photic Stimulation
030217 neurology & neurosurgery
Neuroscience
Subjects
Details
- ISSN :
- 15457885
- Volume :
- 17
- Database :
- OpenAIRE
- Journal :
- PLOS Biology
- Accession number :
- edsair.doi.dedup.....a0cd1ea7a989f4d3c5e7e2e86b97e6bb