For whom the bell tolls: Periodic reactivation of sensory cortex in the gamma band as a substrate of visual working memory maintenancevan Vugt, M., Chakravarthi, R. & Lachaux, J-P., 4-Sep-2014, In : Frontiers in Human Neuroscience. 8, SEP, 10 p., 696.
Research output: Contribution to journal › Article › Academic › peer-review
Working memory (WM) is central to human cognition as it allows information to be kept online over brief periods of time and facilitates its usage in cognitive operations (Luck and Vogel, 2013). How this information maintenance actually is implemented is still a matter of debate. Several independent theories of WM, derived, respectively, from behavioral studies and neural considerations, advance the idea that items in WM decay over time and must be periodically reactivated. In this proposal, we show how recent data from intracranial EEG and attention research naturally leads to a simple model of such reactivation in the case of sensory memories. Specifically, in our model the amplitude of high-frequency activity (>50 Hz, in the gamma-band) underlies the representation of items in high-level visual areas. This activity decreases to noise-levels within 500 ms, unless it is reactivated. We propose that top-down attention, which targets multiple sensory items in a cyclical or rhythmic fashion at around 6–10 Hz, reactivates these decaying gamma-band representations. Therefore, working memory capacity is essentially the number of representations that can simultaneously be kept active by a rhythmically sampling attentional spotlight given the known decay rate. Since attention samples at 6–10 Hz, the predicted WM capacity is 3–5 items, in agreement with empirical findings.
|Number of pages||10|
|Journal||Frontiers in Human Neuroscience|
|Publication status||Published - 4-Sep-2014|
- Attention, ECoG, Gamma oscillations, Working memory, Working memory capacity, amplitude modulation, article, attention, electrocorticography, electroencephalogram, gamma rhythm, human, memory consolidation, neuroanatomy, neuroscience, noise, psychological aspect, sensory cortex, visual memory, working memory
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