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VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Public Defence: How can shared concept cells encode associations?
DTSTART:20210521T170000
DTEND:20210521T190000
DTSTAMP:20260501T142009Z
UID:fe4b3a5015c1a70a097b1682e46acf0d81223f67c42e3212ff88d78d
CATEGORIES:Conferences - Seminars
DESCRIPTION:Experimental evidence suggests that memories of concepts such 
 as 'the actress Jennifer Aniston' or 'the Sidney opera house' are stored i
 n the Medium Temporal Lobe [1\,2]. Each concept is represented by a sparse
  cell assemblies ('memory engram') so that only a small fraction of neuron
 s respond to a concept such as 'the Sidney Opera House'.   Associations 
 between different concepts  ('Jennifer Aniston in the Sidney Opera House'
  ) are related to shared concept cells: assemblies representing two arbit
 rary concepts share less than 1% of neurons\, whereas assemblies represent
 ing previously associated concepts (e.g.\, you have often seen Jennifer An
 iston in the Sidney Opera house) share up to 4-5% of neurons in the Medial
  Temporal Lobe [3].\n\nAssociations between concepts can also be probed by
  free recall of words. Theoretical studies suggest that shared neurons bet
 ween memory engrams are fundamental for the generation of sequences of wor
 ds during free recall [4].\n\nI will present a modeling study of associati
 ve memory using attractor neural networks.  I demonstrate that correlatio
 ns between memory engrams induced by shared concept cells modify the memor
 y recall process and provide a robust way to encode associations between p
 airs of concepts. Moreover\, I will show that the free recall of a chain o
 f concepts is possible in very sparse attractor networks only if engrams a
 re correlated. \n\nOur model provides a possible explanation of how assoc
 iation are stored in highly sparse networks (such as the Medial Temporal L
 obe) and how correlated memories are recalled in the form of association c
 hains. \n\n[1] Quiroga\, R. Quian\, et al. "Invariant visual representat
 ion by single neurons in the human brain." Nature 435.7045 (2005): 1102-
 1107.\n\n[2] Ison\, Matias J.\, and Rodrigo Quian Quiroga. "Selectivity a
 nd invariance for visual object perception." Front Biosci 13 (2008): 488
 9-4903.\n\n[3]  De Falco\, Emanuela\, et al. "Long-term coding of persona
 l and universal associations underlying the memory web in the human brain.
 " Nature communications 7.1 (2016): 1-11.\n\n[4] Naim\, Michelangelo\, 
 et al. "Fundamental law of memory recall." Physical Review Letters 124.1
  (2020): 018101.
LOCATION:https://epfl.zoom.us/j/68895837873
STATUS:CONFIRMED
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