Title
A Neurocomputational Model Of Stimulus-Specific Adaptation To Oddball And Markov Sequences
Abstract
Stimulus-specific adaptation (SSA) occurs when the spike rate of a neuron decreases with repetitions of the same stimulus, but recovers when a different stimulus is presented. It has been suggested that SSA in single auditory neurons may provide information to change detection mechanisms evident at other scales (e. g., mismatch negativity in the event related potential), and participate in the control of attention and the formation of auditory streams. This article presents a spiking-neuron model that accounts for SSA in terms of the convergence of depressing synapses that convey feature-specific inputs. The model is anatomically plausible, comprising just a few homogeneously connected populations, and does not require organised feature maps. The model is calibrated to match the SSA measured in the cortex of the awake rat, as reported in one study. The effect of frequency separation, deviant probability, repetition rate and duration upon SSA are investigated. With the same parameter set, the model generates responses consistent with a wide range of published data obtained in other auditory regions using other stimulus configurations, such as block, sequential and random stimuli. A new stimulus paradigm is introduced, which generalises the oddball concept to Markov chains, allowing the experimenter to vary the tone probabilities and the rate of switching independently. The model predicts greater SSA for higher rates of switching. Finally, the issue of whether rarity or novelty elicits SSA is addressed by comparing the responses of the model to deviants in the context of a sequence of a single standard or many standards. The results support the view that synaptic adaptation alone can explain almost all aspects of SSA reported to date, including its purported novelty component, and that non-trivial networks of depressing synapses can intensify this novelty response.
Year
DOI
Venue
2011
10.1371/journal.pcbi.1002117
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
mismatch negativity,markov chains,event related potential,computational biology,markov chain,synapses,change detection
Auditory cortex,Mismatch negativity,Biology,Markov model,Event-related potential,Markov chain,Speech recognition,Stimulus (physiology),Novelty,Neuronal tuning
Journal
Volume
Issue
ISSN
7
8
1553-734X
Citations 
PageRank 
References 
9
0.97
2
Authors
4
Name
Order
Citations
PageRank
R Mill1284.14
Martin Coath2355.13
Thomas Wennekers323641.75
Susan L. Denham49912.32