Evidence for an optimal algorithm underlying signal combination in human visual cortex

TY - JOUR

T1 - Evidence for an optimal algorithm underlying signal combination in human visual cortex

AU - Baker, Daniel Hart

AU - Wade, Alexander Robert Patrick

N1 - © The Author 2016. Published by Oxford University Press.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - How does the cortex combine information from multiple sources? We tested several computational models against data from steady-state EEG experiments in humans, using periodic visual stimuli combined across either retinal location or eye-of-presentation. A model in which signals are raised to an exponent before being summed in both the numerator and the denominator of a gain control nonlinearity gave the best account of the data. This model also predicted the pattern of responses in a range of additional conditions accurately and with no free parameters, as well as predicting responses at harmonic and intermodulation frequencies between 1 and 30Hz. We speculate that this model implements the optimal algorithm for combining multiple noisy inputs, in which responses are proportional to the weighted sum of both inputs. This suggests a novel purpose for cortical gain control: implementing optimal signal combination via mutual inhibition, perhaps explaining its ubiquity as a neural computation.

AB - How does the cortex combine information from multiple sources? We tested several computational models against data from steady-state EEG experiments in humans, using periodic visual stimuli combined across either retinal location or eye-of-presentation. A model in which signals are raised to an exponent before being summed in both the numerator and the denominator of a gain control nonlinearity gave the best account of the data. This model also predicted the pattern of responses in a range of additional conditions accurately and with no free parameters, as well as predicting responses at harmonic and intermodulation frequencies between 1 and 30Hz. We speculate that this model implements the optimal algorithm for combining multiple noisy inputs, in which responses are proportional to the weighted sum of both inputs. This suggests a novel purpose for cortical gain control: implementing optimal signal combination via mutual inhibition, perhaps explaining its ubiquity as a neural computation.

KW - gain control

KW - signal combination

KW - visual cortex

KW - Kalman filter

KW - Visual Perception/physiology

KW - Humans

KW - Information Storage and Retrieval/methods

KW - Male

KW - Models, Statistical

KW - Evidence-Based Medicine

KW - Neural Inhibition/physiology

KW - Young Adult

KW - Visual Cortex/physiology

KW - Algorithms

KW - Photic Stimulation/methods

KW - Computer Simulation

KW - Evoked Potentials, Visual/physiology

KW - Brain Mapping

KW - Adult

KW - Female

KW - Models, Neurological

KW - Nerve Net/physiology

KW - Synaptic Transmission/physiology

UR - http://www.scopus.com/inward/record.url?scp=85029036481&partnerID=8YFLogxK

U2 - 10.1093/cercor/bhw395

DO - 10.1093/cercor/bhw395

M3 - Article

C2 - 28031176

SN - 1047-3211

VL - 27

SP - 254

EP - 264

JO - Cerebral Cortex

JF - Cerebral Cortex

IS - 1

ER -