Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Magnitude of perceived change in natural images may be linearly proportional to differences in neuronal firing rates
AU - Tolhurst, David J.
AU - To, Michelle P. S.
AU - Chirimuuta, Mazviita
AU - Troscianko, Tom
AU - Chua, Pei-Ying
AU - Lovell, P. George
PY - 2010
Y1 - 2010
N2 - We are studying how people perceive naturalistic suprathreshold changes in the colour, size, shape or location of items in images of natural scenes, using magnitude estimation ratings to characterise the sizes of the perceived changes in coloured photographs. We have implemented a computational model that tries to explain observers' ratings of these naturalistic differences between image pairs. We model the action-potential firing rates of millions of neurons, having linear and non-linear summation behaviour closely modelled on real VI neurons. The numerical parameters of the model's sigmoidal transducer function are set by optimising the same model to experiments on contrast discrimination (contrast 'dippers') on monochrome photographs of natural scenes. The model, optimised on a stimulus-intensity domain in an experiment reminiscent of the Weber-Fechner relation, then produces tolerable predictions of the ratings for most kinds of naturalistic image change. Importantly, rating rises roughly linearly with the model's numerical output, which represents differences in neuronal firing rate in response to the two images under comparison; this implies that rating is proportional to the neuronal response.
AB - We are studying how people perceive naturalistic suprathreshold changes in the colour, size, shape or location of items in images of natural scenes, using magnitude estimation ratings to characterise the sizes of the perceived changes in coloured photographs. We have implemented a computational model that tries to explain observers' ratings of these naturalistic differences between image pairs. We model the action-potential firing rates of millions of neurons, having linear and non-linear summation behaviour closely modelled on real VI neurons. The numerical parameters of the model's sigmoidal transducer function are set by optimising the same model to experiments on contrast discrimination (contrast 'dippers') on monochrome photographs of natural scenes. The model, optimised on a stimulus-intensity domain in an experiment reminiscent of the Weber-Fechner relation, then produces tolerable predictions of the ratings for most kinds of naturalistic image change. Importantly, rating rises roughly linearly with the model's numerical output, which represents differences in neuronal firing rate in response to the two images under comparison; this implies that rating is proportional to the neuronal response.
KW - Photic Stimulation
KW - Memory
KW - Contrast Sensitivity
KW - Neurons
KW - Humans
KW - Discrimination (Psychology)
KW - Models, Theoretical
U2 - 10.1163/187847510X532676
DO - 10.1163/187847510X532676
M3 - Journal article
C2 - 21466148
VL - 23
SP - 349
EP - 372
JO - Seeing and Perceiving
JF - Seeing and Perceiving
SN - 1878-4755
IS - 4
ER -