Data from: Neurons in primate visual cortex alternate between responses to multiple stimuli in their receptive field

A fundamental question concerning representation of the visual world in
our brain is how a cortical cell responds when presented with more than a
single stimulus. We find supportive evidence that most cells presented
with a pair of stimuli respond predominantly to one stimulus at a time,
rather than a weighted average response. Traditionally, the firing rate is
assumed to be a weighted average of the firing rates to the individual
stimuli (response-averaging model) (Bundesen et al., 2005). Here, we also
evaluate a probability-mixing model (Bundesen et al., 2005), where neurons
temporally multiplex the responses to the individual stimuli. This
provides a mechanism by which the representational identity of multiple
stimuli in complex visual scenes can be maintained despite the large
receptive fields in higher extrastriate visual cortex in primates. We
compare the two models through analysis of data from single cells in the
middle temporal visual area (MT) of rhesus monkeys when presented with two
separate stimuli inside their receptive field with attention directed to
one of the two stimuli or outside the receptive field. The spike trains
were modeled by stochastic point processes, including memory effects of
past spikes and attentional effects, and statistical model selection
between the two models was performed by information theoretic measures as
well as the predictive accuracy of the models. As an auxiliary measure, we
also tested for uni- or multimodality in interspike interval
distributions, and performed a correlation analysis of simultaneously
recorded pairs of neurons, to evaluate population behavior.