A critical aspect of the network model is that the fixed weights of the eye position modulation are always reliable,

so that the transformation of the visual responses occurs accurately at all times. Our results show that the eye-position modulation of visual responses is not always reliable. For at least 150 ms after a saccade, visual responses of LIP neurons either reflect the presaccadic orbital position (the consistent cells) or are unrelated to their steady-state gain fields (the inconsistent cells). A simple calculation that uses the steady-state ensemble of visual responses as a set of basis functions or the hidden layer of a neural network at all times would be grossly inaccurate in this epoch. Nonetheless, monkeys make accurate saccades to stimuli flashed immediately after a conditioning saccade, even when there is a dissonance between the Screening Library research buy retinal location of the stimulus and the saccade necessary to acquire it. We cannot exclude that the immediate postsaccadic responses of the inconsistent cells reflects an alternate set of gain fields that is accurate but different from the steady-state set. Therefore,

it is possible that the brain could calculate target position from this temporary set of gain fields using an click here algorithm that ignores the consistent cells, decodes the immediate postsaccadic responses of the inconsistent cells, Ergoloid and gradually changes as the ensemble of responses

revert to their steady-state values at a collection of different times. No formulation of the gain-field model has ever made an exception for stimuli flashed immediately after a saccade. For example, Pouget and Sejnowski emphasize the reliability of the gain field values: “Choosing the hidden units in advance greatly simplifies optimization since the input weights are fixed and only the weights from the hidden to the output units need to be determined” (Pouget and Sejnowski, 1994). In light of our results, if the model is to choose the hidden units in advance, it must now factor in the timing of the most recent saccade in order to decide whether to use the steady-state values for all gain-modulated neurons or the immediate postsaccadic values of the inconsistent cells. The second theory, originated by Hermann von Helmholtz, is that rather than using eye position, the brain calculates a spatially accurate saccadic vector, using a corollary discharge of the intervening saccade to adjust the sensory representation of target position. The modern descendent of this theory is the phenomenon of receptive field remapping: this process remaps the receptive fields of visual neurons so that a stimulus that will be brought into the receptive field by a saccade, or that flashes and disappears before a saccade, will drive the cell.