 However, the results may also reflect the involvement of attention, which seems to have a modulatory effect on the extent of priming elicited.This theory is based on the idea that because downstream neurons are sensitive to both the firing rates and the timing of those inputs, efficiencies in processing may be gained through synchronised activation.Evidence of synchronisation associated with repeated stimuli include phase locking found between two regions of the cat visual cortex while measuring spike synchronisation for trained compared with novel stimuli and suppressed firing and increased synchrony of spikes with repetition of odour puffs to locust's antennae.