Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
Answer:
The increased activity prior to the saccade reflects a shift in attention to the stimulus inside that neuron's receptive field.
Explanation:
They observed that the neurological basis of attention, first made in the superior colliculus has been extended to a number of areas in both the dorsal and ventral streams.
