Static mechanisms
Pages 17

Static mechanisms set up a single activation gradient over items, which is then held static during the course of sequence generation. Sequence production is accomplished by virtue of the refractoriness of item representations-as each item is produced, it is removed from the competition for output in the next sequence position, where the next most active item will “win”. In such a system it is desirable that items should remain refractory for a long period, as items produced near the beginning of the sequence will have a large input from the activating mechanism, which will still be present towards the end of the sequence. The use of a static activation mechanism places two constraints on a CQ system which may or may not be disadvantageous, depending on the details of the model. First, the final activation level of each successive item in the sequence must be lower than its predecessor. Second, unless there is some means to control the refractory periods of individual item representations (which is generally assumed not to be the case), it is not possible to cater for sequences that contain repeated items.