Abstract: In the study on human cognitive mechanism, the way of collecting data from patients begins to become an important technique in cognitive neuroscience recently. In the past few years, authors have found some brain-damaged patients with semantic category-specific deficit who show a relatively lower cognitive ability in some specific semantic categories than in other ones. By means of the wonderful finding, a new study area is developed for exploring the structure and function of semantic memory system. In the present paper, we focus on introducing the finding and four new semantic memory theories based on it , and survey the human semantic memory.

Key words: semantic category-specific deficit, semantic memory, cognitive ability.