Ullman reviews several psycholinguistic and neurolinguistic studies that support the declarative/procedural model. There are two prevalent perspectives of TOT states&colon; the psycholinguistic perspective and the metacognitive perspective. He presented the generative grammar as a coherent abstract description of this underlying psycholinguistic reality. This is evidence for both the metacognitive perspective as well as the psycholinguistic perspective. This contradicts any and all psycholinguistic descriptions of aphasia, the only language related brain damage. Chomsky's argument had a forceful impact on psycholinguistic research. As such, science fiction works of this era often contradict actual psycholinguistic theories. A second influence is the psycholinguistic study of speech comprehension and production. She is also interested in language profiling, evolution of language and psycholinguistic theory. Pseudowords are also sometimes called wug words in the context of psycholinguistic experiments. These psychological signatures were then mathematically compared with the psycholinguistic profile of "Double Falsehood". This task is commonly used in psycholinguistic studies of child language. For this, Gouin preceded psycholinguistic theory of the 20th century. Psycholinguistic research in idiom comprehension began in the 1970s. In many psycholinguistic models this is considered to be at least a two-stage process.