Three language production studies indicate that amnesic H.M. produces speech errors unlike everyday slips-of-the-tongue. Study 1 was a naturalistic task: H.M. and six controls closely matched for age, education, background and IQ described what makes captioned cartoons funny. Nine judges rated the descriptions blind to speaker identity and gave reliably more negative ratings for coherence, vagueness, comprehensibility, grammaticality, and adequacy of humor-description for H.M. than the controls. Study 2 examined “major errors”, a novel type of speech error that is uncorrected and reduces the coherence, grammaticality, accuracy and/or comprehensibility of an utterance. The results indicated that H.M. produced seven types of major errors reliably more often than controls: substitutions, omissions, additions, transpositions, reading errors, free associations, and accuracy errors. These results contradict recent claims that H.M. retains unconscious or implicit language abilities and produces spoken discourse that is “sophisticated,” “intact” and “without major errors.” Study 3 examined whether three classical types of errors (omissions, additions, and substitutions of words and phrases) differed for H.M. versus controls in basic nature and relative frequency by error type. The results indicated that omissions, and especially multi-word omissions, were relatively more common for H.M. than the controls; and substitutions violated the syntactic class regularity (whereby, e.g., nouns substitute with nouns but not verbs) relatively more often for H.M. than the controls. These results suggest that H.M.’s medial temporal lobe damage impaired his ability to rapidly form new connections between units in the cortex, a process necessary to form complete and coherent internal representations for novel sentence-level plans. In short, different brain mechanisms underlie H.M.’s major errors (which reflect incomplete and incoherent sentence-level plans) versus everyday slips-of-the tongue (which reflect errors in activating pre-planned units in fully intact sentence-level plans). Implications of the results of Studies 1–3 are discussed for systems theory, binding theory and relational memory theories.
Perception of speech disorders: Difference between the degree of intelligibility and the degree of severity
Conclusion: There is an argument for measuring intelligibility at the surface code level with a word recognition test or ordinal scales and for allowing the use of interval scales for severity judgment.
Development of speech intelligibility and narrative abilities and their interrelationship three and five years after paediatric cochlear implantation
This study sought to determine the level of speech intelligibility, narrative abilities, and their interrelationship in 18 Finnish children implanted at the average age of three years, four months. Additionally, background factors associated with speech intelligibility and storytelling ability were examined. Speech intelligibility was examined by means of an item identification task with five listeners per child. Three and five years after activation of the implant, the children reached average intelligibility scores of 53% and 81%, respectively. The story generation abilities of the implanted children exceeded their hearing age by one year, on average. This was found after comparing their results with those of normally-hearing two- to six-year-olds (N = 49). According to multiple regression analysis, comorbidity (number of additional needs), chronological age, and/or age at activation usually explained from 46% to 70% of the variation in speech intelligibility and narrative abilities. After controlling for age, communication mode, and number of additional needs, speech intelligibility and ability to narrate were statistically significantly associated with each other three years after activation, but not anymore five years after activation.
from the International Journal of Audiology