Electropalatographic assessment of articulatory timing characteristics in dysarthria following traumatic brain injury

Electropalatography (EPG) is an instrumental technique that records the location and timing of tongue-to-palate contacts during speech (Hardcastle, 1984; Hardcastle, Gibbon, & Jones, 1991a; Hardcastle, Jones, Knight, Trudgeon, & Calder, 1989). Such a technique would be valuable in objectively assessing the articulatory disturbances exhibited by individuals with dysarthria following traumatic brain injury (TBI). To date, however, only a limited number of studies have reported using EPG for this purpose. The aims of the present study were to use EPG to assess the articulatory timing characteristics exhibited by three male subjects (aged 23, 27, and 29 years) with dysarthria following severe TBI and to examine the EPG results in relation to perceptual and physiological (nonspeech) findings. A word list, consisting of the lingual consonants, / t, d, s, z, k, g /, in the word-initial position of single-syllable real words of CV and CVC construction (where V = / a /), was read aloud three times by each subject while wearing an EPG palate. The results obtained by the TBI subjects were compared with a non-neurologically impaired control and are discussed in a series of three case discussions. Both longer and shorter consonant phase durations were exhibited, as were the features of undershooting and overshooting. The findings demonstrated that electropalatography provides greater insight into the nature of the underlying articulatory disturbances exhibited by individuals with dysarthria following TBI.