The assessment of severe lexical disorders in Italian individuals with aphasia

Tests and batteries used in the evaluation of language impairments are overly complex and often ineffective (too difficult) in the assessment of post-stroke patients affected by severe aphasia (global aphasia). The present study reports details on the construction and standardization of a new Italian battery of tasks, specifically designed to assess severe lexical disorders in acquired aphasia (Battery for the Assessment of Severe Acquired Lexical Damage in Italian, BASALDI). The battery is composed of a common set of 64 stimuli (concrete nouns), belonging to both living and non-living categories, and consists of four lexical tasks assessing picture naming, repetition, reading aloud, and oral comprehension. The item selection was based on word frequency, word length, and phonological-articulatory complexity, namely the presence of continuant vs. plosive phones, a variable that may interact with word production in case of severe language damage. Standardization (naming agreement) of a new set of 64 colored images and normative data on Italian healthy subjects pooled across homogenous subgroups for age, gender, and education are reported. Finally, for the four tasks, percentile ranks and z-scores were calculated from a pool of 92 left brain-damaged patients affected by aphasia of different types and severity. The battery allows a fine investigation of lexical disorders, being suitable for diagnostic assessment of mild-to-moderate and severe aphasic lexical deficits, detection of changes over time, and possible dissociations between tasks.