Theory of Mind and referring expressions after Traumatic Brain Injury

Background: This study focused on the linguistic consequences of damage to Theory of Mind (TOM) in patients after Traumatic Brain Injury (TBI). It was designed to extend a previous study that tested the consequences of TOM impairment (aTOMia) on referring abilities in right-hemisphere damaged patients. Aims: To explore whether aTOMia in patients with TBI affects their use and comprehension of various referring expressions (definite and indefinite noun phrases, proper names and pronouns). Methods and Procedures: We identified individuals with TOM impairment (aTOMia) in a group of 15 TBI patients using a battery of six types of TOM task. We then tested two groups of TBI patients: participants with aTOMia and participants without aTOMia, compared to a control group of non brain-damaged participants. Four TOM-related language tasks assessed their ability to vary the use of referring expressions according to the knowledge of the discourse partners. Outcomes and Results: Five of the participants showed TOM impairment (aTOMia), whereas ten showed intact-TOM ability. The two groups did not differ according to most neuropsychological measures, or on grammatical performance. On the TOM-related language tasks the participants with aTOMia performed consistently worse than the participants with TBI and intact-TOM, and the control group. Conclusions: Individuals after TBI do not form a homogenous group regarding their TOM abilities. Some patients show TOM-related language impairment, and should be considered for language evaluation and treatment focusing on aspects of language that depend on TOM ability.