Development and psychometric properties of an informant assessment scale of theory of mind for adults with traumatic brain injury

Abstract

Impairment of theory of mind (ToM) is a common phenomenon following traumatic brain injury (TBI) that has clear effects on patients' social functioning. A growing body of research has focused on this area, and several methods have been developed to assess ToM deficiency. Although an informant assessment scale would be useful for examining individuals with TBI, very few studies have adopted this approach. The purpose of the present study was to develop an informant assessment scale of ToM for adults with traumatic brain injury (IASToM-aTBI) and to test its reliability and validity with 196 adults with TBI and 80 normal adults. A 44-item scale was developed following a literature review, interviews with patient informants, consultations with experts, item analysis, and exploratory factor analysis (EFA). The following three common factors were extracted: social interaction, understanding of beliefs, and understanding of emotions. The psychometric analyses indicate that the scale has good internal consistency reliability, split-half reliability, test-retest reliability, inter-rater reliability, structural validity, discriminate validity and criterion validity. These results provide preliminary evidence that supports the reliability and validity of the IASToM-aTBI as a ToM assessment tool for adults with TBI.

Theory of Mind in Adults with Traumatic Brain Injury

“…Persons with TBI were impaired in 'awareness of social context' (48) that includes both cognitive and affective ToM. Also, Zhang et al, (59) attested that persons with TBI were impaired in cognitive and affective ToM. Ilaria et al, (55) indicated that patients with TBI were impaired in cognitive but not affective ToM.…”

Impaired theory of mind in adults with traumatic brain injury: A replication and extension of findings

“…ToM typically is tested by presenting the examinee with spoken or written short stories followed by several questions. The following is an example from a published ToM battery (Zhang, et al, 2015): Liu bought her friend Zhang a crystal bowl for a wedding gift. Zhang had a big wedding and there were a lot of presents to keep track of.…”

“…and 4) How would Liu feel? Stories are read aloud and the authors do not state if written text also is provided, although other tasks in the same battery include written copies to “minimize memory load” (Zhang, et al, 2015, p. 9).…”

“…In addition, there are larger group differences when WM demands are increased (Matsuoka, Kotani, & Yamasato, 2012), and reduced between-group differences on ToM tasks when effects of WM are controlled (Bibby & McDonald, 2005). Overall, adults with TBI make fewer errors on first-order ToM tasks than on second-order, faux pas, and indirect speech tasks (Martin-Rodriguez & Leon-Carrion, 2010), which typically employ multiple embedded clauses (e.g., what did he think about what she thought) and, like the story from Zhang and colleagues (2015), require participants to track perspective changes across agents.…”