title: Cognitive factors underpinning poor expressive communication skills after traumatic brain injury: theory of mind or executive function?
abstract: OBJECTIVE
  The ability to see things from another's perspective, that is, have a theory of mind (ToM), is essential to effective communication. So too is the ability to regulate verbal output, that is, to exercise executive control. People with traumatic brain injuries (TBIs) have impaired communication abilities, but the extent to which this reflects ToM versus executive dysfunction is unclear. This study explored the relative contributions of executive abilities, specifically flexibility and inhibition and ToM abilities in language production post-TBI.
  
  
  METHODS
  Twenty-five adults (18 males: mean age of 48.2 years, SD = 12.0 years) with moderate to severe TBI (posttraumatic amnesia = 69.2, SD = 54.6 days) and 28 noninjured adults (19 males: mean age 49.0, SD = 12.2 years) completed three sets of communication tasks with low executive demands, high flexibility, and high inhibition demands. Within each, parallel versions had low or high ToM requirements.
  
  
  RESULTS
  For low executive and high flexibility tasks, scores on the high ToM versions were predicted by scores on the low ToM versions, suggesting that poor performance was explained by the executive demands the parallel tasks had in common. The exception was the high inhibition task. In this case, speakers with TBI had differential difficulty with the high ToM version, that is, they had specific difficulty inhibiting self-referential thoughts in order to cater for another's perspective.
  
  
  CONCLUSIONS
  We found problems with inhibiting the self-perspective accords with descriptive accounts of the egocentric nature of some communication patterns following TBI, which points to potential targets for remediation.
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Skye
authors.initials: S
authors.lastname: McDonald
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Alison
authors.initials: A
authors.lastname: Gowland
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Rebekah
authors.initials: R
authors.lastname: Randall
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Alana
authors.initials: A
authors.lastname: Fisher
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Katie
authors.initials: K
authors.lastname: Osborne-Crowley
authors.affiliation: School of Psychology, University of New South Wales.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Honan
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications / Q000523:psychology*; D056344:Executive Function; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012938:Social Perception; D056345:Theory of Mind; D014705:Verbal Behavior