title: Planning following stroke: a relational complexity approach using the tower of london.
abstract: Planning on the 4-disk version of the Tower of London (TOL4) was examined in stroke patients and unimpaired controls. Overall TOL4 solution scores indicated impaired planning in the frontal stroke but not non-frontal stroke patients. Consistent with the claim that processing the relations between current states, intermediate states, and goal states is a key process in planning, the domain-general relational complexity metric was a good indicator of the experienced difficulty of TOL4 problems. The relational complexity metric shared variance with task-specific metrics of moves to solution and search depth. Frontal stroke patients showed impaired planning compared to controls on problems at all three complexity levels, but at only two of the three levels of moves to solution, search depth and goal ambiguity. Non-frontal stroke patients showed impaired planning only on the most difficult quaternary-relational and high search depth problems. An independent measure of relational processing (viz., Latin square task) predicted TOL4 solution scores after controlling for stroke status and location, and executive processing (Trail Making Test). The findings suggest that planning involves a domain-general capacity for relational processing that depends on the frontal brain regions.
authors.affiliation: Behavioural Basis of Health Program, Griffith Health Institute, School of Applied Psychology, Griffith University , Gold Coast, QLD , Australia.
authors.forename: Glenda
authors.initials: G
authors.lastname: Andrews
authors.affiliation: Behavioural Basis of Health Program, Griffith Health Institute, School of Applied Psychology, Griffith University , Brisbane, QLD , Australia.
authors.forename: Graeme S
authors.initials: GS
authors.lastname: Halford
authors.affiliation: Behavioural Basis of Health Program, Griffith Health Institute, School of Applied Psychology, Griffith University , Brisbane, QLD , Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Chappell
authors.affiliation: Centre for National Research on Disability and Rehabilitation Medicine (CONROD), Griffith Health Institute, Griffith University , Meadowbrook, QLD , Australia.
authors.forename: Annick
authors.initials: A
authors.lastname: Maujean
authors.affiliation: Behavioural Basis of Health Program, Griffith Health Institute, School of Applied Psychology, Griffith University , Brisbane, QLD , Australia.
authors.forename: David H K
authors.initials: DH
authors.lastname: Shum
keywords: Tower of London; frontal lobes; goal ambiguity; moves to solution; planning; relational complexity; search depth; stroke