Hierarchical organization of scripts: converging evidence from FMRI and frontotemporal degeneration.
The present study examined the organization of complex familiar activities, known as "scripts" (e.g., "going fishing"). We assessed whether events in a script are processed in a linear-sequential manner or clustered-hierarchical manner, and we evaluated the neural basis for this processing capacity. Converging evidence was obtained from functional neuroimaging in healthy young adults and from behavioral and structural magnetic resonance imaging (MRI) data in patients with focal neurodegenerative disease. In both studies, participants judged the order of consecutive event pairs taken from a script. Event pairs either were clustered together within a script or were from different clusters within the script. Controls judged events more accurately and quickly if taken from the same cluster within a script compared with different clusters, even though all event pairs were consecutive, consistent with the hierarchical organization of a script. Functional magnetic resonance imaging associated this with bilateral inferior frontal activation. Patients with progressive nonfluent aphasia or behavior-variant frontotemporal dementia did not distinguish between event pairs from the same cluster or from different clusters within a script. Structural MRI associated this deficit with significant frontal cortical atrophy. Our findings suggest that frontal cortex contributes to clustering events during script comprehension, underlining the role of frontal cortex in the hierarchical organization of a script.
Farag
Christine
C
Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA.
Troiani
Vanessa
V
Bonner
Michael
M
Powers
Chivon
C
Avants
Brian
B
Gee
James
J
Grossman
Murray
M
D000203:Activities of Daily Living; D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D016000:Cluster Analysis; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply* / Q000473:pathology; D057174:Frontotemporal Lobar Degeneration / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007600:Judgment / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D055815:Young Adult
D010100:Oxygen