How does the brain support script comprehension? A study of executive processes and semantic knowledge in dementia
Cognitive Neuroscience Division, Sergievsky Center, Columbia University Medical Center, New York, NY 10032, USA. Neuropsychology
(Impact Factor: 3.27).
06/2006; 20(3):307-18. DOI: 10.1037/0894-418.104.22.1687
The neuropsychological substrate of scripts, routines which guide much of human behavior, is unclear. We propose a model of script comprehension characterized by the interaction of semantic knowledge for script content, and executive resources that organize this knowledge into goal directed behavior. We examined these neuropsychological components by asking participants with Alzheimer's disease (AD) and frontotemporal dementia (behavioral disorder/dysexecutive syndrome (BDD) and semantic dementia (SD) subtypes), to judge the coherence of four-phrase scripts. The BDD group detected significantly fewer sequencing errors than semantic errors; the AD and SD groups detected these errors with equal frequency. Independent semantic measures predicted both semantic and sequencing script errors, while executive measures predicted sequencing errors only. Findings support a multi-component model of script comprehension.
Available from: Ashley Boller
- "Previous studies have demonstrated the contribution of executive resources to the organization of narrative discourse in both comprehension and production. In comprehension, one study showed that non-aphasic patients with bvFTD exhibited deficits in judging the ordering of events in a brief script, although their ability to identify semantically anomalous single events was relatively spared (Cosentino et al., 2006). A follow-up study of comprehension, using the same materials as the present report, showed that bvFTD patients, like the DLB/PDD patients in the present study, were impaired in appreciating the closer association of events within a cluster compared to adjacent events in different clusters (Farag et al., 2010). "
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ABSTRACT: Patients with Lewy body spectrum disorders (LBSD) such as Parkinson's disease, Parkinson's disease with dementia, and dementia with Lewy bodies exhibit deficits in both narrative comprehension and narrative expression. The present research examines the hypothesis that these impairments are due to a material-neutral deficit in organizational executive resources rather than to impairments of language per se. We predicted that comprehension and expression of narrative would be similarly affected and that deficits in both expression and comprehension of narrative would be related to the same anatomic distribution of prefrontal disease.
We examined 29 LBSD patients and 26 healthy seniors on their comprehension and expression of narrative discourse. For comprehension, we measured accuracy and latency in judging events with high and low associativity from familiar scripts such as "going fishing." The expression task involved maintaining the connectedness of events while narrating a story from a wordless picture book.
LBSD patients were impaired on measures of narrative organization during both comprehension and expression relative to healthy seniors. Measures of organization during narrative expression and comprehension were significantly correlated with each other. These measures both correlated with executive measures but not with neuropsychological measures of lexical semantics or grammar. Voxel-based morphometry revealed overlapping regressions relating frontal atrophy to narrative comprehension, narrative expression, and measures of executive control.
Difficulty with narrative discourse in LBSD stems in part from a deficit of organization common to comprehension and expression. This deficit is related to prefrontal cortical atrophy in LBSD.
Available from: Chiara Incoccia
- "Therefore, similar to the landmark task, our action-order judgment task engaged a set of cerebral areas devoted to the identification of single elements (actions) as well as areas thought to store the organized representations of these elements. In light according to the two-component model of script knowledge (Cosentino et al., 2006), areas activated in the TPJ are " low level areas " , whereas regions in the prefrontal cortex are " high level areas " responsible for the ordering process. "
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ABSTRACT: INTRODUCTION: The ability to navigate in a familiar environment mainly relies on route knowledge, that is, a mental representation of relevant locations along a way, sequenced according to a navigational goal. Despite the clear ecological validity of this issue, route navigation and route knowledge have been scarcely investigated and little is known about the neural and cognitive bases of this navigational strategy. Using functional magnetic resonance imaging (fMRI) we tested the validity of the predictions based on the main cognitive models of spatial knowledge acquisition about route-based navigation. METHODS: An order judgment task was used with two conditions (route and activity). Subjects were required to detect potential mismatches between a current sensory input and expectations deriving from route and activity knowledge. RESULTS: A medial occipto-temporal (e.g., lingual gyrus, calcarine cortex, fusiform gyrus, parahippocampal cortex) network was found activated during the route task, whereas a temporo-parietal (temporo-parietal junction) and frontal (e.g., Broca's area) network was related to the activity task. CONCLUSIONS: Functional data are congruent with cognitive models of route-based navigation. The route task activated areas related to both landmark identity and landmark order. Data are discussed in view of route-based navigation models.
Available from: Vanessa Troiani
- "Thus, they were less accurate overall and slower in their judgments than controls. One previous study found that script performance is compromised primarily by degraded semantic knowledge in patients with AD (Grafman et al. 1991), and our prior work showed a deficit in script comprehension due in part to impoverished semantic knowledge in SemD but not bvFTD (Cosentino et al. 2006). Nevertheless, AD and SemD patients distinguished between Within-Hierarchy and Different-Hierarchy pairs of events. "
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ABSTRACT: 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.
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