title: The processing of actions and action-words in amyotrophic lateral sclerosis patients.
abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with prime consequences on the motor function and concomitant cognitive changes, most frequently in the domain of executive functions. Moreover, poorer performance with action-verbs versus object-nouns has been reported in ALS patients, raising the hypothesis that the motor dysfunction deteriorates the semantic representation of actions. Using action-verbs and manipulable-object nouns sharing semantic relationship with the same motor representations, the verb-noun difference was assessed in a group of 21 ALS-patients with severely impaired motor behavior, and compared with a normal sample's performance. ALS-group performed better on nouns than verbs, both in production (action and object naming) and comprehension (word-picture matching). This observation implies that the interpretation of the verb-noun difference in ALS cannot be accounted by the relatedness of verbs to motor representations, but has to consider the role of other semantic and/or morpho-phonological dimensions that distinctively define the two grammatical classes. Moreover, this difference in the ALS-group was not greater than the noun-verb difference in the normal sample. The mental representation of actions also involves an executive-control component to organize, in logical/temporal order, the individual motor events (or sub-goals) that form a purposeful action. We assessed this ability with action sequencing tasks, requiring participants to re-construct a purposeful action from the scrambled presentation of its constitutive motor events, shown in the form of photographs or short sentences. In those tasks, ALS-group's performance was significantly poorer than controls'. Thus, the executive dysfunction manifested in the sequencing deficit -but not the selective verb deficit- appears as a consistent feature of the cognitive profile associated with ALS. We suggest that ALS can offer a valuable model to study the relationship between (frontal) motor centers and the executive-control machinery housed in the frontal brain, and the implications of executive dysfunctions in tasks such as action processing.
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Italy; Department of Psychology, Harvard University, Cambridge, MA, US. Electronic address: liuba.papeo@gmail.com.
authors.forename: Liuba
authors.initials: L
authors.lastname: Papeo
authors.affiliation: Area of Neuroscience, Scuola Internazionale di Studi Superiori Avanazati - SISSA, Trieste, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Cecchetto
authors.affiliation: S.C. Clinica Neurologica, Azienda Ospedaliera "Ospedali Riuniti", Trieste, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Mazzon
authors.affiliation: S.C. Clinica Neurologica, Azienda Ospedaliera "Ospedali Riuniti", Trieste, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Granello
authors.affiliation: S.C. Clinica Neurologica, Azienda Ospedaliera "Ospedali Riuniti", Trieste, Italy.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Cattaruzza
authors.affiliation: S.O.C. Neurologia, Azienda Ospedaliero Universitaria "Santa Maria della Misericordia", Udine, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Verriello
authors.affiliation: S.O.C. Neurologia, Azienda Ospedaliero Universitaria "Santa Maria della Misericordia", Udine, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Eleopra
authors.affiliation: Area of Neuroscience, Scuola Internazionale di Studi Superiori Avanazati - SISSA, Trieste, Italy.
authors.forename: Raffaella I
authors.initials: RI
authors.lastname: Rumiati
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D032882:Comprehension / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Action processing; Action sequencing; Amyotrophic lateral sclerosis; Dysexecutive syndrome; Noun-verb dissociations