. 2014 Jan-Mar;8(1):3–13. doi: 10.1590/S1980-57642014DN81000002

Table 1.

Summary of studies investigating action/verb semantics in patients with Parkinson's disease.

Behavioral evidence
Authors	Participants	Medication	Tasks	Experimental details	Principal findings
Bertella et al. (2002)⁵⁰	22 PD patients and 20 healthy controls.	Not specified	52 pictures of objects and 50 pictures of actions to be orally named.	Not specified.	A verb/noun dissociation with a relative deficit for verbs was found in PD patients.
Péran et al. (2003)⁵¹	34 nondemented PD patients and 34 healthy controls.	ON State	Noun- and verb-generation tasks, using two intracategory (noun/noun and verb/verb generation) and two intercategory (noun/verb and verb/noun) tasks.	40 concrete nouns and 40 action verbs matched for lexical frequency and length.	PD patients were impaired on the tasks involving verb/verb and noun/verb generation. Significant correlations were found between DRS scores and performance on the noun/verb task.
Cotelli et al. (2007)³⁴	32 PD patients in initial stage (ON) and 15 healthy controls.	ON State (32)	Object Picture naming (60) and verbs with hands (60), of varying difficulty.	Objects and verbs were matched by word frequency and word length.	PD patients had impairments in naming objects and actions, with poorer performance for actions.
Crescentini et al. (2008)⁴⁸	20 PD patients in initial stage and 20 healthy controls.	ON State (16)	Verbs and names generation (name-verb, name-name).	Concreteness and frequency were calculated.	PD patients had deficits both for verbs and names generations, with poorer performance for verbs.
Castner et al. (2008)⁵²	8 PD patients who had received surgery for deep brain stimulation (DBS) and 15 healthy controls .	With and without DBS	4 probe-response conditions-namely, noun-noun, verb-noun, noun-verb and verb-verb conditions.	Nouns and verbs were matched for spoken lexical frequency.	Without DBS, patients had a selective deficit in verb generation compared to the control group. DBS resulted in more errors in patients for the noun-noun and verb-verb conditions. Verb generation errors were correlated with item selection constraints (i.e. the degree to which a response competes with other response alternatives) in the DBS, but not without stimulation.
Boulenger et al. (2008)⁴¹	10 PD patients without dementia (ON and OFF) and 10 healthy controls.	ON and OFF States	Priming task- 140 words (70 action verbs with hands and 70 concrete names).- 140 pseudowords (70 pseudoverbs and 70 pseudonames).- 280 non-words.	Verbs and nouns used in the task were matched for frequency, length, bigram and trigram frequency and phonological complexity Imageability and age of acquisition were also taken into account.	Priming effect for verbs was smaller in OFF than in ON situation. Reaction times modulated by Levodopa.
Rodríguez-Ferreiro et al. (2009)⁵³	28 PD patients without dementia.28 patients with AD.28 healthy controls.	Not specified	Naming 50 object pictures and 50 action pictures.Pictures of verbs and naming were extracted from Snodgrass and Vanderwart.	These were matched by name agreement and frequency, age of acquisition, imageability and number of phonemesVisual complexity was higher in verb pictures.	Naming actions was more difficult for PD patients.
Silveri et al. (2012)³⁵	12 PD patients without dementia.	ON and OFF states	Naming 50 object pictures and 50 action pictures.	Stimulus were matched by word frequency, age of acquisition, typicality and agreement of response; not matched by imageability (lower for verbs) and word length.	OFF resulted in less accuracy and greater reaction time, especially for verbs.
Herreira and Cuetos (2012)³⁹	20 PD patients.20 healthy controls.	ON and OFF states	Semantic word generation of 10 words and 10 verbs.	Without restriction of verbs generation.	OFF was associated with the generation of less semantically similar verbs than ON. Generation differences in verbs was evident when PD OFF were compared with controls.
Herreira et al. (2012)⁴⁹	22 PD patients.20 healthy controls.	ON and OFF states	4 verbal fluency tasks: phonological fluency, semantic fluency (animals and supermarket) and action fluency (things you can do).	Patients were asked to produce as many words as they could from each category in 60 s.	Differences in ON and OFF were found in number of words. PD OFF produced fewer words on the phonological and action fluency tasks compared to controls. Differences were found between PD OFF and controls in frequency for the action-word category.
Herreira et al.(2012)⁴⁴	49 PD patients and 19 healthy older adult controls.	ON State	Participants were asked to name pictures of Actions, extracted from the Object and Action naming battery or the IPNP- International Picture Naming Project database.	Subsets of 25 high (e.g. “to dig”) and low (e.g. “to sleep”) motor-association action verb were matched for visual complexity, name agreement, frequency, age of acquisition, imageability and number of syllables and phonemes.	PD patients obtained poorer results in response to pictures with high motor content compared to those with low motor association. PD patients performance appeared to be negatively affected by the level of motion-related semantic content associated to each verb.
Ibáñez et al. (2012)⁴²	17 PD patients, 15 healthy controls, 2 epilepsy patients undergoing surgery.	ON State	Action and sentence compatibility effect and Kissing and dancing test.	Judgments of actions with and/or without hands, psycholinguistic variables not specified.	PD patients with better cognitive performance had fewer deficits on both tests.
Fernandino et al. (2013)⁴³	20 PD patients without dementia and 20 healthy controls.	ON State - Levodopa (17)	Priming TasksLexical decision - 80 verbs (action and abstract verbs) and 80 pseudowords).Semantic Judgment - 120 action verbs and 120 abstract verbs.	Stimuli were matched in number of letters, phonemes, syllables, orthographic and phonological neighbors; lemma frequency.	PD patients had higher reaction times to verbs (equal for action and abstract verbs) in Lexical Decision and were less accurate for action verbs than abstract verbs in semantic judgment.Differences in Priming effect were not observed in abstract and action verbs.
Fernandino et al. (2013)⁴⁰	20 PD patients without dementia and 20 healthy controls.	ON State - Levodopa (17)	Judgment of sentences containing action verbs used with literal and figurative meanings (idioms), control conditions with other abstract sentences.	Conditions were matched for sentence length (letters, phonemes, syllables, and words), response times and accuracy in lexical decision for the content words in the sentence, according to the English Lexicon Project database.	Compared to controls, PD patients had higher reaction times for action verbs both in literal and figurative sentences.
Kemmerer et al. (2013)³²	10 PD patients without dementia and 10 healthy controls.	ON and OFF states	Similarity judgment of four classes of action verbs (running, hitting, cutting, speaking) and two classes of non-action verbs (change of state, emotional states).	Verbs were similar in frequency and letter length. Psych verbs (emotional states) had more letters than others.	Patients and controls had similar accuracy rates but higher reaction times under all conditions.
Neuroimaging studies
Authors	Participants	Medication	Tasks	Experimental details	Principal findings
Péran et al. (2013)³⁷	8 PD patients without dementia].fMRI study.	ON and OFF states	Exhibition of pictures of biological objects and tools to: 1. name objects (objn) 2. Naming of action that could result from the figure (Gena) 3. creating objects for action (MSoA).	Pictures were extracted from Snodgrass and Vanderwart normalized data set, and balanced for frequency and length.	Compared to objn: Gena generated greater activation of the left prefrontal cortex and left medial precuneus; - MSoA generated greater activation of prefrontal cortex and occipital-parietal junction bilaterally. State ON> OFF: (Gena) - premotor areas (MsoA) - premotor areas and thalamus.
Peran et al. (2009)³⁸	14 PD patients without dementia in ON state.fMRI study.	ON state - PD Medications	Pictures of biological objects and tools Exhibition whose interest was: 1. naming objects; 2. election of action that could result from picture.	Pictures were extracted from Snodgrass and Vanderwart normalized data set, and were balanced for frequency and length.	Preferential involvement of the prefrontal cortex, Broca's area and anterior cingulate cortex to generate verbs. There was no specific activation of objects and verbs as the category.
Letter et al. (2012)⁴⁷	7 PD patients.EEG - LORETA.	ON and OFF States	Reading of 30 action verbs and 30 non-action verbs.	The series consisted of 30 hand action verbs (e.g. to sew, to point) and 30 non-action verbs (e.g. to leave, to develop). All verbs consisted of two syllables, matched with respect to word form frequency, and imageability.	ON state resulted in strong currents to all cerebral areas analyzed, with most obvious difference for ON state in the left hemisphere.

PD: Parkinson's disease; DBS: Deep Brain Stimulation; AD: Alzheimer's disease; ON state: cognitive evaluation was undertaken in a patient under the influence of medication; OFF state: cognitive evaluation was undertaken in a patient not under the influence of medication; EEG: Electroencephalography; Loretta: Low Resolution Electromagnetic Tomography.