STIMA: a short screening test for ideo-motor apraxia, selective for action meaning and bodily district

Abstract

We propose STIMA, a short test for ideo-motor apraxia, allowing us to quantify the apraxic deficit according to action meaning and affected body segment. STIMA is based on a neurocognitive model holding that there are two processes involved in action imitation (i.e., a semantic route for recognizing and imitating known gestures, and a direct route for reproducing new gestures). The test allows to identify which imitative process has been selectively impaired by brain damage (direct vs. semantic route) and possible deficits depending on the body segment involved (hand/limb vs. hand/fingers). N = 111 healthy participants were administered with an imitation task in two separated blocks of known and new gestures. In each block, half of the gestures were performed mainly with the proximal part of the upper limb and the remaining half with the distal one. It resulted in 18 known gestures (nine proximal and nine distal) and 18 new gestures (nine proximal and nine distal) for a total of 36. Each gesture was presented up to a maximum of two times. Detailed criteria are used to assign the final imitation score. Cut offs, equivalent scores and main percentile scores were computed for each subscale. Participants imitated better known than new gestures, and proximal better than distal gestures. Age influenced performance on all subscales, while education only affected one subscale. STIMA is easy and quick to administer, and compared to previous tests, it offers important information for planning adequate rehabilitation programs based on the functional locus of the deficit.

Anatomical and spatial matching in imitation: Evidence from left and right brain-damaged patients

“…VOSP scr.¼ screening task; VOSP obj. ¼ object decision task; BORB MFM ¼ Minimal Feature Match Test of the Birmingham Object Recognition Battery (Riddoch and Humphreys, 1993); IA¼ test for ideational apraxia (De Renzi and Lucchelli, 1988); IMA ¼ test for ideomotor apraxia (Tessari et al, 2015). t.i.¼ test interrupted because the patient was not able to perform the task.…”

“…The patients' performance in the spatial condition is reported in Table 2, as the procedure used in this condition overlaps with the standard testing for ideomotor apraxia (Tessari et al, 2015). The two main experimental tasks are schematized.…”

“…Patients and controls were asked to imitate, one after the other, 18 meaningful intransitive gestures and 18 meaningless gestures, derived from the meaningful ones by modifying the spatial relationship between the effector and the main body axis (Tessari et al, 2015). The presentation of the meaningful and meaningless gestures was blocked and the meaningless gestures were presented always first, to prevent participants from selecting the direct, non-semantic, route for both types of gestures (Tessari and Rumiati, 2004).…”

“…VOSP scr.¼ screening task; VOSP obj. ¼object decision task; IA¼ test for ideational apraxia (De Renzi and Lucchelli, 1988); IMA ¼test for ideomotor apraxia (Tessari et al, 2015). Patients are sorted alphabetically by their initials.…”

“…This task is a standardized test usually adopted in the neuropsychological assessment to detect deficits in imitation (Tessari et al, 2015).…”