A 0-100 VAS of mean pain intensity during one week

completed during 7 days, will be used to capture the weekly average of pain intensity (0 = no pain to 100 = the worst imaginable pain, via pain diary). This data will be used either in its raw, continuous form or as a transformed dichotomous variable, yes/no chronic PLP. A cutoff value of PLP intensity ≤20/100 will be used, because from a clinical perspective, pain intensity ≤20 is considered low and will seldom prompt a request for analgesic treatment.

Pain will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

Sense of ownership and agency over phantom limb

Sense of ownership and agency over phantom limb will be a behavioral marker for function of the multisensory integration network. It will be evaluated using a self-report questionnaire with demonstrated sensitivity to detect changes after MT. Six of the questionnaire's 8 items (on a 5-point Likert scale) will be used to assess sense of ownership and agency of upper limb and will be adjusted for the lower limb. Mean scores of 3 questions will evaluate the sense of ownership, and 3 others, the sense of agency, as recommended.

Sense of ownership and agency over phantom limb will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

The Hospital Anxiety and Depression Scale (HADS)

The researchers' marker for function of the fronto-striatal-amygdala circuit, will be assessed via the Hospital Anxiety and Depression Scale (HADS), a self-report 14-item questionnaire focusing on nonphysical symptoms, which measures anxiety and depression, both demonstrated associations with changes in fronto-striatal connectivity. The HADS uses a 0-21 scoring scale, with each item rated on a 4-point Likert scale (0-3). A score of 0-7 is considered normal, 8-10 indicates a mild disorder, 11-14 suggests a moderate disorder, and 15-21 points to a severe disorder.

Anxiety and Depression will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

The Short Form McGill Pain Questionnaire

The researchers' marker for function of the fronto-striatal-amygdala circuit, will also be assessed via the Short Form McGill Pain Questionnaire, which assesses various affective qualities of pain and has demonstrated validity in neuropathic populations. Four affective descriptors rated on a 0-10 numerical rating scale will be summarized.

The Affective qualities of pain will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

The Conditioned Pain Modulation (CPM)

Endogenous pain inhibition will be a psychophysical marker for function of the fronto-PAG circuit. It will be evaluated by the conditioned pain modulation (CPM) paradigm, based on the systemic pain-inhibits-pain phenomenon. The conditioning stimulus will be administrated by immersing the palm in a cold-water bath (14°C). The test stimulus applied on the contralateral (to the conditioning stimulus) lower leg will include individually calibrated heat pain stimulus applied for 20 sec, while averaging pain intensity scores on a VAS Scale (0=no pain, 100= the worst imaginable pain) reported at time 0, 10, and 20 sec. CPM is calculated by subtracting pain scores of the test stimulus given alone from those given with the conditioning stimulus, as recommended.

The CPM score will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

Frequency of PLP paroxysms

Frequency of PLP paroxysms, known to be correlated with PLP intensity or to be affected by neuromodulation techniques applied in PLP, will be evaluated daily for 1 week. Paroxysm will be defined as a period when PLP clearly increases above background pain level; frequency will be evaluated by the average value of the daily score on a 0-100 VAS (0="never during the day" to 100="very frequently").

Frequency of PLP paroxysms will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

Stump pain

Stump pain, known to be correlated with PLP intensity or to be affected by neuromodulation techniques applied in PLP, will be evaluated daily for 1 week. It will be evaluated by the average value of the daily score on a 0-100 VAS (0="not painful at all" to 100="the worst imaginable pain").

Stump pain will be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

Phantom sensations

Phantom sensations, known to be correlated with PLP intensity or to be affected by neuromodulation techniques applied in PLP, will be evaluated daily for 1 week. It will be evaluated by the average value of the daily score on a 0-100 VAS (0="no sensations" to 100="very intense").

Phantom sensations be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)

Telescoping

Telescoping, known to be correlated with PLP intensity or to be affected by neuromodulation techniques applied in PLP, will be evaluated daily for 1 week. Telescoping will be evaluated by the average value of the daily score on a 0-100 VAS (0="no telescoping sensations" to 100="very intense telescoping sensations").

Telescoping be compared between baseline and 4 weeks after the end of the 4 weeks intervention (meaning, comparing baseline to timepoint number 3, which is exactly 8 weeks from the end of the baseline week)