The effect of tactile and visual sensory inputs on phantom limb awareness
Bibliographic record
Abstract
Multiple sensory stimuli contribute to the conscious awareness of the body. It is well known that limb amputation can result in abnormal body awareness, but the manner in which the CNS constructs and updates a body schema after injury is largely unknown. The purpose of the present study was to systematically evaluate the effects of sensory inputs on phantom limb awareness (PLA) shortly after unilateral upper extremity amputation. The location, quality and intensity of spontaneous and tactile-evoked phantom sensations and awareness were assessed in 13 amputees who were referred sequentially for their initial post-operative rehabilitation. Subjects were tested in three visual conditions: (i) with their eyes open; (ii) with their eyes closed; and (iii) while they viewed their intact hand in a mirror, which created an illusion of their amputated hand (i.e. mirror visual illusion). The mirror illusion was also used to test the effect of combined visual and movement-related stimuli during active voluntary movement. Spontaneous PLA was reported by 12 of the 13 amputees and was not affected by normal visual inputs. Tactile stimulation of the residual limb or face evoked dual percepts in six amputees; i.e. these amputees perceived these touch stimuli as if they were being applied both to the stimulus site and also to a location on the missing limb. This mislocalization phenomenon was most prevalent in the eyes-closed condition. Thus, normal vision can strongly override the phantom component of touch-evoked dual percepts. In eight cases, the visual illusion of the missing limb transiently enhanced the spontaneous conscious awareness of the phantom limb. However, the visual illusion did not change the capacity of a tactile stimulus to induce dual percepts. These findings demonstrate that (i) phantom awareness of an amputated body part is common within the 14 months after traumatic upper extremity amputation, (ii) evoked dual percepts are less common than spontaneous PLA, (iii) visual, tactile and sensorimotor systems contribute to PLA, (iv) subtle changes in congruence of sensory information affects both evoked dual percepts and spontaneous PLA, however, (v) sensorimotor information pertaining to the state of the motor system can strongly influence spontaneous PLA, whereas the visual system can predominantly influence evoked PLA.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".