Vibrotactile thresholds of the Non-Pacinian I channel: II. Predicting the effects of contactor location on the phalanx
| Autor: | Burak Güçlü, Stanley J. Bolanowski |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Physiology
Models Neurological Population Action Potentials Stimulus (physiology) Vibration Fingers Predictive Value of Tests Electric Impedance medicine Animals Humans Computer Simulation Detection theory education Mathematics Contactor Communication education.field_of_study Computational neuroscience business.industry Mechanical impedance Haplorhini Decision rule Markov Chains Sensory Systems Mechanoreceptor medicine.anatomical_structure Touch Sensory Thresholds Cats Biological system business Mechanoreceptors |
| Zdroj: | Somatosensory & Motor Research. 22:57-68 |
| ISSN: | 1369-1651 0899-0220 |
| DOI: | 10.1080/08990220512331387971 |
| Popis: | The firing-rate-based population model for rapidly-adapting (RA) mechanoreceptive fibers by Güçlü and Bolanowski is extended by including temporal-response properties of RA fibers. This representation allows for the generation of action-potential (spike) times for each fiber when a sinusoidal, steady-state stimulus is applied onto the skin. Signal detection theory was used to predict human psychophysical thresholds. Specifically, the effects of sensorineural innervation pattern, stimulus-contactor location and selected decision rules on the model predictions were studied. The predicted thresholds were lowest when the decision rule was one spike and highest when many active fibers were required for detection. These predictions were empirically tested by measuring vibrotactile thresholds of the Non-Pacinian I (NP I) channel, which required the special techniques discussed in the preceding article. Although the model predicted thresholds to decrease distally due to the known innervation density which is higher distally, the thresholds of the NP I psychophysical channel were found to be approximately constant (20-25 dB re 1 microm peak amplitude) from the proximal site on the terminal phalanx to the most distal portion. Interestingly, the mechanical impedance of the skin was found not to be constant along the proximo-distal axis. This latter result implies that the space-invariant mechanical attenuation function used in the model may not be valid at every location on the fingertip. Because of this, the discrepancy between the model's predictions and the psychophysical results may be reconciled. |
| Databáze: | OpenAIRE |
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