Sensory Illusions Essay


1. How did vibration of the biceps muscle affect the volunteer's ability to sense joint position? Was this expected?
2. Vibration changes our perception of joint position sense. Explain the mechanism behind this?
3. What happened to the volunteer's ability to correctly weight-match when holding a constant load?
4. Can you think of any implications the above finding may have?
5. How did vibration of the biceps brachii tendon affect the volunteer's ability to weight-match? Was this expected? Why or why not?
6. Grasp Your Nose. Describe the sensation?
7. Palm of Hand on the Head. Describe the sensation?
8. Chin in Hand. Describe the sensation?
9. Describe the mechanism behind the tonic vibration reflex (TVR). How does this explain the illusions?


1. The vibration of the biceps muscle affect the volunteer’s ability to sense joint position almost consistent and quickly for the non-dominating arm where as less consistent and quick for the dominating arm according to the data shown by control results. The sense ability of the dominating arm is high as compared to the non-dominating arm. The discrepancy in the measurement is less in case of non-dominating arm where as high for dominating arm. The overall discrepancy according to the controls results is less than zero. Whereas according to the vibration results sense ability is not consistent for both non-dominating and dominating arm. The discrepancy in the measurement is positive and high. The mean discrepancy is high for vibration results and less for controls results.
No, it is not expected as the dominating arm has more sense ability for control and less for vibration.
2. There are mainly two types of joints one is abnormal joint and the other is normal joint so first we have to check the type of joint as the most of the disturbances are on abnormal joints and if the joint is normal than there will be no disturbances. Sometimes the abnormal joint appears like normal joint then there is less need to test more proximal joints. So we have to test more and more joints until we did not find a successful normal joint. If we do not understand the type of joint then the perception made by us will prove wrong as we tested different joint.
3. The volunteer’s ability to correctly weight-match when holding a constant load is good and correct in most of the cases but in some cases volunteer’s sense ability is wrong. The volunteer’s sense ability is not good in comparing same weights. The volunteer senses correctly in most cases when holding a weight equals to the reference weight but fails to sense when the weight is equal to the reference weight.

4. The number of errors in weight-match task of control result is less as compare to the weight-match task of vibration result. It is because the volunteer tells the test weight equals to the reference weight but it is little more than the reference weight. So I think that the volunteer may have implications in measuring a constant weight.
5. The vibration of the biceps brachii tendon affect the volunteer’s ability to weight-match as the biceps of the dominating arm is more sensible so it gives a approximate correct answer where as the biceps of non-dominating arm is less sensible so it gives a less appropriate result.
Yes, it is expected because the controlling and measuring ability of dominating arm is always greater than the non-dominating arm.
6. The main operation of nose is to sense the smell that it is pleasant, unpleasant or neutral. The other operation is that it is useful in taking breath so when we grasp our nose it feels like having problem in taking breath also we will be unable to sense the smell of goods or environment. Also concentrates the eyes on the hand. When we grasp our nose with a hand the smell sense organs unable to operate and cannot work properly until and unless they did not get the input from nose. It will feel like having little pain in top edge of nose between the two eyes.
7. The sensation or feelings when we put the palm of hand on the head are like we have covered the whole head with a heavy thing and feels like the palm is heavy. This activity also makes the concentration of our mind and eyes under the palm. If we keep the palm on head for a longer period then it will also result in slow blood circulation rate in hand and will causes some pain in hand after a long period of time. If we continue keep the palm on head the head will start paining.
8. ‘Body schema’ is defined as a posture of human body, whose main function is to understand the impressions coming from the sensory impulses and then express them in such a way that the final sensation of human body of different positions of body parts, location arises into awareness exciting with a next to kin to somewhat that already has been occurred. When the chin is in hand the senses are like a little pain in head right in the middle of for-head. If we move the hand slowly it feels amazing. It involves the aspects the central brain. If we hold the chin in hand with some pressure it will affect the mouth organs and it will start paining.
9. It has to record that in every sequence of vibrating motivation stretch the muscle, exhilarating the main sensory ending of the influence spindle, causes them to fire. Intervening time, the minor endings and ‘Golgi tendon’ organs come into sight to be fewer responsive to the vibrations. Furthermore, the main sensory endings give the impression to be proficient to pardon in regularity with pulsation at a rate of recurrence of 90 to 390 Hz. Electro my graphic study show that there would be a quantity of nervousness which appear straight away later than the submission of pulsation. This nervousness will get higher gradually and increasingly over the next fifteen to twenty two seconds prior to accomplishment a area of little variation in isotonic tonic vibration reflex. Motivation of the main sensory ending of the sway spindle cause sacking of the main motor neuron puddle afferent fibres which in turn stimulate the motor neuron puddle of the spinal string, most important to sluggish shot in the arm slimming down of the tremble muscle. So, this sluggish shot in the arm slimming down occur from beginning to end composite spinal and innermost spontaneous effect bow mechanisms. So, It has to be hassled that tonic vibrating reflex is not a simple spinal reflex, but a grouping of in cooperation spinal and supra-spinal mechanism.

Refrences :-

1. Wiley Online Library: Login Options. 2015. Wiley Online Library: Login Options. [ONLINE] Available at: [Accessed 10 March 2015].
2. Blasdell, Karen Sue. Transcendental Meditation And The Tonic Vibration Reflex. 1974. Print.
3. Zaidell LN, Mileva KN, Sumners DP, Bowtell JL (2013) Experimental Evidence of the Tonic Vibration Reflex during Whole-Body Vibration of the Loaded and Unloaded Leg. PLoS ONE 8(12): e85247. doi:10.1371/journal.pone.0085247
4. Smith RL, Brunolli J. Shoulder kinesthesia after anterior glenohumeral joint dislocation.Phys Ther1989;69:106–12.
5. Voight ML, Hardin JA, Blackburn TA, et al. The effect of muscle fatigue on and the relationship of arm dominance to shoulder proprioception. J Orthop Sports Phys Ther1996;23:348–52.
6. L?nn J , Crenshaw AG, Djupsj?backa M, et al. Position sense testing: influence of starting position and type of displacement. Arch Phys Med Rehabil 2000;81:592–7.
7. Grigg P . Peripheral neural mechanisms in proprioception. Journal of Sports Rehabilitation1994;3:2–17.
8. Annals of Neurology Volume 38, Issue 2, pages 155–162, August 199, DOI: 10.1002/ana.410380206

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