1. YenningLee
September28,2010
Period3
Touch Sensitivity Lab
Introduction
The skinof the humanbodyhas many touchreceptors.However,thesetouchreceptorsare spread
out across the skinwithsome areashavinga densernumberof receptors. Inthe followingactivity,
the palm,volar,fingertips,forearmandneckwill be subjectedtoatwo-pointtouchdiscriminationto
determine whichareaisthe mostsensitive totouch.
Procedure
The experimentwill be conductedbypairsof students.One studentwill have theireyesclosed while
another student will mark a point with a pen on a particular area that is to be tested on(for example,
the palmor the fingertips). Withtheireyesstillclosed,the studentbeingmarkedonwill use their
ownpento mark the pointtheyfelt. The twopointswill thenbe measuredintothe closestdistance
inmillimeters. 5trialswill be made oneachbodypart and the experimentwillbe repeatedonthe
palm,volarsurface (backof the hand),fingertips,forearmandbackof the neck.
Data and Observation
Figure 1
Student Palm Volar Fingertips Forearm Back of the
Neck
monty 3 2 6 26 10
tony 1 8 2 21 8
david 9 11 4 11 17
sirin 10 9 4 9 11
robin 12 10 3 14 9
yenning 7 7 3 19 15
lily 7 11 4 27 23
Amelia 6 11 5 23 13
grace 4 10 3 26 18
almu 10 16 6 18 24
curtis 9 9 3 9 17
tevin 6 8 2 19 20
Anavi 10 10 3 12 6
charlisa 5 21 1 8 5
Mean 7.07 10.21 3.50 16.93 14.00
Each numberpresentedbythe studentisanaverage of data fromfive trialsroundedtothe nearest
millimeter.The meanatthe endof the chart referstothe total average of the datasetof all students
on the categorizedbodypart.

2. Figure 2
Palm Volar Fingertip Forearm Neck
Palm x S VS VS VS
Volar x VS S A
Fingertip x VS VS
Forearm x N
Neck x
Key:S = Significant,VS=VerySignificant,N =Not Significant,A = AlmostSignificant
Conclusion
As can be observed infigure 1,the fingertipshasthe leastdifference indistance betweenpoints
made,makingitthe most sensitivesurface totouchoutof all the bodyparts. The forearmhas the
largestaverage distance betweenpoints,makingitthe leastsensitivepart. However,itshouldbe
consideredthatthere wasnoparticularlyassignedfingertoexperimentonmeaningthateach
studentmayhave conductedthe activityona differentfingereachtime.Thiscanproduce errorsas
it isnot knowwhetherornoteach fingerhasthe same amountof touch receptors. The datacan be
seenasa patternsince the largestsurface areasoutof the group, the forearmandthe back of the
neckhas the largestaverage difference betweenpoints. Thus,the areaof the surface testedonmay
have an effectonthe resultsaslarge bodyparts like the forearmmayhave touch receptorsmore
spreadout onthe areathan the fingertipswhichmayhave denselypackedtouchreceptorsdue toits
small surface area. Figure 2 representsthe significanceof the dataof each bodypart comparedto
anotherusingthe statisticsprogramGraphpad. Accordingto the chart, the data set withthe largest
difference,the fingertipsandthe forearmshave averysignificantdifference meaningthere islittle
to no chance that the data setscan share the same figures.However,the forearmandneckhaving
onlyan average difference of 2.93 millimetersislistedasnotsignificantmeaningthatitislikelythat
the data setsmay share the same figures.