Tactile acuity

Question 1

which cell determines tactile acuity and why

Answer 1

merkel discs (SA1)
- more densely packed in the fingertip
- can tell at 1mm of distance (best acuity)

Question 2

how does tactile acuity change across the fingers

Answer 2

decreases from index finger to pinky
decreases from fingertip to palm

Question 3

does the density of merkel cells change in fingertips

Answer 3

no - number of merkel cells in all fingertips is about the same

Question 4

what is tactile acuity based on mainly (2)

Answer 4

amount/concen of cells in a specific region
how much space the part of the body has in the somatosensory cortex

Question 5

what is the relationship between acuity and representation in S1

Answer 5

negative correlation
- decrease in representation = decrease in acuity

Question 6

can acuity change with training

Answer 6

yes - representation of digits can increase with training (central plasticity) leading to increase in acuity

Question 7

when does acuity peak and why

Answer 7

peaks in early adulthood (1mm)
declines in older adults (>2mm by 60-60yo)
due to neurons in the periphery dying off

Question 8

do females or males have better tactile acuity

Answer 8

females
- due to averagely smaller fingers with the same amount of merkel cells (higher density)

Question 9

what is central plasticity

Answer 9

representation of areas can increase in S1 when tacile acuity is trained