The receptive field varies in size. The larger the receptive field is,
the greater the area that it detects changes in but also less precise perception, and vice versa
. Hence, areas with the most sensitive two-point discrimination should have a high density of receptors with small receptive fields.
What is the relationship between two-point receptor density and tactile sensitivity?
An area of skin with a greater density of touch receptors is
more sensitive to touch
and can discriminate between two points closer together than an area with a lower density of touch receptors.
What is the relationship between the two point threshold and the receptive field?
The model predicts that the two-point threshold
is higher in the long axis of receptive fields
. In the human it is higher in the long axis of the arm, which might mean that the receptive fields are elongated in this axis too.
What influences the two-point threshold?
There are various factors that can influence two-point discrimination values including
test site, sex, test modality, age, device, and applied force
3 , 10 , 25
, 26
. It is well established that spatial acuity varies from one body site to another
24
.
What type of receptors are involved with two-point discrimination?
The tactile system, which is activated in the two-point discrimination test, employs several types of receptors. A
tactile sensory receptor
can be defined as the peripheral ending of a sensory neuron and its accessory structures, which may be part of the nerve cell or may come from epithelial or connective tissue.
Why some areas of the body are more sensitive to two-point discrimination than others?
Why do you think one area is more sensitive than another? The part of your brain that receives information from your sensory neurons doesn’t treat all parts of the body equally. The reason you are more sensitive on your fingertips than your elbow is that
there are many more sensory neurons on your fingertips
.
What is two-point discrimination test used for?
The two-point discrimination test is used to assess
if the patient is able to identify two close points on a small area of skin, and how fine the ability to discriminate this are
. It is a measure of tactile agnosia, or the inability to recognize these two points despite intact cutaneous sensation and proprioception.
What parts of the body are most and least sensitive to two-point discrimination?
Different areas of the body have receptive fields of different sizes, giving some better resolution in two-point discrimination. The tongue and finger pads have very high resolution, while
the back has very low
. This is illustrated as the distance where the two points can be felt as separate.
What part of your body has the best two-point discrimination?
Parts of the body with
the highest densities of touch receptors
will have the greatest degree of two-point discrimination. Places such as the fingertips and lips will be able to sense 2 toothpicks even when they’re very close together.
Which body part has the lowest two-point threshold?
Two-point threshold is smallest in
the finger
(2 mm). Two-point threshold on the forearms is 30 mm; on the back it is 70 mm. Fingers are analogous to the fovea in the retina (but different because they work best when scanned over an object).
Why does the two-point threshold data make sense?
Again, the two-point threshold is defined as the distance between two points at which
an individual recognizes he or she is being touched by two objects rather than one
. This is important in recognizing how a person is sensing and if their ability to sense falls within historical guidelines.
What is true about the two-point threshold test?
What is true about the two-point threshold test?
The location where the subject detects two points at their smallest distance apart contains the greatest density of touch receptors
. … Areas with the most accurate tactile localization have the smallest two-point threshold.
What is the two-point threshold?
A measure of tactile acuity defined as the smallest separation at which two points applied simultaneously to the skin can be clearly distinguished from a single point. It varies from
1 or 2 millimetres in the finger pads and tongue to more than 60 millimetres on the upper arm, upper thigh, and back
.
What does the two-point discrimination test measure quizlet?
Two-point discrimination is
the ability to discern that two nearby objects touching the skin are truly two distinct points, not one
. … The smallest distance between two points that still results in the perception of two distinct stimuli is recorded as the patient’s two-point threshold.
Why are there different sizes of receptive fields?
The receptive field size of neurons in primary visual cortex
depends strongly on the stimulus contrast
. The size can be more than two times larger when measured with low contrast stimuli than when measured with high contrast stimuli.
