psychology cutaneous sensitivities

CUTANEOUS CUTANEOUS SENSITIVITY SENSITIVITY

What are What are Cutaneous Cutaneous

Sensitivities?Sensitivities?

A group of A group of SkinSkin

SensesSenses

PRESSUREPRESSURE

PAINPAIN

COLDCOLD

and and WARMTHWARMTH

What produce What produce these these

experiences?experiences?

STIMULISTIMULIIt is anything that may cause an organism to

react

SURFACE OF THE SURFACE OF THE SKIN SKIN the covering, or integument, of the body's surface that both provides protection and receives sensory stimuli from the external environment

RECEPTORSRECEPTORSa receptor is found in the dermis or epidermis. 

Pressure spots vary in density for various areas in the body.

The intensity of stimulus also differ depending on the spots where to react.

There are more pressure spots found in the periphery of the body. (the part that is away from the central or core regions)

The pressure receptors mediate the sensations known as the vibration of tickle.

The pressure in movement is the result of the intermittent stimulation.

Pain spots have great density than pressure spots.

The stimulus to the sensation of the warmth and cold is the application of the body to respond to the temperature above or below 0°C.

The normal human body temperature is 32.2°C and the warmth and cold ranges according to the adaptation condition of the body.

What is What is

Kinesthesis ?Kinesthesis ?

It is a sense of active movement. These are sensitivities arising from the

structures involve in body movements. It provides an automatic system for

coordinating our muscles when we talk, walk, use our hands etc.

Kinesthetic Kinesthetic Receptors Receptors

(Proprioceptors) (Proprioceptors)

are found in three are found in three distinct areas:distinct areas:

MUSCLESMUSCLES

The receptors in the muscles signals relaxation of the muscles.

TENDONSTENDONS Those

located in the tendons signal the contraction of the muscles.

JOINTSJOINTS Lastly, the

receptors in the joints are stimulated whenever a limb moves, changing the position of the bones in the joints.

Types of Types of ProprioceptPropriocept

ors:ors:

PACINIAN CORPUSCLES AND PACINIAN CORPUSCLES AND FREE NERVE ENDINGSFREE NERVE ENDINGS

These are found in the ligaments of the joints and in the bone coverings near these joints.

GOLGI SPINDLESGOLGI SPINDLES

These are located in the tendons

MUSCLE SPINDLESMUSCLE SPINDLES

These are in the muscles themselves.

The movements of the muscles, joints or tendons affects the proprioceptors.

The “muscle sense” is where the information flows to the brain and making skilled coordination of the muscular movement possible.

BASIC BASIC PSYCHOPHYPSYCHOPHY

SICSSICS

PsychophysicsPsychophysics is the study of Psychology that studies sensory limits, sensory adaptation and other topics that are related to physical properties of stimuli and psychological experiences.

It is described as “the analysis of perceptual processes by studying the effect on a subject's experience or behavior of systematically varying the properties of a stimulus along one or more physical dimensions” or in short or in short “the scientific study of the relation between stimulus and sensation”

SENSORY ADAPTATIONSENSORY ADAPTATION

A process that alters the relationship between stimuli and sensation.

It is also the weakened magnitude of a sensation resulting from the prolonged presentation of stimulus, and the decline in sensitivity to a constant stimulus.

THRESHOLDTHRESHOLD

It is the point at which a stimulus is strong enough to be detected by activating a sensory receptor cell (initiates sensory transduction by creating graded potentials or action potentials in the same cell or in an adjacent one).

KINDS OF SENSORY THRESHOLDKINDS OF SENSORY THRESHOLD

Absolute Threshold- the smallest or lowest strength of a stimulus that can evoke a sensation.

Eg.1. Vision- a participant can detect the presence of a

candle flame in the dark.2. Hearing- a participant can detect the ticking

sound of clock.3. Taste- one teaspoon of sugar in two gallons of

water.4. Smell-  the smallest amount of perfume that a

subject is able to smell in a large room.

Difference Threshold - also known as the just noticeable difference (JND)

It is the minimum difference in stimulation that a person can detect 50 percent of the time

Eg.1. For example, let's say I asked you to put your

hand out and in it I placed a pile of sand. Then, I add tiny amounts of sand to your hand and ask you to tell me when you notice any change in the overall weight. As soon as you can detect any change in the weight, that difference between the weight of the sand before I added that last bit of sand and the amount of sand after I added it, is the difference threshold.

KINDS OF SENSORY THRESHOLDKINDS OF SENSORY THRESHOLD

ERNST WEBERERNST WEBER

A German physiologist that explained the consistent relationship between the physical world and psychological experiences.

The principle is called the Weber’s Law. It holds that for each sense, the size of

JND is a constant proportion of the size of the initial stimulus.

GUSTAV THEODOR GUSTAV THEODOR FECHNERFECHNER

The Fechner’s Law broadened the application of Weber’s Law by linking the subjective experience of the intensity of stimulation with the actual magnitude of stimulus.

Fechner’s Law is the logarithmic relation with between subjective and objective stimulus intensity.