Psych 267 Chapter 14

Front 1

Somatosensory system

Back 1

The somatosensory system has both interoceptive and exteroceptive functions. 4 main components of the somatosensory system are: Nocioception, Hapsis, Proprioception, Balance.

Front 2

Nocioception

Back 2

The perception of pain and temperature.

Front 3

Hapsis

Back 3

The perception of objects using touch and pressure.

Front 4

Proprioception

Back 4

Knowledge of the position of your limbs in space.

Front 5

Balance

Back 5

Controlled by the vestibular system in the inner ear.

Front 6

Skin

Back 6

One of the largest organs in our body. Contains receptors for pain and touch. Also important for keeping bacteria, viruses etc., out.

Front 7

Epidermis

Back 7

Is the skins outermost layer. Comprised of dead skin cells. Contains mechanoreceptors.

Front 8

Dermis

Back 8

Below the epidermis. contains mechanoreceptors.

Front 9

Subcutaneous

Back 9

Below the dermis

Front 10

Rapidly adapting receptors

Back 10

Respond quickly to sudden changes, but adapt quickly.

Front 11

Slowly adapting receptors

Back 11

If you push down hard on your arm, the receptors do not adapt as quickly.

Front 12

Mechanoreceptors

Back 12

Sensory receptors that respond to pressure, stretch or vibration.

Front 13

The spinal cord and dermatomes

Back 13

Receives afferent sensory information from nerves in the body part adjacent to it.

Front 14

Dorsal column medial lemniscal system (dorsal column system)

Back 14

Fine touch and proprioception

Front 15

Spinothalamic tract (spinothalamic system)

Back 15

Pain and temperature.

Front 16

Plasticity in cortical body maps

Back 16

Jenkins and Merzenich exposed monkeys to repeated tactile stimulation of the index fingertip for 3 months. Repeated sensory stimulation caused an increase in the amount of tissue processing information from that part of the body.

Front 17

Phantom limb

Back 17

After amputating a limb, some patients claim that they can still feel their limb. Some even feel sensations on the phantom limb when another body part is stimulated.

Front 18

Tactile acuity

Back 18

A measure of how precisely people can perceive detailed tactile information. 2 methods generally used, two point discrimination, and grating acuity.

Front 19

Merkel's receptors

Back 19

Are important for perceiving fine details. HIgh concentration on the fingertips. Slow adapting.

Front 20

Pacinian corpuscles

Back 20

Are important for coding vibration and touch. Fast adapting.

Front 21

Acuity and receptor spacing

Back 21

Acuity is linked both to the type of receptor as well as the spacing between receptors. The smaller the spacing between receptors, the greater the acuity.

Front 22

Receptive field

Back 22

The location on the skin that, when stimulated causes the receptor to fire. Cortical neurons in S1 have receptive fields that differ in size depending on which part of the body is represented. Cortical magnification.

Front 23

Perceiving vibration: Pacinian corpuscles

Back 23

Pacinian corpuscles respond well to high frequency indentation which makes them sensitive to vibration.

Front 24

Duplex theory of texture perception

Back 24

Suggests that texture perception relies on spatial and temporal cues.

Front 25

Spatial cues

Back 25

How the surface elements are spaced with respect to one another. Works well for larger features.

Front 26

temporal cues

Back 26

Vibrations that occur when skin moves across a fine surface.

Front 27

Hollins and Reisner exp.

Back 27

Had participants judge the roughness of two fine surfaces using magnitude estimation. The ability to distinguish between two surfaces increased when they were allowed to move their fingers across it. Relies mostly on signals from pacinian corpuscles.

Front 28

Active touch

Back 28

Exploring an object by moving it around in your hands.

Front 29

Passive touch

Back 29

Passive stimulation without active exploration.

Front 30

Haptic perception

Back 30

Exploration of 3D objects with the hand. requires the interaction between the sensory system, motor system and cognition.

Front 31

Tactile agnosia

Back 31

Inability to recognize objects using tactile input. Very rare, usually results from lesions in somatosensory association cortex.

Front 32

Apperceptive tactile agnosia

Back 32

Cannot copy items using tactile information

Front 33

Associative tactile agnosia

Back 33

Can copy, but still cannot identify items from tactile information

Front 34

Nocioceptive pain

Back 34

Pain caused by activation in the free nerve endings in the skin.

Front 35

Direct pathway model

Back 35

Assumed that pain responses were created in receptors in the skin and were sent directly to the brain.

Front 36

Problems with the direct pathway model

Back 36

Pain can occur when there is no stimulation on the skin (phantom limb). Pain can be influenced by attention (some people do not know they are injured until their attention is directed towards it.)

Front 37

Gate control model of pain

Back 37

Pain signals enter the spinal cord and are sent to S1. Additional pathways can act as a 'gate' to increase or decrease pain signals leaving the spinal cord. Substantia gelatinosa (SG)

Front 38

S fibers

Back 38

Carry pain signals from nocioceptors

Front 39

L fibers

Back 39

Carry info about tactile stimulation

Front 40

T cells

Back 40

Transmit pain signals to the brain

Front 41

Central control

Back 41

Signals coming from the brain to help reduce pain sensation, attention and hypnosis.

Front 42

Back 42