ch 15 - the cutaneous senses, part 1

Question 1

epidermis

Answer 1

the outer layers of the skin, including a layer of dead skin cells

Question 2

dermis

Answer 2

the layer of skin below the epidermis

Question 3

mechanoreceptors

Answer 3

receptors that respond to mechanical stimulation of the skin such as pressure, stretching or vibration

Question 4

what are 2 types of mechanoreceptors?

Answer 4

Merkel receptor and Meissner corpuscle

Question 5

merkel receptor

Answer 5

a disk shaped receptor in the skin associated w/ slowly adapting fibers and the perception of fine details

Question 6

meissner corpuscle

Answer 6

receptor in skin associated with RA1 mechanoreceptors. important for perceiving tactile slip and controlling the force needed to grip objects

Question 7

cutaneous receptive field

Answer 7

area of skin that when stimulated, influences the firing of a neuron

Question 8

slowly adapting fibers

Answer 8

fibers that keep firing as long as the stimulus is present (ex: merkel receptors)

Question 9

rapidly adapting fiber

Answer 9

fires only when the stimulus is 1st applied and when its removed (ex: meissner)

Question 10

ruffini cylinder

Answer 10

receptor in the skin associated with slowly adapting fibers. its involved in perceiving stretching

Question 11

Pacinian corpuscle

Answer 11

receptor associated w/ rapidly adapting fibers. its responsible for our perception of vibration and fine textures when moving fingers over a surface

Question 12

what are the pathways from the skin to the cortex and within the cortex

Answer 12

the medial lemniscal pathway and the spinothalamic pathway

Question 13

medial lemniscal pathway

Answer 13

pathway in spinal cord that transmits signals from the skin toward the thalamus (related to position of limbs and perceiving touch)

Question 14

spinothalamic pathway

Answer 14

nerve pathway in the spinal cord that conducts nerve impulses from the skin to the somatosensory area of the thalamus (has to do with signals related to temp. and pain)

Question 15

secondary somatosensory cortex

Answer 15

area that processes neural signals related to touch, temperature, and pain

Question 16

homunuclis

Answer 16

the topographic map of the body in the somatosensory cortex

Question 17

tactile acuity

Answer 17

the capacity to detect details of stimuli presented to the skin

Question 18

2-point threshold

Answer 18

way of measuring tactile acuity that is the smallest separation between 2 points on the skin that’s perceived as 2 points

Question 19

surface texture

Answer 19

physical texture of a surface created by peaks and valleys

Question 20

duplex theory of texture perception

Answer 20

our perception of texture depends on both spatial and temporal cues

Question 21

spatial cues

Answer 21

info about the texture of a surface that’s determined by the size, shape, and distribution of surface elements like bumps + grooves

provided by large surface elements that can be felt when the skin moves across or is pressed into the elements

Question 22

temporal cues

Answer 22

info about the texture of a surface that’s provided by the rate of vibrations that occur as we move our fingers across the surface

Question 23

haptic perception

Answer 23

the perception of 3D objects by touch

Question 24

active touch

Answer 24

touch in which the observer plays an active role in touching and exploring an object, usually w/ their hands

Question 25

passive touch

Answer 25

occurs when touch stimuli are applied to the skin

Question 26

how do you identify objects by haptic exploration?

Answer 26

exploratory procedures: peoples movements of their hands and fingers while they’re identifying 3D objects by touch (ex: pressure, contour following)

Question 27

interpersonal/social touch

Answer 27

one person touching another

Question 28

how is social touch sensed?

Answer 28

CT afferents: unmyelinated nerve fibers found in hairy skin that are involved in social touch

Question 29

how is CT afferent recorded

Answer 29

microneurography: inserting a metal electrode w/ a very fine tip just under the skin

Question 30

social touch hypothesis

Answer 30

CT afferent and their central projections are responsible for social touch

Question 31

what are the other touch systems?

Answer 31

discriminative functions of touch: sensing details, texture, vibration, and objects

affective function of touch: the eliciting of emotions by touch

Question 32

how does top-down processing affect touch

Answer 32

people’s thoughts about who’s touching them can influence their perception of pleasantness