Chapter 2. Prehension

466 THE GRASPING HAND
a h Generalized delta rule
Denervation, and sweating, 219,221f
Depression (movement), 357f, 358
Dermal papillae, 208f. 209
Dermatoglyphics. g Fingerprints
Dermis, 206,207,208f. 209
Dexterity, as grasp attribute, 25
Dextrous Robot Hand Workshop, vi
Difference vector (equation), 127-28
Digital joint receptors, 226
Digital manipulative pattern grasp, 27
Direct theory, of planning of prehension, 64
Direction
of force application, 263
of object, in erturbation studies, 16Of,
161,16.!
and planes of the body, 349-50
Directional grasp, 19t, 30,371t. 376
Directional terms, of the body, 349-50
Disk zrasu. 2Ot. 371t
Dispakiiap,'of a neural network, 97
Distal grasp, 3721 375
Distal palmar crease, 206
Distanie, of object
and binocular vision, 184
and cenzral vision, 182f, 183
and grasp component, 51,52f, 154
memory for, 119, 120
and monocular vision, 184
in pelturbation studies, 16142,165
and transport component, 142, 145,154
Distributed processing task plans, 67-70.68f
Dorsal skin, 208
Double grasp, 28f, 35
Dowels, as grasped objects, 155-56, 16365,
164f. 166-69,168f, 172f, 189,254f.
261 -62,286f
Drill, as grasped object, 27
Drive Fingers Guarded Schema, 195f, 196,291f
Dynamic grasp
characteristics, 268
POS~URS, 19t, 25,27-28,371t
tripod grasp, 27,36,270
types of marupulatmn, 269-70
Dynamic movements, classification of, 27Of,
270-7 1
Dynamics, definition, 1011
E
Eccrine sweat glands. gee also Sweating
conditioning of, 217-18
sweat beads, 215f
Elasticity, of skin, 210
Elastin, 207
Elbow
joints, 362t
muscle activity during lifting, 256
muscles, 362t
Electrical prosthetic hand, 410-12
Elevation (movement), 357f, 358
ELITE system, 148
EMG (electromyographic activity)
in finger Opening and pinching, 193f
during grasping, 192-94, 193f
during lifting, 256,257f.
258
prior to grasping, 193f
Enclose Schema
and ballpark model, 188
and palm-focused model of grasping, 194
Enclosing
as different from preshaping, 191, 192
and grasp component, 145
as guarded motion, 19 1-94
and perception of volume, 231,2325 233t
phases, 292-93
time, 152
Encompass grasp, 2Ot, 371t
End-state comfort effect, 103
Endpoint
kinematic variables, 117n
trajectory gemeration, 110
Environmentally-defined goals, of prehension,
17
Epidermis, 206-7,208f, 209
Equilibrium
configuration, of muscles, 122
definition, 122,243
and stable grasp, 243,244,246
Evolutionary constraints, on grasping, 308t,
325
Experimental models, use of, 9,37,342f, 343
Expert systems. see also Computational models
of prehension
choosing virtual fingers, 93-94
definitim, 83
for grasp selection, 83-85
and mapping virtual fingers, 289
Exploratory movements
distribution of temporal frequencies,
267f
and object properties, 204.23 1-34
and task requirements, 281
control by autonomic nervous system,
214-22
types, 336
distribution of, in humans, 214f
Extension (movement), 358
innervation of, during contact with
Extension grasp, 19t, 2Ot, 37Ot, 372f
object, 220-22,221f, 297f
External precision grasp, 2Ot, 27,28f, 371t
and papillary ridges, 214
Exteroceptors, 11 1-12
and skin layers, 208f
Extrinsic object properties
and stab17 grasp, 204
and activation of arm muscles, 53, 143
definition, 53.76
(Letters after page numbers: f=figure; n=footnote; t-table.)