Chapter 2. Prehension

480 THE GRASPING HAND
and opposition vector, 82f
as perceived by neural networks, 86
and planning of prehension, 80-83
and timing of hand closure, 153
Tasks
and prehensile classifications, 22-25,
24f, 26f
and tool use, 6
Taxonomy, definition, 36-37. gee also
Classification, prehensile
Teacup, as grasped object, 31
Temperature, perception of, 231,2325 233t,
234
Tem ral constraints, of neural networks, 133
TenG receptors, 226
Tension lines, of skin, 206
Texture, of object
and friction, 249
and grasp component, 156
perception of, 231,232,233t. 233-34
and sensory information during lifting,
253
and transport component, 156
Thalamus
as connector between parietal and motor
conex. 120
and graspZgl73f
Thermal sweating, 215-16.218
Three jaw chuck grasp, 20t 27,335.37Ot.
372f. 374,380
Throwing, deceleration phase of, 146, 147f
Thumb
as antenna, 30
innervation, 367t
joints, 364t
movement speed during grasping, 49,151
muscles, 364t
opposition, 3 In
in pad opposition, 145,171,377
in palm opposition, 373
in perturbation studies, 157-58, 16Of
in power grasp, 23,24f
in precision grast 24f ,
and prehensile c ssifications, 27
in rapid pinching tasks, 153f. 153-54
Thumb-toward bias effect, 103
Time-based Coordination of transpon and
erasn 190
Timi& o? movement, and object weight, 155-56
Tip grasp, lSf, 19t, 2Ot, 21,35,262,263t,
37ot. 372f. 375
Tip pinch. Tip grasp
Tools, and hand, 4,6
Topographical organization, of motor conex,
113f
Torques, joint
and computational models of prehension,
138-41, 139f, 200
and fingertip force, 240-42
generating. - - 138-41
and yd opposition, 264
and F3.376
TOTE (Test-Operate-Test-Exit) program, 68f,
69,105
Touch, and phases of prehension, 60
Training, of neural networks, 86,87f, 88f,
133,388-94
Training set, definition, 391
Trajectories
arm, 128-29
joint, 131-34
Trajectoly planning, 109, 110-15. See als~ Planning of prehension; Task plans
definition, 115
determination of desired trajectory,
115-16
theory, 65
VITE model, 200
Transitional hase, of lifting, 251f. 252
Transport, orgrasped object
and force application, 269-70
and static grasp, 268
Transport Arm Schema, 189,190
Transpon component. see also Reaching
and accessibility constraints, 151-52
affected by object distance, 142
of arm, and grasping component, 149-50
and ballpark model, 189
coupling with grasp component, 199
definitim, 51
and goals for task performance, 200
kinematic features of prehensile
behaviors, 197
and neural networks, 98-101
and object distance, 154, 162
and object location, 200
and object properties, 199
and object size, 154,163,167
and object texture, 156
and object weight, 269-70
and pad opposition, 171
and palm, 194
in permrbation studies, 158f. 159, 163
relation to grasp Component, 58-59.290
velocity profile of, 145
and visual information, 178-79, 181,184
Transverse plane, of the body, 35Of
Tripod grasp, 19t, 2ot, 27,36,335,37&
Turning dial, as dynamic hand movement, 272t
Turning pen, as dynamic hand movement, 272t
Twiddle, 1%. 27,270,271,272t. 371t
Twirling, 103,276-278,277f
Twist
definition, 235-37,236f
space quality measure, 274
system, 236f. 237
U
Ulnar deviation (movement), 357f. 358
(Letters aiier page numbers: fdigure; n=footnote; t-table.)