Hoofdstuk 10

Question 1

Degrees of Freedom problem

Answer 1

infinite number of motor solutions for acting on an object

Question 2

Motor Programs

Answer 2

stored routinges that specify certain motor parameters of an audience (e.g. relative timing of strokes)

• they may code general aspects of the movement (e.g. timing of different components) rather than the actual means of performing the movement (the joints and musclles)

Question 3

Somatosensation

Answer 3

a cluster of perceptual proceses that relate to skin and body (thermal sensation, touch, pain, limb position)

Question 4

Proprioception

Answer 4

knowledge of the position of the limbs in space

Question 5

Sensorimotor transformation

Answer 5

linking together perceptual knowledge of objects in space and knowledge of the position of one’s body to enable objects to be acted on (also: remapping)

Question 6

Homunculus sProblem

Answer 6

There is no “I” in the brain that makes all kinds of action decisions

Question 7

Frontal Lobe

Answer 7

1/3 of cortical area. Moving posterior to anterior = function becomes less specific to movement and action

Primary Motor Cortex - initiates voluntary movement
Premotor Regions - online coordination of movements
Prefrontal Regions - plan and select actions according to goals

Question 8

Somatotopically Organized

Answer 8

different regions of the primary motor cortex represent different regions of the body

Question 9

Hemiplegia

Answer 9

damage to one side of the primary motor cortex results in a failure to voluntarily move the other side of the body

Question 10

Population Vector

Answer 10

the sum of the preferred tunings of neurons multiplied by their firing rates

Question 11

FEF = Frontal Eye Fields

Answer 11

Brodmanns area 8 - separate region of the frontal lobes

Question 12

Eye Movement is primarily guided by external senses (vision and hearing)

Answer 12

where as skeletal - based movements rely on proprioceptive information concerning the position of the limbs (somatosensory cortex)

Question 13

Premotor Cortex

Answer 13

Area immediately in front of (lateral) the priamry motor cortex

• linking acion with visual objects in the environment; the medial area is known as the supllementary motor area and deals with well learned actions (ones that don’t place strong demand on monitoring the environment)
• the lateral premotor cortex recceives signals via the parietal cortex (dorsal route in vision), whereas the medial premotor cortex (SMA) receives strong proprioceptive signals concerning the current position of the limbs

Question 14

Prefrontal regions lie anteriorly to the premotor regions

Answer 14

and are principally involved in planning and higher aspects of the control of action

Question 15

Preserveration

Answer 15

repeating an action that has already been performed and is no longer relevant

Question 16

Utilization Behavior

Answer 16

impulsively acting on irrrelevant objects

Question 17

SAS Model (Norman and Shallice)

Answer 17

Supervisory Attentional System

Question 18

Contention Scheduling

Answer 18

• the mechanism that selects one particular schema to be enacted from a host of competing schemas (form of motor attention)
• competition between schemas is key part of this model

Question 19

Decision to act

Answer 19

is directly determined by the activation levels of schemas

Question 20

Sense of Agency

Answer 20

subjective feeling that voluntary actions are owned and controlled by the actor

Question 21

Forward Model

Answer 21

a representation of the motor command (efference copy) is used to predict the sensory consequences of an action (links together action intention and action outcome)

Question 22

Changes (predictions) in visual input environment

Answer 22

may arise via interactions between frontally based action systems and structures such as the cerebellum and superior colliculus (for sensory consequences of eye movement)

Question 23

Intentional Binding

Answer 23

voluntary actions and their sensory consequences appear closer in time

Question 24

Mirror Neuron

Answer 24

responds to goal-directeed action performed by oneself or by others

• ventral premotor cortex (Area F5) responds both during performance and the observation of the same action
• tuned to precise actions that are goal directed

Question 25

"What" Route

Answer 25

Ventral Stream from occipital to temporal

Question 26

"Where" Route

Answer 26

Dorsal Stream from occipital to parietal

Question 27

Optic Ataxia

Answer 27

- Damage to occipitoparietal junction - unable to accurately reach toward objects under visual guidance

Question 28

PRR Parietal Reach Region

Answer 28

part of the occipito parietal cortex that responds to reading movements - Neurons effectively code the distance and direction needed to move a hand from its current visually perceived location to another endpoint

Question 29

Sensorimotor Transformation

Answer 29

the dorsal stream that transforms visually based information into motor based actions

Question 30

Hand Movement = Reaching

Answer 30

Eye movement = Saccade

Question 31

Area LIP (lateral Intraparietal)

Answer 31

neurons in this region effectively code the distance and direction needed to move the eyes from the current location to a visual stimulus in its receptive field

Question 32

LIP/PRR

Answer 32

Preferred direction ddepends on locaation of sensory information Primary Motor Cortex : movement direction alone

Question 33

Grasping may require greater processing of object-based properties than reaching or pointing

Answer 33

- Reaching PRR (occipitoparietal region) - Grasping AIP (anterior intraparietal area) + premotor cortex * responds to manipulate shapes of 3D objects (from vision or touch) * connections to motor regions of frontal lobe (premotor area and FEF) + infero temporal cortex of the visual ventral stream which is involved in object recognition

Question 34

VIP Ventral Intraparietal Area

Answer 34

- part of the intraparietal sulcus that responds to objects close to the body and in body-centered (as opposed to gaze-centered) coordinates - head + hand centered neurons

Question 35

Tools, repesented in the brain at several levels

Answer 35

1) stored visual by visual ventral stream 2) semantic representation - medial and anterior temporal lobes 3) volumetric represenntation - visual + motoric for grasping (AIP in Parietal Lobes) 4) motor-based component-gestures- left inferior parietal lobe

Question 36

Affordances

Answer 36

structural properties of objects imply certain usages

Question 37

Ideomotor Apraxia

Answer 37

inability to produce appropriate gestures given an objecct, word or command

Question 38

Object-based actions

Answer 38

reside predominantly in the left hemisphere

Question 39

The Basal Ganglia

Answer 39

regulate action via a balaance of action-promoting and action-inhibiting pathways and are particularly involved in self-generated actions (prepared in the supplementary motor area). Parkinson + huntington are disruptions of this balance Hyperkinetic (increase in movement) Hypokinetic (reduction in movement)

Question 40

Cerebellar loop

Answer 40

involved in coordination of movements - Basal Ganglia Loop - 5 loops consisting of excitatory and inhibitory pathways * direct route that promotes action (increases activity in cortex) * indirect route that inhibits action (decreases activity in cortex)