Neurorobotics:From Vision to Action 62.4 The Role of Mirror Systems 1469 object as a set of possible affordances.whereas the ven- also support recognition of the action when performed tral stream(via the inferotemporal cortex,IT)is able to by others-and it is this recognition of the actions of recognize what the object is.The latter information is others that has created the greatest interest in mirror passed to th eprefrontal cortex (PFC)which can then,on neurons and systems. the basis of the current goals of the organism,bias the The MNS model of Oztop and Arbib [62.112]pro- choice of affordances appropriate to the task at hand. vides some insight into the anatomy while focusing on Neuroanatomical data (as analyzed by Rizzolatti and the learning capacities of mirror neurons.Here,the task Luppino [62.1101)suggest that PFC and IT may mod-is to determine whether the shape of the hand and its ulate action selection at the level of the parietal cortex.trajectory are on track to grasp an observed affordance Figure 62.6 gives a partial view of the FARS model up-of an object using a known action.The model is orga- dated to show this modified pathway.The affordance nized around the idea that the AlP-F5canonical pathway selected by AIP activates F5 neurons to command the emphasized in the FARS model (Fig.62.6)is comple- appropriate grip once they receive a go signal from an-mented by another pathway 7b-F5mimor.As shown other region,F6,of the prefrontal cortex.F5 also accepts in Fig.62.7 (middle diagonal),object features are pro- signals from other PFC areas to respond to working cessed by AIP to extract grasp affordances,these are sent memory and instruction stimuli in choosing among the on to the canonical neurons of F5 that choose a particular available affordances.Note that this same pathway could grasp.Recognizing the location of the object(top diago- be implicated in tool use,bringing in semantic knowl- nal)provides parameters to the motor programming area edge as well as perceptual attributes to guide the dorsal F4 which computes the reach.The information about system (see Jolnson-Frey [62.1111). the reach and the grasp is taken by the motor cortex With this,we turn to the mirror system.Since grasp-MI (=F1)to control the hand and the arm.The rest of ing a complex object requires careful attention to motion the figure provides components that can learn and apply of,e.g.,fingertips relative to the object we hold that key criteria for activating a mirror neuron,recogniz- the primary evolutionary impetus for the mirror system ing that the preshape of the observed hand corresponds was to facilitate feedback control of dexterous move-to the grasp that the mirror neuron encodes and is ap- ment.We now show how parameters relevant to such propriate to the object,and that the hand is moving on feedback could be crucial in enabling the monkey to as- an appropriate trajectory.Making crucial use of input sociate the visual appearance of what it is doing with from the superior temporal sulcus (STSa;see Perrett the task at hand.The key side-effect will be that this et al.[62.113]and Carey et al.[62.1141),schemas at the feedback-serving self-recognition is so structured as to bottom left recognize the shape of the observed hand, Dorsal stream: MIP LIP Locations Motor program clPS VIP (reach) F4 Motor execution F5 AIP MI Canon. Moto Part P Object (gsp [ens!A recognition Mirror Action IT recognition Fig.62.7 The mirror neuron sys- Object affordance STSa 7b Hand state association Hand and arm tem (MNS)model (see Oztop and control Hand shape Arbib [62.921).Note that this basic and motion mirror system for grasping crucially 7a MNS core links the visual process of the superior Hand/object ntral str Objects temporal sulcus(STS)to the parietal regions(b)and premotor regions(F5) which have been shown to contain mirror neurons for manual actionsNeurorobotics: From Vision to Action 62.4 The Role of Mirror Systems 1469 object as a set of possible affordances, whereas the ven￾tral stream (via the inferotemporal cortex, IT) is able to recognize what the object is. The latter information is passed to th eprefrontal cortex (PFC) which can then, on the basis of the current goals of the organism, bias the choice of affordances appropriate to the task at hand. Neuroanatomical data (as analyzed by Rizzolatti and Luppino [62.110]) suggest that PFC and IT may mod￾ulate action selection at the level of the parietal cortex. Figure 62.6 gives a partial view of the FARS model up￾dated to show this modified pathway. The affordance selected by AIP activates F5 neurons to command the appropriate grip once they receive a go signal from an￾other region, F6, of the prefrontal cortex. F5 also accepts signals from other PFC areas to respond to working memory and instruction stimuli in choosing among the available affordances. Note that this same pathway could be implicated in tool use, bringing in semantic knowl￾edge as well as perceptual attributes to guide the dorsal system (see Johnson–Frey [62.111]). With this, we turn to the mirror system. Since grasp￾ing a complex object requires careful attention to motion of, e.g., fingertips relative to the object we hold that the primary evolutionary impetus for the mirror system was to facilitate feedback control of dexterous move￾ment. We now show how parameters relevant to such feedback could be crucial in enabling the monkey to as￾sociate the visual appearance of what it is doing with the task at hand. The key side-effect will be that this feedback-serving self-recognition is so structured as to Locations Objects M1 F4 LIP MIP F5 VIP Canon. Mirror Motor execution Object location AIP MNS core Visual cortex Object affordances 7a STSa 7b cIPS IT Hand/object Spatial relation Object affordance Hand state association Ways to grab this "thing" "It's a mug" Hand and arm control Motor program (reach) Motor program (grasp) Action recognition Ventral stream: Recognition Hand shape and motion recognition Object recognition Object features Dorsal stream: Affordances Fig. 62.7 The mirror neuron sys￾tem (MNS) model (see Oztop and Arbib [62.92]). Note that this basic mirror system for grasping crucially links the visual process of the superior temporal sulcus (STS) to the parietal regions (b) and premotor regions (F5) which have been shown to contain mirror neurons for manual actions also support recognition of the action when performed by others – and it is this recognition of the actions of others that has created the greatest interest in mirror neurons and systems. The MNS model of Oztop and Arbib [62.112] pro￾vides some insight into the anatomy while focusing on the learning capacities of mirror neurons. Here, the task is to determine whether the shape of the hand and its trajectory are on track to grasp an observed affordance of an object using a known action. The model is orga￾nized around the idea that the AIP→F5canonical pathway emphasized in the FARS model (Fig. 62.6) is comple￾mented by another pathway 7b → F5mirror. As shown in Fig. 62.7 (middle diagonal), object features are pro￾cessed by AIP to extract grasp affordances, these are sent on to the canonical neurons of F5 that choose a particular grasp. Recognizing the location of the object (top diago￾nal) provides parameters to the motor programming area F4 which computes the reach. The information about the reach and the grasp is taken by the motor cortex M1 (=F1) to control the hand and the arm. The rest of the figure provides components that can learn and apply key criteria for activating a mirror neuron, recogniz￾ing that the preshape of the observed hand corresponds to the grasp that the mirror neuron encodes and is ap￾propriate to the object, and that the hand is moving on an appropriate trajectory. Making crucial use of input from the superior temporal sulcus (STSa; see Perrett et al. [62.113] and Carey et al. [62.114]), schemas at the bottom left recognize the shape of the observed hand, Part G 62.4