Coding of modified body schema during tool use by macaque postcentral neurones

“141 Iriki, A. et al. (1996) Coding of modified body schema during tool use by macaque postcentral neurones.”

“It is also supported by the results that cortical neurons may modulate their firing rate either during use of tools (Iriki et al. 1996), according to cursor movement on the screen rather than underlying arm movements (Alexander and Crutcher 1990; Shen and Alexander 1997), or in relation to the…”

“A tennis player experiences the racquet as an extension of her arm, and some intriguing recent experiments suggest that bimodal neurons likewise extend their visual receptive fields when the monkey uses a tool (Iriki et al 1996).”

“Indeed, parietal activity in both monkeys (Iriki et al. 1996) and humans (Gallivan et al. 2009) is stronger when objects are within reach.”

“Research on tool use has demonstrated the neurophysiological mechanisms underlying incorporation of tools in both primates (Iriki et al., 1996) and humans (Berti & Frassinetti, 2000; Farné & Ladavas, 2000; Yamamoto & Kitazawa, 2001a, 2001b).”

“If this were confirmed, it would suggest that the tool became incorporated into a putative brain representation of the hand wielding it [1] and that visual stimuli presented at the tip of the tool might be coded by the brain in a similar fashion to those presented directly at the hand [ 29 ].”

“The most interesting finding was that the visual RFs were not fixed in their extension, but expanded when the monkey prepared for a specific motor action.”

“For example, after a monkey has been trained to use a rake to grab food morsels, neurons in the intraparietal sulcus that normally respond to visual stimuli near the hand now also respond to stimuli near the rak”

“, 1996), as well as during observation of grasping movements (Buccino sad, 1999) or by a tool (Iriki et al., 1996).”

“Iriki et al. (1996) suggested that the bimodal neurons that modify their visual receptive field when the monkey reaches for an object with a stick, the neural correlate of an expanded image of the hand.”

“Intensively used tools and objects become tightly connected to the subject’s cognitive architecture: in monkeys, for example, the receptive fields of visuotactile neurons in the parietal lobe are modified during the use of tools, thereby helping the tool to be assimilated into the body schema (116).”

“(378) trained macaque monkeys to reach toward distant objects, which could not be accomplished by using their arms alone, by utilizing an external tool: a rake.”

“Finally, Iriki et al. (1996b) found that neurons throughout the postcentral sulcus and anterior/medial bank of the intraparietal sulcus were strongly modulated by attentional and motivational factors – during a rewarded buttonpushing task, cells in the anterior bank of the IPS began firing strongly when the cue stimul…”

“Sensorimotor non-conscious maps of the body are plastic, as suggested by the behavioral effects of tool use in human and nonhuman primates (Berti & Frassinetti 2000; Farnè et al. 2005; Iriki et al. 1996), and their adaptive functional role might be better captured within such a wider framework.”

“Farné and Làdavas [65] conducted a patient study even closer in procedure to Iriki and colleagues’ [58] work on monkeys.”

“…multisensory correlation and thus is compatible with related findings on hand ownership that have been reported for bimodal visuo-tactile neurons in the premotor and intraparietal sulcus region that are anchored to the hand (Graziano et al., 2000; Iriki et al., 1996; Maravita and Iriki, 2004).”

“He revises his perceptual apprehension of the peripersonal1 both because he can sweep faster than he can touch and because he has extended his peripersonal .eld [Iriki et al. 1996; Ladavas 1998].”

“Reachability neurons did not fire when the monkey did not intend to reach ( Iriki et al., 1996 ), and visual attention was not affected by holding a tool when the tool was not used to reach (Maravita et al., 2002).”

“Jeannerod & Pacherie, 2004)? Georgieff and Jeannerod’s (1998) concept of a ‘‘who system’’ which discriminates between self and non-self on the basis of non-overlapping areas of neuronal activation simultaneous with mirror system activation is one proposal. Consistent with this idea,it has recently been shown that alth…”

“The rake, or the pliers, might simply become, with training, a prolongation of the arm, as shown by the response properties of neurons recorded from the medial wall of the IPS of these trained monkeys (Iriki et al., 1996; Hihara et al., 2006).”

“REED, GRUBB, AND STEELE logical and neuropsychological research suggest that representations of peripersonal space (i.e., space immediately next to the skin surface) may be generated from the activity of bimodal neurons that respond to both tactile and visual stimuli presented near the body (e.g., Duhamel, Colby, & Go…”

“The neural basis of this phenomenon could be further studied by applying our paradigm to the multimodal tactile–visual neurons recently discovered in the primate brain ( Iriki et al., 1996, 2001 ).”

“period of tool-use to reach food pellets placed out of reach, the visual receptive fields of IPS neurons in macaques extended toward the space where the tool was operated (Iriki et al., 1996).”

“More than 15 years ago, Iriki et al. (1996) observed that the body scheme could be modified by training macaques to use a rake to retrieve food that was otherwise out of reach.”

“This suggestion was substantiated much later by neurophysiological data showing that cortical neurons responsive to both somatosensory and visual stimuli extended their receptive fields along a rake that a monkey used to retrieve distant objects (Iriki et al., 1996).”

“Therefore, in close agreement with both neurophysiological and neuropsychological findings (Iriki et al., 1996; Maravita et al., 2001), these results suggest that plastic modifications of PPS require the tool to be actively utilized in a task.”

“However, in area 5 of the monkey brain, neurons with both visual and tactile receptive fields have been described (Graziano et al. 2000; Iriki et al. 1996; Sakata et al. 1973).”

“These findings suggest that the motor training aimed to use a tool can change not only the body schema (see Maravita & Iriki, 2004; Iriki et al., 1996) but also the motor representation of body parts involved in goal-directed actions.”

“In the monkey, the receptive fields that encode near space enlarge when the animal uses a stick to reach for a food pellet (Iriki et al., 1996).”

“On the other hand, contact could also be included as a component of our ego space in a similar way as external objects and tools can be included in our body scheme (Berti and Frassinetti 2000; Iriki et al. 1996; Ivanenko et al. 1997).”

“In particular, they describe bimodal neurons, in the medial anterior intraparietal sulcus and in the post-central gyrus, whose visual receptive fields expand following tool use training so as to encompass the tool in addition to the hand or arm (Iriki et al., 1996; Maravita and Iriki, 2004).”

“Irikis’ findings in the monkey (Iriki et al. 1996), showing enlarged visual RFs of bimodal neurons in the parietal cortex after training with a rake, as well as humans tool-use studies showing changes of multisensory interactions in the peripersonal space of both healthy subjects and neurological…”

“Some authors (i.e. Iriki et al. 1996; Maravita and Iriki 2004) have proposed that the extension of PPS after tooluse reflects a plastic modification in BR, such that the tool is incorporated as a part of the body (Berlucchi and Aglioti 1997; Critchley 1979; Head and Holmes 1911; Holmes and Spence…”

“Indeed, single cell recordings from the inferior parietal lobule of the macaque brain showed that the extent of the peripersonal space can be modified by tool use (Iriki et al. 1996).”

“Several animal studies also found neurons in the parietal cortex responding to both tactile and visual stimulations [e.g., Bremmer et al., 2001; Graziano et al., 2000; Graziano, 1999; Iriki et al., 1996].”

“Maravita and Iriki [27] investigated the integration of a tool into one’s body schema in a macaque monkey that was retrieving food with the help of a rake.”

“This finding is also consistent with the activity of ‘distal type’ neurons previously reported ( Iriki et al., 1996 ), whose visual receptive fields specifically extended along the axis of the tool used by the monkey.”

“This result would be in close agreement with studies on monkeys which showed that tools can become part of the body, being included in its representation (Iriki et al., 1996, 2001).”

“Tool-use in the monitor and modification of coding of the hand image along the tool As earlier reported (Iriki et al., 1996), the visual RF of these bimodal neurons extend to include a hand-held tool used to retrieve distant food.”

“, 2009, 2012), and macaque monkey neurophysiology (Iriki et al., 1996) suggest that following training, a tool may actually become incorporated into the body schema of the actor and coded as an extension of the hand/limb.”

“The combination of such taskdependent, adaptive neural plasticity and the resultant possibility that neurons and networks may multiplex for different perceptual tasks may be an important mechanism in A1 underlying active listening and a general principle of cortical processing during attentive behavior in other sensor…”

“Visual responsiveness has not previously been reported in the human PCS, although some of the multisensory neurons described in the IPS of monkeys were on the anterior bank of this sulcus (Iriki et al., 1996) and thus may have been in area 2 (Iwamura, 1998).”

“Increased extinction when wielding the stick could be predicted on the basis of recent physiological results from multimodal neurons in the intraparietal sulcus [13].”

“Data reproduced, with permission, from [11,13,14,25,38,54,89].”

“…between anterior and medial portions of the intraparietal cortex (Grefkes and Fink, 2005) and posterior superior parietal (Mountcastle et al., 1975; Iriki et al., 1996; Graziano et al., 2000), inferior parietal (Hyvärinen and Poranen, 1974; Luppino and Rizzolatti, 2000), and premotor (Rizzolatti…”

“Physiological studies of visuotactile body representation have demonstrated that bimodal neurons in area 5 and PEa are related to coding of the egocentric reference frame and may also contribute to monitoring of one’s own body (Graziano, Cooke, & Taylor, 2000; Obayashi, Tanaka, & Iriki, 2000; Iriki, Tanaka, & Iwamura,…”

“…superior parietal cluster is likely to be the human homologue of monkey area 5 (as well as adjacent area 2) where multisensory and sensorimotor neurons have been extensively described by using invasive electrophysiological recordings (Graziano et al., 2000; Iriki et al., 1996; Sakata et al., 1973).”