Intentional Maps in Posterior Parietal Cortex

“Both eye displacement and eye position–related signals are found in the PPC (Mountcastle et al. 1975).”

“Thus any spatial transformations conducted in the postero-dorsal stream may be based on a multisensory reference fram”

“Originally thought of as a saccade planning area (Gnadt & Andersen 1988), a debate arose as to whether the responses in LIP are related to visual attention (Colby & Goldberg 1999) or to the intention to make saccades (Andersen & Buneo 2002).”

“…memory may seem surprising because traditional views suggest that parietal cortex subserves processes associated with sensory-motor integration and visual-spatial attention (Andersen and Buneo 2002; Colby and Goldberg 1999; Corbetta and Shulman 2002; Heilman and Gonzalez Rothi 1993; Mesulam 1999).”

“For largely technical reasons, the saccadic-control system has been intensively studied over the past three decades as a model for understanding sensory-motor control in general (Andersen and Buneo, 2002; Colby and Goldberg, 1999).”

“…one asks which parameters are represented by neural activity, in which reference frames, and how these representations are transformed from one reference frame to another (e.g., Andersen & Buneo 2002, Batista et al. 2007, McGuire & Sabes 2011, MulletteGillman et al. 2009, Pesaran et al. 2006).”

“Saccades are generated from the frontal eye field (FEF) via descending drive through the superior colliculus (SC) (for a review see Andersen and Buneo, 2002); therefore, it was hypothesized that signals from the SC could act as efference copy back to the FEF (Sommer and Wurtz, 2002).”

“A critical analysis of these different signals is outside the scope of this review (but see Ref”

“In this review, we refer to intention as movement planning at a cognitive level rather than at the level of movement execution (Andersen and Buneo, 2002).”

“ramping activity is motor intention, as LIP is specifically involved with planning saccades (Andersen and Buneo, 2002).”

“PPC is engaged in higher-order aspects of motor behaviors (18).”

“This places the point for the middle quintile near [1,1] on these plots.”

“A number of “classical” PPC functions that are well known from electrophysiological studies in macaque monkey [23,24] have recently been probed in topographic areas of human PPC (Table 1).”

“…other arm-related parietal areas, such as areas V6A, 5, and 7 (Johnson et al., 1996; Stepniewska et al., 2005; Fattori et al., 2001; Galletti et al., 1997; Andersen and Buneo, 2002; Buneo et al., 2002; Ferraina et al., 2001; Kalaska, 1996; Battaglia-Mayer et al., 2000; Culham and Kanwisher, 2001).”

“Monkey parietal cortex contains multiple functionally and anatomically defined areas that are believed to be functionally specialized for sensory attention, motor intention, and decision making (Andersen and Buneo 2002; Colby and Goldberg 1999; Glimcher 2003).”

“Such functional and anatomical overlap has previously led researchers to debate whether neural responses in hubs of the attention network are related to either spatial attention [20] or the intention to make a saccade [21], with some arguing that spatial attention and saccades are inseparably coupled [22, 23].”

“These areas also receive and process sensory input (Andersen and Buneo, 2002; Gold and Shadlen, 2007) and project directly to premotor cortex (Andersen and Buneo, 2002; Desmurget and Sirigu, 2009).”

“In monkey parietal cortex, neurons have been recorded that signal the monkey’s decision to move (Platt and Glimcher, 1999) and intention to move (Andersen and Buneo, 2002).”

“Moreover, this gaze strategy (whereby cursor and saccadic eye movements are launched from the same locations, albeit at different times) might help to establish a mapping between hand actions and eye movements in gaze-centered coordinates [33,64,65].”

“…encodes strictly the probability suggest that human decision making is almost always based on relative values (cf. Kahneman and Tversky,or intention to make a saccade (Andersen and Buneo, 2002) because activity remained constant across blocks 1979). of trials while response probability varied.”

“Indeed, evidence for dynamic shifts in auditory receptive fields have been documented in the primate superior colliculus (e.g. Jay and Sparks, 1987) and parietal cortex (see Andersen and Buneo, 2002).”

“The emergence of these different areas in the primate brain presumably reflects the need to orchestrate the movements of the fingers, hands, limbs, head, and eyes in different ways to support a range of skilled visually guided behavior (Goodale and Milner 1992; Milner and Goodale 1995; Andersen and Buneo 2002).”

“AIP is functionally distinct from the caudally adjacent oculomotor lateral intraparietal (LIP) area (Jeannerod et al. 1995; Sakata et al. 1997; Colby 1998; Andersen and Buneo 2002).”

“These findings provide new and additional evidence that the PPC is involved in movement planning (Snyder et al., 1997; Andersen and Buneo, 2002).”

“In the macaque, the parietal cortex is known to consist of a number of specialized subfields that are concerned with both eye and arm movements and receive somatosensory, auditory, and visual inputs (Colby and Goldberg 1999; Andersen and Buneo 2002).”

“Despite clear evidence for functional specialization of movement planning and performance in motor, premotor, and parietal cortical areas (Andersen & Buneo 2002, Buneo & Andersen 2006, Luppino & Rizzolatti 2000), it has become evident from NIS experiments that large networks of neurons are active…”

“These visually-guided movements require sensory-motor transformations to convert incoming visual information about target location into outgoing patterns of muscle activity (Andersen and Buneo, 2002; Kalaska et al., 1997; Shadmehr and Wise, 2005).”

“, in this case to one or the other choice target, or that it represents a motor preparatory signa”

“monkey and fMRI in normal humans, namely that a homologous ‘parietal reach region’ is involved in planning (Andersen and Buneo, 2002; Connolly et al., 2003) and in executing reaching Figure 3.”

“The presence of this type of motor response is in line with the anatomical connections of this area with the caudal part of the superior parietal and cingulate cortices (areas PEc, MIP, V6A, PEci and area 23), including the functionally defined parietal reaching region (PRR; see Andersen & Buneo, 2002 ), and with both…”

“Anderson and Buneo (2002) have proposed that the parietal cortex is a suitable candidate region for creating high level cognitive plans for movement, given its central role in combining sensory and motor information within a common reference frame.”

“Eye-Hand Coordination It is well known from neurophysiological and neuroimaging studies that oculomotor signals (whether related to corollary discharge or proprioception) influence the cortical network involved in hand-reaching movements (Andersen and Buneo, 2002; DeSouza et al., 2000).”

“Within the visual system, this property is considered a key mechanism for updating the retino-centric coordinates as a function of changes in eye position, and thus generating a stable and accurate representation of the visual space (Andersen and Buneo, 2002; Colby and Goldberg, 1999).”

“Some neurons have response fields that are defined by both eye - and limb - centered representations or eye - and head - centered representations , indicating that they encode spatial location in both coordinate frames ( Andersen and Buneo , 2002 , 2003 ) .”

“In macaques, supporting evidence comes from neurophysiological (Sakata et al., 1995; Andersen and Buneo, 2002; Buneo et al., 2002; Fattori et al., 2005), neuroanatomical (Rizzolatti and Matelli, 2003) and inactivation (Gallese et al., 1994) studies.”

“PRR includes V6A (Andersen & Buneo, 2002), and he human homologue of V6, neighboring V6A, has tentatively een located dorsally to V3 (Dechent & Frahm, 2003; Pitzalis t al., 2004).”

“Monkey (Bruce and Goldberg, 1985; Schlag and Schlag-Rey, 1987; Schall and Thompson, 1999; Andersen and Buneo, 2002) and human (Sweeney et al., 1996; Luna et al., 1998; Grosbras et al., 2001; Connolly et al., 2002; Cornelissen et al., 2002; Curtis and D'Esposito, 2003b; DeSouza et al., 2003; Brown et al., 2004) studies…”

“Likewise , establish - ing correlations between hand and eye motor commands would allow the specification of hand motor commands in gaze - centered coordinates ( Andersen and Buneo , 2002 ; Engel et al .”

“This is consistent with the known role of PPC in visually guided behavior (Andersen and Buneo, 2002) and in mediating shifts of spatial attention (Corbetta et al., 1991; Vandenberghe et al., 2001; Yantis et al., 2002; Bisley and Goldberg, 2003).”

“, 2001 ; Andersen and Buneo , 2002 ; Paz et al .”

“Several studies (Snyder et al., 1997; Thoenissen et al., 2002; Desmurget et al., 2009) suggest that motor intention is mediated by the posterior parietal cortex (for reviews see Crammond, 1997; Andersen and Buneo, 2002).”

“These data, along with others, have led to the idea that cells in the PPC form a distributed representation of movement plans or intentions to make movements to specific goal locations (39).”

“Modulations in these spatially selective regions thus reflect changes in dynamic representations of attentional priority that index the location of currently selected objects in the scene and may serve to guide spatially targeted motor interactions with the environment ( Andersen and Buneo 2002 ).”

“Single-unit recordings from PPC in monkeys are consistent with a role in space-based attention and motor planning (Colby and Goldberg, 1999; Andersen and Buneo, 2002).”

“The more anterior IPS activations (green) lateral of the yellow cluster might correspond (at least in anatomical location) to macaque areas 7a and AIP, also involved in hand movements (Andersen and Buneo, 2002).”

“…shows that the PPc contains several distinct, but functionally connected, neural populations coding multisensory stimuli relative to a variety of body-part-centered reference frames (see Andersen & Buneo, 2002; Avillac, Deneve, Olivier, Pouget, & Duhamel, 2005; Colby, 1998; Grefkes & Fink, 2005).”

“Posterior parietal cortex has been implicated in the generation of motor plans via transformations of sensory inputs from multiple modalities ( Anderson and Buneo, 2002 ) and may integrate representations of reward information in the service of perceptual decisionmaking (Platt and Glimcher, 1999; Gold and Shadlen, 200…”

“3A,B) was a continuation of the activity already present during the cue epoch, which is consistent with a role of AIP, and of the parietal cortex in general, in working memory (Mountcastle et al., 1975; Sakata et al., 1995; Murata et al., 2000; Andersen and Buneo, 2002).”

“In areas 7a and LIP (Andersen and Mountcastle, 1983; Andersen et al., 1985), the response of individual neurons to visual stimuli is modulated by the eye position in the orbit, a phenomenon rarely observed in absence of attentive fixation.”

“…not substantially different from other brain regions outside the visual and motor cortices, including lateral intraparietal cortex, the frontal eye fields, and superior colliculus (Schall, 1991; Platt and Glimcher, 1998; Andersen and Buneo, 2002; Gold and Shadlen, 2002; Bisley and Goldberg, 2003).”

“However, the heoretical debate between the parietal involvement in attenion or intention (Andersen & Buneo, 2002; Colby & Goldberg, 999) can even concern the mental representation of the locaion of the goal.”

“In the 'lateral intraparietal area' and the 'parietal reach region' there are maps for controlling eye-movements and reaching movements, respectively (Andersen & Buneo, 2002).”

“Evidence from memory reach studies have shown that MIP and area 5 encode the intended endpoint of an impending reach well after a target cue has been extinguished (Snyder et al., 1997; Andersen and Buneo, 2002; Musallam et al., 2004).”

“Having subregions dedicated to the planning of eye, reaching, and grasping movements, PPC provides different sub-mechanisms for integrating visual, proprioceptive and tactile inputs (Andersen & Buneo, 2002).”

“Eye position signals are known to influence the cortical reach related network (Andersen and Buneo 2002) and therefore to contribute to the neural commands to the limb.”

“…to play a special role in coordinating visually guided spatial behavior, including attending, looking, and reaching (Culham and Kanwisher, 2001; Andersen and Buneo, 2002; Astafiev et al., 2003), as well as in coding the spatial and nonspatial attributes of auditory stimuli (Grunewald et al.,…”