Biological entities from single cells to organs and organisms all have boundaries. Yet these boundaries are semi-permeable, allowing fuel to enter, waste products to leave, and mechanisms for cooperation and competition with neighboring entities. Boundary permeability therefore requires some means of recognition, allowing cells and organisms to distinguish between self and other, mine and not-mine (Mukherjee, Reference Mukherjee2022).
Decades of human behavioral research has documented that the psychological self extends to the ideas of one's mind, the parts of one's body, and the physical possessions and locations associated with one's body (Belk, Reference Belk1988; Sommer, Reference Sommer, Bechtel and Churchman2002). The “implicit rules of ownership” referenced by Boyer (Reference Boyer2022) very much follow the implicit rules for possessing one's own body parts. An everyday example is road rage, where perceived infractions of an automobile's intentions are treated as direct bodily violations.
Boyer's framework for ownership proposes a unidirectional flow from inputs to outputs (Boyer, Reference Boyer2022), thus ignoring two critical features of humans as embodied agents. Our first point is that the specific capabilities of a body influence the inputs to the system. We privilege the inputs that correspond to the actions we are capable of performing, tending to ignore inputs for which we have no action possibilities. Our second point is that an agent's actions change the state of the body and its relation to the environment. This means that our actions directly contribute to our appraisal of the objects we encounter and what we consider as “ours” or “theirs” (Fig. 1).
Action capabilities directly influence perceptual inputs
Boyer (Reference Boyer2022) describes contiguity as a relevant cue that facilitates ownership intuitions. But he fails to point out that many other relations between agent and object have a powerful influence on the input channels that eventually lead to actions. For instance, experts in a given perceptual domain such as rock climbers, bird watchers, and automotive enthusiasts, all see and act on objects in their domain at a finer level of detail than novices (Tanaka & Philibert, Reference Tanaka and Philibert2022). This corresponds to what Gibson (Reference Gibson1977) referred to as action affordances. How one is capable of acting on their world fundamentally changes perceptual inputs. It is not merely sharing space or time with an object that is vital to privileging its perception, it is the capacity to act on that object that fundamentally changes how we represent and feel about it. When objects are within reach, action-related areas of human cortex respond more vigorously than when they are out of reach (Gallivan, Cavina-Pratesi, & Culham, Reference Gallivan, Cavina-Pratesi and Culham2009). People are able to respond more quickly to perceptual input that is near one's hand (Perry, Amarasooriya, & Fallah, Reference Perry, Amarasooriya and Fallah2016; Reed, Grubb, & Steele, Reference Reed, Grubb and Steele2006), and to locations that are the target of actions (Andersen & Mountcastle, Reference Andersen and Mountcastle1983; Snyder, Reference Snyder2000). These influences on the way we perceive an object then have a direct influence on the actions we plan and initiate (Barton, Matthis, & Fajen, Reference Barton, Matthis and Fajen2017; Lee, Lishman, & Thomson, Reference Lee, Lishman and Thomson1982; Sarpeshkar, Abernethy, & Mann, Reference Sarpeshkar, Abernethy and Mann2017; Savelsbergh, Whiting, & Bootsma, Reference Savelsbergh, Whiting and Bootsma1991; Todd, Reference Todd1981; Witt, Reference Witt2011). These and other studies strongly support the expansion of Boyer's input space to include the important role that humans acting on, and having the capacity to act on objects, has in determining ownership intuitions.
Actions influence the emotional and cognitive appraisal of objects
A wealth of research shows a much more intimate coupling between action and perception than the sequential stages of see −> decide −> act (Nakayama, Moher, & Song, Reference Nakayama, Moher and Song2023). Neurons in the premotor and motor regions of the brain implicated in self-action also respond when observing others perform the same actions (Rizzolatti, Fogassi, & Gallese, Reference Rizzolatti, Fogassi and Gallese2001). Merely planning a movement increases the neural activity in human early visual and auditory cortices (Gale et al., Reference Gale, Areshenkoff, Honda, Johnsrude, Flanagan and Gallivan2021; Gallivan, Chapman, Gale, Flanagan, & Culham, Reference Gallivan, Chapman, Gale, Flanagan and Culham2019). When we act on an emotionally neutral object, our actions enhance that object's appeal in subsequent evaluations (Chapman, Gallivan, & Enns, Reference Chapman, Gallivan and Enns2015; Peck & Shu, Reference Peck and Shu2009; Wispinski, Lin, Enns, & Chapman, Reference Wispinski, Lin, Enns and Chapman2021). Conversely, ignoring some objects in order to act selectively on others decreases their subsequent emotional appeal (De Vito & Fenske, Reference De Vito and Fenske2018; Fenske & Raymond, Reference Fenske and Raymond2006; Griffiths & Mitchell, Reference Griffiths and Mitchell2008; Kiss et al., Reference Kiss, Goolsby, Raymond, Shapiro, Silvert, Nobre and Eimer2007; Raymond, Fenske, & Westoby, Reference Raymond, Fenske and Westoby2005; Silver, Stahl, Loiotile, Smith-Flores, & Feigenson, Reference Silver, Stahl, Loiotile, Smith-Flores and Feigenson2020). Even regular involuntary interaction with objects that are initially appraised as negative contributes to their increased emotional appeal over time (Dudarev, Manaligod, Enns, & Todd, Reference Dudarev, Manaligod, Enns and Todd2022). Arbitrarily assigning some objects as “mine” and then moving them toward one's body leads to subsequent improved memory of those objects, compared to objects assigned as “yours” and/or moved away from one's body (Truong, Chapman, Chisholm, Enns, & Handy, Reference Truong, Chapman, Chisholm, Enns and Handy2016). All of these studies indicate that the actions we plan and take contribute to updating our perceptual states, which in turn make new objects and experiences available to us, and the cycle continues.
Conclusion
Humans are embodied agents and ownership intuitions follow directly from the extended self of every individual. First, we argue that our capabilities as active agents directly alter the perceptual inputs that give rise to ownership intuitions. Second, we argue that rather than modeling the extended self with the sequential stages of perceive −> decide −> act, we should consider a fully dynamical system, where the actions we take are as influential in determining the decisions we make as the perceptual inputs to those decisions (Nakayama et al., Reference Nakayama, Moher and Song2023; Wispinski, Gallivan, & Chapman, Reference Wispinski, Gallivan and Chapman2020). From this perspective, we may not only be the recipients of intuitive notions of ownership via the shared evolutionary history of all humans, but we have the capacity to shape and even alter those intuitions, through the actions we take today and the decisions we make for the future.
Biological entities from single cells to organs and organisms all have boundaries. Yet these boundaries are semi-permeable, allowing fuel to enter, waste products to leave, and mechanisms for cooperation and competition with neighboring entities. Boundary permeability therefore requires some means of recognition, allowing cells and organisms to distinguish between self and other, mine and not-mine (Mukherjee, Reference Mukherjee2022).
Decades of human behavioral research has documented that the psychological self extends to the ideas of one's mind, the parts of one's body, and the physical possessions and locations associated with one's body (Belk, Reference Belk1988; Sommer, Reference Sommer, Bechtel and Churchman2002). The “implicit rules of ownership” referenced by Boyer (Reference Boyer2022) very much follow the implicit rules for possessing one's own body parts. An everyday example is road rage, where perceived infractions of an automobile's intentions are treated as direct bodily violations.
Boyer's framework for ownership proposes a unidirectional flow from inputs to outputs (Boyer, Reference Boyer2022), thus ignoring two critical features of humans as embodied agents. Our first point is that the specific capabilities of a body influence the inputs to the system. We privilege the inputs that correspond to the actions we are capable of performing, tending to ignore inputs for which we have no action possibilities. Our second point is that an agent's actions change the state of the body and its relation to the environment. This means that our actions directly contribute to our appraisal of the objects we encounter and what we consider as “ours” or “theirs” (Fig. 1).
Figure 1. Boyer's framework requires at least two extensions to be consistent with a current understanding of embodied cognition (Foglia & Wilson, Reference Foglia and Wilson2013) and the extended self (Belk, Reference Belk1988). (1) The capabilities of a person's body have a direct influence on the inputs that govern their actions. (2) The actions taken by a body have direct influence on all of cognition, including perception, emotional appraisal, and decision making.
Action capabilities directly influence perceptual inputs
Boyer (Reference Boyer2022) describes contiguity as a relevant cue that facilitates ownership intuitions. But he fails to point out that many other relations between agent and object have a powerful influence on the input channels that eventually lead to actions. For instance, experts in a given perceptual domain such as rock climbers, bird watchers, and automotive enthusiasts, all see and act on objects in their domain at a finer level of detail than novices (Tanaka & Philibert, Reference Tanaka and Philibert2022). This corresponds to what Gibson (Reference Gibson1977) referred to as action affordances. How one is capable of acting on their world fundamentally changes perceptual inputs. It is not merely sharing space or time with an object that is vital to privileging its perception, it is the capacity to act on that object that fundamentally changes how we represent and feel about it. When objects are within reach, action-related areas of human cortex respond more vigorously than when they are out of reach (Gallivan, Cavina-Pratesi, & Culham, Reference Gallivan, Cavina-Pratesi and Culham2009). People are able to respond more quickly to perceptual input that is near one's hand (Perry, Amarasooriya, & Fallah, Reference Perry, Amarasooriya and Fallah2016; Reed, Grubb, & Steele, Reference Reed, Grubb and Steele2006), and to locations that are the target of actions (Andersen & Mountcastle, Reference Andersen and Mountcastle1983; Snyder, Reference Snyder2000). These influences on the way we perceive an object then have a direct influence on the actions we plan and initiate (Barton, Matthis, & Fajen, Reference Barton, Matthis and Fajen2017; Lee, Lishman, & Thomson, Reference Lee, Lishman and Thomson1982; Sarpeshkar, Abernethy, & Mann, Reference Sarpeshkar, Abernethy and Mann2017; Savelsbergh, Whiting, & Bootsma, Reference Savelsbergh, Whiting and Bootsma1991; Todd, Reference Todd1981; Witt, Reference Witt2011). These and other studies strongly support the expansion of Boyer's input space to include the important role that humans acting on, and having the capacity to act on objects, has in determining ownership intuitions.
Actions influence the emotional and cognitive appraisal of objects
A wealth of research shows a much more intimate coupling between action and perception than the sequential stages of see −> decide −> act (Nakayama, Moher, & Song, Reference Nakayama, Moher and Song2023). Neurons in the premotor and motor regions of the brain implicated in self-action also respond when observing others perform the same actions (Rizzolatti, Fogassi, & Gallese, Reference Rizzolatti, Fogassi and Gallese2001). Merely planning a movement increases the neural activity in human early visual and auditory cortices (Gale et al., Reference Gale, Areshenkoff, Honda, Johnsrude, Flanagan and Gallivan2021; Gallivan, Chapman, Gale, Flanagan, & Culham, Reference Gallivan, Chapman, Gale, Flanagan and Culham2019). When we act on an emotionally neutral object, our actions enhance that object's appeal in subsequent evaluations (Chapman, Gallivan, & Enns, Reference Chapman, Gallivan and Enns2015; Peck & Shu, Reference Peck and Shu2009; Wispinski, Lin, Enns, & Chapman, Reference Wispinski, Lin, Enns and Chapman2021). Conversely, ignoring some objects in order to act selectively on others decreases their subsequent emotional appeal (De Vito & Fenske, Reference De Vito and Fenske2018; Fenske & Raymond, Reference Fenske and Raymond2006; Griffiths & Mitchell, Reference Griffiths and Mitchell2008; Kiss et al., Reference Kiss, Goolsby, Raymond, Shapiro, Silvert, Nobre and Eimer2007; Raymond, Fenske, & Westoby, Reference Raymond, Fenske and Westoby2005; Silver, Stahl, Loiotile, Smith-Flores, & Feigenson, Reference Silver, Stahl, Loiotile, Smith-Flores and Feigenson2020). Even regular involuntary interaction with objects that are initially appraised as negative contributes to their increased emotional appeal over time (Dudarev, Manaligod, Enns, & Todd, Reference Dudarev, Manaligod, Enns and Todd2022). Arbitrarily assigning some objects as “mine” and then moving them toward one's body leads to subsequent improved memory of those objects, compared to objects assigned as “yours” and/or moved away from one's body (Truong, Chapman, Chisholm, Enns, & Handy, Reference Truong, Chapman, Chisholm, Enns and Handy2016). All of these studies indicate that the actions we plan and take contribute to updating our perceptual states, which in turn make new objects and experiences available to us, and the cycle continues.
Conclusion
Humans are embodied agents and ownership intuitions follow directly from the extended self of every individual. First, we argue that our capabilities as active agents directly alter the perceptual inputs that give rise to ownership intuitions. Second, we argue that rather than modeling the extended self with the sequential stages of perceive −> decide −> act, we should consider a fully dynamical system, where the actions we take are as influential in determining the decisions we make as the perceptual inputs to those decisions (Nakayama et al., Reference Nakayama, Moher and Song2023; Wispinski, Gallivan, & Chapman, Reference Wispinski, Gallivan and Chapman2020). From this perspective, we may not only be the recipients of intuitive notions of ownership via the shared evolutionary history of all humans, but we have the capacity to shape and even alter those intuitions, through the actions we take today and the decisions we make for the future.
Acknowledgements
We would like to thank Veronica Dudarev for insightful comments on this commentary.
Financial support
J. T. E. is supported by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (RPB-12R80005-2017). C. S. C. is supported by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (RGPIN-2020-05396).
Competing interest
None.