Agency + Body Ownership Flashcards
Longo et al (2008)
The experience of the embodied self is a complex conscious state with several dissociable components
Tsakiris et al (2007)
Among these are a sense of ownership and a sense of agency over one’s actions
Van den Bos et al (2002)
Body ownership is continuous and omnipresent: we experience BO not only during voluntary actions but also during passive movement and rest.
Blakemore et al. (2002)
In contrast, agency is only induced when voluntary action occurs: agency is linked closely to the generation of efferent moto signals and the monitoring of their effect.
(Descartes, 1637)
One perspective is that body ownership and agency are interdependent. This view is informed by…
- the observation that we feel ownership over our body and not objects because we can control the movement of the former but not the latter
The additive view suggests that the sense of agency should involve…
the sense of body ownership, plus an additional experience of voluntary control
Some neuroimaging research supports the additive model by…
… showing that agency and body ownership have shared neural correlates
To investigate the neural correlates of body ownership, the RHI can be induced while participants undergo fMRI scanning… This illusion involves_____ (?)
… inducing a sense of ownership over a fake rubber hand by synchronously stroking the rubber hand and the participant’s own hand which is out of view (Botnivick and Cohen, 1998)
Activity in the ___ ___ ___ is associated with the illusion of ownership of the rubber hand and is present during ____ conditions only (?)(?)
right posterior insula
synchronous conditions
Ehrsson et al., (2004)
Tsakiris et al., (2007)
- Demonstrates body ownership
To investigate the neural correlates of agency, researchers have manipulated the…
visual feedback of movement to alter the experience of one’s body in action
Activity in the __ __ __ correlated with the degree of match between performed and viewed movement and thus with _____ (?)
right posterior insula
self-attribution (agency)
Farrer (2003)
However, these studies investigating the neural correlates of agency cannot separate the contribution of ___________, that are present in bodily action.
efferent and afferent signals
With undisturbed visual feedback of action, there is a 3-way match between ____, ____, and ____.
efferent motor commands; afferent proprioceptive signals; and vision.
Therefore, any effects observed in this condition could be due to a)___ b)___ c)___ d)___
(a) efferent commands and proprioceptive signals
(b) efferent commands and visual feedback
(c) proprioceptive signals and visual feedback [i.e. Body ownership!, not agency]
(d) a complex interaction between all three signals.
Therefore, any neural correlates of the degree of ‘match’ between performed and seen movement may actually be due to…
… proprioceptive-visual comparisons (relating to a sense of body-ownership)
These neuroimaging studies may, therefore, confound the neural correlates of agency and body-ownership (?)
Tsakiris et al. (2010)
One way to disentangle these effects (i.e. interaction between vision, Proprioception & motor commands) is to compare…
active to passive movement
Both active and passive movement involve…
physically comparable movement, proprioceptive feedback, and vision
active and passive movement differ in that… (?)
only voluntary (active) movement depend on a cascade of preparatory cognitive-motor processes within the brain’s frontal lobes, making this condition agency-specific (Haggard, 2008).
Tsakiris et al (2010)
Longo & Haggard (2009).
- manipulated body-ownership by presenting real-time or delayed visual feedback of movements as synchronous visual feedback causes body-parts and bodily events to be attributed to the self (?)
-
Tsakiris et al (2010) manipulated agency by comparing finger movement that was _____, this is based on the premise that ____ (?)
actively generated by participants or passively generated by experimenter, this is based on the premise that temporal congruence between sensory and motor signals can produce a sense of agency during voluntary movements (Longo, 2009).
Self-report results from Tsakiris et al (2010)?
What does this suggest?
Participants reported significantly more agency and body ownership in the active synchronous condition than any other condition.
This suggests that the agency strengthens the feeling of BO - supporting the additive model.
Neuroimaging results from Tsakiris et al (2010)?
What does this suggest?
The analysis revealed no suprathreshold activation common to agency (induced via active movement) and body-ownership (induced via passive movement).
Instead, body ownership and agency were associated with distinct patterns of activation.
This supports the view that agency and body ownership are independent processes.
Which syndrome supports the independent processes account?
anarchic hand syndrome
What is anarchic hand syndrome? (??)
patients report a lack of agency over the anarchic hand while simultaneously retaining a sense of ownership (Della et al, 1994; Marcel, 2003).
Which patients experience agency but not body ownership?
anosognosia for hemiplegia (with somatoparphrenic delusions)
Case study for AHP? (?)
one case study reported a participant who claimed her arm belonged to someone else (thus displaying a lack of ownership). However, when asked to move the arm, the patient would deny paralysis and report her ability to move it voluntarily (Fotopolou et a, 2008) (thus displaying the presence of a sense of agency).
Causal inference model of body ownership (?)
(Kilteni et al. 2015): Bayesian causal inference model – brain calculates probability of it being your hand based on multisensory information, action and high-level knowledge.
Motor information (e.g. agency) is not essential for but contributes to body ownership.
Burin (2017)
How does BO contribute to Ag?
- Showed that illusory ownership of a fake hand (rhi) triggered an illusory sense of agency over its movements at both the explicit (Qs) and implicit (sensory attenuation).
- When embodied hand pressed putton (delivered electrical stimulus to PS) the movement was misatributed to the PSs will at explicit and implicit level (stimulus intensity attenuated) - as it happened when own hand delivered stimulus
- Included 180deg control condition to pinpoint the effect of ownership (rather than just synchrony)
- Therefore, BO promotes agency, suggesting addive model
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