Agency + Body Ownership

Question 1

Longo et al (2008)

Answer 1

The experience of the embodied self is a complex conscious state with several dissociable components

Question 2

Tsakiris et al (2007)

Answer 2

Among these are a sense of ownership and a sense of agency over one’s actions

Question 3

Van den Bos et al (2002)

Answer 3

Body ownership is continuous and omnipresent: we experience BO not only during voluntary actions but also during passive movement and rest.

Question 4

Blakemore et al. (2002)

Answer 4

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.

Question 5

(Descartes, 1637)

Answer 5

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

Question 6

The additive view suggests that the sense of agency should involve…

Answer 6

the sense of body ownership, plus an additional experience of voluntary control

Question 7

Some neuroimaging research supports the additive model by…

Answer 7

… showing that agency and body ownership have shared neural correlates

Question 8

To investigate the neural correlates of body ownership, the RHI can be induced while participants undergo fMRI scanning… This illusion involves_____ (?)

Answer 8

… 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)

Question 9

Activity in the ___ ___ ___ is associated with the illusion of ownership of the rubber hand and is present during ____ conditions only (?)(?)

Answer 9

right posterior insula
synchronous conditions
Ehrsson et al., (2004)
Tsakiris et al., (2007)

• Demonstrates body ownership

Question 10

To investigate the neural correlates of agency, researchers have manipulated the…

Answer 10

visual feedback of movement to alter the experience of one’s body in action

Question 11

Activity in the __ __ __ correlated with the degree of match between performed and viewed movement and thus with _____ (?)

Answer 11

right posterior insula
self-attribution (agency)
Farrer (2003)

Question 12

However, these studies investigating the neural correlates of agency cannot separate the contribution of ___________, that are present in bodily action.

Answer 12

efferent and afferent signals

Question 13

With undisturbed visual feedback of action, there is a 3-way match between ____, ____, and ____.

Answer 13

efferent motor commands; afferent proprioceptive signals; and vision.

Question 14

Therefore, any effects observed in this condition could be due to a)___ b)___ c)___ d)___

Answer 14

(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.

Question 15

Therefore, any neural correlates of the degree of ‘match’ between performed and seen movement may actually be due to…

Answer 15

… proprioceptive-visual comparisons (relating to a sense of body-ownership)

Question 16

These neuroimaging studies may, therefore, confound the neural correlates of agency and body-ownership (?)

Answer 16

Tsakiris et al. (2010)

Question 17

One way to disentangle these effects (i.e. interaction between vision, Proprioception & motor commands) is to compare…

Answer 17

active to passive movement

Question 18

Both active and passive movement involve…

Answer 18

physically comparable movement, proprioceptive feedback, and vision

Question 19

active and passive movement differ in that… (?)

Answer 19

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).

Question 20

Tsakiris et al (2010)

Longo & Haggard (2009).

Answer 20

• 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 (?)

-

Question 21

Tsakiris et al (2010) manipulated agency by comparing finger movement that was _____, this is based on the premise that ____ (?)

Answer 21

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).

Question 22

Self-report results from Tsakiris et al (2010)?

What does this suggest?

Answer 22

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.

Question 23

Neuroimaging results from Tsakiris et al (2010)?

What does this suggest?

Answer 23

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.

Question 24

Which syndrome supports the independent processes account?

Answer 24

anarchic hand syndrome

Question 25

What is anarchic hand syndrome? (??)

Answer 25

patients report a lack of agency over the anarchic hand while simultaneously retaining a sense of ownership (Della et al, 1994; Marcel, 2003).

Question 26

Which patients experience agency but not body ownership?

Answer 26

anosognosia for hemiplegia (with somatoparphrenic delusions)

Question 27

Case study for AHP? (?)

Answer 27

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).

Question 28

Causal inference model of body ownership (?)

Answer 28

(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.

Question 29

Burin (2017)

Answer 29

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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