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Introspecting on the Timing of One's Actions in a Visuo-Motor Synchronization Task.

Gzorea A, Rider D - Front Psychol (2011)

Bottom Line: By means of a new visuo-motor synchronization paradigm we test the frequently made proposition that one's feeling of having voluntarily made a decision to act is in fact postdictively established contingent on the outcome of his action rather than on its aim.Instead, response time distributions were bimodal for the shortest (0 ms) and longest (500 ms) SIs and widely spread for intermediate SIs.To all three questions asked, subjects' responses strongly correlated with SI itself (r = 0.62-0.76) and barely with their actual response times (r = 0.03-0.42).

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Psychologie de la Perception, Université Paris Descartes and CNRS Paris, France.

ABSTRACT
By means of a new visuo-motor synchronization paradigm we test the frequently made proposition that one's feeling of having voluntarily made a decision to act is in fact postdictively established contingent on the outcome of his action rather than on its aim. Subjects had to (1) synchronize a key-press with the end of a random synchronization interval (SI) shorter or longer than their reaction time (RT) and (2) judge thereafter whether (Q1) SI had been long enough to allow synchronization, (Q2) their motor response had been "reactive" (i.e., close to their RT) or delayed, or (Q3) whether SI was short or long. SI was denoted by the filling-up time of an annular "gauge." In principle, the "synchronization" key-press should be reactive for SI ≤ RT and delayed in proportion with SI for SI > RT. Instead, response time distributions were bimodal for the shortest (0 ms) and longest (500 ms) SIs and widely spread for intermediate SIs. To all three questions asked, subjects' responses strongly correlated with SI itself (r = 0.62-0.76) and barely with their actual response times (r = 0.03-0.42). Hence subjects' introspective judgments on their trial-by-trial potential capability to synchronize their motor response (Q1) and on their reactive vs. delayed response mode reflected the objective cause of their action rather than being "corrupted" by its outcome (namely their actual response time). That subjects could not reliably decide whether their motor response was reactive or delayed implies that they did not have retrospective access to (or did not remember) their motor decisions which amounts to say that they could not decide on the intentionality of their actions.

No MeSH data available.


Reaction times (RT; black symbols), points of subjective synchronization derived from the cumulative Gaussian fits of the “Yes” responses as a function of the SI (PSS_SI) and as a function of subjects’ synchronization response time (PSS_RsT) and the means of these RsT (Av_RsT) as measured or derived from the different experiments. RTs measured in response to the instantaneously filled (SI = 0) gage and to a gage filling over 0 to 500 ms intervals are shown as the black circle and square, respectively. RT derived from the fastest RsT distribution to the instantaneously filled gage in the synchronization Experiment 1 is shown a the black triangle. PSS and Av_RsT derived from responses to questions 1, 2, and 3 are shown as circles, squares, and triangles with their colors referring to the Experiment where they have been assessed (red, Experiment 1; blue, Experiment 2). The solid red circle is the PSSSI from Experiment 1 used as the midpoint of the SI range tested in Experiment 2. Each symbol is the average over the five participants with the vertical bars showing 1SE.
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Figure 4: Reaction times (RT; black symbols), points of subjective synchronization derived from the cumulative Gaussian fits of the “Yes” responses as a function of the SI (PSS_SI) and as a function of subjects’ synchronization response time (PSS_RsT) and the means of these RsT (Av_RsT) as measured or derived from the different experiments. RTs measured in response to the instantaneously filled (SI = 0) gage and to a gage filling over 0 to 500 ms intervals are shown as the black circle and square, respectively. RT derived from the fastest RsT distribution to the instantaneously filled gage in the synchronization Experiment 1 is shown a the black triangle. PSS and Av_RsT derived from responses to questions 1, 2, and 3 are shown as circles, squares, and triangles with their colors referring to the Experiment where they have been assessed (red, Experiment 1; blue, Experiment 2). The solid red circle is the PSSSI from Experiment 1 used as the midpoint of the SI range tested in Experiment 2. Each symbol is the average over the five participants with the vertical bars showing 1SE.

Mentions: Additional support for this conclusion transpires from a closer look at subjects’ PSSs and RTs. As already noted, RTs are practically identical when directly measured in the preliminary RT experiments with the gage instantaneously filled (SI = 0) or filling-up over 0 to 500 ms intervals or when derived from the fastest RsT distribution to the instantaneously filled up gage in the synchronization Experiment 1 (black circle, square, and triangle in column “RT” of Figure 4). To answer the introspective Qs 1 and 2, subjects must, in principle, refer their responses to their introspected RT. The fact that the PSSSI (column “PSS_SI” in Figure 4) derived from their answers to these questions (Q1, solid red and open blue circles for Experiments 1 and 2, respectively; Q2, open blue square, Experiment 2) are about equal to their RTs, while the corresponding PSSRsT (column “PSS_RsT”; same colors and symbols) differ markedly from the RTs as well as across experiments (circle vs. square) and subjects (error bars) support the notion that subjects’ introspection was based on the SIs rather than on their own RsT. As the mean of the SIs used in Experiment 2 was by construction equal to the PSSSI derived in Experiment 1 (red solid circle), the PSSs derived from subjects’ responses to Q3 (that bore on the SI itself) should coincide with the mean SI. This is the case for the PSSSI but not for the PSSRsT implying once again that subjects based their responses to Q3, as they should have, on the estimated SI and not on their own RsT. Hence, subjects base their judgments on the objective duration of the interval they have to synchronize with whether in response to an introspective (Q1, Q2) or “objective” (Q3) question. Finally, the possibility that subjects calibrated their responses (whatever the question asked) relatively to their average RsT is not supported by the data as these averages (“AV_RsT” column in Figure 4) are significantly above subjects’ RT and PSSSI.


Introspecting on the Timing of One's Actions in a Visuo-Motor Synchronization Task.

Gzorea A, Rider D - Front Psychol (2011)

Reaction times (RT; black symbols), points of subjective synchronization derived from the cumulative Gaussian fits of the “Yes” responses as a function of the SI (PSS_SI) and as a function of subjects’ synchronization response time (PSS_RsT) and the means of these RsT (Av_RsT) as measured or derived from the different experiments. RTs measured in response to the instantaneously filled (SI = 0) gage and to a gage filling over 0 to 500 ms intervals are shown as the black circle and square, respectively. RT derived from the fastest RsT distribution to the instantaneously filled gage in the synchronization Experiment 1 is shown a the black triangle. PSS and Av_RsT derived from responses to questions 1, 2, and 3 are shown as circles, squares, and triangles with their colors referring to the Experiment where they have been assessed (red, Experiment 1; blue, Experiment 2). The solid red circle is the PSSSI from Experiment 1 used as the midpoint of the SI range tested in Experiment 2. Each symbol is the average over the five participants with the vertical bars showing 1SE.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108554&req=5

Figure 4: Reaction times (RT; black symbols), points of subjective synchronization derived from the cumulative Gaussian fits of the “Yes” responses as a function of the SI (PSS_SI) and as a function of subjects’ synchronization response time (PSS_RsT) and the means of these RsT (Av_RsT) as measured or derived from the different experiments. RTs measured in response to the instantaneously filled (SI = 0) gage and to a gage filling over 0 to 500 ms intervals are shown as the black circle and square, respectively. RT derived from the fastest RsT distribution to the instantaneously filled gage in the synchronization Experiment 1 is shown a the black triangle. PSS and Av_RsT derived from responses to questions 1, 2, and 3 are shown as circles, squares, and triangles with their colors referring to the Experiment where they have been assessed (red, Experiment 1; blue, Experiment 2). The solid red circle is the PSSSI from Experiment 1 used as the midpoint of the SI range tested in Experiment 2. Each symbol is the average over the five participants with the vertical bars showing 1SE.
Mentions: Additional support for this conclusion transpires from a closer look at subjects’ PSSs and RTs. As already noted, RTs are practically identical when directly measured in the preliminary RT experiments with the gage instantaneously filled (SI = 0) or filling-up over 0 to 500 ms intervals or when derived from the fastest RsT distribution to the instantaneously filled up gage in the synchronization Experiment 1 (black circle, square, and triangle in column “RT” of Figure 4). To answer the introspective Qs 1 and 2, subjects must, in principle, refer their responses to their introspected RT. The fact that the PSSSI (column “PSS_SI” in Figure 4) derived from their answers to these questions (Q1, solid red and open blue circles for Experiments 1 and 2, respectively; Q2, open blue square, Experiment 2) are about equal to their RTs, while the corresponding PSSRsT (column “PSS_RsT”; same colors and symbols) differ markedly from the RTs as well as across experiments (circle vs. square) and subjects (error bars) support the notion that subjects’ introspection was based on the SIs rather than on their own RsT. As the mean of the SIs used in Experiment 2 was by construction equal to the PSSSI derived in Experiment 1 (red solid circle), the PSSs derived from subjects’ responses to Q3 (that bore on the SI itself) should coincide with the mean SI. This is the case for the PSSSI but not for the PSSRsT implying once again that subjects based their responses to Q3, as they should have, on the estimated SI and not on their own RsT. Hence, subjects base their judgments on the objective duration of the interval they have to synchronize with whether in response to an introspective (Q1, Q2) or “objective” (Q3) question. Finally, the possibility that subjects calibrated their responses (whatever the question asked) relatively to their average RsT is not supported by the data as these averages (“AV_RsT” column in Figure 4) are significantly above subjects’ RT and PSSSI.

Bottom Line: By means of a new visuo-motor synchronization paradigm we test the frequently made proposition that one's feeling of having voluntarily made a decision to act is in fact postdictively established contingent on the outcome of his action rather than on its aim.Instead, response time distributions were bimodal for the shortest (0 ms) and longest (500 ms) SIs and widely spread for intermediate SIs.To all three questions asked, subjects' responses strongly correlated with SI itself (r = 0.62-0.76) and barely with their actual response times (r = 0.03-0.42).

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Psychologie de la Perception, Université Paris Descartes and CNRS Paris, France.

ABSTRACT
By means of a new visuo-motor synchronization paradigm we test the frequently made proposition that one's feeling of having voluntarily made a decision to act is in fact postdictively established contingent on the outcome of his action rather than on its aim. Subjects had to (1) synchronize a key-press with the end of a random synchronization interval (SI) shorter or longer than their reaction time (RT) and (2) judge thereafter whether (Q1) SI had been long enough to allow synchronization, (Q2) their motor response had been "reactive" (i.e., close to their RT) or delayed, or (Q3) whether SI was short or long. SI was denoted by the filling-up time of an annular "gauge." In principle, the "synchronization" key-press should be reactive for SI ≤ RT and delayed in proportion with SI for SI > RT. Instead, response time distributions were bimodal for the shortest (0 ms) and longest (500 ms) SIs and widely spread for intermediate SIs. To all three questions asked, subjects' responses strongly correlated with SI itself (r = 0.62-0.76) and barely with their actual response times (r = 0.03-0.42). Hence subjects' introspective judgments on their trial-by-trial potential capability to synchronize their motor response (Q1) and on their reactive vs. delayed response mode reflected the objective cause of their action rather than being "corrupted" by its outcome (namely their actual response time). That subjects could not reliably decide whether their motor response was reactive or delayed implies that they did not have retrospective access to (or did not remember) their motor decisions which amounts to say that they could not decide on the intentionality of their actions.

No MeSH data available.