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Measuring unconscious cognition: Beyond the zero-awareness criterion.

Schmidt T - Adv Cogn Psychol (2008)

Bottom Line: This paper discusses two different lines of attack for establishing unconscious cognition in such experiments.In particular, it is argued here that priming effects in speeded pointing movements (Schmidt, Niehaus, & Nagel, 2006) occur in the absence of the recurrent processing that is often assumed to be a necessary condition for awareness (for instance, DiLollo, Enns, & Rensink, 2000; Lamme & Roelfsema, 2000).Feedforward tasks such as this might thus be used to measure the time-course of unconscious processing directly, before intracortical feedback and awareness come into play.

View Article: PubMed Central - PubMed

Affiliation: Department of Cognitive Psychology, University of Giessen, Germany.

ABSTRACT
Visual masking can be employed to manipulate observers' awareness of critical stimuli in studies of masked priming. This paper discusses two different lines of attack for establishing unconscious cognition in such experiments. Firstly, simple dissociations between direct measures (D) of visual awareness and indirect measures (I) of processing per se occur when I has some nonzero value while D is at chance level; the traditional requirement of zero awareness is necessary for this criterion only. In contrast, double dissociations occur when some experimental manipulation has opposite effects on I and D, for instance, increasing priming effects despite decreasing prime identification performance (Schmidt & Vorberg, 2006). Double dissociations require much weaker measurement assumptions than other criteria. An attractive alternative to this dissociation approach would be to use tasks that are known to violate necessary conditions of visual awareness altogether. In particular, it is argued here that priming effects in speeded pointing movements (Schmidt, Niehaus, & Nagel, 2006) occur in the absence of the recurrent processing that is often assumed to be a necessary condition for awareness (for instance, DiLollo, Enns, & Rensink, 2000; Lamme & Roelfsema, 2000). Feedforward tasks such as this might thus be used to measure the time-course of unconscious processing directly, before intracortical feedback and awareness come into play.

No MeSH data available.


Related in: MedlinePlus

Data patterns and assumptions necessary to interpret a simple dissociation as						evidence for nonzero unconscious information. An arrow from information						source a to measure B indicates that							B is some function of a.							S-shaped inset symbols denote that weak monotonicity is						assumed for that function. Abbreviations as explained in main text.							a) Data pattern required for a simple dissociation. Direct						and indirect measures are plotted in an opposition space in effect size						units. Evidence for a simple dissociation is given by data points lying on						the stippled vertical line such that I > 0 while							D = 0. b) A simple dissociation gives						evidence for nonzero unconscious information if it can be assumed that							D is an exhaustive function of c and						that I is a weakly monotonic function of						u. c) Alternatively, a simple dissociation						gives evidence for nonzero unconscious information if I is						an exclusive measure of u. Adapted from Schmidt and Vorberg							(2006).
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Figure 1: Data patterns and assumptions necessary to interpret a simple dissociation as evidence for nonzero unconscious information. An arrow from information source a to measure B indicates that B is some function of a. S-shaped inset symbols denote that weak monotonicity is assumed for that function. Abbreviations as explained in main text. a) Data pattern required for a simple dissociation. Direct and indirect measures are plotted in an opposition space in effect size units. Evidence for a simple dissociation is given by data points lying on the stippled vertical line such that I > 0 while D = 0. b) A simple dissociation gives evidence for nonzero unconscious information if it can be assumed that D is an exhaustive function of c and that I is a weakly monotonic function of u. c) Alternatively, a simple dissociation gives evidence for nonzero unconscious information if I is an exclusive measure of u. Adapted from Schmidt and Vorberg (2006).

Mentions: Given that D-I mismatch is efficiently avoided, how can the model of only conscious processing be disproved? The traditional way of doing this is the zero-awareness criterion, which produces what we call a simple dissociation of direct and indirect measures: zero D in the presence of nonzero I (Figure 1). If we start from this finding, we quickly see that we don’t get very far without additional assumptions, because the observation that I(c, u) > 0 only implies that c > 0, u > 0, or both. Can we use the fact that D(c, u) = 0 to make sure that c = 0? Not quite, because D(c, u) = 0 does not imply c = 0 under weak monotonicity assumptions: D may simply fail to respond to changes in information, so that there could be some c that D was not able to detect. To work around this problem, we have to make the stronger assumption that D is an exhaustive measure of conscious information, that is, that D is a strictly monotonic function of c (Reingold & Merikle, 1988; see Schmidt & Vorberg, 2006, for a more general proof). This means that D is able to detect any change in c whatsoever, so that D(c, u) = 0 implies c = 0. Given this exhaustiveness assumption, we can finally use the fact that c can no longer drive the indirect effect: I(c, u) = I(0, u) > 0 implies u > 0, which says that there is nonzero unconscious information in the system.


Measuring unconscious cognition: Beyond the zero-awareness criterion.

Schmidt T - Adv Cogn Psychol (2008)

Data patterns and assumptions necessary to interpret a simple dissociation as						evidence for nonzero unconscious information. An arrow from information						source a to measure B indicates that							B is some function of a.							S-shaped inset symbols denote that weak monotonicity is						assumed for that function. Abbreviations as explained in main text.							a) Data pattern required for a simple dissociation. Direct						and indirect measures are plotted in an opposition space in effect size						units. Evidence for a simple dissociation is given by data points lying on						the stippled vertical line such that I > 0 while							D = 0. b) A simple dissociation gives						evidence for nonzero unconscious information if it can be assumed that							D is an exhaustive function of c and						that I is a weakly monotonic function of						u. c) Alternatively, a simple dissociation						gives evidence for nonzero unconscious information if I is						an exclusive measure of u. Adapted from Schmidt and Vorberg							(2006).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864967&req=5

Figure 1: Data patterns and assumptions necessary to interpret a simple dissociation as evidence for nonzero unconscious information. An arrow from information source a to measure B indicates that B is some function of a. S-shaped inset symbols denote that weak monotonicity is assumed for that function. Abbreviations as explained in main text. a) Data pattern required for a simple dissociation. Direct and indirect measures are plotted in an opposition space in effect size units. Evidence for a simple dissociation is given by data points lying on the stippled vertical line such that I > 0 while D = 0. b) A simple dissociation gives evidence for nonzero unconscious information if it can be assumed that D is an exhaustive function of c and that I is a weakly monotonic function of u. c) Alternatively, a simple dissociation gives evidence for nonzero unconscious information if I is an exclusive measure of u. Adapted from Schmidt and Vorberg (2006).
Mentions: Given that D-I mismatch is efficiently avoided, how can the model of only conscious processing be disproved? The traditional way of doing this is the zero-awareness criterion, which produces what we call a simple dissociation of direct and indirect measures: zero D in the presence of nonzero I (Figure 1). If we start from this finding, we quickly see that we don’t get very far without additional assumptions, because the observation that I(c, u) > 0 only implies that c > 0, u > 0, or both. Can we use the fact that D(c, u) = 0 to make sure that c = 0? Not quite, because D(c, u) = 0 does not imply c = 0 under weak monotonicity assumptions: D may simply fail to respond to changes in information, so that there could be some c that D was not able to detect. To work around this problem, we have to make the stronger assumption that D is an exhaustive measure of conscious information, that is, that D is a strictly monotonic function of c (Reingold & Merikle, 1988; see Schmidt & Vorberg, 2006, for a more general proof). This means that D is able to detect any change in c whatsoever, so that D(c, u) = 0 implies c = 0. Given this exhaustiveness assumption, we can finally use the fact that c can no longer drive the indirect effect: I(c, u) = I(0, u) > 0 implies u > 0, which says that there is nonzero unconscious information in the system.

Bottom Line: This paper discusses two different lines of attack for establishing unconscious cognition in such experiments.In particular, it is argued here that priming effects in speeded pointing movements (Schmidt, Niehaus, & Nagel, 2006) occur in the absence of the recurrent processing that is often assumed to be a necessary condition for awareness (for instance, DiLollo, Enns, & Rensink, 2000; Lamme & Roelfsema, 2000).Feedforward tasks such as this might thus be used to measure the time-course of unconscious processing directly, before intracortical feedback and awareness come into play.

View Article: PubMed Central - PubMed

Affiliation: Department of Cognitive Psychology, University of Giessen, Germany.

ABSTRACT
Visual masking can be employed to manipulate observers' awareness of critical stimuli in studies of masked priming. This paper discusses two different lines of attack for establishing unconscious cognition in such experiments. Firstly, simple dissociations between direct measures (D) of visual awareness and indirect measures (I) of processing per se occur when I has some nonzero value while D is at chance level; the traditional requirement of zero awareness is necessary for this criterion only. In contrast, double dissociations occur when some experimental manipulation has opposite effects on I and D, for instance, increasing priming effects despite decreasing prime identification performance (Schmidt & Vorberg, 2006). Double dissociations require much weaker measurement assumptions than other criteria. An attractive alternative to this dissociation approach would be to use tasks that are known to violate necessary conditions of visual awareness altogether. In particular, it is argued here that priming effects in speeded pointing movements (Schmidt, Niehaus, & Nagel, 2006) occur in the absence of the recurrent processing that is often assumed to be a necessary condition for awareness (for instance, DiLollo, Enns, & Rensink, 2000; Lamme & Roelfsema, 2000). Feedforward tasks such as this might thus be used to measure the time-course of unconscious processing directly, before intracortical feedback and awareness come into play.

No MeSH data available.


Related in: MedlinePlus