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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 double dissociation as						evidence for nonzero unconscious information. a) Data pattern						required for a double dissociation. Evidence for a double dissociation is						given by any pair of data points that can be connected by a straight line						with negative slope anywhere in D-I space.							b) A double dissociation gives evidence for nonzero						unconscious information if it can be assumed that I and							D are weakly monotonic functions of c.						Further assumptions need not be made, leaving c and							u to interact freely on both measures. Adapted from						Schmidt and Vorberg (2006).
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Figure 2: Data patterns and assumptions necessary to interpret a double dissociation as evidence for nonzero unconscious information. a) Data pattern required for a double dissociation. Evidence for a double dissociation is given by any pair of data points that can be connected by a straight line with negative slope anywhere in D-I space. b) A double dissociation gives evidence for nonzero unconscious information if it can be assumed that I and D are weakly monotonic functions of c. Further assumptions need not be made, leaving c and u to interact freely on both measures. Adapted from Schmidt and Vorberg (2006).

Mentions: One interesting way to circumvent the exhaustiveness or exclusiveness assumptions is to let awareness vary over experimental conditions. It may then be possible to establish a double dissociation, which consists of finding an experimental manipulation that changes D and I in opposite directions (Figure 2). In particular, any pair of experimental conditions that leads to opposite orderings of data points in direct and indirect measures gives evidence for a double dissociation. An example would be a priming experiment with two (or more) masking conditions where the priming effect increases over experimental conditions while prime identification performance decreases. It is intuitively clear that two measures of visual information going in opposite directions cannot be monotonically driven by a single information source, and a formal proof of this can be found in our paper (Schmidt & Vorberg, 2006)4. Our concept of double dissociations is analogous to the widely used methodology in neuropsychology and medicine (Shallice, 1988; Sternberg, 2001).


Measuring unconscious cognition: Beyond the zero-awareness criterion.

Schmidt T - Adv Cogn Psychol (2008)

Data patterns and assumptions necessary to interpret a double dissociation as						evidence for nonzero unconscious information. a) Data pattern						required for a double dissociation. Evidence for a double dissociation is						given by any pair of data points that can be connected by a straight line						with negative slope anywhere in D-I space.							b) A double dissociation gives evidence for nonzero						unconscious information if it can be assumed that I and							D are weakly monotonic functions of c.						Further assumptions need not be made, leaving c and							u to interact freely on both measures. 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 2: Data patterns and assumptions necessary to interpret a double dissociation as evidence for nonzero unconscious information. a) Data pattern required for a double dissociation. Evidence for a double dissociation is given by any pair of data points that can be connected by a straight line with negative slope anywhere in D-I space. b) A double dissociation gives evidence for nonzero unconscious information if it can be assumed that I and D are weakly monotonic functions of c. Further assumptions need not be made, leaving c and u to interact freely on both measures. Adapted from Schmidt and Vorberg (2006).
Mentions: One interesting way to circumvent the exhaustiveness or exclusiveness assumptions is to let awareness vary over experimental conditions. It may then be possible to establish a double dissociation, which consists of finding an experimental manipulation that changes D and I in opposite directions (Figure 2). In particular, any pair of experimental conditions that leads to opposite orderings of data points in direct and indirect measures gives evidence for a double dissociation. An example would be a priming experiment with two (or more) masking conditions where the priming effect increases over experimental conditions while prime identification performance decreases. It is intuitively clear that two measures of visual information going in opposite directions cannot be monotonically driven by a single information source, and a formal proof of this can be found in our paper (Schmidt & Vorberg, 2006)4. Our concept of double dissociations is analogous to the widely used methodology in neuropsychology and medicine (Shallice, 1988; Sternberg, 2001).

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