Response priming

With the term response priming or Reaktionsbahnung refers to a particular form of priming in the psychology of perception . Generally consist priming effects that the reaction (engl. Response ) (Engl. Target stimulus on a target ) from the previous presentation of a Bahnungsreizes (engl. Prime ) will be affected. The specialty of response priming is that both stimuli follow one another very quickly and are linked to alternative motor responses. If a test subject performs a quick reaction in order to classify the target stimulus, a prime that appeared recently can trigger response conflicts if it is assigned to a different response alternative than the target stimulus. These response conflicts are reflected in the behavioral data in the form of so-called priming effects, for example in response times and error rates. A special property of response priming effects is their independence from the conscious perception (visibility) of the prime.

Response priming as a visomotor effect

As early as 1962, Fehrer and Raab reported experiments in which test subjects were supposed to react as quickly as possible to the appearance of a stimulus by pressing a single button, the visibility of which was greatly reduced by so-called metacontrast masking (see below). They found that the reaction time was independent of the conscious visibility of the stimulus; H. The reaction to clearly visible stimuli was just as quick as to barely visible stimuli ( Fehrer-Raab effect ). Rosenbaum and Kornblum used the term response priming for the first time in 1982 in connection with an experimental paradigm in which parts of motor responses were primed by stimuli. The modern procedure of response priming was developed in the 80s and 90s by Peter Wolff, Werner Klotz, Ulrich Ansorge and Odmar Neumann at Bielefeld University. Another important development took place in the mid-1990s by Dirk Vorberg's working group at the Technical University of Braunschweig.

Fig. 1: a) Typical sequence of a round in the response priming paradigm. The test person reacts as quickly and as correctly as possible to the shape of the target stimulus (here outer shape: diamond or square) with a corresponding key reaction. Shortly beforehand, a prime appears (also a diamond or square) that influences the reaction to the target stimulus. The period of time between the onset of the prime and the onset of the target stimulus is known as stimulus onset asynchrony (SOA). In many response priming experiments, the target stimulus also serves to visually mask the prime. Therefore, a second task is often used, in which the subject must try to identify the masked Prime. b) Prime and target stimuli are consistent if they are associated with the same motor response and inconsistent if they are associated with different responses. c) The masking effect of the target stimulus can strongly influence the conscious perception (visibility) of the prime.

In experimental paradigms that use the response priming method, subjects must respond to a specific target stimulus. In a simple experiment, this could be one of two geometric stimuli that are assigned to two corresponding reaction buttons (e.g. diamond - left button, square - right button). The experiment then consists of many successive rounds in which the test subject must always press left when a diamond appears and right when a square appears. In each round, shortly before the presentation of the respective target stimulus, a prime appears, which also has the response-triggering properties of the target stimulus, i.e. is itself a diamond or a square (Fig. 1a). If the prime and target stimulus are linked to the same reactions (diamond follows diamond, square after square), they are considered consistent (also "congruent", "compatible"); if they are linked to different reactions (diamond follows square, square after diamond), as inconsistent (also "incongruent", "incompatible"; Fig. 1b). The time interval between the onset of the prime and the onset of the target stimulus is called stimulus onset asynchrony (SOA). Typically, SOAs of approximately 100 ms (milliseconds) or less are used.

Priming effects occur when the prime influences the motor reaction to the target stimulus: consistent primes accelerate the reaction times, inconsistent primes slow them down (Fig. 2). Priming effects in reaction times are usually determined as the difference between the mean reaction times in the consistent and inconsistent runs. In addition, consistent primes only very rarely lead to response errors (i.e. incorrect reactions to the target stimulus), while the error frequency with inconsistent primes can be very high. Both in the response times and in the error rates, the priming effects typically increase with the SOA, resulting in the typical scissor-like course of the effect in diagrams. This means: the later the target stimulus follows the Prime, the more influence the Prime has on the reaction times. With an average response time of 350 to 450 ms, the response priming effect can increase to over 100 ms; it is one of the numerically largest effects of reaction time research.

Fig. 2: Typical response priming effects over time (fictitious data). Consistent primes (blue) reduce the reaction times, inconsistent primes (purple) increase them. In addition, consistent primes very rarely lead to response errors, while the error rate for inconsistent primes can be very high. Both in response times and in error rates, the priming effects typically increase with SOA.

Today it is considered certain that the increase in the effect with SOA is due to the fact that the prime has more and more time to influence the reaction before the actual target stimulus can become effective in the motor. This follows clearly from the analysis of the time course of motor activity in the EEG, in primed pointing movements in force measurements and in simulation studies. The magnitude of the priming effect therefore depends on both the stimulus properties and the properties of the task. Primes with higher stimulus energy (i.e. higher contrast, longer duration, etc.) as well as tasks with simple stimulus discriminations lead to large priming effects, while primes with lower stimulus energy and difficult differentiation tasks lead to smaller effects. Priming effects can be enhanced by visual attention drawn to its position or relevant features in good time before the prime is presented.

The time course described applies to SOAs of up to approx. 100 ms. The effect can increase even further for longer SOAs. Under certain conditions, however, a reversal of the effect can also be observed, in which inconsistent primes lead to faster reactions to the target stimulus than consistent primes. This effect is often referred to as the "negative compatibility effect".

Masked priming

Response priming can be used to study unconscious cognition phenomena . The conscious visibility of the prime can be systematically changed with the help of a masking stimulus, until the prime is completely invisible. This is done by presenting the masking stimulus shortly before or after the prime. The visibility of the prime can be raised by various measures, e.g. B. Forced choice discrimination, detection judgments, brightness judgments and other measures. In many response priming experiments, the target stimulus itself serves to mask the prime (Fig. 1). The so-called metacontrast masking is achieved in that the prime is followed by a mask that surrounds it so that both stimuli have adjacent contours. For example, a circle can be masked by a larger ring whose inner dimensions correspond to the outer dimensions of the circle. Metacontrast is a form of reverse visual masking; H. the visibility of the prime is reduced by the presentation of a subsequent stimulus.

Fig. 3 shows typical masking courses depending on SOA, prime and target stimulus, with the target stimulus also serving as a mask. The discriminatory performance of a test person who has the task of guessing the shape of the prime (diamond or square) in each round could serve as a measure of the conscious visibility of the prime . Without masking, the performance would be practically perfect: the test subject could easily name the prime correctly as a diamond or square in each run. With complete masking of the prime, however, the performance would be at the random level (Fig. 3 left). In many experiments, however, the masking processes are less extreme (Fig. 3 right). The vast majority of experiments lead to what is known as type A masking, which is strongest between prime and mask for a short SOA and decreases with increasing SOA, so that the prime is always easier to distinguish. Under certain conditions, type B masking can also occur, where the masking effect is strongest with medium SOA, but the prime is easier to distinguish with shorter or longer SOAs. Type B masking can mainly occur with metacontrast masking, but is sensitive to the properties of the prime and mask. In addition, the masking process can vary greatly from person to person.

Fig. 3: Typical patterns of reverse masking (fictitious data). When the subject tries to identify the prime, the accuracy of the answer depends on the strength of the prime's masking. Without masking, the Prime can be recognized practically perfectly (purple), while the recognition performance drops to a random level (50%) with complete masking (red) (left figure). Depending on the type of mask, other time courses can also arise (right figure). With what is known as type A masking, the masking effect is greatest when the prime and target stimulus follow one another briefly, and becomes weaker (purple) with increasing SOA. With type B masking, the masking effect is stronger with medium SOAs than with shorter or longer SOAs (red). Type B masking can occur under certain stimulus conditions with metacontrast masking.

Independence from response priming and visual awareness

Experiments show that the time course of the response priming effect (increasing effect with increasing SOA) is independent of the time course of the masking. Klotz and Neumann (1999) demonstrated response priming effects with complete masking of the prime. Vorberg et al. varied the time course of masking by changing the relative duration of primes and target stimuli. Target stimuli were arrows that could point left or right, and primes were smaller arrows that were metacontrast masked by the target stimuli. When the test subjects had to decide in which direction the primes were pointing, all types of masking processes illustrated in Fig. 3 could be generated depending on the condition: complete visibility, complete masking, type A masking and type B masking. However, if the test subjects were to react as quickly as possible to the direction of the target stimulus, almost identical priming effects resulted in all conditions. The time course of these effects was always the same (increasing with the SOA), regardless of whether the primes were completely visible or completely invisible and regardless of whether the visibility increased or decreased with the SOA. Priming effects can therefore increase even if the visibility of the prime decreases. Such opposite time courses of priming and visual awareness of the prime show that both processes are based on different mechanisms. This finding could be confirmed in many other experiments in which numerous dissociations between masking and priming effects emerged. The independence of priming and visual awareness speaks clearly against the traditional view, according to which unconscious priming processes are at best a residual ability that remains to a small extent when the recognizability of the stimuli has fallen below a certain threshold. This view has repeatedly led to sharp criticism of research on unconscious or subliminal perception, but it is believed to be fundamentally wrong. Rather, the motor activation by masked primes is apparently independent of reverse masking processes, provided that the visibility of the primes is only determined by the type of mask, while the prime stimulus itself remains unchanged. That means: visually unconscious (invisible) stimuli can, in a short time interval and under certain conditions, influence motor reactions in the same way as conscious stimuli.

variants

Provided that one is aware of the role of certain influential variables, response priming can be used in numerous experimental variants and to investigate a variety of questions in cognitive psychology . The most frequently used form of uses a prime and a target stimulus at the same screen position, with the target stimulus also serving as a mask (often based on the principle of metacontrast masking). In many experiments, two different target stimuli are also shown at the same time, preceded by two primes in the same positions. The test subject must then differentiate between the two target stimuli and react to the position of the target stimulus relevant to the task. Sometimes three types of stimuli are used (prime, mask, target stimulus), especially if the SOA between prime and target stimulus has to be very long. Sometimes no mask is used at all. Prime and target stimulus do not have to be in the same positions: one stimulus can also flank the other, as is the case in the Eriksen paradigm. As far as we know today, the Eriksen effect could be a special case of response priming.

Response priming effects have been demonstrated with a variety of stimuli and discrimination tasks, including a. geometric stimuli, color stimuli different types of arrows natural images (animals vs. objects), vowels and consonants letters and digits. In one study, chess configurations were presented as primes and target stimuli, and the test subjects had to decide whether the king was in chess. A variety of types of masking have also been used. Some experiments measure, instead of key reactions (which are usually done with two alternative answers), speech reactions, targeted pointing movements, eye movements or so-called readiness potentials, which record the motor activation in the brain and are measured with methods of electroencephalography . Also, imaging techniques such as magnetic resonance imaging are used. Still other experiments use more than two alternative reactions. Mattler (2003) was able to show that response priming can not only influence motor behavior, but also cognitive operations such as shifting spatial attention or switching between reaction time tasks.

Theories

Fig. 4: Basic assumptions of the theory of direct parameter specification and the action trigger approach. If a reaction to the target stimulus has been sufficiently practiced, the reaction can be prepared to such an extent that only a single critical stimulus characteristic is necessary to trigger the reaction. Triggering by the Prime then takes place quickly and directly, without the need for a conscious representation of the stimulus. Parallel to the triggering of the response in the visomotor system, a conscious representation of the prime arises, which, however, can be subject to processes of visual masking and does not play a role in the motor process in the current test run. Newer variants of the theory emphasize the role of the so-called “trigger conditions”, which determine the form in which stimuli and reactions are linked.

Three theories that explain the positive response priming effect are presented below. For an overview of the explanations for the negative compatibility effect, see Sumner (2007).

Direct parameter specification

The theory of direct parameter specification (Fig. 4) was developed by Odmar Neumann at Bielefeld University to explain the Fehrer-Raab effect and the earliest response priming studies. This theory is based on the assumption that at the beginning of the experiment, the test person acquires rules for the stimulus-response assignment, which are available in automated form after a short period of practice . Once this exercise phase has been completed, the reaction can be prepared to such an extent that only a single critical stimulus characteristic (e.g. diamond vs. square) is required to trigger the reaction. This incoming stimulus characteristic then defines the last remaining action parameter ("action parameter", e.g. left vs. right reaction). The action is triggered quickly and directly, without the need for a conscious representation of the stimulus. Response priming is explained by the fact that the prime with its stimulus properties triggers exactly the same processes of direct parameter specification that, according to the instructions, should only occur through the target stimulus. Parallel to the triggering of responses in the visomotor system, a conscious representation of prime and target stimulus arises, which can, however, be subject to processes of visual masking. The conscious representation, however, does not play a role in the motor reaction to primes and target stimuli in the current experiment.

Action trigger approach

The “action trigger account” was developed by Wilfried Kunde , Andrea Kiesel and Joachim Hoffmann at the University of Würzburg. This approach emphasizes that reactions to unconscious stimuli are triggered neither by semantic analysis nor by previously learned stimulus-response associations. Instead, it is assumed that a Prime fits into an existing “action release condition” and thus triggers the reaction, similar to a key that opens a lock. This always happens in two consecutive steps. First, “action triggers” are kept active in working memory for an expected or known task, which are intended to trigger a specific motor reaction. These “action triggers” are formed in the instruction and practice phase of the experiment. In the second step, called "online stimulus processing", a comparison is made to determine whether a displayed stimulus fits into a known scheme. If this is the case, the linked reaction is triggered automatically. An example would be the task of saying whether a given number is greater or less than five: when presenting the numbers “1” to “4” the left button should be pressed, when presenting the numbers “6” to “9” the right button . As a result of the instruction, “action triggers” are formed which automatically trigger the corresponding reaction when the relevant stimulus is presented. An important prediction of this theory is that reactions can also be triggered by primes that never appear as targets themselves, but meet the trigger conditions.

Here, too, the conscious representation of the stimulus does not play a role in the current motor activation; however, it can lead to the fact that reaction criteria are strategically changed in later trials (for example to avoid incorrect answers). Overall, this theory can be understood as a further development of the concept of direct parameter specification.

Rapid Chase Theory

Fig. 4: Schematic representation of the rapid chase theory. Prime and target stimulus deliver a chase through the visomotor system (i.e. from visual to motor areas). Since the prime has a time head start, it can initiate a motor reaction assigned to it and control this reaction the longer the longer the SOA is between prime and target stimulus. When the actual target stimulus then arrives in the motor system, it can either continue the reaction triggered by the prime (consistent condition) or must redirect it (inconsistent condition). The rapid chase theory assumes that the prime and target stimulus trigger waves of neural activity that traverse the visomotor system in strict sequence in the form of feedforward cascades that do not mix or overlap. Therefore, the initial response to the prime must be independent of all properties of the actual target stimulus.

The "Rapid Chase Theory" was presented in 2006 by Thomas Schmidt, Silja Niehaus and Annabel Nagel. It combines the model of direct parameter specification with the observation that newly appearing visual stimuli trigger an activity wave in the visomotor system that spreads rapidly from visual areas to motor areas . As the speed of propagation of this wave of activity is very high, Victor Lamme and Pieter Roelfsema from the University of Amsterdam have proposed that this is initially a pure feedforward process ( feedforward sweep ): a cell that is reached by the wave front must be its own Passing on activity without being able to integrate feedback from other cells beforehand. At the same time, Lamme and Roelfsema assume that such feedforward processing alone is not sufficient to create visual awareness of a stimulus: this requires feedback processes and recurrent (recurring) processing loops that can also connect distant areas of the brain.

According to the rapid chase theory, the prime and target stimulus successively trigger such “feedforward sweeps” that ultimately reach motor areas of the brain. There motor processes are triggered one after the other; here, too, the triggering takes place automatically and without involvement of the conscious mind. Since the prime has a time advantage, the prime and target stimulus deliver a “rapid chase” through the visomotor system. Since the prime signal reaches the motor cortex first, it initiates the motor response associated with it. The shorter the SOA, the earlier the target stimulus signal can start tracking. Only when the target stimulus signal has also arrived in the motor cortex can it continue the motor reaction (if it is consistent with the prime) or redirect it (if it is inconsistent with the prime). This explains why response priming effects increase with SOA: the longer the SOA, the longer the prime can control the reaction on its own, and the further it can steer the reaction process in a certain direction. If necessary, the Prime can also provoke an error (this results in the very frequently observed priming effects in the error rates). Such a process of motor activation by Prime and Target was already described in 2003 by Dirk Vorberg and co-workers in a mathematical model and also agrees with early EEG findings on response priming. According to the rapid chase theory, response priming effects are independent of visual awareness because they are carried by fast feedforward processes, while the creation of a conscious representation depends on slower, recurrent processes.

The most important prediction of the rapid chase theory is that the feedforward sweeps of the prime and target stimuli should be strictly sequential. This strict sequence should be reflected in the time course of the motor responses, and there should be an early period in which the response is controlled solely by the Prime, but is independent of any properties of the actual target stimulus. These predictions can be examined particularly well using the time course of primed pointing movements. Here it can be seen that the pointing movement begins at a fixed time after the appearance of the prime (not the actual target stimulus) and initially takes place in the direction of the prime. If the prime and target stimulus are inconsistent, the target stimulus can reverse the pointing direction "on the fly" and steer it in the right direction; the longer the SOA, the longer and further the finger moves in the direction of the misleading prime. Schmidt, Niehaus and Nagel were able to show that the earliest phase of such primed pointing movements only depends on the properties of the prime (here the color contrast of red versus green primes), but not on the properties of the target stimulus (the time of its appearance, its color contrast or its masking effect) . These findings could be confirmed with various methods and stimuli.

Since the rapid chase theory regards response priming as a feedforward process, it assumes that the priming effects arise before recurrent and feedback processes can intervene in the processing. The theory therefore puts forward the controversial thesis that response priming effects represent a measure of the preconscious processing of visual information, which can differ fundamentally from the representation of the stimuli in visual consciousness.

Individual evidence

^ ^A ^b E. Fehrer, D. Raab: Reaction time to stimuli masked by metacontrast. In: Journal of Experimental Psychology. No. 63, 1962, pp. 143-147.
↑ DA Rosenbaum, S. Kornblum: A priming method for investigating the selection of motor responses. In: Acta Psychologica. No. 51, 1982, pp. 223-243.
↑ ^a ^b ^c ^d W. Klotz, P. Wolff: The effect of a masked stimulus on the response to the masking stimulus. In: Psychological Research. No. 58, 1995, pp. 92-101.
^ ^A ^b ^c ^d ^e W. Klotz, O. Neumann: Motor activation without conscious discrimination in metacontrast masking. In: Journal of Experimental Psychology: Human Perception and Performance. No. 25, 1999, pp. 976-992.
↑ ^a ^b ^c U. Ansorge, W. Klotz, O. Neumann: Manual and verbal responses to completely masked (unreportable) stimuli: Exploring some conditions for the metacontrast dissociation. In: Perception. No. 27, 1998, pp. 1177-1189.
↑ U. Ansorge, O. Neumann, SI Becker, H. Kälberer, H. Kruse: Sensorimotor supremacy: Investigating conscious and unconscious vision by masked priming. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 257-274.
↑ ^a ^b ^c ^d ^e ^f ^g ^h D. Vorberg, U. Mattler, A. Heinecke, T. Schmidt, J. Schwarzbach: Different time courses for visual perception and action priming. In: Proceedings of the National Academy of Sciences USA. No. 100, 2003, pp. 6275-6280.
↑ ^a ^b ^c H. Leuthold, B. Kopp: Mechanisms of priming by masked stimuli: Inferences from event-related brain potentials. In: Psychological Science. No. 9, 1998, pp. 263-269.
↑ ^a ^b ^c ^d M. Eimer, F. Schlaghecken: Effects of masked stimuli on motor activation: Behavioral and electrophysiological evidence. In: Journal of Experimental Psychology: Human Perception and Performance. No. 24, 1998, pp. 1737-1745.
↑ ^a ^b ^c M. Eimer, F. Schlaghecken: Response facilitation and inhibition in subliminal priming. In: Biological Psychology. No. 64, 2003, pp. 7-26.
↑ ^a ^b U. Mattler: Delayed flanker effects on lateralized readiness potentials. In: Experimental Brain Research. No. 151, 2003, pp. 272-288.
↑ ^a ^b ^c ^d N. Vath, T. Schmidt: Tracing sequential waves of rapid visuomotor activation in lateralized readiness potentials. In: Neuroscience. No. 145, 2007, pp. 197-208.
↑ ^a ^b ^c ^d ^e ^f ^g T. Schmidt: The finger in flight: Real-time motor control by visually masked color stimuli. In: Psychological Science. No. 13, 2002, pp. 112-118.
↑ ^a ^b ^c ^d ^e ^f ^g ^h T. Schmidt, S. Niehaus, A. Nagel: Primes and targets in rapid chases: Tracing sequential waves of motor activation. In: Behavioral Neuroscience. No. 120, 2006, pp. 1005-1016.
↑ ^a ^b ^c ^d ^e ^f ^g T. Schmidt, F. Schmidt: Processing of natural images is feedforward: A simple behavioral test. In: Attention, Perception & Psychophysics. No. 71, 2009, pp. 594-606.
^ U. Mattler: Flanker effects on motor output and the late-level response activation hypothesis. In: The Quarterly Journal of Experimental Psychology. No. 58A, 2005, pp. 577-601.
↑ P. Sumner, P.-C. Tsai, K. Yu, P. Nachev: Attentional modulation of sensorimotor processes in the absence of perceptual awareness. In: Proceedings of the National Academy of Sciences USA. No. 103, 2006, pp. 10520-10525.
↑ ^a ^b T. Schmidt, A. Seydell: Visual attention amplifies response priming of pointing movements to color targets. In: Perception & Psychophysics. No. 70, 2008, pp. 443-455.
^ ^A ^b ^c ^d F. Schmidt, T. Schmidt: Feature-based attention to unconscious shapes and colors. In: Attention, Perception, Psychophysics. No. 72, 2010, pp. 1480-1494.
↑ P. Jaskowski: The negative compatibility effect with nonmasking flankers: A case for mask-triggered inhibition hypothesis. In: Consciousness & Cognition. No. 17, 2008, pp. 765-777.
↑ ^a ^b R. Verleger, P. Jaskowski, A. Aydemir, RHJ van der Lubbe, M. Groen: Qualitative differences between conscious and nonconscious processing? On inverse priming induced by masked arrows. In: Journal of Experimental Psychology. No. 133, 2004, pp. 494-515.
^ ^A ^b A. Lingnau, D. Vorberg: The time course of response inhibition in masked priming. In: Perception & Psychophysics. No. 67, 2005, pp. 545-557.
^ ST Klapp, LB Hinkley: The negative compatibility effect: Unconscious inhibition influences reaction time and response selection. In: Journal of Experimental Psychology: General. No. 131, 2002, pp. 255-269.
↑ ^a ^b P. Sumner: Negative and positive masked priming - implications for motor inhibition. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 317-326.
↑ ^a ^b ^c B. G. Breitmeyer, H. Öğmen: Visual masking. In: Scholarpedia. 2 (7), 2007, p. 3330.
^ U. Ansorge, BG Breitmeyer, SI Becker: Comparing sensitivity across different processing measures under metacontrast masking conditions. In: Vision Research. No. 47, 2007, pp. 3335-3349.
↑ U. Ansorge, SI Becker, B. Breitmeyer: Revisiting the metacontrast dissociation: Comparing sensitivity across different measures and tasks. In: Quarterly Journal of Experimental Psychology. No. 62, 2009, pp. 286-309.
↑ ^a ^b B. G. Breitmeyer, H. Öğmen: Visual masking. Oxford University Press, Oxford 2006.
↑ ^a ^b ^c V. DiLollo, JT Enns, RA Rensink: Competition for consciousness among visual events: The psychophysics of re-entrant visual processes. In: Journal of Experimental Psychology: General. No. 129, 2000, pp. 481-507.
^ T. Albrecht, S. Klapötke, U. Mattler: Individual differences in metacontrast masking are enhanced by perceptual learning. In: Consciousness and Cognition. No. 19, 2010, pp. 656-666.
^ T. Schmidt, D. Vorberg: Criteria for unconscious cognition: Three types of dissociation. In: Perception & Psychophysics. No. 68, 2006, pp. 489-504.
↑ ^a ^b B. G. Breitmeyer, T. Ro, NS Singhal: Unconscious color priming occurs at stimulus-not percept-dependent levels of visual processing. In: Psychological Science. No. 15, pp. 198-202.
↑ ^a ^b ^c ^d S. Dehaene, L. Naccache, G. Le Clec'H, E. Koechlin, M. Mueller, G. Dehaene-Lambertz, PF van de Moortele, D. Le Bihan: Imaging unconscious semantic priming. In: Nature. No. 395, 1998, pp. 597-600.
↑ S. Fellows, R. Tabaza, M. Heumann, W. Klotz, O. Neumann, M. Schwarz, J. Noth, R. Topper: Modification of a functional motor task by non-consciously perceived sensory stimuli. In: Neuroreport. No. 13, 2002, pp. 637-640.
↑ ^a ^b A. Kiesel, W. Kunde, C. Pohl, MP Berner, J. Hoffmann: Playing chess unconsciously. In: Journal of Experimental Psychology: Learning, Memory, and Cognition. No. 35, 2009, pp. 292-298.
^ ^A ^b ^c U. Mattler: Priming of mental operations by masked stimuli. In: Perception & Psychophysics. No. 65, 2003, pp. 167-187.
↑ ^a ^b T. Schmidt, S. Miksch, L. Bulganin, F. Jäger, F. Lossin, J. Jochum, P. Kohl: Response priming driven by local contrast, not subjective brightness. In: Attention, Perception & Psychophysics. No. 72, 2010, pp. 1556-1568.
^ CW Eriksen: Discrimination and learning without awareness: A methodological survey and evaluation. In: Psychological Review. No. 67, 1960, pp. 279-300.
↑ D. Holender: Semantic activation without conscious identification in dichotic listening, parafoveal vision, and visual masking: A survey and appraisal. In: Behavioral and Brain Sciences. No. 9, 1986, pp. 1-23.
↑ D. Holender, K. Duscherer: Unconscious perception: The need for a paradigm shift. In: Perception & Psychophysics. No. 66, 2004, pp. 872-881.
↑ P. Cardoso-Leite, A. Gorea: On the perceptual / motor dissociation: A review of concepts, theory, experimental paradigms and data interpretations. In: Seeing and Perceiving. No. 23, 2010, pp. 89-151.
^ F. Schmidt, A. Haberkamp, T. Schmidt: Dos and don'ts in response priming research. In: Advances in Cognitive Psychology. No. 7, 2011, pp. 120-131.
^ T. Schmidt, A. Haberkamp, GM Veltkamp, A. Weber, A. Seydell-Greenwald, F. Schmidt: Visual processing in rapid-chase systems: Image processing, attention, and awareness. In: Frontiers in Psychology. No. 2, 2011, pp. 1-16.
↑ ^a ^b B. A. Eriksen, CW Eriksen: Effects of noise letters upon the identification of a target letter in a nonsearch task. In: Perception & Psychophysics. No. 16, 1974, pp. 143-149.
^ W. Schwarz, A. Mecklinger: Relationship between flanker identifiability and compatibility effect. In: Perception & Psychophysics. No. 57, 1995, pp. 1045-1052.
↑ P. Jaskowski, M. Slosarek: How important is the prime's gestalt for subliminal priming? In: Consciousness & Cognition. No. 16, 2007, p. 485.497.
^ ^A ^b ^c W. Kunde, A. Kiesel, J. Hoffmann: Conscious control over the content of unconscious cognition. In: Cognition. No. 88, 2003, pp. 223-242.
^ J. Schwarzbach, D. Vorberg: Response priming with and without awareness. In: H. Öğmen, BG Meyer (Ed.): The first half second: The microgenesis and temporal dynamics of unconscious and conscious visual processes. MIT Press, Cambridge, MA.
↑ P. Jaskowski, A. Bialunska, M. Tomanek, R. Verleger: Mask- and distractor-triggered inhibitory processes in the priming of motor responses: An EEG study. In: Psychophysiology , No. 45, 2008, pp. 70-85.
↑ ^a ^b O. Neumann: Direct parameter specification and the concept of perception. In: Psychological Research. No. 52, 1990, pp. 207-215.
↑ ^a ^b ^c A. Kiesel, W. Kunde, J. Hoffmann: Mechanisms of subliminal response priming. In: Advances in Cognitive Psychology. No. 1-2, 2007, pp. 307-315.
^ J. Bullier: Integrated model of visual processing. In: Brain Research Reviews. No. 36, 2001, pp. 96-107.
^ ^A ^b ^c V. AF Lamme, PR Roelfsema: The distinct modes of vision offered by feedforward and recurrent processing. In: Trends in Neurosciences. No. 23, 2000, pp. 571-579.
↑ SJ Thorpe, D. Fize, C. Marlot: Speed of processing in the human visual system. In: Nature. No. 381, 1996, pp. 520-522.
↑ R. Vanrullen, SJ Thorpe: Surfing a wave spike down the ventral stream. In: Vision Research. No. 42, pp. 2593-2615.
^ W. Klotz, M. Heumann, U. Ansorge, O. Neumann: Electrophysiological activation by masked primes: Independence of prime-related and target-related activities. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 449-465.

[Fehrer1-1] A ^b E. Fehrer, D. Raab: Reaction time to stimuli masked by metacontrast. In: Journal of Experimental Psychology. No. 63, 1962, pp. 143-147.

[2] DA Rosenbaum, S. Kornblum: A priming method for investigating the selection of motor responses. In: Acta Psychologica. No. 51, 1982, pp. 223-243.

[Klotz3-3] W. Klotz, P. Wolff: The effect of a masked stimulus on the response to the masking stimulus. In: Psychological Research. No. 58, 1995, pp. 92-101.

[Klotz4-4] A ^b ^c ^d ^e W. Klotz, O. Neumann: Motor activation without conscious discrimination in metacontrast masking. In: Journal of Experimental Psychology: Human Perception and Performance. No. 25, 1999, pp. 976-992.

[Ansorge5-5] U. Ansorge, W. Klotz, O. Neumann: Manual and verbal responses to completely masked (unreportable) stimuli: Exploring some conditions for the metacontrast dissociation. In: Perception. No. 27, 1998, pp. 1177-1189.

[6] U. Ansorge, O. Neumann, SI Becker, H. Kälberer, H. Kruse: Sensorimotor supremacy: Investigating conscious and unconscious vision by masked priming. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 257-274.

[Vorberg7-7] ↑ ^a ^b ^c ^d ^e ^f ^g ^h D. Vorberg, U. Mattler, A. Heinecke, T. Schmidt, J. Schwarzbach: Different time courses for visual perception and action priming. In: Proceedings of the National Academy of Sciences USA. No. 100, 2003, pp. 6275-6280.

[Leuthold8-8] H. Leuthold, B. Kopp: Mechanisms of priming by masked stimuli: Inferences from event-related brain potentials. In: Psychological Science. No. 9, 1998, pp. 263-269.

[Eimer9-9] M. Eimer, F. Schlaghecken: Effects of masked stimuli on motor activation: Behavioral and electrophysiological evidence. In: Journal of Experimental Psychology: Human Perception and Performance. No. 24, 1998, pp. 1737-1745.

[Eimer10-10] M. Eimer, F. Schlaghecken: Response facilitation and inhibition in subliminal priming. In: Biological Psychology. No. 64, 2003, pp. 7-26.

[Mattler11-11] U. Mattler: Delayed flanker effects on lateralized readiness potentials. In: Experimental Brain Research. No. 151, 2003, pp. 272-288.

[Vath12-12] N. Vath, T. Schmidt: Tracing sequential waves of rapid visuomotor activation in lateralized readiness potentials. In: Neuroscience. No. 145, 2007, pp. 197-208.

[Schmidt13-13] ↑ ^a ^b ^c ^d ^e ^f ^g T. Schmidt: The finger in flight: Real-time motor control by visually masked color stimuli. In: Psychological Science. No. 13, 2002, pp. 112-118.

[Schmidt14-14] ↑ ^a ^b ^c ^d ^e ^f ^g ^h T. Schmidt, S. Niehaus, A. Nagel: Primes and targets in rapid chases: Tracing sequential waves of motor activation. In: Behavioral Neuroscience. No. 120, 2006, pp. 1005-1016.

[Schmidt15-15] ↑ ^a ^b ^c ^d ^e ^f ^g T. Schmidt, F. Schmidt: Processing of natural images is feedforward: A simple behavioral test. In: Attention, Perception & Psychophysics. No. 71, 2009, pp. 594-606.

[16] U. Mattler: Flanker effects on motor output and the late-level response activation hypothesis. In: The Quarterly Journal of Experimental Psychology. No. 58A, 2005, pp. 577-601.

[17] P. Sumner, P.-C. Tsai, K. Yu, P. Nachev: Attentional modulation of sensorimotor processes in the absence of perceptual awareness. In: Proceedings of the National Academy of Sciences USA. No. 103, 2006, pp. 10520-10525.

[Schmidt18-18] T. Schmidt, A. Seydell: Visual attention amplifies response priming of pointing movements to color targets. In: Perception & Psychophysics. No. 70, 2008, pp. 443-455.

[Schmidt19-19] A ^b ^c ^d F. Schmidt, T. Schmidt: Feature-based attention to unconscious shapes and colors. In: Attention, Perception, Psychophysics. No. 72, 2010, pp. 1480-1494.

[Jaskowski20-20] P. Jaskowski: The negative compatibility effect with nonmasking flankers: A case for mask-triggered inhibition hypothesis. In: Consciousness & Cognition. No. 17, 2008, pp. 765-777.

[Verleger21-21] R. Verleger, P. Jaskowski, A. Aydemir, RHJ van der Lubbe, M. Groen: Qualitative differences between conscious and nonconscious processing? On inverse priming induced by masked arrows. In: Journal of Experimental Psychology. No. 133, 2004, pp. 494-515.

[Lingnau22-22] A ^b A. Lingnau, D. Vorberg: The time course of response inhibition in masked priming. In: Perception & Psychophysics. No. 67, 2005, pp. 545-557.

[Klapp23-23] ST Klapp, LB Hinkley: The negative compatibility effect: Unconscious inhibition influences reaction time and response selection. In: Journal of Experimental Psychology: General. No. 131, 2002, pp. 255-269.

[Sumner24-24] P. Sumner: Negative and positive masked priming - implications for motor inhibition. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 317-326.

[Breitmeyer25-25] B. G. Breitmeyer, H. Öğmen: Visual masking. In: Scholarpedia. 2 (7), 2007, p. 3330.

[Ansorge26-26] U. Ansorge, BG Breitmeyer, SI Becker: Comparing sensitivity across different processing measures under metacontrast masking conditions. In: Vision Research. No. 47, 2007, pp. 3335-3349.

[Ansorge27-27] U. Ansorge, SI Becker, B. Breitmeyer: Revisiting the metacontrast dissociation: Comparing sensitivity across different measures and tasks. In: Quarterly Journal of Experimental Psychology. No. 62, 2009, pp. 286-309.

[Breitmeyer28-28] B. G. Breitmeyer, H. Öğmen: Visual masking. Oxford University Press, Oxford 2006.

[Dilollo29-29] V. DiLollo, JT Enns, RA Rensink: Competition for consciousness among visual events: The psychophysics of re-entrant visual processes. In: Journal of Experimental Psychology: General. No. 129, 2000, pp. 481-507.

[Albrecht30-30] T. Albrecht, S. Klapötke, U. Mattler: Individual differences in metacontrast masking are enhanced by perceptual learning. In: Consciousness and Cognition. No. 19, 2010, pp. 656-666.

[Schmidt31-31] T. Schmidt, D. Vorberg: Criteria for unconscious cognition: Three types of dissociation. In: Perception & Psychophysics. No. 68, 2006, pp. 489-504.

[Breitmeyer32-32] B. G. Breitmeyer, T. Ro, NS Singhal: Unconscious color priming occurs at stimulus-not percept-dependent levels of visual processing. In: Psychological Science. No. 15, pp. 198-202.

[Dehaene33-33] S. Dehaene, L. Naccache, G. Le Clec'H, E. Koechlin, M. Mueller, G. Dehaene-Lambertz, PF van de Moortele, D. Le Bihan: Imaging unconscious semantic priming. In: Nature. No. 395, 1998, pp. 597-600.

[Fellows34-34] S. Fellows, R. Tabaza, M. Heumann, W. Klotz, O. Neumann, M. Schwarz, J. Noth, R. Topper: Modification of a functional motor task by non-consciously perceived sensory stimuli. In: Neuroreport. No. 13, 2002, pp. 637-640.

[Kiesel35-35] A. Kiesel, W. Kunde, C. Pohl, MP Berner, J. Hoffmann: Playing chess unconsciously. In: Journal of Experimental Psychology: Learning, Memory, and Cognition. No. 35, 2009, pp. 292-298.

[Mattler36-36] A ^b ^c U. Mattler: Priming of mental operations by masked stimuli. In: Perception & Psychophysics. No. 65, 2003, pp. 167-187.

[Schmidt37-37] T. Schmidt, S. Miksch, L. Bulganin, F. Jäger, F. Lossin, J. Jochum, P. Kohl: Response priming driven by local contrast, not subjective brightness. In: Attention, Perception & Psychophysics. No. 72, 2010, pp. 1556-1568.

[Eriksen38-38] CW Eriksen: Discrimination and learning without awareness: A methodological survey and evaluation. In: Psychological Review. No. 67, 1960, pp. 279-300.

[Holender39-39] D. Holender: Semantic activation without conscious identification in dichotic listening, parafoveal vision, and visual masking: A survey and appraisal. In: Behavioral and Brain Sciences. No. 9, 1986, pp. 1-23.

[Holender40-40] D. Holender, K. Duscherer: Unconscious perception: The need for a paradigm shift. In: Perception & Psychophysics. No. 66, 2004, pp. 872-881.

[Cardoso41-41] P. Cardoso-Leite, A. Gorea: On the perceptual / motor dissociation: A review of concepts, theory, experimental paradigms and data interpretations. In: Seeing and Perceiving. No. 23, 2010, pp. 89-151.

[Schmidt16-42] F. Schmidt, A. Haberkamp, T. Schmidt: Dos and don'ts in response priming research. In: Advances in Cognitive Psychology. No. 7, 2011, pp. 120-131.

[Schmidt17-43] T. Schmidt, A. Haberkamp, GM Veltkamp, A. Weber, A. Seydell-Greenwald, F. Schmidt: Visual processing in rapid-chase systems: Image processing, attention, and awareness. In: Frontiers in Psychology. No. 2, 2011, pp. 1-16.

[Eriksen42-44] B. A. Eriksen, CW Eriksen: Effects of noise letters upon the identification of a target letter in a nonsearch task. In: Perception & Psychophysics. No. 16, 1974, pp. 143-149.

[Schwarz43-45] W. Schwarz, A. Mecklinger: Relationship between flanker identifiability and compatibility effect. In: Perception & Psychophysics. No. 57, 1995, pp. 1045-1052.

[Jaskowski44-46] P. Jaskowski, M. Slosarek: How important is the prime's gestalt for subliminal priming? In: Consciousness & Cognition. No. 16, 2007, p. 485.497.

[Kunde45-47] A ^b ^c W. Kunde, A. Kiesel, J. Hoffmann: Conscious control over the content of unconscious cognition. In: Cognition. No. 88, 2003, pp. 223-242.

[Schwarzbach46-48] J. Schwarzbach, D. Vorberg: Response priming with and without awareness. In: H. Öğmen, BG Meyer (Ed.): The first half second: The microgenesis and temporal dynamics of unconscious and conscious visual processes. MIT Press, Cambridge, MA.

[Jaskowski47-49] P. Jaskowski, A. Bialunska, M. Tomanek, R. Verleger: Mask- and distractor-triggered inhibitory processes in the priming of motor responses: An EEG study. In: Psychophysiology , No. 45, 2008, pp. 70-85.

[Neumann48-50] O. Neumann: Direct parameter specification and the concept of perception. In: Psychological Research. No. 52, 1990, pp. 207-215.

[Kiesel49-51] A. Kiesel, W. Kunde, J. Hoffmann: Mechanisms of subliminal response priming. In: Advances in Cognitive Psychology. No. 1-2, 2007, pp. 307-315.

[Bullier50-52] J. Bullier: Integrated model of visual processing. In: Brain Research Reviews. No. 36, 2001, pp. 96-107.

[Lamme51-53] A ^b ^c V. AF Lamme, PR Roelfsema: The distinct modes of vision offered by feedforward and recurrent processing. In: Trends in Neurosciences. No. 23, 2000, pp. 571-579.

[Thorpe52-54] SJ Thorpe, D. Fize, C. Marlot: Speed of processing in the human visual system. In: Nature. No. 381, 1996, pp. 520-522.

[vanRullen53-55] R. Vanrullen, SJ Thorpe: Surfing a wave spike down the ventral stream. In: Vision Research. No. 42, pp. 2593-2615.

[Klotz54-56] W. Klotz, M. Heumann, U. Ansorge, O. Neumann: Electrophysiological activation by masked primes: Independence of prime-related and target-related activities. In: Advances in Cognitive Psychology. No. 3, 2007, pp. 449-465.