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1.  Encoding strategy affects false recall and recognition: Evidence from categorical study material 
The present research investigated memory vulnerability to distortions. Different encoding strategies were used when categorized lists were studied. The authors assumed that an imagery strategy would be responsible for decreasing false memories more than a word-whispering strategy, which is consistent with the model of semantic access and previous research in the Deese-Roediger-McDermott paradigm (the DRM paradigm; Deese, 1959; Roediger & McDermott, 1995). A normative study of category lists and 4 experiments were conducted to verify the memory vulnerability to different encoding strategies (imagery, word-whispering, control). Half of subjects recalled and half recognized previously studied words. The results revealed a marked reduction in false recognition and recall after imagery encoding, relative to after word-whispering encoding.
PMCID: PMC3664540  PMID: 23717349
false memory; imagery encoding; categorical study lists; mnemonic strategies
2.  Early dynamics of the semantic priming shift 
Semantic processing of sequences of words requires the cognitive system to keep several word meanings simultaneously activated in working memory with limited capacity. The real- time updating of the sequence of word meanings relies on dynamic changes in the associates to the words that are activated. Protocols involving two sequential primes report a semantic priming shift from larger priming of associates to the first prime to larger priming of associates to the second prime, in a range of long SOAs (stimulus-onset asynchronies) between the second prime and the target. However, the possibility for an early semantic priming shift is still to be tested, and its dynamics as a function of association strength remain unknown. Three multiple priming experiments are proposed that cross-manipulate association strength between each of two successive primes and a target, for different values of short SOAs and prime durations. Results show an early priming shift ranging from priming of associates to the first prime only to priming of strong associates to the first prime and all of the associates to the second prime. We investigated the neural basis of the early priming shift by using a network model of spike frequency adaptive cortical neurons (e.g., Deco & Rolls, 2005), able to code different association strengths between the primes and the target. The cortical network model provides a description of the early dynamics of the priming shift in terms of pro-active and retro-active interferences within populations of excitatory neurons regulated by fast and unselective inhibitory feedback.
PMCID: PMC3664541  PMID: 23717346
association strength; concept; interstimulus interval; multiple priming; prime duration
3.  Retrospective perceptual distortion of position representation does not lead to delayed localization 
Previous studies have reported retrospective influences of visual events that occur after target events. In the attentional attraction effect, a position cue presented after a target stimulus distorts the target’s position towards that of the cue. The present study explored the temporal relationship between stimulus presentation and reaction time (RT) in this effect in two experiments. Participants performed a speeded localization task on two vertical lines, the positions of which were to be distorted by an additional attentional cue. No significant difference in RTs was found between the conditions with simultaneous and delayed cues. RTRT was modulated by the perceived (rather than physical) alignment of the lines. In Experiment 2, we manipulated the strength of attentional capture by modulating the color relevance of the cue to the target. Trials with cues producing stronger attentional capture (with cues of a different color from the targets) were found to induce apparently stronger distortion effects. This result favors the notion that the observed repulsion and attraction effects are driven by attentional mechanisms. Overall, the results imply that the attentional shift induced by the cue might occur rapidly and complete before the establishment of conscious location representation of the cue and the target without affecting overall response time.
PMCID: PMC3664542  PMID: 23717348
attention; distortion; reaction time; retrospective; space
4.  Number perseveration in healthy subjects: Does prolonged stimulus exposure influence performance on a serial addition task? 
Perseverative behavior characterizes mainly patients with severe psychopathology, but it can also be observed in healthy individuals. The aim of the reported experiment was to investigate a serial addition task that elicits strong perseverative behavior in normal subjects by examining the significance of perseveration in the final step of this addition task (Gardner, 1971) as a function of time availability. The classical serial addition task, which was used in the experiment, consisted of 4 consecutive digit decreases in the added numbers following a constant digit (1,000 + 40 + 1,000 + 30 + 1,000 + 20 + 1,000 + 10) and required an additive calculation. The main questions were how and if color and time variations could influence perseverative responses in this task and whether memory performance and relevant mathematical knowledge of the participants could have an effect on responses. The sample of subjects participating in the experiment consisted of 300 healthy university students (112 male, 188 female) ranging from 17 to 40 years of age. They were divided in 5 groups of 60 subjects each. A memory digit span and spatial test were administered and relevant scores were taken for each subject of the 5 groups. Obtained results suggest the presence of a strong perseverative error in the final step of the presentation of digits for the large majority of subjects and for all 5 conditions. It seems that time and color changes and the memory span of the participants have no detectable effect on performance on this specific serial addition task.
PMCID: PMC3664543  PMID: 23717347
perseveration; serial addition task; color variation; time variation
5.  Confidence intervals for two sample means: Calculation, interpretation, and a few simple rules 
Valued by statisticians, enforced by editors, and confused by many authors, standard errors (SEs) and confidence intervals (CIs) remain a controversial issue in the psychological literature. This is especially true for the proper use of CIs for within-subjects designs, even though several recent publications elaborated on possible solutions for this case. The present paper presents a short and straightforward introduction to the basic principles of CI construction, in an attempt to encourage students and researchers in cognitive psychology to use CIs in their reports and presentations. Focusing on a simple but prevalent case of statistical inference, the comparison of two sample means, we describe possible CIs for between- and within-subjects designs. In addition, we give hands-on examples of how to compute these CIs and discuss their relation to classical t-tests.
PMCID: PMC3699740  PMID: 23826038
confidence intervals; graphical data presentation; repeated measures; within-subjects designs; between-subjects designs
6.  Visual movement perception in deaf and hearing individuals 
A number of studies have investigated changes in the perception of visual motion as a result of altered sensory experiences. An animal study has shown that auditory-deprived cats exhibit enhanced performance in a visual movement detection task compared to hearing cats (Lomber, Meredith, & Kral, 2010). In humans, the behavioural evidence regarding the perception of motion is less clear. The present study investigated deaf and hearing adult participants using a movement localization task and a direction of motion task employing coherently-moving and static visual dot patterns. Overall, deaf and hearing participants did not differ in their movement localization performance, although within the deaf group, a left visual field advantage was found. When discriminating the direction of motion, however, deaf participants responded faster and tended to be more accurate when detecting small differences in direction compared with the hearing controls. These results conform to the view that visual abilities are enhanced after auditory deprivation and extend previous findings regarding visual motion processing in deaf individuals.
PMCID: PMC3699779  PMID: 23826037
deafness; cross-modal plasticity; localization of motion; direction of motion
7.  Attentional capture by emotional faces in adolescence 
Poor decision making during adolescence occurs most frequently when situations are emotionally charged. However, relatively few studies have measured the development of cognitive control in response to emotional stimuli in this population. This study used both affective (emotional faces) and non-affective (letter) stimuli in two different flanker tasks to assess the ability to ignore task-irrelevant but distracting information, in 25 adults and 25 adolescents. On the non-emotional (letter) flanker task, the presence of incongruent flanking letters increased the number of errors, and also slowed participants’ ability to identify a central letter. Adolescents committed more errors than adults, but there were no age-related differences for the reaction time interference effect in the letter condition. Post-hoc testing revealed that age-related differences on the task were driven by the younger adolescents (11-14 years); adults and older adolescents (15-17 years) were equally accurate in the letter condition. In contrast, on the emotional face flanker task, not only were adolescents less accurate than adults but they were also more distracted by task-irrelevant fearful faces as evidenced by greater reaction time interference effects. Our findings suggest that the ability to self-regulate in adolescents, as evidenced by the ability to suppress irrelevant information on a flanker task, is more difficult when stimuli are affective in nature. The ability to ignore irrelevant flankers appears to mature earlier for non-affective stimuli than for affective stimuli.
PMCID: PMC3699780  PMID: 23826039
adolescence; cognitive control; flanker task; affective; non-affective; risk taking
8.  Mental rotation performance in soccer players and gymnasts in an object-based mental rotation task 
In this study, the effect of motor expertise on an object-based mental rotation task was investigated. 60 males and 60 females (40 soccer players, 40 gymnasts, and 40 non-athletes, equivalent males and females in each group) solved a psychometric mental rotation task with both cube and human figures. The results revealed that all participants had a higher mental rotation accuracy for human figures compared to cubed figures, that the gender difference was reduced with human figures, and that gymnasts demonstrated a better mental rotation performance than non-athletes. The results are discussed against the background of the existing literature on motor experts, mental rotation performance as well as the importance of the testing situation and the test construction.
PMCID: PMC3700661  PMID: 23833695
embodied cognition; motor expertise; gender effect; rotational experts
9.  Does the athletes’ body shape the athletes’ mind? A few ideas on athletes’ mental rotation performance. Commentary on Jansen and Lehmann 
Athletes exhibit differences in perceptual-cognitive abilities when compared to non-athletes. Recent theoretical developments focus on the role of the athletes’ body in perceptual-cognitive tasks such as mental rotation tasks. It is assumed that the degree to which stimuli in mental rotation tasks can be embodied facilitates the mental rotation process. The implications of this assumption are discussed and ideas for future research are presented.
PMCID: PMC3700736  PMID: 23833696
embodiment; mental simulation; congruency effect
10.  Advances in experimental psychopatholinguistics: What can we learn from simulation of disorder-like symptoms in human volunteers? 
Advances in Cognitive Psychology  2013;9(2):102-111.
For more than a century, work on patients with acquired or developmental language disorders has informed psycholinguistic models of normal linguistic processing in healthy persons. On the other hand, such models of healthy language processing have been used as blue-prints to gain further insights into the impairments of patients with language pathologies. Against the exemplary background of language production, the first part of this paper reflects this relationship and formulates a desideratum for naturalistic albeit controlled experimental settings. Two recent examples of behavioural and neurofunctional research are presented in which aphasia-like speech symptoms were elicited in healthy control subjects. In the second part, this idea to investigate disorder-like symptoms which are being experimentally induced for the course of the study is further pursued in the field of reading and dyslexia research. Here, it is argued, again on the basis of behavioural and neurofunctional data, that such an approach is advantageous in at least two respects:
1. It allows a much more stringent control of experimental factors and confounds than could be potentially achieved in a clinical setting.
2. It allows in-extenso piloting of experiments with healthy volunteers before actually recruiting selected (and sometimes rare) patients.
It will be concluded that the experimental simulation of disorder-like symptoms in easily accessible healthy volunteers may be a useful approach to understand novel aspects of a language disorder on the basis of a human neurocognitive model of this disorder.
PMCID: PMC3700744  PMID: 23833697
aphasia; dyslexia; errors; simulation; language
11.  Emergence of spontaneous anticipatory hand movements in a probabilistic environment 
In this article, we present a novel experimental approach to the study of anticipation in probabilistic cuing. We implemented a modified spatial cuing task in which participants made an anticipatory hand movement toward one of two probabilistic targets while the (x, y)-computer mouse coordinates of their hand movements were sampled. This approach allowed us to tap into anticipatory processes as they occurred, rather than just measuring their behavioral outcome through reaction time to the target. In different conditions, we varied the participants’ degree of certainty of the upcoming target position with probabilistic pre-cues. We found that participants initiated spontaneous anticipatory hand movements in all conditions, even when they had no information on the position of the upcoming target. However, participants’ hand position immediately before the target was affected by the degree of certainty concerning the target’s position. This modulation of anticipatory hand movements emerged rapidly in most participants as they encountered a constant probabilistic relation between a cue and an upcoming target position over the course of the experiment. Finally, we found individual differences in the way anticipatory behavior was modulated with an uncertain/neutral cue. Implications of these findings for probabilistic spatial cuing are discussed.
PMCID: PMC3700745  PMID: 23833694
anticipation; prediction; probabilistic spatial cuing; statistical learning; computer mouse tracking
12.  Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind 
Theory of Mind (ToM) is the ability to infer other people’s mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM.
PMCID: PMC3709103  PMID: 23853676
fMRI; affective and cognitive theory of mind; ToM; mentalizing; basal ganglia; simulation; social cognition
13.  Attitudes and cognitive distances: On the non-unitary and flexible nature of cognitive maps 
Advances in Cognitive Psychology  2013;9(3):121-129.
Spatial relations of our environment are represented in cognitive maps. These cognitive maps are prone to various distortions (e.g., alignment and hierarchical effects) caused by basic cognitive factors (such as perceptual and conceptual reorganization) but also by affectively loaded and attitudinal influences. Here we show that even differences in attitude towards a single person representing a foreign country (here Barack Obama and the USA) can be related to drastic differences in the cognitive representation of distances concerning that country. Europeans who had a positive attitude towards Obama’s first presidential program estimated distances between US and European cities as being much smaller than did people who were skeptical or negative towards Obama’s ideas. On the basis of this result and existing literature, arguments on the non-unitary and flexible nature of cognitive maps are discussed.
PMCID: PMC3783936  PMID: 24155860
cognitive geography; cognitive distortions; cognitive map; heuristics; social attitudes; continental drift; Obama; mental wall; distance estimations; distortion; bias
14.  More than meets the eye: The attentional blink in multisensory environments. Commentary on Kranczioch and Thorne 
Advances in Cognitive Psychology  2013;9(3):143-145.
Temporal fluctuations of attention can influence performance of cognitive tasks substantially. A common paradigm to investigate temporal fluctuations of attention is the attentional blink paradigm. Kranczioch and Thorne (2013) report new evidence for the impact of auditory stimuli on the visual attentional blink in the current issue of Advances in Cognitive Psychology.
PMCID: PMC3783935  PMID: 24155862
attentional blink; cross-modal; auditory-visual; reliability
15.  An orienting response is not enough: Bivalency not infrequency causes the bivalency effect 
Advances in Cognitive Psychology  2013;9(3):146-155.
When switching tasks, occasionally responding to bivalent stimuli (i.e., stimuli with relevant features for two different tasks) slows performance on subsequent univalent stimuli, even when they do not share relevant features with bivalent stimuli. This performance slowing is labelled the bivalency effect. Here, we investigated whether the bivalency effect results from an orienting response to the infrequent stimuli (i.e., the bivalent stimuli). To this end, we compared the impact of responding to infrequent univalent stimuli to the impact of responding to infrequent bivalent stimuli. For the latter, the results showed a performance slowing for all trials following bivalent stimuli. This indicates a long-lasting bivalency effect, replicating previous findings. For infrequent univalent stimuli, however, the results showed a smaller and shorter-lived performance slowing. These results demonstrate that the bivalency effect does not simply reflect an orienting response to infrequent stimuli. Rather it results from the conflict induced by bivalent stimuli, probably by episodic binding with the more demanding context created by them.
PMCID: PMC3783937  PMID: 24155863
bivalent stimuli; task switching; cognitive control; episodic context binding
16.  Simultaneous and preceding sounds enhance rapid visual targets: Evidence from the attentional blink 
Advances in Cognitive Psychology  2013;9(3):130-142.
Presenting two targets in a rapid visual stream will frequently result in the second target (T2) being missed when presented shortly after the first target (T1). This so-called attentional blink (AB) phenomenon can be reduced by various experimental manipulations. This study investigated the effect of combining T2 with a non-specific sound, played either simultaneously with T2 or preceding T2 by a fixed latency. The reliability of the observed effects and their correlation with potential predictors were studied. The tone significantly improved T2 identification rates regardless of tone condition and of the delay between targets, suggesting that the crossmodal facilitation of T2 identification is not limited to visual-perceptual enhancement. For the simultaneous condition, an additional time-on-task effect was observed in form of a reduction of the AB that occurred within an experimental session. Thus, audition-driven enhancement of visual perception may need some time for its full potential to evolve. Split-half and test-retest reliability were found consistently only for a condition without additional sound. AB magnitude obtained in this condition was related to AB magnitudes obtained in both sound conditions. Self-reported distractibility and performance in tests of divided attention and of cognitive flexibility correlated with the AB magnitudes of a subset but never all conditions under study. Reliability and correlation results suggest that not only dispositional abilities but also state factors exert an influence on AB magnitude. These findings extend earlier work on audition-driven enhancement of target identification in the AB and on the reliability and behavioural correlates of the AB.
PMCID: PMC3783938  PMID: 24155861
attentional blink; sound; tone; practice; crossmodal facilitation; reliability
17.  Insights into sleep's role for insight: Studies with the number reduction task 
Advances in Cognitive Psychology  2013;9(4):160-172.
In recent years, vibrant research has developed on “consolidation” during sleep: To what extent are newly experienced impressions reprocessed or even restructured during sleep? We used the number reduction task (NRT) to study if and how sleep does not only reiterate new experiences but may even lead to new insights. In the NRT, covert regularities may speed responses. This implicit acquisition of regularities may become explicitly conscious at some point, leading to a qualitative change in behavior which reflects this insight. By applying the NRT at two consecutive sessions separated by an interval, we investigated the role of sleep in this interval for attaining insight at the second session. In the first study, a night of sleep was shown to triple the number of participants attaining insight above the base rate of about 20%. In the second study, this hard core of 20% discoverers differed from other participants in their task-related EEG potentials from the very beginning already. In the third study, the additional role of sleep was specified as an effect of the deep-sleep phase of slow-wave sleep on participants who had implicitly acquired the covert regularity before sleep. It was in these participants that a specific increase of EEG during slow-wave sleep in the 10-12 Hz band was obtained. These results support the view that neuronal memory reprocessing during slow-wave sleep restructures task-related representations in the brain, and that such restructuring promotes the gain of explicit knowledge.
PMCID: PMC3902672  PMID: 24605175
sleep; insight; implicit learning; explicit knowledge; EEG; ERPs
18.  Editorial to the special issue Neuronus 
Advances in Cognitive Psychology  2013;9(4):156-159.
Did you visit the Neuronus conferences in the years 2012 and 2013 in Kraków? If not, then you certainly should have a close examination of this special issue including this introduction to at least have a glimpse of an idea of the highly interesting topics in the field of cognitive neuroscience that were presented at these conferences. If you were there, it is for sure a good choice to focus on this special issue as well, first to refresh your minds (we know our memories are far from perfect), but especially to see what happened with research of the presenters at these conferences.
PMCID: PMC3902697  PMID: 24605174
right ear advantage; attention; EEG; beta band; visual word form area; disorders of consciousness; functional connectivity; default mode network; DTI; structural connectivity; MUC model; N400; neural oscillations; schizophrenia; insight; sleep; social cognition; lateralized power spectra; motion-based Simon effect; reaction time distribution; Adolf Beck
19.  The building blocks of social communication 
Advances in Cognitive Psychology  2013;9(4):173-183.
In the present review, social communication will be discussed in the context of social cognition, and cold and hot cognition. The review presents research on prosody, processing of faces, multimodal processing of voice and face, and the impact of emotion on constructing semantic meaning. Since the focus of this mini review is on brain processes involved in these cognitive functions, the bulk of evidence presented will be from event related potential (ERP) studies as this methodology offers the best temporal resolution of cognitive events under study. The argument is made that social communication is accomplished via fast acting sensory processes and later, top down processes. Future directions both in terms of methodology and research questions are also discussed.
PMCID: PMC3902830  PMID: 24605176
social cognition; ERP; social communication
20.  Lateralized power spectra of the EEG as an index of visuospatial attention 
Advances in Cognitive Psychology  2013;9(4):184-201.
The electroencephalogram (EEG) was measured in an endogenous orienting paradigm where symbolic cues indicated the likely side of to-be-discriminated targets. Combined results of event-related lateralizations (ERLs) and a newly derived measure from wavelet analyses that we applied on the raw EEG and individual event-related potentials (ERPs), the lateralized power spectra (LPS) and the LPS-ERP, respectively, confirmed the common view that endogenous orienting operates by anterior processes, probably originating from the frontal eye fields, modulating processing in parietal and occipital areas. The LPS data indicated that modulation takes place by increased inhibition of the irrelevant visual field and/or disinhibition of the relevant to-be-attended visual field. Combined use of ERLs, the LPS, and the LPS-ERP indicated that most of the involved processes can be characterized as externally evoked, either or not with clear individual differences as some evoked effects were only visible in the LPS-ERERP, whereas few processes seemed to have an internally induced nature. Use of the LPS and the LPS-ERP may be advantageous as it enables to determine the involvement of internally generated lateralized processes that are not strictly bound to an event like stimulus onset.
PMCID: PMC3902831  PMID: 24605177
visuospatial attention; inhibition; ERPs; ERLs; wavelets
21.  Adolf Beck: A pioneer in electroencephalography in between Richard Caton and Hans Berger 
Advances in Cognitive Psychology  2013;9(4):216-221.
Adolf Beck, born in 1863 in Kraków (Poland), joined the Department of Physiology of the Jagiellonian University in 1889, to work directly under the prominent professor in physiology Napoleon Cybulski. Following his suggestion, Beck started studies on the electrical brain activity of animals. He recorded negative electrical potentials in several brain areas evoked by peripheral sensory impulses. Using this technique, Beck localised various centres in the brain of several animal species. In doing this, he discovered continuous electrical oscillations in the electrical brain activity and noted that these oscillations ceased after sensory stimulation. This was the first description of desynchronization in electrical brain potentials. He published these findings in 1890 in the German Centralblatt für Physiologie. Immediately, an intense discussion arose under physiologists on the question who could claim being the founder of electroencephalography. Ultimately, Richard Caton from Liverpool showed that he had performed similar experiments in monkeys years earlier. Nevertheless, Beck added several new elements to the nature of electrical brain activity, such as evoked potentials and desynchronization. In looking back, Adolf Beck can be regarded, next to Richard Caton and together with Hans Berger (who later introduced the electrical brain recording method to humans), as one of the founders of electroencephalography.
PMCID: PMC3902832  PMID: 24605179
Adolf Beck; pioneer in electroencephalography; spontaneous oscillations; evoked potentials; desynchronization of brain waves; Richard Caton; Hans Berger
22.  Space positional and motion SRC effects: A comparison with the use of reaction time distribution analysis 
Advances in Cognitive Psychology  2013;9(4):202-215.
The analysis of reaction time (RT) distributions has become a recognized standard in studies on the stimulus response correspondence (SRC) effect as it allows exploring how this effect changes as a function of response speed. In this study, we compared the spatial SRC effect (the classic Simon effect) with the motion SRC effect using RT distribution analysis. Four experiments were conducted, in which we manipulated factors of space position and motion for stimulus and response, in order to obtain a clear distinction between positional SRC and motion SRC. Results showed that these two types of SRC effects differ in their RT distribution functions as the space positional SRC effect showed a decreasing function, while the motion SRC showed an increasing function. This suggests that different types of codes underlie these two SRC effects. Potential mechanisms and processes are discussed.
PMCID: PMC3902833  PMID: 24605178
stimulus-response correspondence; Simon effect; space positional SRC effect; motion SRC effect; RTRT distribution analysis
23.  Dissociating effects of subclinical anxiety and depression on cognitive control 
Even at subclinical levels, anxiety and depression are associated with impaired cognitive control. It is unclear, though, to what extent these deficits reflect a common underlying dysfunction. Using a non-affective hybrid masked prime-Simon task, we obtained several measures of within- and between- trial inhibitory behavioral control in 80 young, healthy volunteers, together with measures of their anxiety and depression levels. Neither depression nor anxiety affected low-level within-trial control, or any of the between-trial control measures. However, increased levels of depression, but not of anxiety, were associated with impaired high-level within-trial control (increased Simon effect). Results indicate that depression, but not anxiety, impairs voluntary online response-control mechanisms independent of affective content.
PMCID: PMC3303107  PMID: 22419965
cognitive control; inhibition; subclinical depression; subclinical anxiety; hybrid masked prime-Simon task
24.  Time-course of hemispheric preference for processing contralateral relevant shapes: P1pc, N1pc, N2pc, N3pc 
A most sensitive and specific electrophysiological indicator of selective processing of visual stimuli is the N2pc component. N2pc is a negative EEG potential peaking 250 ms after stimulus onset, recorded from posterior sites contralateral to relevant stimuli. Additional deflections preceding or following N2pc have been obtained in previous studies, possibly produced by specific stimulus features or specific prime-target sequences. To clarify the entire time-course of the contralateral- ipsilateral (C-I) difference recorded from the scalp above visual cortex in response to left-right pairs of targets and distracters, C-I differences were here compared between two types of stimuli and between stimuli that were or were not preceded by masked neutral primes. The C-I difference waveform consisted of several peaks, termed here P1pc (60-100 ms after target onset), N1pc (120-160 ms), N2pc (220-280 ms), and N3pc (360-400 ms). Being markedly enhanced when stimuli were preceded by the neutral primes, P1pc may indicate a response to stimulus change. Also, when stimuli were primed, N2pc reached its peak earlier, thereby tending to merge with N1pc. N3pc seemed to increase when target discrimination was difficult. N1pc, N2pc, and N3pc appear as three periods of one process. N3pc probably corresponds to L400 or SPCN as described in other studies. These observations suggest that the neurophysiological basis of stimulus-driven focusing of attention on target stimuli is a process that lasts for hundreds of milliseconds, with the relevant hemisphere being activated in an oscillating manner as long as required by the task.
PMCID: PMC3303108  PMID: 22419963
N2pc; attention; event-related potentials; P1pc; N1pc; N3pc; SPCN
25.  Attentional sensitization of unconscious visual processing: Top-down influences on masked priming 
Classical theories of automaticity assume that automatic processes elicited by unconscious stimuli are autonomous and independent of higher-level cognitive influences. In contrast to these classical conceptions, we argue that automatic processing depends on attentional amplification of task-congruent processing pathways and propose an attentional sensitization model of unconscious visual processing: According to this model, unconscious visual processing is automatic in the sense that it is initiated without deliberate intention. However, unconscious visual processing is susceptible to attentional top-down control and is only elicited if the cognitive system is configured accordingly. In this article, we describe our attentional sensitization model and review recent evidence demonstrating attentional influences on subliminal priming, a prototypical example of an automatic process. We show that subliminal priming (a) depends on attentional resources, (b) is susceptible to stimulus expectations, (c) is influenced by action intentions, and (d) is modulated by task sets. These data suggest that attention enhances or attenuates unconscious visual processes in congruency with attentional task representations similar to conscious perception. We argue that seemingly paradoxical, hitherto unexplained findings regarding the automaticity of the underlying processes in many cognitive domains can be easily accommodated by our attentional sensitization model. We conclude this review with a discussion of future research questions regar-ding the nature of attentional control of unconscious visual processing.
PMCID: PMC3303109  PMID: 22419966
automatic processes; unconscious visual processing; attentional control; semantic priming; visuo-motor priming; subliminal perception; consciousness

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