Geänderte Inhalte

Background: When subjects use cues to prepare for a likely stimulus or a likely response, reaction times are facilitated by valid cues but prolonged by invalid cues. In studies on combined expectancy effects, two cues can independently give information regarding two dimensions of the forthcoming task. In certain situations, cueing effects on one dimension are reduced when the cue on the other dimension is invalid. According to the Adjusted Expectancy Model, cues affect different processing levels and a mechanism is presumed which is sensitive to the validity of early level cues and leads to online adjustment of expectancy effects at later levels. To examine the predictions of this model cueing of stimulus modality was combined with response cueing. Results: Behavioral measures showed the interaction of cueing effects. Electrophysiological measures of the lateralized readiness potential (LRP) and the N200 amplitude confirmed the predictions of the model. The LRP showed larger effects of response cues on response activation when modality cues were valid rather than invalid. N200 amplitude was largest with valid modality cues and invalid response cues, medium with invalid modality cues, and smallest with two valid cues. Conclusion: Findings support the view that the validity of early level expectancies modulates the effects of late level expectancies, which included response activation and response conflict in the present study. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Visual stimuli that are made invisible by a following mask can nonetheless affect motor responses. To localize the origin of these target priming effects we used the psychological refractory period paradigm. Participants classified tones as high or low, and responded to the position of a visual target that was preceded by a prime. The stimulus onset asynchrony (SOA) between both tasks varied. In Experiment 1 the tone task was followed by the position task and SOA dependent target priming effects were observed. When the visual position task preceded the tone task in Experiment 2, with short SOA the priming effect propagated entirely to the tone task yielding faster responses to tones on visually congruent trials and delayed responses to tones on visually incongruent trials. Together, results suggest that target priming effects arise from processing before and at the level of the central bottleneck such as sensory analysis and response selection. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

We typically fixate targets such that they are projected onto the fovea for best spatial resolution. Macular degeneration patients often develop fixation strategies such that targets are projected to an intact eccentric part of the retina, called pseudofovea. A longstanding debate concerns which pseudofovea-location is optimal for non-foveal vision. We examined how pseudofovea position and eccentricity affect performance in visual search, when vision is restricted to an off-foveal retinal region by a gaze-contingent display that dynamically blurs the stimulus except within a small viewing window (forced field location). Trained normally sighted participants were more accurate when forced field location was congruent with the required scan path direction; this contradicts the view that a single pseudofovea location is generally best. Rather, performance depends on the congruence between pseudofovea location and scan path direction.

Investigated cumulative repetition priming of words and pseudowords presented in a rapid serial visual stream in a series of 6 experiments. A total of 88 college students (14 male, aged 18-41 years) participated in the experiments in which they were required to count forenames occurring in a visually presented word stream of 200 words and pseudowords and then perform lexical decision tasks for words and pseudowords which had or had not previously been seen. The experiments provided clear evidence of cumulative repetition priming, with repetition effects proving greater with increasing presentation frequency. While words consistently showed facilitatory priming, priming was consistently inhibitory for pseudowords. For pseudowords, repetition priming was generally smaller than that found for words. The experiments yielded no evidence of priming differences for pseudowords with different frequencies. In contrast, word frequency effects were obtained when the prime was processed for 250 but not for 80 ms. Results suggest that massive repetition priming does not appear to depend on conscious recollection at test and also demonstrated that priming does not decay even when measured after 7 minutes. The findings of an experiment with delays of 1 day revealed the significance of response learning and also demonstrated a clear dissociation between word and pseudoword repetition priming. In closing, implications of the findings are discussed.

Hundreds of studies have found that humans’ decisions are strongly influenced by the opinions of others, even when making simple perceptual decisions. In this study, we aimed to clarify whether this effect can be explained by social influence biasing (early) perceptual processes. We employed stimulus evoked potentials, lateralized readiness potentials (LRPs) and a diffusion model analysis of reaction time data to uncover the neurocognitive processes underlying social conformity in perceptual decision-making. The diffusion model analysis showed that social conformity was due to a biased uptake of stimulus information and accompanied by more careful stimulus processing. As indicated by larger N1- amplitudes, social influence increased early attentional resources for stimulus identification and discrimination. Furthermore, LRP analyses revealed that stimulus processing was biased even in cases of non-conformity. In conclusion, our results suggest that the opinion of others can cause individuals to selectively process stimulus information supporting this opinion, thereby inducing social conformity. This effect is present even when individuals do not blindly follow the majority but rather carefully process stimulus information. (PsycINFO Database Record (c) 2017 APA, all rights reserved)

Need for cognition (NFC) refers to dispositional differences in cognitive motivation and has been frequently found to predict higher-order cognition, such as attitude formation and decision making. Based on recent evidence, this study examined whether NFC already relates to relatively early perceptual processes. Using a metacontrast masking paradigm (N = 137), we found that high-NFC individuals were more likely to use target-specific perceptual cues providing valid information for target discrimination, while low-NFC individuals were more likely to use less reliable heuristic cues for their judgement. Intriguingly, our results suggest that core mechanisms of NFC (focussed/elaborative vs. peripheral/heuristic processing by differential utilization of environmental cues) can not only be found in reflective higher-order cognition, but similarly in behavioral indicators of early visual processing. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Our ability to identify even complex scenes in rapid serial visual presentation (RSVP) is astounding, but memory for such items seems lacking. Rather than pictures, we used streams of more than 200 verbal stimuli, rushing by on the screen at a rate of more than 12 items per second while participants had to detect infrequent names (Experiments 1 and 2) or words written in capitals (Experiment 3). By direct and indirect tests, we investigated what is remembered of these masses of task-irrelevant distractor words and pseudowords embedded in an RSVP stream. Lexical decision, the indirect test applied either immediately after each stimulus train or with a delay, revealed strong long-term priming effects. Relative to stimuli not shown before, lexical decisions were faster and more accurate to words but slower to pseudowords. The size of these effects mirrored how often words and pseudowords had occurred in a stream, suggesting that memory traces are strengthened with successive presentations and survive for several minutes at least. Moreover, in a direct test (old–new categorization), words as well as pseudowords benefited from prior occurrence in an RSVP stream if they had occurred more than once. These findings parallel recent physiological and behavioral evidence for memory consolidation of distractor pictures in RSVP and highlight that, despite huge numbers of interfering stimuli, distractor words and pseudowords exhibit long-lasting memory effects. Consolidation seems to progress at higher cognitive levels at the same time that subsequent stimuli are perceptually processed. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Metacontrast masking occurs when a mask follows a target stimulus in close spatial proximity. Target visibility varies with stimulus onset asynchrony (SOA) between target and mask in individually different ways leading to different masking functions with corresponding phenomenological reports. We used individual differences to determine the processes that underlie metacontrast masking. We assessed individual masking functions in a masked target discrimination task using different masking conditions and applied factor-analytical techniques on measures of sensitivity. Results yielded two latent variables that (1) contribute to performance with short and long SOA, respectively, (2) relate to specific stimulus features, and (3) differentially correlate with specific subjective percepts. We propose that each latent variable reflects a specific process. Two additional processes may contribute to performance with short and long SOAs, respectively. Discrimination performance in metacontrast masking results from individually different weightings of two to four processes, each of which contributes to specific subjective percepts. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Examined whether participants with different objective performance nonetheless subjectively experience the stimulation in the same way in 4 experiments. In Experiments 1 and 2 the same 30 subjects (mean age 23 years) participated. In Experiment 3 only 29 of the original 30 participated (1 underachiever refused to participate again), and in Experiment 4 a new group of 31 subjects (mean age 22 years) took part. In one group of observers objective performance increased with increasing target-mask stimulus onset asynchrony (SOA), whereas in another group performance decreased with increasing SOA. In addition, a group of overachievers showed ceiling effects whereas a group of underachievers hardly exceeded chance levels of performance irrespective of SOA. The differences between observers' objective measures of performance correspond to differences in participants' phenomenological reports of subjective experience. This indicates that participants differ in their access to specific perceptual cues that they use spontaneously to solve the task. When participants were instructed to use only a single specific cue, the instructed cue determined participants' objective performance considerably in 2 experiments. Nevertheless, masking functions remained similar with and without the cued instruction, and the effect of cues depended on the initial masking function of individuals. Findings suggest that individuals with different masking functions differ also in terms of phenomenology, used cues, and response strategy. The authors conclude that the relation between subjective experience, reported usage of perceptual cues, and objective performance in the metacontrast masking task deserves further investigation.

Replies to a comment by T. Bachmann (same issue) on a study by T. Albrecht, S. Klaptöke, and U. Mattler (same issue) on individual differences in metacontrast masking. In this study, it was found that perceptual learning enhanced 2 groups of observers with qualitative individual differences in metacontrast masking. The issues raised included initial similarities and differences in Type A and Type B observers, whether the results can be attributed to a difference in direct phenomenal experience or in criteria, and an emphasis on the importance of individual data. It is indicated that the observers were similar at the beginning of each experiment, and that further research is needed in order to locate the source of the observed individual differences and to determine what the groups have in common and where they differ. Furthermore, it is argued that the observers were not able to choose which feature they used, and that perceptual learning either improves conscious perception or the use of criteria. Finally, the importance of the data of individual participants in experimental psychology is highlighted.

In metacontrast masking target visibility is modulated by the time until a masking stimulus appears. The effect of this temporal delay differs across participants in such a way that individual human observers’ performance shows distinguishable types of masking functions which remain largely unchanged for months. Here we examined whether individual differences in masking functions depend on different response criteria in addition to differences in discrimination sensitivity. To this end we reanalyzed previously published data and conducted a new experiment for further data analyses. Our analyses demonstrate that a distinction of masking functions based on the type of masking stimulus is superior to a distinction based on the target–mask congruency. Individually different masking functions are based on individual differences in discrimination sensitivities and in response criteria. Results suggest that individual differences in metacontrast masking result from individually different criterion contents. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

In vision research metacontrast masking is a widely used technique to reduce the visibility of a stimulus. Typically, studies attempt to reveal general principles that apply to a large majority of participants and tend to omit possible individual differences. The neural plasticity of the visual system, however, entails the potential capability for individual differences in the way observers perform perceptual tasks. We report a case of perceptual learning in a metacontrast masking task that leads to the enhancement of two types of adult human observers despite identical learning conditions. In a priming task both types of observers exhibited the same priming effects, which were insensitive to learning. Findings suggest that visual processing of target stimuli in the metacontrast masking task is based on neural levels with sufficient plasticity to enable the development of two types of observers, which do not contribute to processing of target stimuli in the priming task. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Professionally edited videos entail frequent editorial cuts - that is, abrupt image changes from one frame to another. The impact of these cuts on human eye movements is currently not well understood. In the present eye-tracking study, we experimentally gauged the degree to which color and visual continuity contributed to viewers' eye movements following cinematic cuts. In our experiment, viewers were presented with two edited action sports movies on the same screen but they were instructed to watch and keep their gaze on only one of these movies. Crucially, the movies were frequently interrupted and continued after a short break either at the same or at switched locations. Hence, viewers needed to rapidly recognize the continuation of the relevant movie and re-orient their gaze toward it. Properties of saccadic eye movements following each interruption probed the recognition of the relevant movie after a cut. Two key findings were that (i) memory co-determines attention after cuts in edited videos, resulting in faster re-orientation toward scene continuations when visual continuity across the interruption is high than when it is low, and (ii) color contributes to the guidance of attention after cuts, but its benefit largely rests upon enhanced discrimination of relevant from irrelevant visual information rather than memory. Results are discussed with regard to previous research on eye movements in movies and recognition processes. Possible future directions of research are outlined.

Eye fixations allow the human viewer to perceive scene content with high acuity. If fixations drive visual memory for scenes, a viewer might repeat his/her previous fixation pattern during recognition of a familiar scene. However, visual salience alone could account for similarities between two successive fixation patterns by attracting the eyes in a stimulus-driven, task-independent manner. In the present study, we tested whether the viewer’s aim to recognize a scene fosters fixations on scene content that repeats from learning to recognition as compared to the influence of visual salience alone. In Experiment 1 we compared the gaze behavior in a recognition task to that in a free-viewing task. By showing the same stimuli in both tasks, the task-independent influence of salience was held constant. We found that during a recognition task, but not during (repeated) free viewing, viewers showed a pronounced preference for previously fixated scene content. In Experiment 2 we tested whether participants remembered visual input that they fixated during learning better than salient but nonfixated visual input. To that end we presented participants with smaller cutouts from learned and new scenes. We found that cutouts featuring scene content fixated during encoding were recognized better and faster than cutouts featuring nonfixated but highly salient scene content from learned scenes. Both experiments supported the hypothesis that fixations during encoding and maybe during recognition serve visual memory over and above a stimulus-driven influence of visual salience. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Films, TV shows, and other edited dynamic scenes contain many cuts, which are abrupt transitions from one video shot to the next. Cuts occur within or between scenes, and often join together visually and semantically related shots. Here, we tested to which degree memory for the visual features of the precut shot facilitates shifting attention to the postcut shot. We manipulated visual similarity across cuts, and measured how this affected covert attention (Experiment 1) and overt attention (Experiments 2 and 3). In Experiments 1 and 2, participants actively viewed a target movie that randomly switched locations with a second, distractor movie at the time of the cuts. In Experiments 1 and 2, participants were able to deploy attention more rapidly and accurately to the target movie’s continuation when visual similarity was high than when it was low. Experiment 3 tested whether this could be explained by stimulus-driven (bottom-up) priming by feature similarity, using one clip at screen center that was followed by two alternative continuations to the left and right. Here, even the highest similarity across cuts did not capture attention. We conclude that following cuts of high visual similarity, memory-guided attention facilitates the deployment of attention, but this effect is (top-down) dependent on the viewer’s active matching of scene content across cuts. (PsycINFO Database Record (c) 2017 APA, all rights reserved)

We tested whether viewers have cognitive control over their eye movements after cuts in videos of real-world scenes. In the critical conditions, scene cuts constituted panoramic view shifts: Half of the view following a cut matched the view on the same scene before the cut. We manipulated the viewing task between two groups of participants. The main experimental group judged whether the scene following a cut was a continuation of the scene before the cut. Results showed that following view shifts, fixations were determined by the task from 250 ms until 1.5 s: Participants made more and earlier fixations on scene regions that matched across cuts, compared to nonmatching scene regions. This was evident in comparison to a control group of participants that performed a task that did not require judging scene continuity across cuts, and did not show the preference for matching scene regions. Our results illustrate that viewing intentions can have robust and consistent effects on gaze behavior in dynamic scenes, immediately after cuts. (PsycINFO Database Record (c) 2017 APA, all rights reserved)

[Correction Notice: An Erratum for this article was reported in Vol 95 of Animal Behaviour (see record [rid]2014-36193-024[/rid]). The authors specify that with regard to the faecal cortisol analyses an 11-oxoetiocholanolone immunoassay (Möstl, Maggs, Schrötter, Besenfelder, & Palme, 2002; Wallner, Möstl, Dittami, & Prossinger, 1999) was applied to measure cortisol equivalent metabolites in faeces.] Colour signals play a major role in social and sexual communication in a broad range of animal species. Previous studies on nonhuman primates showed that intense female skin coloration attracts male attention. We investigated (1) whether sexually active male Japanese macaques are attracted by intensely coloured female skin, (2) whether a preference for intense skin coloration results from the increased colour contrast between the skin area and its surroundings irrespective of the red chromaticity, and (3) whether the endocrine status of sexually active males affects their attentional selectivity (or preference) for salient female sexual skin coloration. We conducted two behavioural experiments in two consecutive mating seasons. First, we presented two female face images coloured in a natural range of red skin coloration on monitors. Second, we presented the same faces dissociated from the red chromaticity while maintaining their initial colour contrast properties. In both experiments we analysed male selective visual attention and approaches as a function of stimulus type. Faecal samples were collected after each experiment to analyse focal males' cortisol and testosterone excretion rates. We found that female facial skin coloration triggered selective behaviour in social-living male Japanese macaques. Variances in colour contrast also triggered males' selective orienting towards an intensely coloured face image but the red chromaticity remained essential to induce prolonged male interest. Furthermore, elevated cortisol facilitated male preferences for the intensely coloured female faces, sociosexual stimuli that are presumably highly relevant during the mating season. Future studies may pursue the principle of colour contrast in male attentional behaviour with respect to subtle colour changes expressed by females throughout the reproductive cycle. Cortisol-related physiological processes should be considered in studies on mating-relevant selective attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved)

In visual search for pop-out targets, search times are shorter when the target and nontarget colors from the previous trial are repeated than when they change. This priming effect was originally attributed to a feature weighting mechanism that biases attention toward the target features, and away from the non-target features. However, more recent studies have shown that visual selection is strongly context-dependent: according to a relational account of feature priming, the target color is always encoded relative to the non-target color (e.g., as redder or greener). The present study provides a critical test of this hypothesis, by varying the colors of the search items such that either the relative color or the absolute color of the target always remained constant (or both). The results clearly show that color priming depends on the relative color of a target with respect to the nontargets but not on its absolute color value. Moreover, the observed priming effects did not change over the course of the experiment, suggesting that the visual system encodes colors in a relative manner from the start of the experiment. Taken together, these results strongly support a relational account of feature priming in visual search, and are inconsistent with the dominant feature-based views. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

How quickly do children and adults interpret scalar lexical items in speech processing? The current study examined interpretation of the scalar terms some vs. all in contexts where either the stronger (some = not all) or the weaker interpretation was permissible (some allows all). Children and adults showed increased negative deflections in brain activity following the word some in some-infelicitous versus some-felicitous contexts. This effect was found as early as 100 ms across central electrode sites (in children), and 300–500 ms across left frontal, fronto-central, and centro-parietal electrode sites (in children and adults). These results strongly suggest that young children (aged between 3 and 4 years) as well as adults quickly have access to the contextually appropriate interpretation of scalar terms.

One of the most important social cognitive skills in humans is the ability to “put oneself in someone else’s shoes,” that is, to take another person’s perspective. In socially situated communication, perspective taking enables the listener to arrive at a meaningful interpretation of what is said (sentence meaning) and what is meant (speaker’s meaning) by the speaker. To successfully decode the speaker’s meaning, the listener has to take into account which information he/she and the speaker share in their common ground (CG). We here further investigated competing accounts about when and how CG information affects language comprehension by means of reaction time (RT) measures, accuracy data, event-related potentials (ERPs), and eye-tracking. Early integration accounts would predict that CG information is considered immediately and would hence not expect to find costs of CG integration. Late integration accounts would predict a rather late and effortful integration of CG information during the parsing process that might be reflected in integration or updating costs. Other accounts predict the simultaneous integration of privileged ground (PG) and CG perspectives. We used a computerized version of the referential communication game with object triplets of different sizes presented visually in CG or PG. In critical trials (i.e., conflict trials), CG information had to be integrated while privileged information had to be suppressed. Listeners mastered the integration of CG (response accuracy 99.8%). Yet, slower RTs, and enhanced late positivities in the ERPs showed that CG integration had its costs. Moreover, eye-tracking data indicated an early anticipation of referents in CG but an inability to suppress looks to the privileged competitor, resulting in later and longer looks to targets in those trials, in which CG information had to be considered. Our data therefore support accounts that foresee an early anticipation of referents to be in CG but a rather late and effortful integration if conflicting information has to be processed. We show that both perspectives, PG and CG, contribute to socially situated language processing and discuss the data with reference to theoretical accounts and recent findings on the use of CG information for reference resolution.