Visual feature vs. conjunction searches as a robust manipulation of perceptual load

It has previously been suggested that Lavie’s Perceptual Load Theory can be assessed using feature vs. conjunction search tasks. In this study we manipulated load using a novel paradigm which retains the key features of both classic Load Theory and Feature Integration Theory paradigms. This new paradigm has the advantage of an inbuilt manipulation check which is necessary for future research to translate Load Theory to applied contexts. Across five experiments, we demonstrate the robust nature of this paradigm, which functions with extended display times, large, complex stimuli and when conditions are intermixed on a trial-by-trial basis. We also rule out dilution as a possible cause of these results. The results of all five experiments provide evidence that the feature vs. conjunction search dichotomy is an effective means of imposing low and high perceptual load while controlling for working memory load.     

The Spreading of Alternatives: Is it the Perceived Choice or Actual Choice that Changes our Preference?

After making a difficult choice, the preference rating of a chosen alternative tends to increase, and the rating of the rejected one tends to decrease. Such a change of preference is called spreading of alternatives. It is unclear whether it is the choice itself, or the choice one believes one has made that leads to preference change. Using a facial attractiveness task, we addressed this question by setting up an experiment to measure how the actual choice and perceived choice changed the preference. In the current study, participants first rated the attractiveness of female faces, and then made a choice between two faces that they had rated the same, after which, they re‐rated the female faces. Notably, in the re‐rating session, participants were given either veridical, false, or no feedback about their prior choice. This way, we were able to measure the functions of actual choice and perceived choice in rating changes. Results showed that both actual action and perceived action exert significant influence in shaping preference. The veridical feedback enhanced the spreading of alternatives effect whereas the false feedback weakened this effect, indicating that preference can be modulated by explicit manipulation. Copyright © 2016 John Wiley & Sons, Ltd.     

How something can be said about telling more than we can know: on choice blindness and introspection

The legacy of Nisbett and Wilson’s classic article, Telling More Than We Can Know: Verbal Reports on Mental Processes (1977), is mixed. It is perhaps the most cited article in the recent history of consciousness studies, yet no empirical research program currently exists that continues the work presented in the article. To remedy this, we have introduced an experimental paradigm we call choice blindness [Johansson, P., Hall, L., Sikström, S., &; Olsson, A. (2005). Failure to detect mismatches between intention and outcome in a simple decision task. Science, 310(5745), 116–119.]. In the choice blindness paradigm participants fail to notice mismatches between their intended choice and the outcome they are presented with, while nevertheless offering introspectively derived reasons for why they chose the way they did. In this article, we use word-frequency and latent semantic analysis (LSA) to investigate a corpus of introspective reports collected within the choice blindness paradigm. We contrast the introspective reasons given in non-manipulated vs. manipulated trials, but find very few differences between these two groups of reports.     

A dynamical systems interpretation of a dimensional model of emotion

The dimensional structure of emotion was investigated using self reports of induced mood and idiographic and nomothetic analyses. Subjects attended four experimental sessions during which an array of affective states was induced via auditory, visual, and imaginal channels. For each of 118 stimulus events, subjects self-rated their response. Factor analysis yielded the predicted bipolar factors of valence and arousal: these were obtained in group-aggregated analysis and subsequently confirmed as change dimensions at the intraindividual level. Controversy over the fundamental dimensions of affective space was considered with respect to methodological issues such as factor rotation and sampling of data space. Valence and arousal are discussed as motivational, driving parameters of affective experience and a dynamical systems conceptualization of emotion is proposed.     

Vulnerability of facial attractiveness perception to early and multi-year visual deprivation

Judgments of facial attractiveness invariably accompany our perception of faces. Even neonates appear to be capable of making such judgments in a manner consistent with adults. This suggests that the processes supporting facial attractiveness require little, if any, visual experience to manifest. Here we investigate the resilience of these processes to several years of early-onset visual deprivation. Specifically, we study whether congenitally blind children treated several years after birth possess the ability to rate facial attractiveness in a manner congruent to normally sighted individuals. The data reveal significant individual variability in the way each newly sighted child perceives attractiveness. This is in marked contrast to data from normally sighted controls who exhibit strong across-subject agreement in facial attractiveness ratings. This variability may be attributable, in part, to atypical facial encoding strategies used by the newly sighted children. Overall, our results suggest that the development of facial attractiveness perception is likely to be vulnerable to early visual deprivation, pointing to the existence of a possible sensitive period early in the developmental trajectory.     

Sense of Coherence and Gender as a Predictor of the Effect of Laboratory Induced Stress on Cognitive Performance

ABSTRACT. The current experimental study examined sense of coherence (SOC) as a predictor of the effect of induced stress (time limit and posing a threat) on the level of overall cognitive performance (based on three subscales: mathematics, shapes, and analogies). Results indicated the following: (a) induced stress (experimental group, n = 80) scored lower on the overall cognitive score, compared to the no-stress (control group, n = 81); (b) subjects in the stress group with higher SOC performed better on the overall cognitive score, compared to subjects with lower SOC; however, in the no-stress group there was no significant effect of SOC on cognitive performance; (c) females performed lower on the overall cognitive performance, compared to males regardless of type of group; and (d) SOC predicted equally for males and females overall cognitive performance.     

The Role of Stimulus Type and Semantic Category‐Level Attentional Set in Sustained Inattentional Blindness

Abstract: We examined the effect of the stimulus type and semantic categorization of the unexpected stimulus on sustained Inattentional Blindness (IB). Results showed that observers could establish attentional set based on a higher level of semantic categorization, which tuned one's attention to prioritizing semantic content over others. The unexpected stimulus, congruent with the attended objects in semantic categorization, was more likely to be noticed, whereas the incongruent semantic stimulus seemed to be unseen. Semantic category‐level attentional set played a crucial role in breaking through IB. The semantically congruent Chinese characters stimulus was detected and recognized more often than a semantically congruent picture stimulus, indicating that Chinese characters had more power to attract attention to escape sustained IB than pictures involved in visual processing. Presumably the finding of Chinese characters breaking through IB more easily might be due to the fact that Chinese characters look more distinct from pictures, rather than Chinese characters being processed more easily. Further research should be taken to test the semantic processing efficiency between pictures and Chinese characters in sustained IB.     

The effect of display timing on change blindness in pigeons (Columba livia)

Change blindness is a phenomenon in which even obvious changes in a visual scene may go unnoticed. Recent research has indicated that this phenomenon may not be exclusive to humans. Two experiments investigated change blindness in pigeons, using a variant of the widely‐used flicker task to investigate the influence of display timing on change blindness. Results indicate that the duration of time during which a stimulus display is visible influences change detection accuracy, with the effect due to additional search time. The results are discussed in relation to the value of comparative cognition and cross‐species investigations of behavior.     

Presence of ε-martensite as an intermediate phase during the strain-induced transformation of SUS304 stainless steel

We have investigated the formation process of α′-martensite from the γ-phase induced by external strain using in situ synchrotron diffraction experiments, combined with Lorentz transmission electron microscopy (TEM) and high-resolution TEM observations. It is clearly demonstrated that ε-martensite with hexagonal symmetry appears as an intermediate structure during the plastic deformation of SUS304 stainless steel. In addition to stacking faults and dislocations, interfaces between the twin structures presumably play a key role in the formation of ε-martensite.     

Semantically incongruent objects attract eye gaze when viewing scenes for change

Past research has shown that change detection performance is often more efficient for target objects that are semantically incongruent with a surrounding scene context than for target objects that are semantically congruent with the scene context. One account of these findings is that attention is attracted to objects for which the identity of the object conflicts with the meaning of the scene, perhaps as a violation of expectancies created by earlier recruitment of scene gist information. An alternative account of the performance benefit for incongruent objects is that attention is more apt to linger on incongruent objects, as perhaps identifying these objects is more difficult due to conflicting information from the scene context. In the current experiment, we present natural scenes in a change detection task while monitoring eye movements. We find that eye gaze is attracted to these objects relatively early during scene processing.