Eran Chajut

A Rational Look at the Emotional Stroop Phenomenon: A Generic Slowdown, Not a Stroop Effect

The role of Stroop processes in the emotional Stroop effect was subjected to a conceptual scrutiny augmented by a series of experiments entailing reading or lexical decision as well as color naming. The analysis showed that the Stroop effect is not defined in the emotional Stroop task. The experiments showed that reading, lexical decision, and color naming all are slower with emotional words and that this delay is immune to task-irrelevant variation and to changes in the relative salience of the words and the colors. The delay was absent when emotional and neutral words appeared in a single block. A threat-driven generic slowdown is implicated, not a selective attention mechanism associated with the classic Stroop effect.

Selective Attention Improves Under Stress: Implications for Theories of Social Cognition

Three influential perspectives of social cognition entail conflicting predictions regarding the selectivity of performance under stress. According to the attention view, selectivity to the task-relevant attribute improves under stress because of reduced utilization of task-irrelevant attributes. According to the capacity-resource approach, stress depletes attentional resources wherefore selectivity fails for all but chronically accessible information. A third perspective, ironic process theory, similarly holds that selective attention fails under stress but adds that task-irrelevant information is rendered hyperaccessible. The theoretical derivations were tested in a series of experiments using 2 classes of selectivity measures, with special care taken to control for hitherto neglected factors of context The results showed that the selectivity of attention improved under stress, consistent with the prediction of the attention view.

Participation in class and in online discussions: Gender differences

Gender differences between participation in face-to-face and web-based classroom discussions were examined, by comparing the men-women actual participation ratio to the men-women attendance (or login) ratio. It was found that men over-proportionally spoke at the face-to-face classroom whereas women over-proportionally posted messages in the web-based conference. Two alternative explanations are discussed. It is suggested that either women prefer written communication more than men do, or that women prefer written communication over spoken communication. Nonetheless, despite some advantages of virtual discussions, especially for women, the online environment is apparently not attractive enough for either gender.

Changes over time in digital literacy.

The current study is a follow-up on the 2002 empirical study by Eshet-Alkalai and Amichai-Hamburger, which investigated digital literacy skills among different age groups. This study explores changes through time in digital literacy among the same participants 5 years later, and their performance is compared to new matched control groups. Results indicate an improvement over time among all age groups, but especially for the adults, in the tasks that require proficiency and technical control in using technology (e.g., photovisual and branching literacy skills). On the other hand, results indicate a drop in the skills that require creative and critical thinking (e.g., information and reproduction literacy skills), especially for the younger participants. Results show two major patterns of change over time: (a) closing the gap between younger and older participants in the tasks that emphasize proficiency and technical control and (b) widening the gap between younger and older participants in tasks that emphasize creativity and critical thinking. Based on the comparison with the matched control groups, we suggest that experience with technology, and not age, accounts for the observed lifelong changes in digital literacy skills.

You Can Teach Old Dogs New Tricks: The Factors That Affect Changes over Time in Digital Literacy

The expansion of digital technologies and the rapid changes they undergo through time face users with new cognitive, social, and ergonomic challenges that they need to master in order to perform effectively. In recent years, following empirical reports on performance differences between different age-groups, there is a debate in the research literature concerning the nature of these differences: whether they reflect age-related cognitive abilities of the users, or that they are related to the usability and experience of users with the technologies. This study attempts to establish whether changes in digital literacy, through a period of five years, are age-dependent or the result of experience with technology. The study is based on empirical findings from two independent studies of Eshet-Alkalai & Amichai-Hamburger (2004), which investigated digital literacy skills among different age groups, and of Eshet-Alkalai and Chajut (2009), which investigated changes over time in these digital literacy skills among the same participants five years later. In order to distinguish between the age-related and the experiencerelated factors, the present study reports on findings from control groups of a similar age and demographic background, which were tested with tasks similar to Eshet-Alkalai & Chajut (2009). Results show two major patterns of change over time: (1) closing the gap between younger and older participants in tasks that emphasize experience and technical control (photo-visual and branching tasks); (2) widening the gap between younger and older participants in tasks that emphasize creativity and critical thinking (reproduction and information tasks). Based on the results from the control groups, we suggest that experience with technology, and not age-dependent cognitive development, accounts for the observed life-long changes in digital literacy skills. Results, especially the sharp decrease in information skills, suggest that the ability to find information or use digital environments does not guarantee an educated or smart use of digital environments.

Response: When does grasping escape Weber's law?

Summary In a recent study [1], we found that Webers law, a fundamental principle of perception, does not govern visual control of grasping and concluded that different representations of object size are used for action and for perception [1]. Smeets and Brenner [2] suggest instead that grasping is computed on the basis of position rather than on the basis of size, and that this accounts for the apparent absence of Webers law. However, their alternative explanation cannot readily account for memory-based grasping, which does obey Webers law. In this response, we present additional data to show that, even when memory-based and real-time grasping both are executed without visual feedback, only the former obeys Webers law. This dissociation further supports the conclusion that action and perception are sustained by qualitatively different computations.

Avoiding the approach trap: a response bias theory of the emotional Stroop effect.

In the laboratory, people classify the color of emotion-laden words slower than they do that of neutral words, the emotional Stroop effect. Outside the laboratory, people react to features of emotion-laden stimuli or threatening stimuli faster than they do to those of neutral stimuli. A possible resolution to the conundrum implicates the counternatural response demands imposed in the laboratory that do not, as a rule, provide for avoidance in the face of threat. In 2 experiments we show that when such an option is provided in the laboratory, the response latencies follow those observed in real life. These results challenge the dominant attention theory offered for the emotional Stroop effect because this theory is indifferent to the vital approach-avoidance distinction.

Accurate visuomotor control below the perceptual threshold of size discrimination.

Background Human resolution for object size is typically determined by psychophysical methods that are based on conscious perception. In contrast, grasping of the same objects might be less conscious. It is suggested that grasping is mediated by mechanisms other than those mediating conscious perception. In this study, we compared the visual resolution for object size of the visuomotor and the perceptual system. Methodology/Principal Findings In Experiment 1, participants discriminated the size of pairs of objects once through perceptual judgments and once by grasping movements toward the objects. Notably, the actual size differences were set below the Just Noticeable Difference (JND). We found that grasping trajectories reflected the actual size differences between the objects regardless of the JND. This pattern was observed even in trials in which the perceptual judgments were erroneous. The results of an additional control experiment showed that these findings were not confounded by task demands. Participants were not aware, therefore, that their size discrimination via grasp was veridical. Conclusions/Significance We conclude that human resolution is not fully tapped by perceptually determined thresholds. Grasping likely exhibits greater resolving power than people usually realize.

Are spatial and dimensional attention separate? Evidence from Posner, Stroop, and Eriksen tasks

Do various operational definitions of visual attention tap the same underlying process? To address this question, we probed visual selective attention using orientation of attention, flanker, and Stroop tasks. These were embedded in combined designs that enabled assessment of each effect, as well as their interaction. For the orientation task, performance was poorer at unexpected than at expected locations. The flanker effects also differed across the two locations. In contrast, the Stroop effects were comparable at expected and unexpected locations. We conclude that spatial attention (tapped by the orientation and the flanker tasks) and dimensional attention (tapped by the Stroop task) engage separate processes of visual selection, both of which are needed in normal attention processing.

Emotional Dilution of the Stroop Effect: A New Tool for Assessing Attention Under Emotion

In order to gauge in a precise fashion the capture of attention by emotional stimuli, we developed a new tool that imports the classic Stroop effect into the realm of emotion. Strooping the typical emotion tasks enabled the derivation of a pure intraitem measure of attention under emotion. The results of two experiments showed that the classic Stroop effects were smaller with emotion than with neutral words, demonstrating the power of emotion to bias attention. This emotional dilution of the Stroop effect can serve as a general-purpose tool for assessing attention under emotion.