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.     

The stroop effect: It is not the robust phenomenon that you have thought it to be

Five experiments demonstrate that context has a powerful effect on the ease with which people can name (Experiments 1-3) or categorize (Experiments 4-5) a stimulus while ignoring another stimulus, irrelevant or conflicting with the target. Selectivity of attention to the target dimension was gauged through Stroop and Garner effects. When the stimulus values along the target dimension and the to-be-ignored dimension were correlated over the experimental trials, large effects of Stroop and Garner influenced performance. However, when random allocation of values created zero dimensional correlation, the Stroop effects vanished. These results imply that when the nominally irrelevant dimension is in fact correlated with the relevant dimension, participants then attend to the irrelevant dimension and thus open themselves up to Stroop interference. Another variable of context, the relative salience of the constituent dimensions, also affected performance with the more discriminable dimension disrupting selective attention to the less discriminable dimension. The results demonstrate the importance of context in engendering the failure of selective attention and challenge traditional automaticity accounts of the Stroop effect.     

An investigation into some of the underlying associative verbal processes of the stroop colour effect

The Stroop test was examined to throw some light on the verbal basis of the test. When words are presented printed in the wrong colour it is found that the written word provides more interference with response to the colour of print than occurs the other way round (the Stroop effect). It was shown that, by allowing subjects to match the colour of the print with colour patches instead of words, the interference due to the written word can be considerably reduced. In a further experiment, associations were formed by the subjects between nonsense syllables and colours in the course of a paired-associate learning task. When nonsense syllables were presented printed in colours different from those associated with them, it was found that the interference effects depended upon the direction of the stimulus-response association in the paired-associate experiment. It is concluded that the underlying processes in the Stroop effect are primarily verbal and depend partly upon the directionality of previously established verbal associations.     

A model to investigate the mechanisms underlying the emergence and development of independent sitting

When infants first begin to sit independently, they are highly unstable and unable to maintain upright sitting posture for more than a few seconds. Over the course of 3 months, the sitting ability of infants drastically improves. To investigate the mechanisms controlling the development of sitting posture, a single‐degree‐of‐freedom inverted pendulum model was developed. Passive muscle properties were modeled with a stiffness and damping term, while active neurological control was modeled with a time‐delayed proportional‐integral‐derivative (PID) controller. The findings of the simulations suggest that infants primarily utilize passive muscle stiffness to remain upright when they first begin to sit. This passive control mechanism allows the infant to remain upright so that active feedback control mechanisms can develop. The emergence of active control mechanisms allows infants to integrate sensory information into their movements so that they can exhibit more adaptive sitting.     

A contingency model of conflict and team effectiveness

The authors develop and test theoretical extensions of the relationships of task conflict, relationship conflict, and 2 dimensions of team effectiveness (performance and team-member satisfaction) among 2 samples of work teams in Taiwan and Indonesia. Findings show that relationship conflict moderates the task conflict-team performance relationship. Specifically, the relationship is curvilinear in the shape of an inverted U when relationship conflict is low, but the relationship is linear and negative when relationship conflict is high. The results for team-member satisfaction are more equivocal, but the findings provide some evidence that relationship conflict exacerbates the negative relationship between task conflict and team-member satisfaction.     

The Honi phenomenon revisited: factors underlying the resistance to perceptual distortion of one's partner.

An individual being viewed in an Ames room usually appears considerably altered in physical size to an observer. However, some married persons perceive less size distortion of their spouses than a stranger. This instance of selective perceptual distortion, known as the Honi phenomenon, could perhaps reflect differential familiarity and/or emotional involvement toward these stimulus persons. Using heterosexual couples as subjects, we investigated familiarity (i.e., length of the relationship), type of relationship (i.e., dating, engaged, or married), and positive cathexis (i.e., love, liking, and trust of one's partner) as possible mediators of this effect and also explored the impact of some judgemental variations. Neither familiarity nor type of relationship influenced relative perceptual distortion of partner versus stranger. Rather, selective perceptual distortion was directly related to the strength of positive cathexis, principally among females. Only women high in positive cathexis exhibited the Honi phenomenon and perceived a stranger as being more distorted than their partners. In contrast, size judgements by men were affected only by the sequence in which stimulus persons were observed. Implications and interpretations of these findings are discussed.     

Minimal functional brain differences between older adults with and without mild cognitive impairment during the stroop

This investigation compared the neural correlates of inhibition in normal older adults (OAs) and OAs with mild cognitive impairment (MCI). It was hypothesized the MCI group would require a greater amount of resources for inhibition, and therefore display greater functional activation in specific regions of interest (ROIs). Twenty-six OAs without and 17 with MCI completed the Stroop task during functional neuroimaging, and completed additional out-of-scanner neuropsychological measures. During inhibition, there were minimal functional Magnetic Resonance Imaging (fMRI) differences found between groups in a priori specified ROIs and with post-hoc multiple regression analyses. However, these minimal differences did not survive corrected thresholds. Robust differences were found with several tasks of a neuropsychological screening battery. The results of this study suggest only very minimal group differences in fMRI activation during inhibition which may not reliably identify MCI, and this condition may be best detected by traditional neuropsychological techniques.     

A test of the ABC model underlying rational emotive behavior therapy

The ABC model underlying Ellis's Rational Emotive Behavior Therapy predicts that people who think more irrationally should respond to daily stressors or hassles differently than do people who think less irrationally. This study tested this aspect of the ABC model. 192 college students were administered the Survey of Personal Beliefs and the Hassles Scale to measure irrational thinking and daily hassles, respectively. Students who scored higher on overall irrational thinking reported a significantly higher frequency of hassles than did those who scored lower on overall irrational thinking, while students who scored higher on awfulizing and low frustration tolerance reported a significantly greater intensity of hassles than did those who scored lower on awfulizing and low frustration tolerance. This indicates support for the ABC model, especially Ellis's construct of irrational beliefs central to this model.     

A predictive coding model of gaze shifts and the underlying neurophysiology

A comprehensive model of gaze control must account for a number of empirical observations at both the behavioural and neurophysiological levels. The computational model presented in this article can simulate the coordinated movements of the eye, head, and body required to perform horizontal gaze shifts. In doing so it reproduces the predictable relationships between the movements performed by these different degrees of freedom (DOFs) in the primate. The model also accounts for the saccadic undershoot that accompanies large gaze shifts in the biological visual system. It can also account for our perception of a stable external world despite frequent gaze shifts and the ability to perform accurate memory-guided and double-step saccades. The proposed model also simulates peri-saccadic compression: the mis-localization of a briefly presented visual stimulus towards the location that is the target for a saccade. At the neurophysiological level, the proposed model is consistent with the existence of cortical neurons tuned to the retinal, head-centred, body-centred, and world-centred locations of visual stimuli and cortical neurons that have gain-modulated responses to visual stimuli. Finally, the model also successfully accounts for peri-saccadic receptive field (RF) remapping which results in reduced responses to stimuli in the current RF location and an increased sensitivity to stimuli appearing at the location that will be occupied by the RF after the saccade. The proposed model thus offers a unified explanation for this seemingly diverse range of phenomena. Furthermore, as the proposed model is an implementation of the predictive coding theory, it offers a single computational explanation for these phenomena and relates gaze shifts to a wider framework for understanding cortical function.     

A model of the neural mechanisms underlying multisensory integration in the superior colliculus

Much of the information about multisensory integration is derived from studies of the cat superior colliculus (SC), a midbrain structure involved in orientation behaviors. This integration is apparent in the enhanced responses of SC neurons to cross-modal stimuli, responses that exceed those to any of the modality-specific component stimuli. The simplest model of multisensory integration is one in which the SC neuron simply sums its various sensory inputs. However, a number of empirical findings reveal the inadequacy of such a model; for example, the finding that deactivation of cortico-collicular inputs eliminates the enhanced response to a cross-modal stimulus without eliminating responses to the modality-specific component stimuli. These and other empirical findings inform a computational model that accounts for all of the most fundamental aspects of SC multisensory integration. The model is presented in two forms: an algebraic form that conveys the essential insights, and a compartmental form that represents the neuronal computations in a more biologically realistic way.     

A confluence of contexts: asymmetric versus global failures of selective attention to stroop dimensions.

In 6 experiments probing selective attention through Stroop classification, 4 factors of context were manipulated: (a) psychophysical context, the distinctiveness of values along the color and word dimensions; (b) set size context, the number of stimulus values tested; (c) production context, the mode used to respond; and (d) covariate context, the correlation between the dimensions. The psychophysical and production contexts mainly caused an asymmetry in selective attention failure between colors and words, whereas the set size and covariate contexts contributed primarily to the average or global magnitudes of attentional disruption across dimensions. The results suggest that (a) Stroop dimensions are perceptually separable, (b) J.R. Stroop's (1935) classic findings arose from his particular combination of contexts, and (c) stimulus uncertainty and dimensional imbalance are the primary sources of task and congruity effects in the Stroop paradigm.     

Canadian bulk water exports: Analyzing the sun belt conflict using the graph model for conflict resolution

A conflict over the proposed bulk export of water from Canada is systematically studied using the graph model for conflict resolution in order to illustrate how strategic conflicts of this type can be better understood and managed. The ongoing conflict involving a US company, Sun Belt Water Inc., and the Canadian federal and provincial governments is modeled and analyzed using the graph model methodology. This dispute reflects the kinds of controversies that can arise when international trade laws, which stress competition and profits, are in conflict with environmental and social laws. The Sun Belt conflict is especially interesting because of its evolution over several stages; at each stage of the conflict, the objectives of the disputants, and their strategic implications, can be realistically modeled and thereby investigated using the graph model. Amer Obeidi received his B.Sc. in Electrical Engineering from the University of Jordan in 1990 and M.A.Sc. in Management Sciences in 2002 from the University of Waterloo, Ontario, Canada. He is currently pursuing a PhD degree in the Department of Systems Design Engineering, at the University of Waterloo. His currents research interests include confrontation analysis, conflict analysis, negotiation, cognitive and emotional processes effect on decision making, and choice theory. Dr. Hipel’s major research interests are the development and application of conflict resolution and time series analysis techniques from a systems design engineering perspective. The main application areas of these decision technologies are water resources management, hydrology, environmental engineering and sustainable development. Dr. Hipel is the author/co-author of four books, nine edited books, many journal papers and is an associate editor of six international journals. Moreover, he is a professional Engineer and has carried out consulting activities with engineering firms, government agencies, and utilities in many countries. Director of the Laurier Centre for Military Strategic and Disarmament Studies, and Adjunct Professor of Systems Design Engineering at the University of Waterloo. Dr. Kilgour’s research interests lie at the intersection of mathematics, social science, and engineering. He has applied game theory and related formal techniques to analyze decision problems in international security and arms control, environmental management, negotiation and arbitration, voting, fair division, and coalition formation, and has pioneered the development of systems for decision support in strategic conflict. His most recent books are Perfect Deterrence (Cambridge) and Designing Institutions for Environmental and Resource Management (Edward Elgar).     

A model for predicting the choice of conflict management strategies by subordinates in high-stakes conflicts

This paper represents an attempt to understand superior/subordinate conflict from the subordinate's perspective. A decisional model is presented to reflect the subordinate's choice process in selecting a conflict management strategy in high-stakes conflict. The three primary variables posited by the model to determine the subodinate's strategic choice are the subordinate's desire to remain in the organization, the subordinate's perceived congruence between the superior's and his or her own attitudes and beliefs, and the subordinate's perceived protection from arbitrary action. Depending on the subordinate's response to each of the variables, one of five conflict management strategies is selected. These strategies include problem solving, bargaining, appeasing, competing, and withdrawing. It is hoped that such a model will permit the manager to predict the subordinate's conflict behavior and hence aid in conflict management.     

A memory-based model of posttraumatic stress disorder: evaluating basic assumptions underlying the PTSD diagnosis

In the mnemonic model of posttraumatic stress disorder (PTSD), the current memory of a negative event, not the event itself, determines symptoms. The model is an alternative to the current event-based etiology of PTSD represented in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000). The model accounts for important and reliable findings that are often inconsistent with the current diagnostic view and that have been neglected by theoretical accounts of the disorder, including the following observations. The diagnosis needs objective information about the trauma and peritraumatic emotions but uses retrospective memory reports that can have substantial biases. Negative events and emotions that do not satisfy the current diagnostic criteria for a trauma can be followed by symptoms that would otherwise qualify for PTSD. Predisposing factors that affect the current memory have large effects on symptoms. The inability-to-recall-an-important-aspect-of-the-trauma symptom does not correlate with other symptoms. Loss or enhancement of the trauma memory affects PTSD symptoms in predictable ways. Special mechanisms that apply only to traumatic memories are not needed, increasing parsimony and the knowledge that can be applied to understanding PTSD.