Is Speech Arrest during Wada Testing a Valid Method for Determining Hemispheric Representation of Language?

Background and objective: The intracarotid amobarbital procedure, or Wada test, is the method of choice to determine hemispheric representation of language, and is routinely used in the presurgical evaluation for intractable epilepsy. Some investigators perform comprehensive language assessments, but others base language lateralization solely on speech arrest. This study sought to determine whether speech arrest alone during Wada testing provides valid data regarding language lateralization. Methods: The subjects (previously reported) were 21 patients evaluated for intractable epilepsy, who underwent language lateralization by Wada testing and functional MRI (FMRI). For each patient, language representation was determined by calculating: (1) a Wada laterality index based exclusively on speech arrest; (2) a Wada laterality index based on comprehensive language assessment; and (3) an FMRI laterality quotient. Correlation coefficients and categorical classifications were analyzed. Results: There was no significant correlation between the Wada laterality quotient derived from duration of speech arrest and either the comprehensive Wada language laterality score (r= .35,p= .12) or FMRI language laterality score (r= .32,p= .16). Categorical classification as left, right or bilateral language also showed marked discordance between speech arrest and the other two methods. Conclusion: Duration of speech arrest during Wada testing is not a valid measure of language dominance.     

Values and helping behavior: A study in four cultures

Values are important factors in determining individuals' behaviours. Previous studies have examined the relations between values and helping behaviour, but usually in the context of a single culture. The current study examines the relations between personal value types and helping behaviour among university students (N = 722) in four cultures (Germany, Scotland‐UK, Israel and Turkey). Across cultures, the value types of self‐transcendence versus self‐enhancement and conservation versus openness to change were positively related to helping. Specifically, self‐transcendence values were positively related, and self‐enhancement and openness to change values negatively related, to helping behaviour. The correlations pattern did not differ significantly between cultures.     

Gupta’s gambit

After summarizing the essential details of Anil Gupta’s account of perceptual justification in his book Empiricism and Experience, I argue for three claims: (1) Gupta’s proposal is closer to rationalism than advertised; (2) there is a major lacuna in Gupta’s account of how convergence in light of experience yields absolute entitlements to form beliefs; and (3) Gupta has not adequately explained how ordinary courses of experience can lead to convergence on a commonsense view of the world.     

The Effect of Employee Trust of the Supervisor on Enterprising Behavior: A Cross-Cultural Comparison

This study examines the effects of an employee’s affect-based and cognition-based trust of the supervisor on that employee’s enterprising behavior. The extent to which two cultural dimensions, power distance and in-group collectivism, moderate the relationship between the trust measures and enterprising behavior is considered. Trust ratings were provided by 130 U.S. employees, 202 Turkish employees, 101 Polish employees, and 86 Russian employees. Their 519 supervisors then provided ratings of those employees’ enterprising behavior. The results show that both affect-based trust and cognition-based trust have a significant, but modest, effect on the employee’s enterprising behavior. Our findings indicate that both power distance and in-group collectivism do not moderate the proposed trust-behavior relationship although power distance almost reaches the level of significance. We call for further research on other moderating variables to explain the findings.     

The Acuity for Numerosity (but Not Continuous Magnitude) Discrimination Correlates with Quantitative Problem Solving but Not Routinized Arithmetic

Approximate number sense (ANS) acuity refers to the ability to non-symbolically recognize, estimate and operate upon large numerosities. ANS acuity has been reported to be correlated with math achievement in children and adolescents. However, reports of this relationship in adults have been inconsistent. The present study aimed to resolve the inconsistency in the relationship between adults’ ANS acuity and math achievement by contrasting between different kinds of mathematical problem solving. We hypothesized that the correlation between ANS acuity mathematical performance would be stronger when deep quantitative processing is required during problem solving. In Experiment 1, ANS acuity was correlated with Mathematical Reasoning but not Directed Calculation performance. In Experiment 2, ANS acuity was correlated with Two-digit Subtraction (but not Addition) performance only when Regrouping (i.e., borrowing) was required. The results from two experiments demonstrated that ANS acuity was correlated with mathematical performance only when problem solving involved effortful, quantitative processing that goes beyond automatized, routinized arithmetic. In addition, ANS acuity was distinguishable from Area acuity regarding its unique relationship with math achievement, which was unconfounded by the influence of demographic variables and fluid intelligence. Overall, the present results help resolve the inconsistency in previous reports of the correlation between ANS acuity and math achievement in adults.     

Q’Hand: A fully automated apparatus for studying haptic processing of spatially distributed inputs

Q’Hand is an electromechanical system that permits fully automated preparation and presentation of spatially distributed stimulus displays, as well as on-line data acquisition, all under software control. Selected inputs may be presented to any one or combination of the middle three fingertips of both hands. Both accuracy and reaction times are collected on line. Q’Hand was specifically designed to investigate tactile/haptic preattentive and attentive processing of single and multidimensional stimuli. However, it may also be used to study a variety of other research topics, such as pattern recognition, psychophysical issues, and lateralization of somatosensory function. Further, it may be adapted relatively easily for use in clinical settings. For example, with this apparatus, automated psychophysical tests may be designed for the evaluation of the extent of sensory impairment due to peripheral nerve damage otheihander to cortical dysfunction.     

Saliency on a natural scene background: Effects of color and luminance contrast add linearly

In natural vision, shifts in spatial attention are associated with shifts of gaze. Computational models of such overt attention typically use the concept of a saliency map: Normalized maps of center-surround differences are computed for individual stimulus features and added linearly to obtain the saliency map. Although the predictions of such models correlate with fixated locations better than chance, their mechanistic assumptions are less well investigated. Here, we tested one key assumption: Do the effects of different features add linearly or according to a max-type of interaction? We measured the eye position of observers viewing natural stimuli whose luminance contrast and/or color contrast (saturation) increased gradually toward one side. We found that these feature gradients biased fixations toward regions of high contrasts. When two contrast gradients (color and luminance) were superimposed, linear summation of their individual effects predicted their combined effect. This demonstrated that the interaction of color and luminance contrast with respect to human overt attention is—irrespective of the precise model—consistent with the assumption of linearity, but not with a max-type interaction of these features.     

The Explanatory Ambitions of Moral Principles

Moral properties are explained by other properties. And moral principles tell us about moral properties. How are these two ideas related? In particular, is the truth of a given moral principle part of what explains why a given action has a given moral property? I argue “No.” If moral principles are merely concerned with the extension of moral properties across all possible worlds, then they cannot be partial explainers of facts about the instantiation of those properties, since in general necessitation does not suffice for explanation. And if moral principles are themselves about what explains the moral properties under their purview, then by their own lights they are not needed in order to explain those moral properties’ instantiation—unless, that is, the principles exhibit an objectionable form of metaphysical circularity. So moral principles cannot explain why individual actions have moral properties. Nor, I also argue, can they explain why certain other factors explain why those actions have the moral properties that they do, or in some other way govern or mediate such first‐order explanations of particular moral facts. When it comes to the explanation of an individual action's specific moral features, moral principles are explanatorily idle.