Effects of Right- and Left-Hemisphere Damage on Understanding Conversational Implicatures

Processing of implicatures was examined in 27 right-brain-damaged (RBD) and 31 left-brain-damaged (LBD) stroke patients with focal lesions using a new implicatures battery (IB) as part of an exploration of the neural basis and modularity of natural language pragmatics. Following Grice, we sampled implicatures of Quantity, Quality, Relation, and Manner. Verbal implicatures consisted of two-sentence conversational vignettes which are literally problematic. Nonverbal implicatures consisted mostly of famous paintings that are literally problematic (e.g., Magritte's "Le Domain d'Arnheim"). The patient has to identify and solve the problem. To compare with performance on the IB, patients also received a Hebrew adaptation of Gardner and Brownell's Right Hemisphere Communication Battery, a new test of basic speech acts (verbal and nonverbal assertions, questions, requests, and commands), a Hebrew version of the Western Aphasia Battery, and standardized neuropsychological tests. Both LBD and RBD patients were significantly impaired in implicature processing relative to age-matched normal controls. In general, both patient groups showed weak correlations of implicatures with extents of lesions in left perisylvian language area or its right-hemisphere (RH) homolog. However, performance of LBD and RBD patients on the IB revealed different patterns of correlations with other pragmatic, language, and nonlanguage tests. In LBD patients, there was a greater association between performance on verbal and nonverbal implicatures and between performance on implicatures and basic speech acts than in RBD patients. Given the different modes in which right-and left-hemisphere (LH) damage affect the processing of conversational implicatures, it remains to be discovered how the two hemispheres interact to process natural language pragmatics in the normal brain in real time.     

Delay or probability discounting in a model of impulsive behavior: effect of alcohol

Little is known about the acute effects of drugs of abuse on impulsivity and self-control. In this study, impulsivity was assessed in humans using a computer task that measured delay and probability discounting. Discounting describes how much the value of a reward (or punisher) is decreased when its occurrence is either delayed or uncertain. Twenty-four healthy adult volunteers ingested a moderate dose of ethanol (0.5 or 0.8 g/kg ethanol: n = 12 at each dose) or placebo before completing the discounting task. In the task the participants were given a series of choices between a small, immediate, certain amount of money and $10 that was either delayed (0, 2, 30, 180, or 365 days) or probabilistic (i.e., certainty of receipt was 1.0, .9, .75, .5, or .25). The point at which each individual was indifferent between the smaller immediate or certain reward and the $10 delayed or probabilistic reward was identified using an adjusting-amount procedure. The results indicated that (a) delay and probability discounting were well described by a hyperbolic function; (b) delay and probability discounting were positively correlated within subjects; (c) delay and probability discounting were moderately correlated with personality measures of impulsivity; and (d) alcohol had no effect on discounting.     

儿童和青少年信息加工速度发展函数的研究

选择７—１９岁的被试１４０名,对三种不同任务进行操作。结果表明,在句图匹配任务中,儿童反应时是青年反应时的函数,指数函数能较好的描述这种共同的发展变化趋势,但在字母匹配任务中,这种线性关系较差;随着年龄的变化,信息加工速度的下降速率是根据不同的加工任务变化的,简单任务（选择反应和字母匹配）下降速度快,复杂任务（句图匹配）下降速度慢     

Teaching communicative alternatives to socially withdrawn behavior: An investigation in maintaining treatment effects

This study examined the effectiveness of a contextual intervention strategy paired with an existing packaged intervention on the ability to produce increased and durable social involvement among children who displayed socially withdrawn behavior and their peers. Using a multiple baseline design across three socially withdrawn subjects, results indicated that the combination intervention effectively increased social interactions. Results also indicated that the effects of the intervention maintained two months after intervention termination. General implications for the use of the contextual intervention strategy to produce durable treatment outcomes are discussed.     

Hypertension: Cognitive and behavioral considerations

This article reviews literature concerning functional changes resulting from elevated blood pressure, from reduction of blood pressure, and as a result of the medications used to treat high blood pressure. The research reviewed includes the areas of psychomotor speed, intelligence and cognitive processing, sensory and perceptual processes, and emotional and interpersonal behaviors. The conclusions reached are that the deficits noted to date in hypertensive individuals are not extreme nor are they specific. The greatest disadvantage, however, appears in the area of response speed.     

On the exponent in the "generalized" matching equation

A power function equation between ratios of behavior and ratios of reinforcement rates has been called a generalized form of Herrnstein's (1961) matching law, even without a formal relationship having been shown between the two equations. The present work uses a functional relationship to prove that when ratios of reinforcement are not equivalent to ratios of behavior, and the transform leading to this inequality is consistent for every pair of reinforcement rates, the result is a power function relationship between response and reinforcement ratios. The label “generalized matching equation” for the power function equation is thus validated formally.     

A note on ALSCAL: The estimation of the additive constant

A method is given for the least squares regression of a squared variabled ² on the squared variable 0², where the relation between 0 andd is linear. The problem arises in MDS-algorithms where the loss function is defined in terms of squared distances (e.g., ALSCAL). It is pointed out that the Lagrangian multiplier is a root of fourth degree polynomial.     

Locus of control,perceived responsibility for prior fate,and helping behavior

One-hundred-and-sixty adolescents participated in two studies designed to investigate the relationship between $\text{I}\text{E}$ and helping behavior as mediated by the perceived cause of another's need. In the first study, Ss were given the opportunity to help, either “indirectly” or “directly,” a supervisor who had been over- or underpaid in a prior similar task. Internals helped more in the “direct” help than the “indirect” help conditions but their helping behavior and their perceptions of their supervisors were not consistent. The perceptions of the externals were relatively consistent with their greater help of the “overpaid” supervisor. In study 2, the Ss were given additional information to increase the possibility of their making causal attributions as a function of the supervisor's prior fate. Once again, the external subjects' helping behavior reflected their perception of their supervisor's merit. The internal subjects exhibited relatively little helping behavior regardless of their supervisors' prior fate or perceived competence.     

The nonconvergence of factals: A nonmetric common factor analysis

FACTALS is a nonmetric common factor analysis model for multivariate data whose variables may be nominal, ordinal or interval. In FACTALS an Alternating Least Squares algorithm is utilized which is claimed to be monotonically convergent.In this paper it is shown that this algorithm is based upon an erroneous assumption, namely that the least squares loss function (which is in this case a nonscale free loss function) can be transformed into a scalefree loss function. A consequence of this is that monotonical convergence of the algorithm can not be guaranteed.     

Measures of response bias at minimum-detectable luminance levels in the pigeon

Using an operant analogue of the yes-no detection task, six pigeons were trained to detect luminance changes under two different reinforcement-scheduling procedures. In the first, an uncontrolled reinforcement-ratio procedure, the relative frequency of food reinforcers obtained for correct detections was free to vary with the birds' behavior as luminance levels were changed. In the second, a controlled reinforcement-ratio procedure, changes in preference could not alter the relative distribution of food reinforcers between the two response alternatives. Extreme response biases developed as luminance was decreased to threshold in the uncontrolled procedure. No progressive changes in response bias as a function of decreasing luminance were seen in the controlled procedure. Absolute thresholds for light intensity were lower in the controlled than in the uncontrolled procedure.