EEG alpha reactivity and extraversion-introversion

Spectral characteristics of spontaneous EEG and characteristics of the alpha attenuation response (AAR) induced by acoustic stimulation, were analyzed for two groups of subjects selected on the basis of their scores on the extraversion-introversion scale of the Eysenck Personality Questionnaire. While no significant differences were found in basic alpha rhythm, significant differences were manifested in the AAR characteristics. Extraverted subjects habituated to the auditory stimulus while introverts did not. Introverts were generally more responsive to stimulation. The results are discussed in relation to the arousability model proposed by Eysenck and Gray, verifying the relationships with typological dimensions of Superior Nervous Activity, elaborated by the Soviet school.     

Play behaviors of handicapped preschool children in the presence and absence of nonhandicapped peers

Sixteen minimally handicapped children and 18 nonhandicapped children were observed playing as separate classes and as a combined group on their preschool playground. Play behaviors directed toward self, toys, teachers, and peers were recorded using a time sampling procedure. Repeated measures analyses revealed that: (1) handicapped children engaged in less peer-directed and more teacher-directed behaviors than the similar chronological age but developmentally more advanced normal children; (2) a comparison between a subsample of normal and handicapped children who were approximately equivalent on developmental age suggested that the normal children only vocalized more often; (3) when integrated with the normal children, handicapped children engaged in more peer-directed and less teacher-directed behaviors than when playing in the non-integrated situation; (4) during the combined group play situation, normal children directed more behaviors to their own classmates while handicapped children directed approximately equal amounts of behavior to their own classmates and to their normal peers. These results suggest that the normal children were not negatively affected and the handicapped children were positively affected by the integrated play situation.     

Working memory and intrusions of irrelevant information in a group of specific poor problem solvers

An important body of evidence has shown that reading comprehension ability is related to working memory and, in particular, to the success in Daneman and Carpenter's (1980) reading and listening span test. This research tested a similar hypothesis for arithmetic word problems, since, in order to maintain and process the information, they require working memory processes. A group of children possessing average vocabulary but poor arithmetic problem-solving skills was compared with a group of good problem solvers, matched for vocabulary, age, and socioeconomic status. Poor problem solvers presented lower recall and a greater number of intrusion errors in a series of tasks testing working memory and memory for problems. The results obtained over a series of six experimental phases, conducted during a 2-school-year period, offer evidence in favor of the hypotheses that groups of poor problem solvers may have poor performance in a working memory test requiring inhibition of irrelevant information (Hypothesis 1), but not in other short-term memory tests (Hypothesis 2), that this difficulty is related to poor recall of critical information and greater recall of to-be-inhibited information (Hypothesis 3), that poor problem solvers also have difficulty in remembering only relevant information included in arithmetic word problems (Hypothesis 4) despite the fact that they are able to identify relevant information (Hypothesis 5). The results show that problem-solving ability is related to the ability of reducing the memory accessibility of nontarget and irrelevant information.     

Generation speed in Raven''s progressive matrices test

In this paper, we investigate the role of response fluency on a well-known intelligence test, Raven's Advanced Progressive Matrices (APM) test. Finding rules that govern the items is critical in solving this test. Finding these rules is conceptualized as sampling rules from a (statistical) rule distribution until the correct one is attained. Response fluency is then seen as generation speed, or the speed at which a person generates (samples) rules from this distribution. We develop a test that isolates this speed of sampling variable, and a method to check whether this variable was adequately isolated. The score on this test is then compared with performance on the APM test. It is found that the speed at which people sample from such distributions is an important variable in solving APM items.     

Trust and fear of exploitation in a public goods dilemma

The present article presents a brief theoretical overview about the role of trust in promoting cooperation in public goods dilemmas. Until now, no research has been conducted to explore the different psychological variables which are related to trust and which may help clarify the role of trust in public goods dilemmas. This article proposes some theoretical assumptions which explain that trust reduces people's experiences of fear of exploitation. This article also relates the concept of trust to perceptions of fairness and collective efficacy. Finally, some empirical evidence is presented to test these assumptions. Results show that trust seems, indeed, to have an effect on people's experiences of fear and, even more importantly, the power of trust to reduce fear seems to be strongly related to perceptions of fairness and collective efficacy.     

Collective self-esteem, personal self-esteem, and collective efficacy in in-group and outgroup evaluations

In assessing the relationship between self-esteem and in-group/outgroup evaluations, this study examined whether self-esteem is better measured at a collective (collective self-esteem [CSE]) than a personal level (personal self-esteem [PSE]). It was expected that subjects high in CSE would engage in more in-group favoritism (measured by in-group evaluations), whereas those low in CSE would engage in more outgroup derogation (measured by outgroup evaluations). No effect for PSE was predicted. Furthermore, the study explored whether perceptions of collective efficacy may underlie this relationship. Subjects played a public goods task. The in-group's outcome was compared to the outcome of other relevant outgroups, enhancing pressures towards intergroup differentiation. Consistent with the predictions, subjects high in CSE evaluated in-group members more positively than those in low CSE (i.e., in-group favoritism), whereas subjects low in CSE evaluated outgroup members more negatively than those high in CSE (i.e., outgroup derogation). Also in line with our predictions, no effect for PSE was found. Perceptions of collective efficacy appeared to be a mediator of the effect of CSE.     

Nosology and Causal Necessity; The Relation BetweenDefining a Disease and Discovering its Necessary Cause

The problem of disease definition is related to theproblem of proving that a certain agent is thenecessary cause of a certain disease. Natural kindterms like rheumatoid arthritis and AIDS refer toessences which are discoverable rather thanpredeterminate. No statement about such diseases isa priori necessarily true. Because theories onnecessary causes involve natural kind semantics,Koch's postulates cannot be used to falsify or verifysuch theories. Instead of proving that agent A is thenecessary cause of disease D, we include A in atheoretical definition of D, take this to representthe real meaning of D, and discard thepretheoretical definition. This is illustrated byKoch's own attempt to prove he had discovered thenecessary cause of tuberculosis. Methodologicalarguments about disease causation require a clear viewof our use of diagnostic terms. Medical lexicographersshould do more to provide such a view.     

Measuring symbol and icon characteristics: Norms for concreteness, complexity, meaningfulness, familiarity, and semantic distance for 239 symbols

This paper provides rating norms for a set of symbols and icons selected from a wide variety of sources. These ratings enable the effects of symbol characteristics on user performance to be systematically investigated. The symbol characteristics that have been quantified are considered to be of central relevance to symbol usability research and include concreteness, complexity, meaningfulness, familiarity, and semantic distance. The interrelationships between each of these dimensions is examined and the importance of using normative ratings for experimental research is discussed.