An on-line assessment of causal reasoning during comprehension

Fletcher and Bloom (1988) have argued that as readers read narratives, clause by clause, they repeatedly focus their attention on the last preceding clause that contains antecedents but no consequences in the text. This strategy allows them to discover a causal path linking the text's opening to its final outcome while minimizing the number of times long-term memory must be searched for missing antecedents or consequences. In order to test this hypothesis, we examined the reading times of 25 subjects for each clause of eight simple narrative texts. The results show that: (1) causal links between clauses that co-occur in short-term memory (as predicted by the strategy) increase the time required to read the second clause; (2) potential causal links between clauses that never co-occur in short-term memory (again as predicted by the strategy) have no effect on reading time; and (3) reinstatement searches are initiated at the end of sentences that are causally unrelated to the contents of short-term memory or that contain clauses that satisfy goals no longer in short-term memory. These results support the claim that subjects engage in a form of causal reasoning when they read simple narrative texts.     

Testosterone and personality among college students and military veterans

Relationships of serum and saliva to personality were examined among 401 college students in four laboratory studies and 5,236 military veterans in one archival study. Among the students, there were few relationships between testosterone and traditional personality measures. Among the veterans, MMPI scores and DSM-III diagnoses showed testosterone related to drug and alcohol abuse, antisocial and generally intemperate behavior, and effective disorders. Consistent with social control theory, correlations were higher among veterans who were lower in socioeconomic status. It appears likely that testosterone has innate effects that are socially undesirable but can be attenuated by bonds between the individual and society. Effect sizes were small, suggesting that testosterone will have noticeable effects only in large populations or individuals who differ markedly from the population mean. Further research should focus upon antisocial correlates of testosterone and conditions that produce marked changes in testosterone levels.     

Flexibility of Labor, Well-Being, and Stress

After a short introduction into the changing nature of our society and organizations, we outline two kinds of flexibility of labor: qualitative flexibility, that is the degree to which people who work in or for a certain organization can and do perform different tasks, and quantitative flexibility, that is, varying the quantity of personnel and their working hours. Then, the different ways in which we organize our work and organizations are dealt with in terms of quantitative and qualitative flexibility. Next, we survey these ways of organizing on the degree to which they moderate the positive individual outcomes, or individual goals, of work. It can be concluded that quantitatively flexible work, besides some minor positive consequences, may have serious negative consequences for one's well-being, health, and personal development, while qualitative flexibility may have many more advantages, though it may lead to a devastating task overload. Last, we explore some ways to alleviate these negative effects.     

A motor timing experiment implemented using a musical instrument digital interface (MIDI) approach

The musical instrument digital interface (MIDI) offers a way for perception and behavior researchers to implement high-quality experiments using inexpensive, commercially available hardware and software. We describe the MIDI and illustrate its applicability to research using a replication of the oscillator signature finding reported recently by Collyer, Broadbent, and Church (1992, 1994).     

A multidimensional scaling analysis of vowel discrimination in humans and monkeys

Multidimensional scaling (MDS) was used to compare perceptual maps for 10 synthetic English vowels in humans and Old World monkeys (Macaca fuscata andCercopithecus albogularis). Subjects discriminated among the vowels using a repeating background procedure, and reaction times were submitted to an MDS analysis to derive measures of perceived similarity. The dimensions that emerged related to the frequencies of the first(F1), second(F2), and third(F3) formants. Human data indicated a good match to previous MDS studies using rating procedures or confusion matrices: The dominant dimension mapped onto vowelF2, the phonetically most important formant, and the second and third dimensions mapped ontoF1 andF3, respectively.For monkeys, equal weightings occurred forF1 andF2, andF3 was not clearly represented. Monkey sensitivity to the formants appeared to relate to formant amplitudes. If monkeys are giving an accurate representation of the psychoacoustic relations among the formants, then our human results suggest that species-specific mechanisms, reflecting the salience of the phonetic feature of advancement, may contribute to vowel coding in humans.