Bilingualism and Lexical Representation

Forty-eight Hindi-English bilinguals completed two blocks of trials where each trial involved presentation of a letter string requiring a lexical decision. In the first block subjects were exposed to 22 words and 11 non-words in either English or Hindi. In the second block the original words were repeated in either the same language or in the alternative language. In this block the old (repeated) words were mixed with 22 new words, and 22 non-words. Twelve subjects were included in each of the four groups given by the factorial combination of blocks and languages. Reaction time in the lexical decision task was facilitated when words were repeated in the same language (109 and 125 ms in the English-English and Hindi-Hindi groups respectively), but little or no facilitation was observed in the inter-lingual conditions (-22 and 23 ms in the Hindi-English and English-Hindi conditions respectively). The results support the view that lexical representation in bilinguals is language-specific.     

Selective antagonism of the rate-decreasing effect of d-amphetamine by chlorpromazine in a repeated-acquisition task.

Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of four colors. The response chain was maintained by food presentation under a fixed-ratio schedule. When d-amphetamine was administered alone, the overall response rate decreased and the percent errors increased with increasing doses. When a small dose of chlorpromazine, which was ineffective when given alone, was administered in combination with d-amphetamine, the rate-decreasing effect was antagonized. The antagonism was selective, however, in that the error-increasing effect of d-amphetamine was augmented by chlorpromazine. The nature of the joint effect of the two drugs thus depended on the behavioral measure: rate vs. accuracy.     

The Effects of Perceived Activity Choice upon Frequency of Exercise Behavior

The purpose of this study was to investigate the effect of perceived activity choice upon the frequency of exercise behavior of adult women. Thirty-six recent enrollees in a private health club were recruited for involvement in a new exercise program. At an initial organizational meeting, subjects ranked their preferences for different activities and completed a number of self-report inventories. Subjects were paired on the basis of their activity preferences so as to establish two matched groups of subjects. One member of each pair was then randomly assigned to a choice condition while the other was assigned to a no choice control condition. Perceived choice was manipulated at the time of an individual's next visit to the club, with subjects in the choice group being led to believe that their initial activity selections were the basis for their programs whereas subjects in the control group were informed that they had been assigned a standardized exercise program by the club's instructresses. The overall attendance of the choice group was better than that of the control group. Across both groups there was a significant decline in attendance over the 6-week period but the decrement was significantly greater in the control group. At the conclusion of the 6-week period, subjects in the choice condition expressed a greater intention to continue exercising at the club than did subjects in the control condition.     

Training fast and frugal heuristics in military decision making

Fast and frugal heuristics have been used to model decision making in applied domains very effectively, suggesting that they could be used to improve applied decision making. We developed a fast and frugal heuristic for infantry decisions using experts from the British Army. This was able to predict around 80% of their decisions using three cues. Next, we examined the benefits of learning to use the fast and frugal heuristic by training junior officers in the British Army to apply the heuristic and assessing their accuracy and mental workload when making decisions. Their performance was compared to a control condition of junior officers who applied standard military decision methods. Participants using the fast and frugal heuristic made decisions as accurately as participants in the control condition, but with reduced mental demand. This demonstrates that fast and frugal heuristics can be learnt and are as effective as analytic decision methods.     

Learning of a hippocampal-dependent conditioning task changes the binding properties of AMPA receptors in rabbit hippocampus.

The N-methyl-D-asparate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) subtypes of glutamate receptors have been shown to play critical roles in various forms of synaptic plasticity (i.e., learning and memory, long-term potentiation). We previously demonstrated that the binding of [3H]AMPA to the AMPA subtype of glutamate receptors was selectively increased in hippocampus following classical conditioning of the rabbit nictitating membrane response in a delay paradigm. We report here that the same effect was observed in a variant of this learning paradigm that requires the participation of the hippocampus, i.e., trace conditioning of the rabbit nictitating membrane. The binding of [3H]TCP (N-[1-(2-thienyl)cyclo-hexyl]-3,4-piperidine) to the NMDA receptor remained unchanged in all the experimental groups tested. Paired presentations of conditioned and unconditioned stimuli resulted in an increased binding of [3H]AMPA, an agonist of the AMPA receptors, in several hippocampal subfields while the binding of an antagonist, [3H]CNQX (6-nitro-7-cyanoquinoxaline-2,3-dione), was decreased. The results suggest that the learning-induced changes in binding of the ligands to the AMPA receptor reflect changes in affinity of the receptor rather than in the number of sites. These results support the hypothesis that changes in hippocampal glutamate receptors are a corollary of synaptic plasticity in certain forms of learning.     

A review of reinforcement control procedures

A demonstration of the effects of reinforcement requires comparison of response rates in the presence of a contingency with those in another condition that controls for the influence of extraneous variables. We describe several control conditions that have been used in evaluating the effects of positive and negative reinforcement. The methodological rigor and practical utility of each type of control condition are discussed, and recommendations for the use of these conditions are presented.     

The role of language familiarity in voice identification

Four experiments examined the effects of language characteristics on voice identification. In Experiment 1, monolingual English listeners identified bilinguals' voices much better when they spoke English than when they spoke German. The opposite outcome was found in Experiment 2, in which the listeners were monolingual in German. In Experiment 3, monolingual English listeners also showed better voice identification when bilinguals spoke a familiar language (English) than when they spoke an unfamiliar one (Spanish). However, English-Spanish bilinguals hearing the same voices showed a different pattern, with the English-Spanish difference being statistically eliminated. Finally, Experiment 4 demonstrated that, for English-dominant listeners, voice recognition deteriorates systematically as the passage being spoken is made less similar to English by rearranging words, rearranging syllables, and reversing normal text. Taken together, the four experiments confirm that language familiarity plays an important role in voice identification.     

Social Change and Change in Intentions of Iranian Youth Regarding Education,Marriage, and Careers

Effects of large-scale socio-political movements and policy changes on individual attitudes and behaviours have been the focus of attention of social scientists and policy-makers in different countries. For example, concerns have been expressed regarding the effects of the so-called “fundamentalist” Islamic movements on attitudes and behaviours in relation to marriage, family structure, and the roles/rights of women. The Islamic Revolution of 1978 in Iran is usually assumed to have affected such beliefs and behaviours. To test the accuracy of such an assumption, three data sets collected in the same geographical location in 1982, 1984, and 1986 were compared within sex and SES groups. The intentions and aspirations of high school seniors regarding education, marriage, and careers were closer to conservative/traditional expectations in the 1982 sample than in the 1984 and 1986 samples. It is concluded that, even if there was an increase in traditionalism shortly after the Revolution, traditional tendencies have not returned to extreme levels within the few years surveyed, at least among the urban educated youth under study. Alarm regarding a ‘return to fundamentalism” in relation to marriage, family, and women's roles/rights might be less warranted than is commonly assumed.