Showing papers by "School for Advanced Studies in the Social Sciences published in 1991"

Beginnings of prosodic organization: intonation and duration patterns of disyllables produced by Japanese and French infants.

Abstract: In this study, some prosodic aspects of the disyllabic vocalizations (both babbling and words) produced by four French and four Japanese children of about 18 months of age, are examined. F0 contour and vowel durations in disyllables are found to be clearly language-specific. For French infants, rising F0 contours and final syllable lengthening are the rule, whereas falling F0 contours and absence of final lengthening are the rule for Japanese children. These results are congruent with adult prosody in the two languages. They hold for both babbling and utterances identified as words. The disyllables produced by the Japanese infants reflect adult forms not only in terms of global intonation patterns, but also in terms of tone and duration characteristics at the lexical level.

The influence of parafoveal preprocessing and linguistic context on the optimal landing position effect.

Abstract: Several experiments have shown the existence of an optimal landing position effect during isolated word recognition as well as during text reading; both the probability of refixating the test word and the gaze duration are smaller if the eye first fixates near the center of the word than if the eye first fixates other positions in the word. However, recent data indicate that the optimal landing position effect is weakened under normal reading conditions, when words are included in texts. The purpose of the present experiment was to test whether parafoveal preprocessing or linguistic context specific to the text reading situation could be responsible for this weakening. With a paradigm that approximates normal reading, albeit in & somewhat slower manner, it was shown that although the possibility of preprocessing words in parafoveal vision and of predicting them from preceding context globally affected refixation probability and gaze duration on the word, this did not strongly affect the optimal landing position effect. Since the global effects of these factors were comparable to those found by other authors in normal reading, it was concluded that the weakening of the optimal landing position effect during text reading results from the influence of other factors peculiar to this situation. Hypotheses are proposed as explanations of the effects of the manipulated factors on oculomotor behavior.

Chapter 32 Sunspot equilibria in sequential markets models

Abstract: Publisher Summary Equilibrium with rational expectations is a central construct of modern economic theory. The chapter studies surveys, which are primarily aimed at assessing the properties and relevance of this construct in a general equilibrium framework; in particular, they are related to the issue of multiplicity of rational expectation equilibria. The viewpoint discussed in the chapter is associated with the so-called concept of sunspot equilibrium. It focuses on aspects of general equilibrium with rational expectations that have been given a central role in recent literature. It presents the problem of sunspot equilibria in the broader perspective. It also discusses an example of sunspot equilibrium and a simple economic system—namely, a sequential economy with infinite horizon and time independent structure. Furthermore, this economy is one step forward looking and has no predetermined variable.

A comparative analysis of household wealth patterns in france and the united states

Abstract: We find that household wealth is distributed more unequally in the U.S. in 1983 than France in 1986. The Gini coefficient is 0.77 for the U.S. and 0.71 for France. There are also significant differences in the composition of wealth. Owner-occupied housing accounted for half of total assets in France, and only 30 percent in the U.S., while corporate stock and financial securities amounted to 19 percent in the U.S. and 8 percent in France. The debt-equity ratio was 0.13 in France and 0.20 in the U.S. The age-wealth profile in the two countries had the characteristic hump-shape predicted by the life-cycle model, but the profile was much flatter in France and peaked for families aged 50–59 in France, compared to 60–69 in the US.

Directional performances with moving plaids: component-related and plaid-related processing modes coexist.

Abstract: A moving grating oriented ± 45° to the vertical can be perceived at choice as drifting along a left-right or up-down directional axis. When the drifting stimulus is presented alone, direction discrimination thresholds are independent of the specified response-axis. However, they strongly depend on it when the moving stimulus is superimposed on a vertical or horizontal stationary grating. Facilitation is always obtained when the drift direction of the intersections of the two gratings ('blobs') is collinear with the response-axis (i.e. when the orientations of the stationary grating and of the response-axis coincide), while inhibition is observed in the 'noncollinear' cases (i.e. when the orientations of the stationary grating and of the response-axis are orthogonal). These results are generalized in a series of reaction time (RT) experiments where the stimulus configuration described above was set at suprathreshold contrasts and where the orientation/direction of the drifting grating was variable. RT increased when the angle between the response-axis and the direction of the drifting grating increased (uncertainty effect), whether the test stimulus was presented alone, or superimposed on the stationary grating. The uncertainty effect was, however, significantly decreased under 'collinearity' conditions. The attenuation of the uncertainty effect was proportional with the velocity of the blobs and about equal in amount to the RT decrease obtained through the manipulation of the velocity of the drifting grating when presented alone (velocity effect). This observation strongly suggests that both component- and blob/plaid-related information contribute to the directional perception of a compound stimulus and that they sum algebraically.

On the role of refixations in letter strings: The influence of oculomotor factors

Abstract: Recent studies of reading and word recognition have shown that eye-movement behavior depends strongly on the position in the word that the eye first fixates; the probability of refixating in a word is lowest with the eye near the middle of the word, and it increases as the eye fixates to either side. It has generally been assumed that the cause for thisoptimal landing position phenomenon lies in the very strong drop-off of visual acuity even within the fovea; refixation shouid be more likely when the eye starts from a noncentral position, because here less information can be extracted during one fixation. It may, however, be the case that the phenomenon is caused not by acuity drop-off, but by differences in within-word oculomotor scanning tactics as a function of the position that the eye initially fixates. To test this, in the present experiment we kept visual information constant while we varied the initial fixation position. We used homogeneous strings of letters of different length. One letter in each string was different from the rest (e.g., kkkkkok), and this was the letter that the subject initially fixated. This target letter had to be identified before saccading to a comparison string. The position of the target letter in the string was varied from trial to trial. If, owing to acuity limitations, refixations reflect insufficient information extraction, then, because the target letter is always directly fixated, the pattern of refixations in this condition shouid be independent of the first fixation position. However, the obtained refixation probability showed a strong dependence on the position of first fixation. The number of refixations was independent of the absolute length of the letter strings,but it seemed to be influenced by the proportion of the string over which the eye had to pass. The larger this proportion, the higher the probability of refixation. The results suggest that to a cer-tain extent refixations in letter strings (or words) reflect properties of the oculomotor system rather than visual information extraction.

Les Rapports Nord-Sud, la Traite Négrière et le Fuuta Jaloo à la Fin du XVIIIe Siècle

Abstract: Je pars d'un constat : le Fuuta Jaloo theocratique (actuelle republique de Guinee) — un Etat qui se constitue en Afrique de l'Ouest dans la premiere moitie du xviiiie siecle — n'a pu naitre, se maintenir, s'affirmer et se developper qu'en etablissant un systeme economique fonde a la fois sur l'esclavage et la traite negriere. J'entends par la un regime ou l'Etat et la societe des hommes libres tout entiere vont beneficier des captifs, soit en les exploitant comme esclaves soit en les vendant comme marchandises. D'ou une organisation particuliere reposant — principalement par la guerre — sur la production de captifs pour le marche interieur et pour l'exportation. La question de l'esclavage interne, ce que C. Meillassoux definit justement comme l'esclavagisme, ne sera pas abordee ici ; seules m'interessent les relations que l'Etat africain entretenait avec la traite negriere atlantique : des relations que l'on pourrait considerer comme la forme originelle des rapports Nord-Sud.

Aspects of textual continuity linguistic approaches

Abstract: Publisher Summary This chapter provides groundwork, which helps to situate new studies and sets the stage for a general discussion regarding the potential interest of an intersection of approaches in linguistics and psycholinguistics. Interest in linguistics focused on identifying the roles and nature of different markers of text continuity or connectedness used for text composition and construction in different languages. A discussion regarding the current issues in the growing body of literature devoted to markers of text cohesion and connexity. The generally accepted framework allowed researchers to concentrate on specific aspects of text, as the role of topicalization or the lexicon in a text grammar, and the construction of macrostructures.

Aspects of Textual Continuity Psycholinguistic Approaches

Abstract: Publisher Summary This chapter examines the mental operations involved in processing of cohesion markers, the new perspectives, and the problem of the immediacy of referential resolution. Three major features characterize the diversity of studies in this area: a) Investigations of text continuity used widely varying materials, sentence pairs, or texts of varying length. For the most part, materials have been restricted to narratives, with rare examples of descriptive or expository texts. The theoretical issues and the experimental designs behind such experiments are not identical. Methods have changed over the past 10 years. This evolution is due to replacement of classic off-line procedures such as sentence completion, coherence judgment, and recall, by on-line paradigms, which provide a more direct approach to mental operations. The third feature concerns theory. Early studies aimed at identifying the procedures used to search for intersentential referents.

Représentations sociales de la pratique rock en milieu lycéen

Abstract: On trouvera, dans cet article, les resultats d'une enquete par questionnaires, effectuee aupres de 281 lyceens parisiens de 15 a 18 ans. Apres avoir insiste sur la difficulte pratique et theorique de construction d'indices adequats et fideles de questionnement sur l'influence effective du rock, il est precise quel est le modele de reference — en l'occurrence, celui de la culture de masse comme espace d'influences sociales — servant a l'analyse des donnees recueillies. Les resultats permettent de verifier l'existence d'une representation sociale conferant au rock un caractere d'art potentiellement accessible a tous. La pratique rock en groupe est assez minoritaire ches les lyceens meme si l'influence de la musique comme mode de vie et attitude creative reste tres appreciable. Enfin, le statut de minorite des groupes de rock est une variable expliquant le rejet ou la valorisation de ce courant aupres des sujets.

Les purificateurs du rock

Abstract: Les Purificateurs du rock designent, au moyen d'une analogie theorique weberienne, les minorites rock (groupes non reconnus dans le champ de la diffusion culturelle de masse) parisiennes dont J.-M. Seca a realise une ethnographie vers 1987-1988. Modele illustre : celui d'une mecanique individualiste de l'innovation dans la societe de masse. En fin d'article : proposition pour une analyse typologique de ces pratiques sociales.

Organisation Territoriale et Monopole du Thé dans la Chine des Song (960-1059)

Abstract: Territorial Organbation and the Tea Monopoly in Northern-Song China (960-1059). A study of the effects of the location of the monopoly administration in Southern- Huai, which was the first tea-monopoly zone the Song dynasty, sheds light on the link between the evolution of monopoly regulations and the re-unification of the empire during that period. After the territorial break-up of the Five Dynasties the new Song dynasty organized the Southern-Huai tea trade in order to channel profits to the capital Kaifeng. But following the complete reunification of South China in 976, the admi nistration had to strengthen its territorial cohesion in order to fight enemies concen trated on the northern borders. An analysis of the circulation of tea certificates is in fact indicative of the tea-merchant control over the monopoly until the abolition in 1059. Such was the price paid by the administration in order to insure the financial regularity required/or commercial transactions on the borders i.e. in order to control these areas through financial network.