Lexicality and Stimulus Length Effects in Italian Dyslexics: Role of the Overadditivity Effect

The effect of lexicality and stimulus length was studied in 32 third- and fourth-grade Italian dyslexics and in 86 age-matched controls. A visual lexical decision task was used. As proposed by Faust et al. (1999) Faust, M. E., Balota, D. A., Spieler, D. H. and Ferraro, F. R. 1999. Individual differences in information-processing rate and amount: Implications for group differences in response latency. Psychological Bulletin, 125: 777–799. [INFOTRIEVE][CROSSREF][CSA][Crossref], [PubMed], [Web of Science ®] , [Google Scholar], the results were analyzed in terms of raw reaction time (RT) data and using the z-score transformation to control for the presence of overadditivity effects. In terms of RTs, dyslexics showed a larger difference between words and nonwords (lexicality effect) and between short and long stimuli (length effect) than proficient readers. When data were transformed into z scores, only the group by length interaction remained significant while that with lexicality vanished. This pattern indicates that stimulus length has a specific role in Italian dyslexics’ reading deficit; in contrast, slowness in responding to nonwords was not specific but was interpreted as one aspect of dyslexics’ general inability to deal with alphabetical material (overadditivity effect).     

Identification of the 1PL Model with Guessing Parameter: Parametric and Semi-parametric Results

In this paper, we study the identification of a particular case of the 3PL model, namely when the discrimination parameters are all constant and equal to 1. We term this model, 1PL-G model. The identification analysis is performed under three different specifications. The first specification considers the abilities as unknown parameters. It is proved that the item parameters and the abilities are identified if a difficulty parameter and a guessing parameter are fixed at zero. The second specification assumes that the abilities are mutually independent and identically distributed according to a distribution known up to the scale parameter. It is shown that the item parameters and the scale parameter are identified if a guessing parameter is fixed at zero. The third specification corresponds to a semi-parametric 1PL-G model, where the distribution G generating the abilities is a parameter of interest. It is not only shown that, after fixing a difficulty parameter and a guessing parameter at zero, the item parameters are identified, but also that under those restrictions the distribution G is not identified. It is finally shown that, after introducing two identification restrictions, either on the distribution G or on the item parameters, the distribution G and the item parameters are identified provided an infinite quantity of items is available.     

On the Bayesian Nonparametric Generalization of IRT-Type Models

We study the identification and consistency of Bayesian semiparametric IRT-type models, where the uncertainty on the abilities’ distribution is modeled using a prior distribution on the space of probability measures. We show that for the semiparametric Rasch Poisson counts model, simple restrictions ensure the identification of a general distribution generating the abilities, even for a finite number of probes. For the semiparametric Rasch model, only a finite number of properties of the general abilities’ distribution can be identified by a finite number of items, which are completely characterized. The full identification of the semiparametric Rasch model can be only achieved when an infinite number of items is available. The results are illustrated using simulated data.     

Large errors in the perception of vertically are generated by luminance borders (integrated across space) not by subjective borders

The rod-and-frame illusion shows large errors in the judgment of visual vertical in the dark if the frame is large and there are no other visible cues (Witkin and Asch, 1948 Journal of Experimental Psychology 38 762-782). Three experiments were performed to investigate other characteristics of the frame critical for generating these large errors. In the first experiment, the illusion produced by an 11 degrees tilted frame made by luminance borders (standard condition) was considerably larger than that produced by a subjective-contour frame. In the second experiment, with a 33 degrees frame tilt, the illusion was in the direction of frame tilt with a luminance-border frame but in the opposite direction in the subjective-contour condition. In the third experiment, to contrast the role of local and global orientation, the sides of the frame were made of short separate luminous segments. The segments could be oriented in the same direction as the frame sides, in the opposite direction, or could be vertical. The orientation of the global frame dominated the illusion while local orientation produced much smaller effects. Overall, to generate a large rod-and-frame illusion in the dark, the tilted frame must have luminance, not subjective, contours. Luminance borders do not need to be continuous: a frame made of sparse segments is also effective. The mechanism responsible for the large orientation illusion is driven by integrators of orientation across large areas, not by figural operators extracting shape orientation in the absence of oriented contours.     

‘I still have difficulties feeling like a mother’: The transition to motherhood of preterm infants mothers

Objective: The premature birth of their infant can constitute a sudden interruption of the transition to motherhood that requires a reorganisation of the process. The present study aimed to analyse the experience of the transition to motherhood of preterm infants’ mothers, framing it within Stern’s transition to motherhood theory.

Method: A semi-structured interview was administered to 30 mothers during the recovery of the infant in the Neonatal Intensive Care Unit. The interview explored the experience of mothers related to pregnancy, the infant’s birth and recovery.

Results: Thematic Analyses evidenced four interrelated themes: disconnection from the child, perception of maternal inadequacy, loss of parental role and temporal suspension. The themes showed that the mothers’ experience of preterm birth not only concerns the traumatic delivery, but is also embedded in the entire process of becoming a mother within an institutional context.

Conclusions: Results were connected to Stern’s theory. Findings revealed difficulties for preterm mothers that could affect the development of the maternal constellation and thus their transition to motherhood. These difficulties may influence the construction of maternal identity, mother’s representation of their child and the bond with their child.     

Seeking attention: an investigation of salesperson influence strategies used while selling to small retailers

The use of influence strategies is an integral component of the salesperson's role, while selling to retailers. However, it remains a chronically under-researched area, particularly so in emerging markets, which are distinct in terms of retail formats and salesperson challenges. In this study, we investigate influence strategies used by salespersons for selling to retailers in the dominant small retail format in India. Using a combination of observation techniques and in-depth interviews, we allow salesperson influence strategies at play to emerge. In comparison to extant literature, we find evidence for both universality and specificity in the types of influence strategies used at small retail. We identify ‘share of counter’ as a unique small retail phenomenon, potentially requiring a specific set of salesperson influence strategies to succeed. Based on this, a modified typology of salesperson influence strategies, specific to small retail, is proposed. We conclude with a discussion of theoretical and managerial implications for emerging markets, and offer suggestions for future research.