Orthographic neighborhood effects in lexical decision: the effects of nonword orthographic neighborhood size

The effects of large neighborhoods (neighborhood size) and of higher frequency neighbors (neighborhood frequency) were examined as a function of nonword neighborhood size in lexical decision tasks. According to the multiple read-out model (J. Grainger & A. M. Jacobs, 1996), neighborhood size and neighborhood frequency effects should vary systematically as a function of nonword neighborhood size. In these experiments, the nonword context was more extensively manipulated than in previous studies, providing a more complete test of the model's predictions. In addition, simulations were conducted examining the model's ability to account for the facilitatory neighborhood size and neighborhood frequency effects observed in these experiments. The results suggest that the model overestimates the role of inhibition in the orthographic processing of English words.     

What is learned in sequential learning? An associative model of reward magnitude serial-pattern learning

A computational model of sequence learning is described that is based on pairwise associations and generalization. Simulations by the model predicted that rats should learn a long monotonic pattern of food quantities better than a nonmonotonic pattern, as predicted by rule-learning theory, and that they should learn a short nonmonotonic pattern with highly discriminable elements better than 1 with less discriminable elements, as predicted by interitem association theory. In 2 other studies, the model also simulated behavioral "rule generalization," "extrapolation," and associative transfer data motivated by both rule-learning and associative perspectives. Although these simulations do not rule out the possibility that rats can use rule induction to learn serial patterns, they show that a simple associative model can account for the classical behavioral studies implicating rule learning in reward magnitude serial-pattern learning.     

Dispelling the illusion of invulnerability: the motivations and mechanisms of resistance to persuasion

Three studies examined the impact of a treatment designed to instill resistance to deceptive persuasive messages. Study 1 demonstrated that after the resistance treatment, ads using illegitimate authority-based appeals became less persuasive, and ads using legitimate appeals became more persuasive. In Study 2, this resistance generalized to novel exemplars, persevered over time, and appeared outside of the laboratory context. In Study 3, a procedure that dispelled participants' illusions of invulnerability to deceptive persuasion maximized resistance to such persuasion. Overall, the present studies demonstrate that attempts to confer resistance to appeals will likely be successful to the extent that they install 2 conceptual features: perceived undue manipulative intent of the source of the appeal and perceived personal vulnerability to such manipulation.     

Hearing speech against spatially separate competing speech versus competing noise

Listeners had the task of following a target speech signal heard against two competitors either located at the same spatial position as the target or displaced symmetrically to locations flanking it. When speech was the competitor, there was a significantly higher separation effect (maintained intelligibility with reduced target sound level), as compared with either steady-state or fluctuating noises. Increasing the extent of spatial separation slightly increased the effect, and a substantial contribution of interaural time differences was observed. When same- and opposite-sex voices were used, a hypothesis that the similarity between target and competing speech would explain the role for spatial separation was partly supported. High- and low-pass filtering showed that both parts of an acoustically similar competing signal contribute to the phenomenon. We conclude that, in parsing the auditory array, attention to spatial cues is heightened when the components of the array are confusable on other acoustic grounds.     

Patterns of friendship among girls with and without attention-deficit/hyperactivity disorder

Examined patterns of friendship participation, stability, and quality among previously unfamiliar, ethnically diverse girls with attention-deficit/hyperactivity disorder (ADHD; n = 140) and comparison (n = 88) girls, aged 6–12 years, who attended 5-week naturalistic summer camps. Each girl completed sociometric nominations during Weeks 1, 3, and 5 of the camps; friendships were indexed by examining patterns of reciprocal nominations. At each assessment point, girls with ADHD had fewer mutual friends and were more likely to have no friends. Girls with Combined-type ADHD exhibited difficulties maintaining friendships from the beginning to middle of camp, whereas girls with Inattentive-type ADHD demonstrated poor friendship stability from the middle to end of camp. In general, girls with ADHD had higher levels of negative relationship features—including conflict and relational aggression—than did comparison girls, but levels of positive relationship features did not differ across subgroups. Friendship status predicted positive and negative peer regard, controlling for Verbal IQ and diagnostic status. Overall, although girls with ADHD were able to make friends to some extent, they differed from comparison girls in terms of the likelihood of doing so, the ability to maintain the friendships that they did form, and the levels of negative features found in their friendships.     

Mother-infant interactions in western Lowland Gorillas (Gorilla gorilla gorilla): spatial relationships,communication, and opportunities for social learning

This study investigated mother-infant interactions in lowland gorillas (Gorilla gorilla gorilla) with particular focus on the relative role of mothers and infants in creating situations that are potentially conducive to infant social learning. Eleven gorilla mother-infant dyads were focally observed in weekly 1-hr sessions for 12 months. Spatial relationships were affected by age as well as by ambient temperature. Although the youngest infant was encouraged by its mother to walk and climb, mothers showed little or no encouragement in other contexts. In contrast, infants were quite interested in their mothers' activities, on some occasions repeated their mother's behavior, and actively encouraged their mothers to share food, play, or follow them. These findings suggest that gorilla infants are more active than their mothers in creating situations that are potentially conducive to the acquisition of knowledge or skills.     

Measurement of individual differences in children's suggestibility across situations

The authors attempted to use scores on the Video Suggestibility Scale for Children (VSSC, M. H. Scullin & S. J. Ceci, 2001) to predict 50 preschool children's performance during a field study in which they were interviewed suggestively 4 times about both a true event and a suggested event. Among the 25 children over age 4 years 6 months, tendencies on the VSSC to respond affirmatively to suggestive questions ("yield"), change answers in response to negative feedback ("shift"), and the sum of these ("total suggestibility") were all related to lack of accuracy about the true event in the field study and to both accuracy and lack of accuracy about the suggested event. Results support a 2-factor model of suggestibility.