Expectations about numerical events in four lemur species (Eulemur fulvus, Eulemur mongoz, Lemur catta and Varecia rubra)

Although much is known about how some primates—in particular, monkeys and apes—represent and enumerate different numbers of objects, very little is known about the numerical abilities of prosimian primates. Here, we explore how four lemur species (Eulemur fulvus, E. mongoz, Lemur catta, and Varecia rubra) represent small numbers of objects. Specifically, we presented lemurs with three expectancy violation looking time experiments aimed at exploring their expectations about a simple 1+1 addition event. In these experiments, we presented subjects with displays in which two lemons were sequentially added behind an occluder and then measured subjects duration of looking to expected and unexpected outcomes. In experiment 1, subjects looked reliably longer at an unexpected outcome of only one object than at an expected outcome of two objects. Similarly, subjects in experiment 2 looked reliably longer at an unexpected outcome of three objects than at an expected outcome of two objects. In experiment 3, subjects looked reliably longer at an unexpected outcome of one object twice the size of the original than at an expected outcome of two objects of the original size. These results suggest that some prosimian primates understand the outcome of simple arithmetic operations. These results are discussed in light of similar findings in human infants and other adult primates.This revised version was published online in March 2005 with corrections to Fig. 6.     

Dismal: a spreadsheet for sequential data analysis and HCI experimentation

Dismal is a spreadsheet that works within GNU Emacs, a widely available programmable editor. Dismal has three features of particular interest to those who study behavior: (1) the ability to manipulate and align sequential data, (2) an open architecture that allows users to expand it to meet their particular needs, and (3) an instrumented and accessible interface for studies of human-computer interaction (HCI). Example uses of each of these capabilities are provided, including cognitive models that have had their sequential behavior aligned with subject’s protocols, extensions useful for teaching and doing HCI design, and studies in which keystroke logs from the timing package in Dismal have been used.     

Relation of academic support from parents, teachers, and peers to Hong Kong adolescents' academic achievement: the mediating role of academic engagement

The author tested a model hypothesizing that students' self-perceived academic support (from parents, teachers, and peers) is related to their achievement directly and indirectly through their own perceived academic engagement. The participants were 270 adolescents (M age = 15.41 years, range = 14-20 years) from 3 grade levels (Forms 3-5, equivalent to Grades 9-11 in the United States) in a Hong Kong secondary school. The school principal and teachers helped to collect data based on these adolescents' responses to a self-report questionnaire, consisting of a demographic profile and 4 scales assessing their self-perceptions of the extent of parental, teacher, and peer support, and their own academic engagement. Academic achievement was measured by self-reported grades in math, English, and Chinese. Structural equation modeling analyses revealed that adolescents' perceived parental, teacher, and peer support were all indirectly related to their academic achievement mediated by their own perceived academic engagement. The strength of the relationships, however, varied by support system, with perceived teacher support to achievement being the strongest, followed closely by perceived parental support, and then perceived peer support. In addition, both perceived parental support and perceived teacher support were directly related to academic achievement. However, perceived teacher support made the most total (direct and indirect) contribution to student achievement. Perceived peer support had the smallest, nonetheless significant, indirect relationship to academic achievement. However, the negative, direct influence of perceived peer support canceled out its positive, indirect influence on academic achievement.     

Measurement of Cruelty in Children: The Cruelty to Animals Inventory

Cruelty to animals may be a particularly pernicious aspect of problematic child development. Progress in understanding the development of the problem is limited due to the complex nature of cruelty as a construct, and limitations with current assessment measures. The Children and Animals Inventory (CAI) was developed as a brief self- and parent-report measure of F. R. Ascione's (1993) 9 parameters of cruelty. The CAI emerged as a reliable, stable, and readily utilized measure of cruelty using parent and child reports. Children (especially the older children) reported higher rates of cruelty than their parents and boys reported more cruelty than girls. Self- and parent-reports showed good convergence with independent observations of cruelty versus nurturance during free interactions with domestic animals. The results indicate that cruelty to animals can be reliably measured using brief child and parent report measures.     

An investigation of differences between self-injurious behavior and suicide attempts in a sample of adolescents

Data from 390 high school students were collected to examine potential differences between adolescents who had attempted suicide and those who engaged in self-injurious behavior on measures of depression, suicidal ideation, and attitudes toward life and death. Significant differences were found between controls and the self-harm groups on all dependent variables. A significant difference on attitudes toward life was found between the self-injury and suicide attempt groups. Post-hoc regression analyses showed that measures of depression, suicide ideation, and attitudes towards life predicted participants' self-harm categorization. These findings provide preliminary evidence that self-injurious behavior is different from attempted suicide among a community sample of adolescents.     

Preschoolers' comprehension of goal structure in narratives

Preschool children's understanding and use of goals were studied in two experiments. Children heard stories in the presence of pictures or props. The stories were varied by goal success occurring early or late in the story, with late goal success resulting in more causal connections in the narrative. The results showed that children recalled goals spontaneously and that their recall benefited from goal structure of the stories. Pictures benefited the children when the stories were short. Enactment of the props versus static displays of the props did not enhance recall in the second experiment. Preschool children thus demonstrated ability to infer and use goal and causal information in stories for both picture and object support.     

The old and thee, uh, new: disfluency and reference resolution

Most research on the rapid mental processes of on-line language processing has been limited to the study of idealized, fluent utterances. Yet speakers are often disfluent, for example, saying "thee, uh, candle" instead of "the candle." By monitoring listeners' eye movements to objects in a display, we demonstrated that the fluency of an article ("thee uh" vs. "the") affects how listeners interpret the following noun. With a fluent article, listeners were biased toward an object that had been mentioned previously, but with a disfluent article, they were biased toward an object that had not been mentioned. These biases were apparent as early as lexical information became available, showing that disfluency affects the basic processes of decoding linguistic input.     

Changing features do not guide attention in change detection: Evidence from a spatial cuing paradigm

Smilek, Eastwood, and Merikle (2000) demonstrated that the detection of change was facilitated when the target character changed in many rather than few of its features. Specifically, the function relating search response time to display set size was shallower when more features changed than when fewer features changed. The researchers interpreted these results as indicating that large feature changes provide preattentive guidance of focal attention to the location of the change. We tested this preattentive guidance hypothesis by examining change detection performance in the context of a spatial cuing paradigm. The hypothesis predicts that (1) the cost on invalidly cued trials should be less when more features change than when fewer features change, and (2) the features manipulation should have no effect on validly cued trials. In contrast to these predictions, our results show that cuing effects are equivalent across all levels of feature change and that a robust effect of the features manipulation is observable for both validly and invalidly cued trials. We argue that large feature changes do not provide preattentive guidance and in fact can be detected more readilyafter attention is already in place at the target location.