Effects of different training histories upon manufacturing a tool to solve a problem: insight in capuchin monkeys (Sapajus spp.)

Animal Cognition - The emergence of novel behavior is a multilayered phenomenon that comprehends distinct processes. One such process is known as insightful problem solving. “Insight”...     

Cooperative responding in rats maintained by fixed‐ and variable‐ratio schedules

The present study investigated the effects of fixed‐ratio (FR) and variable‐ratio (VR) reinforcement schedules on patterns of cooperative responding in pairs of rats. Experiment 1 arranged FR 1, FR 10, and VR 10 schedules to establish cooperative responding (water delivery depended on the joint responding of two rats). Cooperative response rates and proportions were higher under intermittent schedules than under continuous reinforcement. The FR 10 schedule generated a break‐and‐run pattern, whereas the VR 10 schedule generated a relatively high and constant rate pattern. Experiment 2 evaluated the effects of parametric manipulations of FR and VR schedules on cooperative responding. Rates and proportions of cooperative responding generally increased between ratio sizes of 1 and 5 but showed no consistent trend as the ratio increased from 5 to 10. Experiment 3 contrasted cooperative responding between an FR6 schedule and a yoked control schedule. Coordinated behavior occurred at a higher rate under the former schedule. The present study showed that external consequences and the schedules under which the delivery of these consequences are based, select patterns of coordinated behavior.     

The role of landmarks in cotton-top tamarin spatial foraging: evidence for geometric and non-geometric features

We report experiments on captive cotton-top tamarins (Saguinus oedipus) designed to explore two components of spatial foraging. First, do tamarins have the capacity to extract geometric information concerning the spatial relationship between a landmark and a piece of food located above or below it? Second, when tamarins use a landmark to find a target location, what non-geometric features of the landmark do they encode? To explore these problems, we created an artificial jungle environment and trained subjects to find food either above or below a target object (i.e., landmark). Once subjects successfully located the food, we transformed various features associated with the landmark, including its color, orientation, and shape; we also manipulated the landmark-food reward distance, the overall shape of the jungle, and the number and position of landmarks. Results showed that the tamarins' success in finding the food reward was not affected by landmark color, orientation, number, or overall shape of the jungle, suggesting that with respect to the particular test conditions, these features are not relevant to the representation of a landmark. Subjects also generalized to novel landmark-food distances, suggesting that they had integrated geometric (i.e., above/below) with non-geometric (i.e., color/shape) features. Performance was negatively affected by changes to the shape of the landmark, indicating that this feature is critical to the representation of a landmark. Accepted after revision: 7 August 2001 Electronic Publication     

Career decision-making difficulties of British and Chinese international university students

This study explored cultural and gender differences in career decision-making difficulties (CDMD) experienced by 109 British and 86 Chinese international university students, and the impact of cross-cultural adjustment on the CDMD of Chinese international students. Results showed no significant cultural differences in overall CDMD, and that the cross-cultural adjustment of Chinese participants was not correlated with their difficulty in career decision-making. Significant cultural differences on the sub-categories of the Career Decision-making Difficulties Questionnaire (e.g. Chinese participants were significantly less ready than British participants to make career decisions) and some significant gender differences (e.g. male participants generally experienced fewer difficulties than female participants in career decision-making) were identified. Age and degree level were negatively related to the level of difficulty the participants experienced in career decision-making. Implications for career counselling and future research directions are discussed.     

Measuring Subjective Quality of Life: A Survey to Porto’s Residents

The evaluation of the urban quality of life has been an important aspect of the research concerning the contemporary city and an increasingly support to urban planning and management. As part of a project to monitor the quality of life in the city of Porto, a survey of the resident population was conducted in order to study the citizens’ perceptions of their local quality of life and its evolution in recent years. The opinions of individuals on their level of satisfaction with various fields of the urban quality of life are systematised, as well as their integrated assessment. This analysis is complemented by a multivariate analysis that allows the grouping of the interviewees in large homogenous groups and their social and economic characterisation. Based on the results achieved, we try to highlight the usefulness of the qualitative analysis of the quality of life to support the definition of urban policies.

THIS ARTICLE HAS BEEN RETRACTED: Enumeration of objects and substances in non‐human primates: experiments with brown lemurs (Eulemur fulvus)

Both human infants and adult non‐human primates share the capacity to track small numbers of objects across time and occlusion. The question now facing developmental and comparative psychologists is whether similar mechanisms give rise to this capacity across the two populations. Here, we explore whether non‐human primates’ object tracking abilities are subject to the same constraints as those of human infants. In particular, we examine whether one primate species, the brown lemur (Eulemur fulvus), also fails to represent and enumerate objects when they behave non‐rigidly or non‐cohesively. We presented lemurs with a series of expectancy violation studies involving simple 1 + 1 addition events in which we varied the entities to be enumerated. Like infants, lemurs successfully enumerated the two objects when those objects were rigid, cohesive individuals, but failed to enumerate similar‐looking non‐rigid piles of sand. In contrast to human infants, however, lemurs successfully enumerated non‐cohesive objects that broke into multiple pieces. These results are discussed in light of recent theories about object processing in human infants and adults.     

Learning a foreign language: Effects of tact and listener instruction on the emergence of bidirectional intraverbals

We evaluated the effects of tact and listener instruction on the emergence of bidirectional intraverbal relations with 6 typically developing Brazilian children, using an adapted alternating treatment design with pretest and posttest probes. In listener instruction, participants selected pictures that corresponded to spoken foreign-language words. For tact instruction, children had to vocalize foreign words in the presence of the corresponding pictures. After meeting mastery criteria, bidirectional intraverbal tests assessed vocalizations in Portuguese (native language) following the presentation of the equivalent words in English (foreign language) and vice versa. Tact instruction consistently produced higher levels of emergent intraverbal responding compared to listener instruction, confirming results from previous studies.     

Functional analysis and intervention of perseverative speech in students with high-functioning autism and related neurodevelopmental disabilities

Although perseverative speech is a common characteristic of individuals with high-functioning neurodevelopmental disabilities, little is known about the operant functions of these verbalizations. We conducted analogue functional analyses of perseverative speech for 2 students using reinforcement contingencies that included alone, attention, control, escape, and tangible conditions. Results showed the following patterns: attention only (Charlotte) or multiply determined including an attention function (Paul). We then tested an intervention for perseverative speech maintained by social positive reinforcement that included differential reinforcement of alternative behavior and extinction of perseverative speech for 1 participant. The intervention reduced perseverative speech, but did not increase appropriate speech until we added a prompting component. We then replicated this three-component intervention with Paul. The results showed moderate to high decreases in levels of perseverative speech and increased appropriate verbalizations in both cases. The results systematically replicated the interventions of previous studies by adding a prompting component to the intervention.