Effects of discrimination training on stimulus generalization in pigeons: Role of resistance to extinction and response-produced stimuli

In Experiment 1, two groups (n = 10) of pigeons received 17 sessions of TD (true discrimination) or ND (nondifferential) training with line angles. Seventeen sessions of SS (single stimulus) training with a wavelength preceded this training and two followed it. Subsequent wavelength generalization testing in extinction revealed a sharper TD than ND gradient. This slope difference was evident from the very first test stimulus presentation and remained stable throughout testing. As a consequence of substantial overtraining, there was no reduction of response strength and no sharpening of generalization during testing for either group. In Experiment 2, two groups (n = 16) of pigeons received 10 sessions of TD or PD (pseudodiscrimination) training with line angles, followed by four sessions of SS training with a single wavelength. During this training and in subsequent wavelength generalization testing in extinction, brief blackouts separated stimulus presentations. Again, the TD group yielded the sharper gradient. Although responding weakened and the gradients sharpened during the test, these effects were comparable in the two groups. Furthermore, gradients based on the percentage of trials with at least one response showed the same TD-PD slope difference. This finding indicates that differential control over responding by response-produced feedback is inadequate to account for the TD-PD difference in generalization slope. Both experiments indicate that a purported difference in resistance to extinction is also an inadequate explanation.     

The Interrelation of First-Year College Students’ Critical Thinking Disposition, Perceived Academic Control, and Academic Achievement

While a great deal of research has examined students’ critical thinking skills, less is known about students’ tendencies to use these skills. Specifically, little is known about what factors contribute to students developing a disposition to think critically or what impact this disposition has on college students’ academic achievement. Perceived control, which has been found to be an important factor in college students’ academic success, may be an important factor in developing this disposition. The current longitudinal study examined the reciprocal-effects between critical thinking disposition and perceived academic control, and their comparative influences on academic achievement in 1196 first-year college students. Using a two-wave, two-variable cross-lag structural equation model, a reciprocal-effect was found whereby students’ perceived academic control predicted their subsequent critical thinking disposition, and students’ critical thinking disposition predicted their subsequent perceived academic control. Furthermore, after controlling for high school academic performance, perceived academic control was found to have a stronger impact on students’ GPAs than critical thinking disposition. Implications of fostering a critical thinking disposition and perceived academic control among college students are discussed.

Acquisition of barpressing in rats following experience with response-independent food

In a three-group experiment, one group of rats (response-contingent) learned to contact a food cup for Noyes food pellets delivered according to a fixed-ratio schedule of reinforcement. Subjects in another group received a response-independent pellet each time its yoked counterpart earned one. A third (control) group received the same amount of food as the other two groups each day, but the pellets were delivered in mass. Following this training, the rats were placed in a novel experimental chamber in which all responses on a bar were reinforced with the presentation of food pellets. The results showed the response-independent animals to be slower in acquiring the barpress response than the naive control subjects, and the response-contingent subjects to be the fastest.     

Faculty in Transition: A Longitudinal Analysis of the Role of Perceived Control and Type of Institution in Adjustment to Postsecondary Institutions

As postsecondary institutions undergo major changes in the coming years, they will be hardpressed to maintain the quality of their programs unless they can successfully attract and retain new faculty. Understanding something about the experiences of new faculty should enable postsecondary institutions to be more effective in the recruitment process. The present study examined the adjustment of newly hired faculty at the point of entry into their institutions and subsequently for a three-year period. It was expected that perceived personal control, teaching experience, gender, type of institution, and time would be particularly critical to the adjustment of new faculty. Three surveys were administered one year apart to newly hired, tenure-track faculty who responded to questions about their adjustment experiences. The results indicated that perceived control is a critical factor affecting new hires' emotional well-being, stress levels, job satisfaction, etc., either by itself or in combination with institution type and time. Overall, new hires who were identified as having greater control believed they had more control over their teaching and career in general, were more satisfied with their teaching and their career, had less teaching- and career-related job stress, and were less likely to consider quitting their job. The type of institution also affected new hires' adjustment, with the liberal arts colleges and a comprehensive I institution having the most negative impact compared with a community college and a research I institution. Finally, time had an unexpected negative effect on adjustment. These finding were discussed in relation to the career development of faculty.     

Sensitivity to Visual-Tactile Colocation on the Body Prior to Skilled Reaching in Early Infancy

Two experiments examined perceptual colocation of visual and tactile stimuli in young infants. Experiment 1 compared 4- (n = 15) and 6-month-old (n = 12) infants’ visual preferences for visual-tactile stimulus pairs presented across the same or different feet. The 4- and 6-month-olds showed, respectively, preferences for colocated and noncolocated conditions, demonstrating sensitivity to visual-tactile colocation on their feet. This extends previous findings of visual-tactile perceptual colocation on the hands in older infants. Control conditions excluded the possibility that both 6- (Experiment 1), and 4-month-olds (Experiment 2, n = 12) perceived colocation on the basis of an undifferentiated supramodal coding of spatial distance between stimuli. Bimodal perception of visual-tactile colocation is available by 4 months of age, that is, prior to the development of skilled reaching.     

Cognitive profiling in Chinese developmental dyslexia with attention-deficit/hyperactivity disorders

The cognitive profiles of children with Developmental Reading Disorder (RD) and Attention-Deficit/Hyperactivity Disorders (ADHD) have been extensively studied in alphabetic language communities. Deficits in phonological processing and rapid naming have been implicated as core features of RD although whether the latter is a deficit specific to RD remains controversial. Similar research aiming to explore the cognitive profiles of children with both RD and ADHD in non-alphabetic language communities is limited. The specificity of rapid naming deficit to RD among Chinese has yet to be studied. In the first study, 43 Chinese children with confirmed diagnoses of RD + ADHD were assessed on their cognitive abilities in relating to reading. In the second study, the specificity deficit hypothesis of rapid naming to RD but not ADHD was examined. A digit naming test was administered to the RD + ADHD group (43 subjects) and an ADHD only group (49 subjects). In regard to cognitive profiling, rapid naming and orthographic knowledge were found to be the most common deficits among the Chinese RD + ADHD group. This co-morbid group was also found to have a significant deficit performance on the rapid naming task than the ADHD only group. The present findings support the double dissociation hypothesis in cognitive deficit between RD and ADHD. The results of both studies are discussed with reference to the findings of the Western counterparts.     

Attributional (explanatory) thinking about failure in new achievement settings

Attributional (explanatory) thinking involves the appraisal of factors that contribute to performance and is instrumental to motivation and goal striving. Little is understood, however, concerning attributional thinking when multiple causes are involved in the transition to new achievement settings. Our study examined such complex attributional thinking in the transition from high school to university, a shift from familiar to novel learning environments, in the context of Weiner’s attribution theory (1972, 1985, 1995, 2006). At the start of the academic year, students rated the extent to which each of six common attributions contributed to poor performance to ascertain their relative importance to each other. A fixed order of attributions was reported as contributing to poor performance that was identical across five independent cohorts of first-year students (effort, test difficulty, strategy, professor quality, ability, luck, respectively). Cluster analysis revealed that students differed in combining these attributions into clusters suggesting diminished or enhanced control over poor performance. These differences in attribution clusters were associated with cognitive and affective outcomes at the start of Term 1, and with course grades and GPA at the end of Term 2. Student differences in complex attributional thinking are discussed in terms of transitions to new achievement settings.     

Verbal and spatial encoding of text

Two experiments were conducted which examined conjoint retention of spatial and verbal information in memory. The first experiment examined processing of text with simultaneous active dual coding. With spatial and verbal information from experiment one, the second experiment examined the effects of introducing dual coding prior to text processing and keyed recall to what was encoded prior to reading. Recall of both concrete features and events referring to these features was keyed to constructive encoding processes. Even minimal cueing produced better recall than no cues. Spatial primers produced not only better recall of features, but subjects who encoded spatial primers demonstrated increased ability to recall those primers. Results were interpretet in terms of dual coding theory for encoding and retrieval.     

Achieving scale of farmer reach with improved common bean technologies: the role of village-based advisors

Purpose: We assessed the effectiveness of Village-based Advisors (VBAs) as a novel approach for scaling up improved common bean technologies in southern highlands of Tanzania.

Design/methodology/approach: Data were gathered through focus group discussions (FGDs) and interviews with 11 VBAs and 102 farmers (37% female). The effectiveness of VBAs was assessed based on farmer reach, farmer knowledge, and application of new technologies.

Findings: VBAs played important roles in reaching a wide audience of farmers, with common bean technologies. There was evidence of uptake of promoted common bean practices by farmers, enhanced by judicious incentives such as higher yields, increased land productivity, and labor-saving. VBAs shared information mainly through farm visits and community meetings. Extension materials facilitated VBA engagement of farmers even in informal settings, enhancing information flow beyond village boundaries. The current success of the VBA approach stems from the fact that VBAs are motivated by the rewards they receive – both cash and non-cash.

Practical implications: VBAs are relevant in scaling up improved common bean technologies in rural Tanzania and similar settings, because of farmer understanding and trust. For sustainability, there is need to develop a more systematic incentive structure for VBAs through business development, and knowledge enhancement to keep pace with innovations to address emerging production challenges.

Theoretical implications: Access to extension service providers who are knowledgeable of farmers’ context enhances learning and uptake of innovations.

Originality/value: Results fill information gap on the effectiveness of VBAs as knowledge and input disseminators, achieving scale of farmer reach with agricultural innovations.