The effect of overtraining on a visual discrimination on transfer to a spatial discrimination

Rats were first either trained to criterion or given overtraining on an orientation discrimination and then were given an extradimensional shift to a position discrimination. Overtraining on the visual discrimination facilitated performance on the position discrimination. Implications for mediational theories of discrimination learning were indicated.     

Constant and variable irrelevant cues during intra- and extradimensional transfer

Experiment I compared constant (CI), variable-between (VBI), and variable-within (WVI) irrelevant cues during an extradimensional (ED) shift discrimination. Performance was better for CI than for VBI and better for VBI than for VWI. Experiment II combined CI, VBI, and VWI cues with ED or intradimensional (ID) shifts. Irrelevant-cue conditions did not affect ID performance but did affect ED performance. The typical superiority of ID, as compared to ED, shifts was observed in the VWI condition but not in the CI condition. Implications for mediating-response (i.e., attention or observing-response) theories were indicated.     

Categorical color coding by pigeons

Pigeons were trained on two independent tasks. One involved red and yellow hues, the other involved blue and green hues. For half of the birds, the two tasks were the same (i.e., both tasks were either matching-to-sample, or oddity-from-sample). For the remaining birds, the two tasks were different (i.e., one task was matching-to-sample; the other task was oddity-from-sample). Following acquisition, the pigeons were exposed to test trials on which either the correct or the incorrect comparison hue was replaced with one of the hues from the other task. On yellow-sample trials and on green-sample trials, the pigeons performed as if they had a common code for yellow and green. When there was one comparison available that was appropriate to the “yellow/green” code, performance remained high; but when either both comparisons or neither comparison was appropriate to the “yellow/green” code, performance dropped. The pigeons also tended to code red samples as green and to code blue samples as yellow. The results indicate that pigeons can categorically code colors under conditions that rule out a failure to discriminate among the colors.     

Enhancing the facilitation of online groups in higher education: a review of the literature on face-to-face and online group-facilitation

There still appears to be a gap between what online learning promises and what it can deliver in terms of student learning. Developments in online pedagogies and professional learning appear to lag behind the developments in technology and the promised benefits of technological transformation may not be realised. In this paper, we bring together perspectives that highlight vital aspects of online group-learning by reviewing the group-facilitation literature and the latest online learning literature to interrogate the pedagogical theories and practices currently used in online group-learning in higher education. We specifically focus on the interpersonal interactions between teachers and students, which are described in the online learning literature using the terms instructor immediacy, teaching presence, and social presence. We note differences in the literature regarding how teacher presence is interpreted and enacted and we expound the importance of the personal characteristics of the online teacher. Finally, we provide some signposts that might help course designers and teachers to improve online group learning: the intentional use of effective online learning pedagogies; a deeper understanding of what constitutes teacher presence; and strategies to enact that teacher presence with online groups. Recommendations for further research in online group facilitation are provided.     

Video-assisted thoracoscopic surgery （VATS） for bilateral primary spontaneous pneumothorax

Objective:To review our experience of the treatment of bilateral primary spontaneous pneumothorax (PSP) by video-assisted thoracoscopic surgery (VATS). Materials and methods: Retrospective chart review was followed by an on-clinic or telephone interview. Patients were cared for by one thoracic surgeon in four medical centers or community hospitals in Northern and Central Taiwan. Thirteen patients with bilateral PSP underwent bilateral VATS simultaneously or sequentially from July 1994 to December 2005. Results: Twelve males and one female, with age ranging from 15 to 36 years (mean 23.1 years), were treated with VATS for bilateral PSP, under the indications of bilateral pneumothoracis simultaneously (n=4) or sequentially (n=9). The interval between the first and second contra-lateral VATS procedure for non-simultaneous PSP patients ranged from 7 d to 6 years. Eleven of 13 patients (84.6%) had prominent pulmonary bullae/blebs, and underwent bullae resection with mechanical or chemical pleurodesis. The mean operative time was (45.6±18.3) min (range 25-96 min) and (120.6±28.7) min (range 84-166 min) respectively for the non-simultaneous (second VATS for the recurrence of contralateral side after first VATS) and simultaneous (bilateral VATS in one operation) procedures. There was no postoperative mortality. However, prolonged air leakage (>7 d) occurred in one patient (7.7%) who recovered after conservative treatment. The mean duration of chest tube drainage was 3.1 d and the median follow up period was 3.4 years. Conclusions: VATS is a safe and effective procedure in the treatment of bilateral PSP. Bilateral VATS is only recommended for patients with simultaneously bilateral PSP, because the incidence of recurrence, even with visible bullae, was not so high in my group and in some previous literature. Bilateral VATS in a supine position should only be used in selective cases, because of possible pleural adhesion or hidden bullae on the posterior side.     

The easy-to-hard effect: Transfer along the dimension of orientation in the rat

Long-Evans rats were trained on an easy simultaneous discrimination problem and then transferred to a hard discrimination problem. The discriminanda were different orientations of stripes. In Experiment I, transfer was intradimensional with stimulus generalization controlled. The easy-to-hard effect was not found. In Experiment II transfer was intradimensional and either compatible (nonreversal) or incompatible (reversal). With compatible transfer, rats trained on a prior easy problem learned the hard problem faster than rats trained only on the hard problem. Persistent negative transfer was found with incompatible transfer. Attention was not supported as underlying the easy-to-hard effect. Explanations based on specific sources of intradimensional transfer, such as stimulus generalization or adaptation level, are suggested.