Successive reversals of a discriminated preference for signaled tailshock

Three rats received unmodifiable tailshock at random intervals in a shuttlebox. In a continuous-choice situation, Ss could choose between an auditory signal immediately preceding or immediately following the tailshock. Over repeated daily 3-h sessions, each S acquired a spatial discrimination indicating a strong preference for the signal preceding tailshock. This preference continued undiminished through two successive reversals of the position associated with signaled shock. This demonstration precludes explanations of the preference-for-signaled-shock phenomenon based upon primary reinforcement value or acquired value of the signal, position preferences, and overt modification of the aversiveness of the reinforcer through such means as postural adjustments. An explanation of recent failures to obtain the preference-for-signaled-shock effect is offered.     

Screening for hearing loss in early childhood programs

This study assessed the feasibility of doing hearing screening in Migrant, American Indian and Early Head Start programs using otoacoustic emissions (OAE) technology. Staff members were trained to screen 0–3-year-old children for hearing loss using hand-held OAE equipment and a multi-step screening and referral protocol. Of the 3486 children screened as a part of the study, 77% passed an OAE screening at the first step, 18% more passed an OAE screening at the second step, and 5% were ultimately referred for medical or audiological follow-up. Eighty children were identified as having a hearing loss or disorder of the outer, middle or inner ear requiring treatment. Of these 80, six had permanent bilateral or unilateral hearing loss. Although the protocol suggested that the multi-step screening procedure should be completed within a 4-week time period or less, analysis of the data showed that for children requiring more than an initial OAE screening, the length of time over which the screening was completed ranged from 7 to 12 weeks. The median time required to complete a single OAE screening session was 4 minutes per child. The results demonstrate that OAE screening of young children using this protocol is practical and effective. The implications for conducting periodic hearing screening throughout early childhood are discussed.     

Journalism training in Sri Lanka: meeting the needs of working journalists

The ethnic conflict that has enveloped Sri Lanka since the 1980s has been deeply damaging to Sri Lankan journalism, whose traditions of impartiality and professionalism have been seriously undermined. The BBC World Service Trust has attempted to address these issues through a European‐funded training programme aimed at a broad range of media practitioners in Sri Lanka. This article seeks to assess how successful this programme has been and what lessons can be drawn by training organisations elsewhere who are seeking to implement similar projects.     

Effects of reward amount and reward omission on short-term retention

A series of four experiments studied the retention of the response made on a just-preceding trial as a function of the presence, and amount, of food reward given on that trial. Rats were trained to alternate arm choices in a T-maze, and then were tested for alternation with 5- or 30-sec delays between runs. When the subjects had received prior experience with the reward amounts used in testing, larger rewards led to better retention than did small or no rewards. However, when reward omission first occurred during the test phase, it produced more alternation on the following trial than did reward presence. The results suggest that both reward amount and surprisingness determine short-term retention of responses paired with the rewards.     

Designing informal learning experiences for early career academics using a knowledge ecosystem model

This article presents a ‘knowledge ecosystem’ model of how early career academics experience using information to learn while building their social networks for developmental purposes. Developed using grounded theory methodology, the model offers a way of conceptualising how to empower early career academics through (1) agency (individual and relational) and (2) facilitation of personalised informal learning (design of physical and virtual systems and environments) in spaces where developmental relationships are formed, including programmes, courses, events, community, home and social media. It is suggested that the knowledge ecosystem model is suitable for use in designing informal learning experiences for early career academics.     

Internship: integrating theory and practice

This article describes a number of special features of the internship programme which has been developed at the Southern Cross University (SCU) in collaboration with the North Coast Region of the Department of School Education, the Catholic Education Office with selected primary schools. Arrangements are described for interns’ time spent in classrooms, collaborative teaching strategies which underpin these placements, the security which supports interns’ practice and approaches to integrate their practice with university studies. Processes of appraisal of interns’ development are explained, and the potential of mentoring for their teachers’ professional development is examined. Throughout the article, the congruence of these arrangements with Schools Council recommendations is considered.     

The effect of US omission in classical aversive and appetitive conditioning of rabbits

Rabbits (Oryctolagus cuniculus) were given either a 100% or a 50% reinforcement schedule in classical conditioning. Two groups received an aversive US (shock) and two groups received an appetitive US (water to the oral cavity). With parameter estimates for the two-phase model serving as the dependent variables, it was possible to define more precisely the effect of US omission with the intermittent reinforcement schedule. For the aversive preparation, the major effect of intermittent reinforcement was to increase the duration of Phase 1, a phase during which response likelihood remains constant at its initial value. Only a small proportion of subjects reflected the effect of US omission during Phase 2, the “learning” phase, this being a low operator limit following trials on which neither the CR nor the US occurred. The major effect of US omission for the appetitive preparation was in Phase 2, primarily a result of a minority of subjects having a low operator limit following trials on which neither the CR nor the US occurred. Many subjects required separate operators for trials on which the CR did or did not occur. The results were interpreted to pose difficulties for strength theories of conditioning, and the limitation implied for successful application of the Rescorla-Wagner theory are discussed. The implications of the data for response-contingent interpretations and for individual differences are also discussed.