A new principle of pellet feeder design

Most current commercial devices dispense dry food pellets by moving the pellets horizontally toward a discharge point. Individual pellets, captured by perforations in a horizontal metal disk, are discharged one by one by stepwise rotation of the disk within the pellet reservoir. In our laboratory, where the average pellet discharge rate is some 20,000 pellets per week, feeders of this type produced occasional problems. Some were electronic; others involved failure always to capture a pellet in each perforation, particularly when the pellet supply was low. But the most common problem was an accumulation of pellet chips and dust under and around the perforated disk, which ultimately jammed the mechanism. Despite weekly cleaning and maintenance, troubles arose at least twice a month, prompting a search for a simpler pellet-feeder design which would be more reliable and require less maintenance. The present pellet feeder employs a vertical rather than horizontal design principle. It has been used extensively in operant conditioning applications for more than a year. More than 200,000 pellets have been reliably discharged from a single feeder without a breakdown. No maintenance, other than a weekly cleaning of the discharge tube, has been required.     

Using broad measures of maladjustment to assess psychological states of outpatients with schizophrenia

Two broad indexes of maladjustment derived from two projective tests and administered at two separate points to the same 50 outpatients with schizophrenia showed substantial convergent validity at both testings (r=.52, p<.001; r=.58, p<.001). Conversely, test-retest reliabilities for both indexes were nonsignificant. These findings suggest that broad measures of maladjustment may be more suitable for reflecting current states of adjustment for subjects known to be diagnosed with certain symptoms, the manifestations of which fluctuate over time.     

Indigenous Psychologies: The Meaning of the Concept and its Assessment: Introduction

La signification des concepts de psychologie indigoène et d'indigoénisation, les processus par lesquels ils se réalisent, est exploré dans les quatres premiers articles de ce numéro spécial. Les concepts sont examinés tout d' abord à partir des perspectives plus larges de la psychologie sociale des sciences (Adair) et la psychologie interculturelle (Poortinga), ainsi que dans deux applications concrètes des approches de psychologie indignée au Mexique (Díaz-Loving) et en Corée (Kim, Park, et Park). Dans la seconde partie, trois articles rendent compte des recherches empiriques évaluant l'ampleur du développement indignée en Turquie, ex-URSS, au Venezuela, et Porto-Rico. Cette introduction au numéro spécial résume quelques uns des points communs et des différences dans les contributions.
The meaning of the concepts of indigenous psychologies and of indigenisation, the process by which they are achieved, are explored within the first four articles of this special issue. The concepts are examined initially in the abstract from the broader perspectives of the social psychology of science (Adair) and cross-cultural psychology (Poortinga), and in two concrete applications of indigenous psychology approaches in Mexico (Díaz-Loving) and Korea (Kim, Park, & Park). In the second part of this special issue, three articles report on empirical research assessing the extent of indigenous development that has occurred in Turkey, the former USSR, Venezuela, and Puerto Rico. This introduction summarises some of the commonalities and differences among the contributions.     

The relational versus collective “We” and intergroup allocation: The role of nested group categorization

Intergroup research has focused primarily, if not solely, on how an intergroup comparative context primes social categorization. The current research examines how individual differences, in terms of distinct forms of social self (the relational versus collective self), differentially drive social categorization and zero-sum resource allocation across groups nested within a superordinate group. Results show that the relational self exhibited more ingroup-biased allocations than the collective self; superordinate categorization mediated this relationship. Moreover, the relational self showed more ingroup-biased allocations under the condition of intergroup competition than cooperation; whereas the collective self showed equally unbiased allocations under the conditions of intergroup competition and cooperation. Our research suggests that competition worsens nested group relations for the relational self, but not for the collective self.     

Attentional processes and meditation

Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators’ better visual attention is not just immediate, but extends to contexts separate from meditation practice.