Associative symmetry by pigeons after few-exemplar training

The present experiment investigated whether pigeons can show associative symmetry on a two-alternative matching-to-sample procedure. The procedure consisted of a within-subject sequence of training and testing with reinforcement, and it provided (a) exemplars of symmetrical responding, and (b) all prerequisite discriminations among test samples and comparisons. After pigeons had learned two arbitrary-matching tasks (A-B and C-D), they were given a reinforced symmetry test for half of the baseline relations (B1-A1 and D1-C1). To control for the effects of reinforcement during testing, two novel, nonsymmetrical responses were concurrently reinforced using the other baseline stimuli (D2-A2 and B2-C2). Pigeons matched at chance on both types of relations, thus indicating no evidence for symmetry. These symmetrical and nonsymmetrical relations were then directly trained in order to provide exemplars of symmetry and all prerequisite discriminations for a second test. The symmetrical test relations were now B2-A2 and D2-C2 and the nonsymmetrical relations were D1-A1 and B1-C1. On this test, 1 pigeon showed clear evidence of symmetry, 2 pigeons showed weak evidence, and 1 pigeon showed no evidence. The previous training of all prerequisite discriminations among stimuli, and the within-subject control for testing with reinforcement seem to have set favorable conditions for the emergence of symmetry in nonhumans. However, the variability across subjects shows that methodological variables still remain to be controlled.     

Telehealth Monitoring of Patients with Schizophrenia and Suicidal Ideation

A telehealth system was developed to monitor risk following hospitalization for suicidal ideation. We hypothesized that 3 months of telehealth monitoring will result in a greater reduction in suicidal ideation. Veterans with schizophrenia admitted with recent suicidal ideation and/or a suicidal attempt were recruited into a discharge program of VA Usual Care with daily Health Buddy© monitoring (HB) or Usual Care (UC) alone. Fifteen of 25 were randomized to HB and 10 received UC. Daily adherence in the use of the HB system during months 1–3 was, respectively, 86.9%, 86.3%, and 84.1%. There were significant improvements in Beck Scale for Suicide Ideation scores in HB participants. There were no changes in depressive symptoms. Telehealth monitoring for this population of patients appears to be feasible.     

Multipropositionalism and Necessary a Posteriori identity Statements

We provide an account of necessary a posteriori identity statements that relies upon Perry's multipropositionalism. On our account an utterance of, e.g., ‘Hesperus is Phosphorus', semantically makes available several propositions, one of which is necessary (and a priori) and another of which is a posteriori (and contingent). Since our view resembles two‐dimensionalism, one might assume that it is undermined by the sorts of nesting arguments that Soames and others have raised against two‐dimensionalism. We demonstrate, however, that our account is immune to such nesting arguments.