The role of eye movements in the perception of visually induced autokinesis

Changes in eye position were recorded physiologically while S experienced visually induced autokinesis. Eye movements did not seem to sufficiently explain this phenomenon. Apparent motion was found to be based upon a change in phenomenal rather than retinal location. Special consideration was given to those parameters possibly responsible for paradoxical motion.     

Effects of antipsychotic medication on discrimination learning for institutionalized adults who have mental retardation

Reduction in medication levels of drugs used to suppress inappropriate behavior (chlorpromazine, thioridazine and haloperidol) resulted in increases in performance on a discrimination learning task for seven residents of a state institution who are mentally retarded. After training to criterion on a matching-to-sample task, these participants experienced reductions in medication in an N of 1 AB replication paradigm. Two controls were medication free, and one remained on a stable dosage throughout. Improvement of performance on the first dependent variable (number of trials needed to meet criterion) ranged from 13.8% to 53.3% for the seven participants, while the three controls improved less than 1%. Improvement of performance on the second dependent variable (percentage of correct responses) ranged from 2.7% to 19.7% for experimental subjects; five of the seven subjects exhibited a minimum improvement of 8%. The change in percentage of correct responses for the three controls ranged from ?4.9 to 1.3. Treatment implications are discussed.     

The use of small filament lamps as visual stimuli

The purpose of this note is to draw attention to the fact that the time needed for small filament lamps to reach full brightness is dependent upon the time for which they have been previously switched off. This dependence is a possible source of error in biassed choice reaction sequences, and a circuit is given which avoids the difficulty.     

Using prequestions to enhance learning from reading passages: the roles of question type and structure building ability

ABSTRACT

Answering questions before learning something (“prequestions”) enhances learning. However, these benefits usually occur for information that was asked in the prequestions (i.e. prequestioned material), and not for non-prequestioned material. We reasoned that this narrow benefit may be due to the fact that studies typically use fairly simple prequestions that have a clear answer within one part of the learning material – isolative prequestions. We explored the effects of integrative prequestions that required participants to make connections across different parts of a reading passage. Experiment 1 showed the usual benefit of isolative prequestions on prequestioned but not on non-prequestioned material, but no benefit of integrative prequestions. However, in Experiment 2 when participants were given instructions to seek the answers while reading, integrative prequestions benefited learning of both prequestioned and non-prequestioned material. Individual differences in structure building positively predicted performance, but did not interact with the effects of prequestions.     

Response Selection Contributes to the Preparation Cost for Bimanual Asymmetric Movements

Movement preparation of bimanual asymmetric movements takes more time than bimanual symmetric movements in choice reaction-time conditions. This bimanual asymmetric cost may be caused by increased processing demands on any stage of movement preparation. The authors tested the contributions of each stage of movement preparation to the asymmetric cost by using the additive factors method. This involved altering the stimulus contrast, response compatibility, and response complexity. These manipulations changed the processing demands on stimulus identification, response selection, and response programming, respectively. Any manipulation with a larger reaction time cost than control suggests that stage contributes to the bimanual asymmetric cost. The bimanual asymmetric cost was larger for incompatible stimuli, which supports that response selection contributes to the bimanual asymmetric cost.     

External focus of attention improves performance in a speeded aiming task

Athletic skills are often executed better when learners focus attention externally (e.g., on the trajectory of the ball after a tennis serve), rather than internally (e.g., on the position of their arm) (e.g., Wulf, 2007a). The current study explored the effects of attention focus on learning of speeded responses, and examined whether these benefits hold for retention and transfer. Participants performed a computerized speeded aiming task while focusing on the direction of the cursor (external focus) versus the direction in which their hand moved the mouse (internal focus). One week later, half of the participants performed the same task again (retention), and half performed the task under conditions in which the mouse movements were changed (transfer). Relative to internal focus, external focus led to faster acquisition and better maintenance of speeded responses over the retention interval.     

Pointing out new news, old news, and absent referents at 12 months of age

There is currently controversy over the nature of 1-year-olds' social-cognitive understanding and motives. In this study we investigated whether 12-month-old infants point for others with an understanding of their knowledge states and with a prosocial motive for sharing experiences with them. Declarative pointing was elicited in four conditions created by crossing two factors: an adult partner (1) was already attending to the target event or not, and (2) emoted positively or neutrally. Pointing was also coded after the event had ceased. The findings suggest that 12-month-olds point to inform others of events they do not know about, that they point to share an attitude about mutually attended events others already know about, and that they can point (already prelinguistically) to absent referents. These findings provide strong support for a mentalistic and prosocial interpretation of infants' prelinguistic communication.     

A Priori Causal Models of Natural Selection

Plato articulates a deep perplexity about inquiry in ‘Meno's Paradox’—the claim that one can inquire neither into what one knows, nor into what one does not know. Although some commentators have wrestled with the paradox itself, many suppose that the paradox of inquiry is special to Plato, arising from peculiarities of the Socratic elenchus or of Platonic epistemology. But there is nothing peculiarly Platonic in this puzzle. For it arises, too, in classical Indian philosophical discussions, where it is formulated with great clarity, and analysed in a way that casts it in a new light. We present three treatments of the puzzle in Indian philosophy, as a way of refining and sharpening our understanding of the paradox, before turning to the most radical of the Indian philosophers to tackle it. The Indian philosophers who are optimistic that the paradox can be resolved appeal to the existence of prior beliefs, and to the resources embedded in language to explain how we can investigate, and so move from ignorance to knowledge. Highlighting this structural feature of inquiry, however, allows the pessimist philosopher to demonstrate that the paradox stands. The incoherence of inquiry is rooted in the very idea of aiming our desires at the unknown. Asking questions and giving answers rests on referential intentions targeting objects in a region of epistemic darkness, and so our ‘inquiry sceptic’ also finds structurally similar forms of incoherence in the pragmatics of interrogative discourse.     

Learning and forgetting in schizophrenia

Recent studies of patients with schizophrenia have consistently demonstrated marked deficits on measures of initial learning. However, contradictory results have been reported concerning retention and forgetting. The present study examined the level of initial and delayed recall of stories and visual figures in a group of 76 patients with schizophrenia and 51 normal controls. Schizophrenia patients demonstrated marked impairments in initial and delayed recall as well as significantly worse percentage retention scores. However, schizophrenia patients and healthy controls individually matched on level of initial recall had nearly identical delayed recall performance. The results suggest a primary deficit in the initial acquisition of information rather than an accelerated rate of forgetting in schizophrenia.