The effect of instructions on the apparent reversal of rotary motion in depth

This study concerns experimental investigation of the effect of instructions on the apparent reversal of rotary motion in depth. It was found that subjects instructed to report apparent reversals of an elliptical shape signalled more reversals than subjects who were instructed to report the non-occurrence of reversals. This difference increased over four trials. When the stimulus object was a trapezium window instructions to report reversals led to a higher rate of reversals than did instructions to report non-occurrence, but this difference did not increase significantly over trials.     

Sentence production and working memory

Previous research has shown that subjects can make up sentences faster from related noun pairs than from unrelated pairs. Two experiments tested the proposal that for the related pairs a subject simply has to access stored information but must make up an appropriate relation for unrelated pairs. In both studies the subjects were asked on some trials to remember a digit preload while they made up their sentences. Contrary to an initial prediction, the latencies were faster rather than slower with a preload. Furthermore, a surprise recall test at the end of Experiment 2 showed that there was no difference in the recall of related and unrelated pairs. The results were interpreted as evidence that semantic work was necessary for both types of noun pairs, and that the subjects did less semantic work with a digit preload. This interpretation was further supported by the finding that with the preload the subjects produced a narrower range of semantic relations between the noun pairs.     

Diversity and deliberation: bioethics commissions and moral reasoning

This article considers the sort of diversity in perspective appropriate for a presidential commission on bioethics, and by implication, high-level governmental commissions on ethics more generally. It takes as its point of comparison the respective reports on human cloning produced by the National Bioethics Advisory Commission, appointed by President Bill Clinton, and George W. Bush's President's Council on Bioethics, under the leadership of its original chair, Leon Kass. I argue that the Clinton Commission Report exemplifies forensic diversity (the type of diversity between contesting parties in a legal case), while the Kass Council Report exemplifies academic diversity (the diversity found in a medieval disputatio). Drawing upon Thomas Aquinas, I argue that the type of diversity most appropriate for such advisory bodies is deliberative diversity, which facilitates the President's process of taking counsel. After considering their respective charges, I suggest that neither the Clinton Commission nor the Kass Council possessed an adequate degree of deliberative diversity for their respective tasks.     

What you see is what you get: functional equivalence of a perceptually filled-in surface and a physically presented stimulus

A perceptually filled-in surface, such as occurs during sustained attention to a peripheral stimulus (Troxler fading), can be functionally equivalent to a physically presented stimulus. Observers failed to detect probes that were presented in the location of a filled-in surface that had the same surface attributes as the probes; this was true even though, physically, the probes contrasted with the background. Probe stimuli with surface characteristics different from those of the filled-in surface were detected more often, though not quite as often as when there was no filled-in surface. Together, these findings support the idea that there are two components in perceptual filling: a neural filling-in component and a sustained-attention component, which actively suppresses perceptual processing at the filled-in location. More broadly, they illustrate the interplay of basic visual mechanisms in the creation and representation of visual surfaces and in the coding and detection of changes to these surfaces.     

Anisomycin infused into the hippocampus fails to block "reconsolidation" but impairs extinction: the role of re-exposure duration

Recent studies have reported new evidence consistent with the hypothesis that reactivating a memory by re-exposure to a training context destabilizes the memory and induces "reconsolidation." In the present experiments, rats' memory for inhibitory avoidance (IA) training was tested 6 h (Test 1), 2 d (Test 2), and 6 d (Test 3) after training. On Test 1 the rats were either removed from the shock compartment immediately after entry or retained in the shock context for 200 sec, and intrahippocampal infusions of the protein synthesis inhibitor anisomycin (75 microg/side) were administered immediately after the test. Anisomycin infusions administered after Test 1 impaired IA performance on Test 2 in animals given the brief re-exposure, but impaired extinction in animals exposed to the context for 200 sec. Rats with anisomycin-induced retention impairment on Test 2 demonstrated spontaneous recovery of retention performance on Test 3, whereas rats showing extinction on Test 2 showed further extinction on Test 3. The findings indicate that post-retrieval administration of anisomycin impairs subsequent retention performance only in the absence of extinction and that this impairment is temporary.     

Using food redistribution to reduce packing in children with severe food refusal

Positive- and negative-reinforcement-based procedures typically have targeted acceptance for children with severe food refusal; however, these procedures do not always result in successful swallowing. Once acceptance is achieved, some children expel the food repeatedly or pack (hold or pocket) it in their mouths for extended periods of time. This study evaluated the effects of using food redistribution with a bristled massaging toothbrush to reduce packing and increase consumption in 4 children with severe feeding disorders. Packing was reduced for all children. In addition, latency to clean mouth (the duration of time from acceptance to food no longer being present in the child's mouth in the absence of expulsion) for 2 children decreased when the food-redistribution procedure was used. Results are discussed in terms of the potential operant functions of the food-redistribution procedure.     

On the effectiveness of and preference for punishment and extinction components of function-based interventions

The current study describes an assessment sequence that may be used to identify individualized, effective, and preferred interventions for severe problem behavior in lieu of relying on a restricted set of treatment options that are assumed to be in the best interest of consumers. The relative effectiveness of functional communication training (FCT) with and without a punishment component was evaluated with 2 children for whom functional analyses demonstrated behavioral maintenance via social positive reinforcement. The results showed that FCT plus punishment was more effective than FCT in reducing problem behavior. Subsequently, participants' relative preference for each treatment was evaluated in a concurrent-chains arrangement, and both participants demonstrated a dear preference for FCT with punishment. These findings suggest that the treatment-selection process may be guided by person-centered and evidence-based values.     

The role of treatment acceptability in the initiation of treatment for ADHD

Approximately 50% of families of children with ADHD fail to pursue, or adhere to, recommended treatments. The present study examines parent ratings of the acceptability of pharmacological and behavioral treatments for ADHD and the relationships between these ratings and subsequent pursuit of treatment. Fifty-five families whose children received an evaluation for ADHD completed questionnaires and were contacted 3 to 4 months later to assess their pursuit of treatment. Consistent with previous research, parents rated behavior therapy as more acceptable than medication. Parent ratings of medication acceptability significantly predict pursuit of pharmacological treatment, whereas ratings of the acceptability of behavior therapy do not predict pursuit of this treatment. Preliminary analyses found that Caucasian parents' ratings of medication are significantly higher than those of non-Caucasian parents. Furthermore, Caucasian families were more likely to pursue a recommendation for pharmacological treatment than non-Caucasian families. The clinical and research implications of these results are considered.     

Object updating and the flash-lag effect

Flash lag is a misperception of spatial relations between a moving object and a briefly flashed stationary one. This study began with the observation that the illusion occurs when the moving object continues following the flash, but is eliminated if the object's motion path ends with the flash. The data show that disrupting the continuity of the moving object, via a transient change in size or color, also eliminates the illusion. We propose that this is because a large feature change leads to the formation of a second object representation. Direct evidence for this proposal is provided by the results for a corollary perceptual feature of the disruption in object continuity: the perception of two objects, rather than only one, on the motion path.