A defense of surgical procedures regulation

Theoretical Medicine and Bioethics - Since the advent of drug regulation in 1962, regulatory agencies have been in the practice of using strict standards to test the safety and efficacy of medical...     

Global/local processing and negative priming: the influence of selection difficulty and stimulus exposure

Negative priming is a decrement in performance observed when a previously ignored stimulus is re-presented as a target. The present study examined the relation between selection difficulty and negative priming in five experiments that used hierarchical stimuli (large letters made up by small letters). The results show that negative priming is greater when subjects direct attention to the local level (more difficult selection) than when they direct attention to the global level (less difficult selection). However, that occurs only when exposure of prime and probe is sufficiently long. With shorter presentations, negative priming is still observed but is no longer modulated by selection difficulty. These results suggest that both anticipatory and reactive mechanisms are responsible for the occurrence of negative priming and that instantiation of the reactive mechanism depends on the time available for prime and probe selection. Received: 17 January 2000 / Accepted: 3 July 2000     

Young children's understanding of violations of property rights

The present work investigated young children’s normative understanding of property rights using a novel methodology. Two- and 3-year-old children participated in situations in which an actor (1) took possession of an object for himself, and (2) attempted to throw it away. What varied was who owned the object: the actor himself, the child subject, or a third party. We found that while both 2- and 3-year-old children protested frequently when their own object was involved, only 3-year-old children protested more when a third party’s object was involved than when the actor was acting on his own object. This suggests that at the latest around 3 years of age young children begin to understand the normative dimensions of property rights.     

The positive effect of negative emotions in protracted conflict: The case of anger

Extant research has demonstrated the destructive role that anger plays in the context of intergroup conflict. Among other findings, it has been established that anger elevates public support for aggressive and violent actions towards the outgroup. This finding has been explained by the unique cognitive appraisals, emotional goal, and response tendencies associated with anger, typified by appraised relative strength and high control, motivation to correct perceived wrongdoings, and willingness to engage in risky behavior. In the current work we examine an innovative assumption, according to which the apparent destructive implications of anger are a result of situational range restriction—namely, that anger as a group emotion has been examined almost solely at the escalation stage of conflict. Instead, we propose that the same unique characteristics of anger can bring about constructive political attitudes and support for non-violent policies in the context of systematic efforts to de-escalate a protracted conflict.To test this hypothesis we conducted two studies in which we examined the relationship between anger and the willingness to engage in positive risk-taking and support non-violent policies in the context of political negotiations between adversaries. Results indicate a significant positive relationship, supporting the hypothesis that anger is not an exclusively militant emotion, and its effects are situationally dependent.     

The Isolation of Motivational, Motoric, and Schedule Effects on Operant Performance: A Modeling Approach

Dissociating motoric and motivational effects of pharmacological manipulations on operant behavior is a substantial challenge. To address this problem, we applied a response‐bout analysis to data from rats trained to lever press for sucrose on variable‐interval (VI) schedules of reinforcement. Motoric, motivational, and schedule factors (effort requirement, deprivation level, and schedule requirements, respectively) were manipulated. Bout analysis found that interresponse times (IRTs) were described by a mixture of two exponential distributions, one characterizing IRTs within response bouts, another characterizing intervals between bouts. Increasing effort requirement lengthened the shortest IRT (the refractory period between responses). Adding a ratio requirement increased the length and density of response bouts. Both manipulations also decreased the bout‐initiation rate. In contrast, food deprivation only increased the bout‐initiation rate. Changes in the distribution of IRTs over time showed that responses during extinction were also emitted in bouts, and that the decrease in response rate was primarily due to progressively longer intervals between bouts. Taken together, these results suggest that changes in the refractory period indicate motoric effects, whereas selective alterations in bout initiation rate indicate incentive‐motivational effects. These findings support the use of response‐bout analyses to identify the influence of pharmacological manipulations on processes underlying operant performance.     

Muscarinic receptors activity in the perirhinal cortex and hippocampus has differential involvement in the formation of recognition memory

In this work we probed the effects of post-trial infusions of the muscarinic receptor antagonist scopolamine on object recognition memory formation. Scopolamine was infused bilaterally immediately after the sample phase in the perirhinal cortex or dorsal hippocampus and animals were tested for short-term (90 min) or long-term (24 h) memory. Results showed that scopolamine impaired short-term memory when injected in either the perirhinal cortex or hippocampus. Nevertheless, scopolamine disrupted long-term memory when administrated in the perirhinal cortex but not when applied in the hippocampus. Long-term memory was unaffected when scopolamine was infused 160 min after the sample phase or 90 min before test phase. Our data indicate that short-term recognition memory requires muscarinic receptors signaling in both the perirhinal cortex and hippocampus, whereas long-term recognition memory depends on muscarinic receptors in the perirhinal cortex but not hippocampus. These results support a differential involvement of muscarinic activity in these two medial temporal lobe structures in the formation of recognition memory.     

Where Am I? A new case of developmental topographical disorientation

Recently, developmental topographical disorientation (DTD) was described (Bianchini et al., 2010, J Clin Exp Neuropsychol, 20, 807–27; Iaria & Barton, 2010, Exp Brain Res, 206, 189–96; Iaria, Bogod, Fox, & Barton, 2009, Neuropsychologia, 47, 30–40) as a navigational deficit in the absence of neurological or psychiatric disorders. Here, we reported the case of a healthy subject who presented this disorder. Dr. WAI was a 29‐year‐old right‐handed man with normal development and no clinical history of neurological or psychiatric diseases who was affected by a very pervasive topographical orientation and navigational disorder. A neuroradiological exam confirmed the absence of structural and anatomical alterations of the brain. Dr. WAI was submitted to an extensive neuropsychological examination and to a battery of tests specifically developed to assess developmental topographical disorder. Using this battery, we analysed Dr. WAI's acquisition of navigational information and re‐orientation processes. He showed severe DTD accompanied by deficits of different cognitive processes directly or indirectly involved in navigational skills. Dr. WAI showed a deficit in developing cognitive maps, already found in previous cases, plus difficulties in evaluating distances and computing metric environmental features. He represents a further confirmation of the existence of DTD suggesting dissociations within the disorder related to the level of development of the ability to build cognitive maps and the association of different imagery deficits. Dr. WAI can help in shedding some light on the mechanisms underlying lack of development of navigational skills.