Disturbance cues function as a background risk cue but not as an associative learning cue in tadpoles

Animal Cognition - Chemical information has an important role in the sensory ecology of aquatic species. For aquatic prey, chemical cues are a vital source of information related to predator...     

A cross-modal effect of noise: the disappearance of the alarm reaction of a freshwater fish

Anthropogenic noise pollution is recognized as a major global stressor of animals. While many studies have assessed the unimodal impacts of noise pollution with a focus on intraspecific acoustic communication, little is known about noise pollution on the perception of visual and chemical information. The ‘distracted prey hypothesis’ posits that processing noise interferes with processing other information in the brain. Here, we found evidence for such a cross-modal effect of noise on the antipredator behaviour of a freshwater prey fish, the fathead minnow, Pimephales promelas. In laboratory trials, exposure to noise from a motorboat caused the total absence of the classical fright reaction of minnows to conspecific alarm cues, whereas an ambient noise control had no such impact. In natural habitats, the impairment of such antipredator behaviour due to noise pollution could have major fitness consequences. We discuss how our findings translate to animal ecology and the need for future studies that target specific management decisions regarding noise pollution.     

Employer's obligation of safety and nanomaterials

Health and Safety law at work is influenced by the intervention of the European Union. The model of prevention of occupational risks is set by the 1989 framework directive. The question of its applicability to nanomaterials divides the Commission and the European Parliament. This model was welcomed differently by member states. Employers are generally under an obligation to adopt best means to assure workers' safety, while French law imposes an obligation to get results. This obligation concerns each aspect of the employment contract's execution and is analysed as an effective way to esure the prevention of occupational risks. If risks associated with nanomaterials seem to be taken into consideration by our system of worker protection, it seems however that prevention will be difficult to implement.     

Cognitive Specificity in Trait Anger in Relation to Depression and Anxiety in a Community Sample

The current research explored 16 of Young's schemas in relation to trait anger and to anxiety and depression symptoms among 262 non‐clinical Australian adults with low‐level symptomatology and average anger levels. The study partially replicated previous work with a sample of Spanish students that investigated the relationship between anger, depression, and anxiety and Young's schemas. Predictions derived from Beck's notion of cognitive specificity were examined using structural equation modelling and showed that of the sixteen schemas, Vulnerability was linked to anxiety, Social Isolation and Enmeshment were linked to depression, and Entitlement, Insufficient Self‐Control, Mistrust and Abuse, Subjugation (negatively), and Abandonment were linked to anger. The discrepancies between these and the Spanish findings and the difficulties of other researchers in establishing higher order aggregations of Young's schemas prompted further consideration of the range of such schemas with respect to anger, depression, and anxiety, and the possibility that sample characteristics may play a critical role in determining the varying affect—schema relationships.     

Understanding the role of uncertainty on learning and retention of predator information

Due to the highly variable nature of predation risk, prey animals need to continuously collect information regarding the risk posed by predators. One question that ensues is how long to use this information for? An adaptive framework of predator-related information use predicted that certainty should influence the duration for which information regarding the threatening nature of a species is used in decision-making. It predicts that uncertainty contributes to the reduction in the duration of information use, due to the cost of displaying antipredator behaviours towards non-threatening species. Here, we test this prediction using repetition of conditioning events as a way to increase the certainty associated with the predatory nature of a novel salamander for woodfrog tadpoles. Tadpoles were conditioned 1, 2 or 4 times to recognize a novel salamander as a predator and subsequently tested for their response to the salamander 1?day or 11?days post-conditioning. We found that conditioning repetition did not affect the intensity with which tadpoles learned to respond to the salamander after 1?day. However, after 11?days, tadpoles with fewer conditionings responded to the salamander with a weaker intensity than those that received more conditionings. Our results provide support for the model prediction that an increase in the certainty associated with correctly identifying a predator leads to longer retention of the threat.     

Personality and the response to predation risk: effects of information quantity and quality

Within aquatic ecosystems, chemosensory cues provide valuable public information regarding the form and degree of risk, allowing prey to make informed behavioural decisions. Such cues, however, may vary in both relative concentration detected (i.e. ‘quantity’) and reliability of the information available (i.e. ‘quality’), leading to varying response patterns. Moreover, prey species are also known to exhibit consistent behavioural tactics towards managing risk (i.e. personality), possibly shaping their use of public information. Here, we present two experiments examining the potential interacting effects of personality and the quantity (Experiment 1) or quality (Experiment 2) of public information on the short-term predator avoidance responses of wild-caught Trinidadian guppies under semi-natural conditions. Our first experiment demonstrated that personality shaped responses to a high concentration of alarm cues (high risk), with shyer guppies exhibiting stronger antipredator responses than bolder guppies. When exposed to either low risk or stream water controls, personality had no effect on the intensity of response. Our second experiment demonstrated that personality again shaped the response to high concentrations of alarm cues (a known risk) but not to a novel chemosensory cue (tilapia odour). When exposed to the unknown novel cue, guppies exhibited a relatively high intensity antipredator response, regardless of personality. Combined, our results suggest that individual risk-taking tactics shape the use of public information in a context-dependent fashion.     

Combining Pharmacotherapy with cognitive-behavioral interventions for obsessive-compulsive disorder

This paper reviews the evidence-based literature concerning the efficacy and effectiveness of cognitive behavior therapy (CBT), drug treatment and their combination for obsessive compulsive disorder (OCD). After a brief outline of the seminal studies, the state of the art is presented with reference to the consensual recommendations proposed in the last 10 years. Management of OCD rests on potent selective serotonin reuptake inhibitors and CBT, used separately, sequentially, or concurrently. A hierarchical model for clinical decision-making is reported. With greater severity of OCD, it is recommended to add medications. However, the response rate is still too low in many patients, and some patients remain refractory to any kind of treatment. This stresses the importance of joint efforts of psychological and biological teams to develop new treatments.     

What has happened to Prägnanz? Coding,stability, or resonance

Three theoretical measures of Prägnanz were compared with four data sets. The theoretical measures were a stimulus-coding one (structural information load, SIL), a measure related to within memory processes (stability), and one based on the interaction of perception and memory (resonance). The four data sets were obtained in two experiments and involved goodness rating, grouping, and immediate and delayed recall. A complete set of seven-element binary serial patterns was used in each experiment. Both SIL and resonance were shown to correlate reliably with the data sets across tasks. The resonance measure, however, performed best. Prägnanz thus appears to be explained better by resonance than by stimulus coding or memory storage. Resonance explained all systematic variance in the recall tasks, but not in the other tasks. Regarding these, partial-correlation analyses showed that the effect of stability could be fully reduced to resonance. SIL could not be similarly reduced. Therefore, additional perceptual constraints, other than resonance, would be needed for a complete account of goodness in the judging or grouping tasks.     

Natural teeth and cognitive function in humans

A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50-85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age.