Dementia and suicidal behavior

Behavioral and psychological symptoms of dementia, including depression, might complicate the course of the disorder additionally. Dementia is more frequent in older people and suicide rates are higher in later life than in any other age group. To explore the phenomenology of suicidal behavior in patients with dementia, we searched electronic databases and key journals for original research and review articles on suicide in demented patients using the search terms “suicide, suicidal behavior, dementia, Alzheimer disease, and old age”. Although cognitive impairment could result in a diminishing ability to think flexibly and to solve problems or to cope with conflict, in the early stage of dementia such impairments are absent or mild, and suicidal behavior might be expected, especially following diagnosis. In addition, personality changes based on declining cognitive capacity and the neurochemical imbalances described in late-life depression and in dementia may predispose patients to aggressive or impulsive acts, such as suicide attempt. The literature on suicidal behavior and dementia highlights the need for further research in this area.     

Differentiating sexual preference in men: Using dual task rapid serial visual presentation task

Cognition research suggests that allocating attention resources to evolutionarily relevant stimuli is facilitated suggesting that sexual stimuli interfere with human information processing. In a group of gay (n = 13) and straight men (n = 13) recruited in Finland, Germany and Italy, we investigated if and how sexually relevant visual stimuli affect information processing of both a target one (T1) and a subsequent target two (T2) in a dual target rapid serial visual presentation procedure. We hypothesized that: (1) due to the attentional blink (AB) phenomenon, the accuracy of reporting of T2 would decrease when following accurately identified sexually preferred T1 compared to accurately identified non‐sexually preferred T1; 2) due to the pop out effect, the accuracy of reporting of T1 and T2 would be relatively increased when T1 and T2 were sexually preferred by the participants compared to when they were not. Our findings did not support hypothesis 1 but supported hypothesis 2. We further found that the pop out effect had a good capacity to differentiate sexual preference between the groups of gay and straight men. We conclude that dual target rapid serial visual presentation can be used as an attention‐based measurement to differentiate sexual preference in men. Limitations and the applicability in the field of measuring sexual preference were discussed.     

Sex differences in discrimination reversal learning in the guppy

In several mammalian and avian species, females show a higher performance than males in tasks requiring cognitive flexibility such as the discrimination reversal learning. A recent study showed that female guppies are twice as efficient as males in a reversal learning task involving yellow–red discrimination, suggesting a higher cognitive flexibility in female guppies. However, the possibility exists that the superior performance exhibited by females does not reflect a general sex difference in cognitive abilities, but instead, is confined to colour discrimination tasks. To address this issue, we compared male and female guppies in two different discrimination reversal learning tasks and we performed a meta-analysis of these experiments and the previous one involving colour discrimination. In the first experiment of this study, guppies were tested in a task requiring them to learn to select the correct arm of a T-maze in order to rejoin a group of conspecifics. In experiment 2, guppies were observed in a numerical task requiring them to discriminate between 5 and 10 dots in order to obtain a food reward. Although females outperformed males in one condition of the T-maze, we did not find any clear evidence of females’ greater reversal learning performance in either experiment. However, the meta-analysis of the three experiments supported the hypothesis of females’ greater reversal learning ability. Our data do not completely exclude the idea that female guppies have a generally higher cognitive flexibility than males; however, they suggest that the size of this sex difference might depend on the task.     

Do domestic dogs (<Emphasis Type="Italic">Canis lupus familiaris</Emphasis>) perceive the Delboeuf illusion?

In the last decade, visual illusions have been repeatedly used as a tool to compare visual perception among species. Several studies have investigated whether non-human primates perceive visual illusions in a human-like fashion, but little attention has been paid to other mammals, and sensitivity to visual illusions has been never investigated in the dog. Here, we studied whether domestic dogs perceive the Delboeuf illusion. In human and non-human primates, this illusion creates a misperception of item size as a function of its surrounding context. To examine this effect in dogs, we adapted the spontaneous preference paradigm recently used with chimpanzees. Subjects were presented with two plates containing food. In control trials, two different amounts of food were presented in two identical plates. In this circumstance, dogs were expected to select the larger amount. In test trials, equal food portion sizes were presented in two plates differing in size: if dogs perceived the illusion as primates do, they were expected to select the amount of food presented in the smaller plate. Dogs significantly discriminated the two alternatives in control trials, whereas their performance did not differ from chance in test trials with the illusory pattern. The fact that dogs do not seem to be susceptible to the Delboeuf illusion suggests a potential discontinuity in the perceptual biases affecting size judgments between primates and dogs.     

The influence of confidence on associations among personal attitudes, perceived injunctive norms, and alcohol consumption

Social norms theories hold that perceptions of the degree of approval for a behavior have a strong influence on one's private attitudes and public behavior. In particular, being more approving of drinking and perceiving peers as more approving of drinking, are strongly associated with one's own drinking. However, previous research has not considered that students may vary considerably in the confidence in their estimates of peer approval and in the confidence in their estimates of their own approval of drinking. The present research was designed to evaluate confidence as a moderator of associations among perceived injunctive norms, own attitudes, and drinking. We expected perceived injunctive norms and own attitudes would be more strongly associated with drinking among students who felt more confident in their estimates of peer approval and own attitudes. We were also interested in whether this might differ by gender. Injunctive norms and self-reported alcohol consumption were measured in a sample of 708 college students. Findings from negative binomial regression analyses supported moderation hypotheses for confidence and perceived injunction norms but not for personal attitudes. Thus, perceived injunctive norms were more strongly associated with own drinking among students who felt more confident in their estimates of friends' approval of drinking. A three-way interaction further revealed that this was primarily true among women. Implications for norms and peer influence theories as well as interventions are discussed.     

Breaking down unitization: Is the whole greater than the sum of its parts?

Memory impairments are often observed in aging. Specifically, older adults have difficulty binding together disparate elements (relational memory). We have recently shown that a cognitive strategy known as unitization can mitigate impaired relational learning in the transverse patterning task (TP) in both amnesia and healthy aging. This strategy allows items to be fused together through an interaction such that one item acts upon another. In the context of TP, unitization is comprised of three component processes: (1) fusion, (2) motion, and (3) semantic comprehension of action/consequence sequences. Here, we examine which of these components are sufficient to mitigate age-related impairments. Four groups of older adults were given either the full unitization strategy or one of the three component strategies. Each group of older adults showed impairments in memory for the relations among items under standard training instructions relative to a threshold that marks learning of a winner-take-all rule (elemental threshold). However, participants who were given either the full unitization strategy or the action/consequence-only strategy showed improved performance, which was maintained following the 1-hour delay. Therefore, semantically rich action/consequence interactions are sufficient to mitigate age-related relational memory impairments.     

Probabilistic Logic Under Coherence, Conditional Interpretations, and Default Reasoning

We study a probabilistic logic based on the coherence principle of de Finetti and a related notion of generalized coherence (g-coherence). We examine probabilistic conditional knowledge bases associated with imprecise probability assessments defined on arbitrary families of conditional events. We introduce a notion of conditional interpretation defined directly in terms of precise probability assessments. We also examine a property of strong satisfiability which is related to the notion of toleration well known in default reasoning. In our framework we give more general definitions of the notions of probabilistic consistency and probabilistic entailment of Adams. We also recall a notion of strict p-consistency and some related results. Moreover, we give new proofs of some results obtained in probabilistic default reasoning. Finally, we examine the relationships between conditional probability rankings and the notions of g-coherence and g-coherent entailment.     

The Good Professor

This paper seeks to provide a philosophical analysis of the features of an excellent professor, but a well-balanced one, professionally speaking. What makes for excellence in research, teaching and service is explored in some detail, with attention paid to the contexts of four-year colleges and comprehensive universities in the united states.