Neurocognitive Complications of HIV Disease

Neurocognitive complications are the most common sequelae of HIV infection if the full spectrum of HIV disease—from initial seroconversion to death from advanced AIDS—is considered. Though resembling subcortical neurological disorders from a neuropsychological standpoint, the presentation is variable, and almost any pattern can be seen. Although neuropsychological impairment is often subtle, it can affect day-to-day life and is associated with earlier mortality. It is not clear if milder forms of neurocognitive disturbance necessarily presage advanced dementia, and current data suggest a two-factor model: a subacute relapsing-remitting condition that can occur at any stage of HIV disease and a progressive, more fulminant dementia. The pathological substrates of these conditions are not well characterized, although recent data support the notion that synaptodendritic damage underlies the neuropsychological impairment, and may precede the neuronal loss and other pathological features more characteristic of HIV encephalitis. Some reversibility of neurocognitive disturbance has been reported with zidovudine therapy, though the data are not consistent. New regimens involving protease inhibitors need to be evaluated in terms of benefit to the central nervous system because many drugs of this class do not penetrate the blood-brain barrier efficiently. Finally, studies utilizing experimental treatments that may affect the putative mechanisms of neural injury are in progress.     

Lambek Calculus with Conjugates

Studia Logica - We study an expansion of the Distributive Non-associative Lambek Calculus with conjugates of the Lambek product operator and residuals of those conjugates. The resulting logic is...     

The effects of facial expressions and tears on the speed of sex recognition

The goal of this research was to examine the effects of facial expressions on the speed of sex recognition. Prior research revealed that sex recognition of female angry faces was slower compared with male angry faces and that female happy faces are recognized faster than male happy faces. We aimed to replicate and extend the previous research by using different set of facial stimuli, different methodological approach and also by examining the effects of some other previously unexplored expressions (such as crying) on the speed of sex recognition. In the first experiment, we presented facial stimuli of men and women displaying anger, fear, happiness, sadness, crying and three control conditions expressing no emotion. Results showed that sex recognition of angry females was significantly slower compared with sex recognition in any other condition, while sad, crying, happy, frightened and neutral expressions did not impact the speed of sex recognition. In the second experiment, we presented angry, neutral and crying expressions in blocks and again only sex recognition of female angry expressions was slower compared with all other expressions. The results are discussed in a context of perceptive features of male and female facial configuration, evolutionary theory and social learning context.     

Gender differences in the motivational processing of facial beauty

Gender may be involved in the motivational processing of facial beauty. This study applied a behavioral probe, known to activate brain motivational regions, to healthy heterosexual subjects. Matched samples of men and women were administered two tasks: (a) key pressing to change the viewing time of average or beautiful female or male facial images, and (b) rating the attractiveness of these images. Men expended more effort (via the key-press task) to extend the viewing time of the beautiful female faces. Women displayed similarly increased effort for beautiful male and female images, but the magnitude of this effort was substantially lower than that of men for beautiful females. Heterosexual facial attractiveness ratings were comparable in both groups. These findings demonstrate heterosexual specificity of facial motivational targets for men, but not for women. Moreover, heightened drive for the pursuit of heterosexual beauty in the face of regular valuational assessments, displayed by men, suggests a gender-specific incentive sensitization phenomenon.     

Assertion,Moore, and Bayes

It is widely believed that the so-called knowledge account of assertion best explains why sentences such as “It’s raining in Paris but I don’t believe it” and “It’s raining in Paris but I don’t know it” appear odd to us. I argue that the rival rational credibility account of assertion explains that fact just as well. I do so by providing a broadly Bayesian analysis of the said type of sentences which shows that such sentences cannot express rationally held beliefs. As an interesting aside, it will be seen that these sentences also harbor a lesson for Bayesian epistemology itself.

The role of importance/consequentiality appraisal in flashbulb memory formation: the case of the death of Pope John Paul II

This study investigates how flashbulb memories (FBMs) relative to the death of Pope John Paul II vary according to the persons' evaluation of the event's importance and consequences. In particular, FBMs were investigated in persons who were expected to attribute different degrees of importance/consequentiality to the event as a function of two factors: (1) religious involvement, (2) nationality (Polish, Italian, Swiss). The comparison was made with respect to the following hypothesized determinants of FBMs: surprise, emotional reaction, rehearsal, event memory and especially the attitudes towards the Pope and the appraisal of the importance and the consequences of his death. Structural equation modelling indicates that importance/consequentiality is a fundamental determinant of FBM and is influenced by antecedent personal and social characteristics reflected in the person's attitudes. Moreover, memory consistency seems to be both directly influenced by emotional intensity and indirectly through rehearsal, whereas surprise seems not a critical determinant of FBM. Copyright © 2008 John Wiley & Sons, Ltd.     

Drinking and driving “safely”: Who uses a breathalyzer and when?

Breathalyzers are often promoted on the grounds of safety. However, drivers who use them to avoid illegal blood-alcohol levels inadvertently expose themselves to sleepiness-related risks following alcohol intake. Personal breathalyzers may even be counterproductive if they make more drivers engage in more frequent or habitual drinking and driving. This study explores the extent to which and how drivers use the breathalyzer. We contacted nine major breathalyzer importers in Finland and found out that the estimated number of devices delivered during 2006 was almost 50,000, equaling approximately one percent of population and one-and-a-half percent of driving-license holders. Survey data on a representative sample of Finnish active drivers (N = 1121) showed that 11.5% owned a breathalyzer. More men than women own and use a breathalyzer, and most often the men are aged 36–55 years. These men also use it more often after acute drinking (32% vs. 20% in the whole sample). Seventy-nine percent of breathalyzer use occurs the following day after evening or night drinking. Therefore, while in a smaller percentage of cases the risk involves the additive and interactive effects of alcohol and sleepiness in the evening, most users expose themselves to risks related to daytime sleepiness due to drinking the previous night.     

Redundancy effects of a moving distractor generated by alerting and orienting

Redundancy effects refer to improvement of performance in response to irrelevant stimulation, or distractors. Previously described redundancy effects have mainly been associated with relatively high-level perception. The present study examines whether redundancy effects exist in basic attentional and perceptual systems, such as alerting and orienting. Participants performed speeded detection of briefly presented targets while ignoring moving distractors. The presence/absence of distractors and their spatial relationships with targets were manipulated to dissociate possible alerting and orienting redundancies. The distractor pathway (straightforward vs. chaotic) and its motion predictability (blocked vs. intermixed sequences of straightforward and chaotic trials) were also manipulated. The presence of a distractor resulted in faster responses (alerting redundancy). Furthermore, participants responded faster to targets behind distractors (orienting redundancy). Orienting redundancy was found only in the straightforward condition. This indicates that generating an orienting redundancy effect is a relatively slow process based on continuous observation of motion. Lastly, a blocked sequence of trials improved the alerting redundancy effect in comparison with an intermixed sequence.