Relational integration, inhibition, and analogical reasoning in older adults

The difficulty of reasoning tasks depends on their relational complexity, which increases with the number of relations that must be considered simultaneously to make an inference, and on the number of irrelevant items that must be inhibited. The authors examined the ability of younger and older adults to integrate multiple relations and inhibit irrelevant stimuli. Young adults performed well at all but the highest level of relational complexity, whereas older adults performed poorly even at a medium level of relational complexity, especially when irrelevant information was presented. Simulations based on a neurocomputational model of analogical reasoning, Learning and Inference with Schemas and Analogies (LISA), suggest that the observed decline in reasoning performance may be explained by a decline in attention and inhibitory functions in older adults.     

Differential mastication kinematics of the rabbit in response to food and water: Implications for conditioned movement

Analysis of naturalistic chewing patterns may provide insight into mapping the neural substrates of jaw movement control systems, including their adaptive modification during the classically conditioned jaw movement (CJM) paradigm. Here, New Zealand White rabbits were administered food and water stimuli orally to evaluate the influence of stimulus consistency on masticatory pattern. Chewing patterns were recorded via video camera and movements were analyzed by computerized image analysis. The mandibular kinematics, specifically the extent of dorsal/ventral, medial/lateral, and rostral/caudal movement, were significantly larger in food-evoked than water-evoked chewing. Water-evoked chewing frequency, however, was significantly higher than that of food-evoked movements. In light of known cortical mastication modulatory centers, our findings implicate different neural substrates for the responses to food and water stimuli in the rabbit. A detailed delineation of jaw movement patterns and circuitry is essential to characterize the neural substrates of CJM.     

Locomotion,incidental learning,and the selection

In three experiments, we examined the effects of locomotion and incidental learning on the formation of spatial memories. Participants learned the locations of objects in a room and then made judgments of relative direction, using their memories (e.g., "Imagine you are standing at the clock, facing the jar. Point to the book"). The experiments manipulated the number of headings experienced, the amount of interaction with the objects, and whether the participants were informed that their memories of the layout would be tested. When participants were required to maintain a constant body orientation during learning (Experiment 1), they represented the layout in terms of a single reference direction parallel to that orientation. When they were allowed to move freely in the room (Experiment 2), they seemed to use two orthogonal reference axes aligned with the walls of the enclosing room. Extensive movement under incidental learning conditions (Experiment 3) yielded a mixture of these two encoding strategies across participants. There was no evidence that locomotion, interaction with objects, or incidental learning led to the formation of spatial memories that differed from those formed from static viewing.     

Perceptual judgements of others' tasting experiences: are they enjoying their food?

Motivated by previous work suggesting that infants make stereotypic facial reactions to different tastes, we assessed communicative signals that might enable an adult to interpret the strength, taste, and hedonic value of a liquid flavour another adult is consuming. Four subjects (tasters) were overtly videoed consuming drinks that varied in strength (low, medium, and high concentrations), taste (sweet, sour, bitter, and salty), and hedonic value (taster-rated enjoyment). 26 observers assessed the strength, taste, and taster's enjoyment of the drink from video clips of the tasters. Observers perceived the hedonic value of the drinks to the taster and the drinks' strength based on the tasters' reactions but were generally poor at assessing the specific taste of the drink. For all tastes except the bitter ones, observers might have based their judgements of taste on how much the taster appeared to enjoy the drink. These findings are discussed in terms of communication of food's value.     

Emotional competence and aggressive behavior in school-age children

Examined emotional competence in 87 children, aged 7–10 years, who varied with respect to reports of aggressive behavior to determine whether individual differences in emotional competence characterize children with higher levels of aggressive behavior. Emotional competence was assessed during a 1-hr lab visit that included (a) an observational period consisting of a modified disappointment paradigm, (b) assessment of cognitive and language abilities, and (c) 2 structured emotion interviews. Children with higher levels of aggressive behavior exhibited more intense and frequent expressions of anger, both as reported by mothers and as observed during the disappointment paradigm. Less sophisticated ability to identify the causes of emotion also characterized children with higher levels of aggressive behavior. Gender moderated the relation between aggressive behavior and type of emotion identified such that reports of happiness (in response to receiving a disappointing prize) were associated with lower levels of reported aggressive behavior for boys. The value of assessing children's emotional competence in the context of an emotionally arousing situation is suggested by these findings.     

"Isn't it fun to get the respect that we're going to deserve?" Narcissism, social rejection, and aggression

Across four studies, narcissists were more angry and aggressive after experiencing a social rejection than were nonnarcissists. In Study 1, narcissism was positively correlated with feelings of anger and negatively correlated with more internalized negative emotions in a self-reported, past episode of social rejection. Study 2 replicated this effect for a concurrent lab manipulation of social rejection. In Study 3, narcissists aggressed more against someone who rejected them (i.e., direct aggression). In Study 4, narcissists were also more aggressive toward an innocent third party after experiencing social rejection (i.e., displaced aggression). Narcissists were not more aggressive after social acceptance. Self-esteem plays little role in predicting aggression in response to rejection. These results suggest that the combination of narcissism and social rejection is a powerful predictor of aggressive behavior.     

The effects of different aperture-viewing conditions on the recognition of novel objects

The process of learning the structure of novel objects involves the selective use of information available in the distal stimulus. By allowing participants to explore the object within a limited field of view, we were able to examine more rigorously what regions of the object are actually selected in the learning process. Participants explored objects either by moving a circular aperture over a stationary novel object (the aperture-movement condition), or by moving the object behind a stationary aperture (the object-movement condition). Given the differences in how the spatial layout of object parts is revealed in the two study conditions, we expected that exploration would be more systematic in the aperture-movement condition than it would be in the object-movement condition, and would lead to better object recognition. We show evidence that in the aperture-movement condition exploration patterns were more related to the structure of the object and, as a consequence, the aperture-movement condition resulted in more accurate recognition in a later old--new discrimination test.     

The difference engine: A model of diversity in speeded cognition

A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.     

Topiramate in the preventive treatment of episodic migraine: a combined analysis from pilot,double-blind,placebo-controlled trials

The safety and efficacy of medications for preventive treatment of migraine is the subject of current concern and investigation in health care. Two single-center, double-blind, placebo-controlled studies were conducted to evaluate the efficacy and safety of topiramate for migraine prophylaxis. Seventy patients with a diagnosis of migraine were randomly assigned to topiramate-treated and placebo groups. The studies consisted of a 4-week baseline phase, a 6-8 week titration, and 8-12 weeks of maintenance. Topiramate was titrated from an initial dose of 25 mg/day to a target dose of 100 mg BID. The primary efficacy measure, the mean 28-day migraine frequency, was lower in topiramate-treated patients than in the placebo group (3.2 versus 3.8, P=.001). Similarly, topiramate treatment resulted in a significantly greater mean reduction in migraine frequency than did placebo (1.55 versus 0.47, P=.001) and a significantly higher responder rate (35.3% versus 8.3%, P=.008). Paresthesia was the most common side effect reported with topiramate treatment. Other topiramate-associated adverse events included altered taste, memory impairment, diarrhea, and appetite suppression/weight loss. The rates of discontinuation were similar for the topiramate group (n=10) and the placebo group (n=8). These results suggest that topiramate is effective and well tolerated in the preventive treatment of migraine headaches.     

Computerizing reading training: Evaluation of a latent semantic analysis space for science text

The effectiveness of a domain-specific latent semantic analysis (LSA) in assessing reading strategies was examined. Students were given self-explanation reading training (SERT) and asked to think aloud after each sentence in a science text. Novice and expert human raters and two LSA spaces (general reading, science) rated the similarity of each think-aloud protocol to benchmarks representing three different reading strategies (minimal, local, and global). The science LSA space correlated highly with human judgments, and more highly than did the general reading space. Also, cosines from the science LSA spaces can distinguish between different levels of semantic similarity, but may have trouble in distinguishing local processing protocols. Thus, a domain-specific LSA space is advantageous regardless of the size of the space. The results are discussedin the context of applying the science LSA to a computer-based version of SERT that gives online feedback based on LSA cosines.