Selective influence of second target exposure duration and Task1 load effects in the attentional blink phenomenon

The purpose of the experiments was to constrain the locus of interference in the attentional blink (AB) paradigm. Two visual stimuli, T₁ and T₂, were shown 300 msec apart, and each was followed by a mask. T₁ was an “H,” an “S,” an “ &, ” or a blank field; T₂ consisted of five letters. In Task₁, blank fields and & characters could be ignored, whereas Hs and Ss had to be identified and reported. Task₂ was always to report as many letters as possible from T₂. Task₂ performance was lower when T₁ had to be reported, as expected from the attentional blink phenomenon (AB). The exposure duration of T₂ was also manipulated. More letters could be reported as exposure duration was increased. However, this effect was additive with manipulations of Task₁ processing load that produced the AB effect. Log-linear analyses assuming that effects of T₂ exposure duration and Task₁ load effects occur at functionally distinct stages of processing provided satisfactory fits to the results, suggesting that none of the AB effect occurs as early as those of T₂ exposure duration. The results suggest that the locus of the AB effect is later than the stage(s) of processing affected by exposure duration.     

AEDs and psychotropic drugs in children with autism and epilepsy

The efficacy of antiepileptic drugs (AEDs) and psychotropic medications in children with autism is limited to the treatment of seizures or to specific behaviors such as irritability, impulsivity, hyperactivity, repetitive behaviors, or aggression. The reliability and value of the available data--to determine the efficacy of these medications in autism--are limited by lack of controlled clinical trials, the small number of subjects, the heterogeneity of the population studied, and the brief duration of most drug trials. Indeed, few controlled clinical trials using AEDs in autism, with or without seizures, have been conducted. Because some AEDs also have a positive effect on mood, the benefits that children with autism sometimes obtain from these medications may not be due to the treatment of the abnormal electrical activity or the seizures per se but to an effect on common neuronal systems responsible for both behavior and epilepsy. The relationship between epilepsy and autism, and specifically the effects that abnormal electrical activity may have on the developing brain, may provide some valuable insights into the type of studies that are needed to help us understand the pathophysiology of autism.     

The use of diagrams in analogical problem solving

In four experiments, we examined the impact of perceptual properties on the effectiveness of diagrams in analogical problem solving, using variants of convergence diagrams as source analogues for the radiation problem. Static diagrams representing the initial problematic state (one large line directed at a target) and the final state for a convergence solution (multiple converging lines) were not accessed spontaneously but were often used successfully once a hint to consider the diagram had been provided. The inaccessibility of static diagrams was not alleviated by adding additional diagrams to represent intermediate states (Experiment 1), but spontaneous access was improved by augmenting static diagrams with a verbal statement of the convergence principle (Experiment 3). Spontaneous retrieval and noticing were increased markedly by animating displays representing converging forces and thereby encouraging encoding of the lines as indicating motion toward a target (Experiments 3 and 4). However, neither static nor animated diagrams were effective when the arrows were reversed to imply divergence rather than convergence (Experiment 2). The results indicate that when animation encourages the interpretation of a diagram as a helpful source analogue, it can greatly enhance analogical transfer.     

Processing of global and local information in memory

The experiments reported in this paper were designed to test how global and local information are processed by the memory system. When subjects are required to match a given letter with either a previously presented large capital letter or the small capital letters comprising it, (1) responses to the global level (i.e. the big letter) are faster than responses to the local level (i.e. the small letters), and (2) responses to the latter level only are affected by the consistency between the large and the small letters (Experiment 2), a pattern similar to that obtained in perception (Experiment 1). Such results obtain when subjects are required to attend to only one level with a short ISI between the first and second stimulus, but not when a longer ISI is used (Experiment 5) or when subjects are required to attend to both levels at the same time (Experiments 3 and 4). The results are discussed in the light of a model that postulates a temporal precedence of the global information over the local one at the perceptual level.     

Three obstructions: forms of causation,chronotopoids, and levels of reality

The thesis is defended that the theories of causation, time and space, and levels of reality are mutually interrelated in such a way that the difficulties internal to theories of causation and to theories of space and time can be understood better, and perhaps dealt with, in the categorial context furnished by the theory of the levels of reality. The structural condition for this development to be possible is that the first two theories be opportunely generalized.

Emotion recognition and expression in young obese participants: preliminary study

This study of the presence of alexithymic characteristics in obese adolescents and preadolescents tested the hypothesis of whether they showed impaired recognition and expression of emotion. The sample included 30 obese young participants and a control group of 30 participants of normal weight for their ages. Stimuli, 42 faces representing seven emotional expressions, were shown to participants who identified the emotion expressed in the face. The Level of Emotional Awareness Scale was adapted for children to evaluate their ability to describe their emotions. Young obese participants had significantly lower scores than control participants, but no differences were found in recognition of emotion. The lack of words to describe emotions might suggest a greater prevalence of alexithymic characteristics in the obese participants, but the hypothesis of a general deficit in the processing of emotional experiences was not supported.     

Movements execution in amnestic mild cognitive impairment and Alzheimer's disease

We evaluated the relationship between motor and neuropsychological deficits in subjects affected by amnestic Mild Cognitive Impairment (aMCI) and early Alzheimer's Disease (AD). Kinematics of goal-directed movement of aMCI and AD subjects were compared to those of age-matched control subjects. AD showed a slowing down of motor performance compared to aMCI and controls. No relationships were found between motor and cognitive performances in both AD and aMCI. Our results suggest that the different motor behaviour between AD and aMCI cannot be related to memory deficits, probably reflecting the initial degeneration of parietal-frontal circuits for movement planning. The onset of motor dysfunction in early AD could represent the transition from aMCI to AD.