Selective executive impairments as neuroimmunological manifestations of the human immunodeficiency virus.

Executive processes that predominantly effect people living with human immunodeficiency virus remain to be understood. In the present case-control study, components summarizing executive functions were empirically determined to clarify the nature of executive difficulties observed in individuals with human immunodeficiency virus. One hundred and five seropositive and 62 seronegative healthy adults without comorbidities underwent a comprehensive executive function assessment. Test data were reduced via principal components analysis and component scores were used to investigate whether seropositive adults exhibit selective difficulties in specific executive processes. A three-component solution was found, consisting of updating, inhibition and set-shifting. Group differences between seropositive and seronegative participants were observed only in the updating component. In the present exploratory analyses, significant findings emerged that suggest a selective executive impairment associated with the updating/working memory process in young to middle adulthood seropositive individuals without comorbidities.

The Pattern of Mu Rhythm Modulation During Emotional Destination Memory: Comparison Between Mild Cognitive Impairment Patients and Healthy Controls.

Leading theories of affect development and empirical studies suggest that emotion can enhance memory in older adults. Destination memory which is defined as the ability to remember to whom we told a piece of information is being found to be compromised in aging. In the present study, we sought to assess destination memory using emotional stimuli (Emotional Destination Memory, EDM) in 16 older adults with mild cognitive impairment (MCI) and 16 healthy controls and shed light onto its potential neurophysiological aspects. We measured Mu suppression in frontal and temporal regions via EEG in real time while participants performed the task of EDM. Results showed no group differences in task performance but significant differences in fronto-temporal activations, specifically in electrodes F7 and F8. Differential Mu rhythm pattern was observed between healthy controls and MCI with the first exhibiting Mu suppression and the last Mu enhancement. Furthermore, Mu enhancement in temporal electrodes within the MCI group was associated with lower scores on EDM. The absence of group differences in the task can be explained by the fact that even if there are underlying structural or functional deficits in the MCI group, these deficits are manifested only at neurophysiological level and not at a behavioral level, which is a common pattern in the process of cognitive decline in its initial phases. The overall findings reveal that, even if there are not any behavioral decrements in MCI patients, they show reduced activations in fronto-temporal regions and this can be attributed to general impairment in emotional destination memory due to possible mirror neuron deficiency.

The verbal fluency task in the Greek population: normative data, and clustering and switching strategies.

We assessed 300 healthy adults in Greece on measures of semantic and phonemic verbal fluency in order to develop norms for the Greek population. We also evaluated the strategies that the participants used spontaneously in order to maximize word production, namely clustering and switching techniques. Our tasks comprised three semantic and three phonemic categories. Consistent with previous investigations of English-speaking samples, we found a contribution of demographic variables to word fluency. Specifically, level of education contributed to total word production, number of switches, and number of repetitive responses on both semantic and phonemic tasks, and the average cluster size only on the phonemic task. Age contributed to total word production and cluster size on the semantic task, and to number of switches on both semantic and phonemic tasks. Sex contributed only to total word production on the semantic task. In our sample, clustering and switching strategies were related to total word production on both tasks, suggesting that these strategies were used effectively. We present tables of normative data stratified by age and level of education. We have also included detailed guidelines for scoring clusters relevant to the Greek population.