Executive control in the Simon effect: an electromyographic and distributional analysis

Manual responses to lateralized stimuli are faster for spatially congruent stimulus-response associations than for incongruent associations, even if the stimulus location is irrelevant. This effect, however, decreases as reaction time increases. Recent data suggest that such a decrease reflects online, within-trial executive control. The present study was aimed at testing this hypothesis by analyzing the electromyographic activity of muscles involved in response execution. We focused on the particular trials in which an activation of the muscle involved to the incorrect response preceded the execution of the correct response. A sequential effect analysis, along with an analysis of the reaction time distributions, revealed that after such dual-activation trials, executive control was reinforced. In addition, a distribution analysis of the reaction times associated with such trials compared to the trials without incorrect activation, revealed online, within-trial changes in executive control. Arguments against a late motor locus of the effect of the irrelevant stimulus location are also provided. These results are discussed in terms of current models of cognitive control.     

Impaired skill learning in patients with severe closed-head injury as demonstrated by the serial reaction time (SRT) task

A group of 20 patients who sustained closed-head injury (CHI) and a matched control group of 20 individuals were tested on the serial reaction time (SRT) task. Three different sequence-learning measures were generated from the task: two implicit and one explicit. The two implicit sequence-learning measures include: (1) the learning rate on the first five blocks of the repeated sequence, assumed to reflect primarily general reaction time learning, and (2) the difference between the fifth block of the repeated sequence and the sixth block, a random sequence that reflects implicit sequence-specific learning. In addition, an explicit measure of sequence learning was generated. The results indicate that the CHI group was impaired on the explicit measure of sequence learning. The groups did not differ on general reaction time learning, one of the implicit measures of sequence learning. However, the control group was superior to the CHI group in learning the specific sequence repeated in the SRT task. This pattern of results is unique to the CHI group, corresponding with neither that of amnesic patients nor with that of patients with dysfunction of the basal ganglia (i.e., Parkinson's diseases).     

AIDS/HIV in the work of family therapy trainees

A group of family therapy trainees were asked about their experience at work and knowledge of AIDS/HIV. The majority had already encountered AIDS-related issues in the context of their work. On the whole, they were well informed about AIDS/HIV, although specific gaps in their knowledge were identified. It is recommended that provision be made for the training of family therapists in this area.     

The interface between counselling and neuropsychological assessment of patients with AIDS/HIV

Manifestations of central nervous system dysfunction in adults and children with AIDS/HIV are common. The contribution of counselling in relation to these patients is described. This includes: contributing to the assessment of patients, addressing ‘dreaded issues' while patients are still well, helping patients to find solultions and manage problems, engaging the support of friends and the family in managing patients, ‘translating’ the results for the patient from formal assessments, discussing treatment options and helping parents and prospective parents to manage behaviour problems in their children. Counsellors also have a special role in advising and consulting colleagues about the management of these patients. Counselling in a clinical setting is, however, inextricably bound to limitations in the medical care of this patient group.     

The meaning of bad news in HIV disease: Counselling about dreaded issues revisited

HIV disease is a slow, progressive immunological disorder. As there is neither a cure nor a vaccine, morbidity and mortality arising from HIV infection will continue to challenge health care providers, including those who counsel these patients. Psychological preparation for ‘bad news’ and support for those whose health is deteriorating is an important task in HIV counselling. This paper describes what may be considered bad news for people living with HIV, how to prepare them for unwelcome changes in their medical condition and how to give bad news, should the need arise.     

Psychological consequences of involvement in a new religious movement or cult

It has frequently been suggested that the psychological consequences of involvement in new religious movements or cults can be profound for those who come into contact with them. To explore this further a study was carried out to investigate the relationship between personality, group membership of The Family (a new religious movement or cult) and mental health. Sixty six subjects (22 males, 44 females) in three different groups took part in this study. Group 1: Ex-members who felt negative about their involvement with The Family. Group 2: Present day members of The Family. Group 3: Ex-members who felt positive about their involvement with The Family. They completed two personality inventories (The Revised Eysenck Personality Questionnaire combined with the psychoticism scale of the Short Form of the Revised Eysenck Personality Questionnaire and the Beck Sociotrophy-Autonomy Scale). The results from this study were consistent with previous research indicating that experiences within the group increase social dependency and decrease autonomy for those who leave, whilst increasing the need for autonomous or individualistic achievement and lessening social conformity for present day members. This study suggests that some of the psychological difficulties which people have reported experiencing on leaving these groups are likely to be alleviated, to a degree, by time and from contact with a support group.     

Distributional reaction time properties in the Eriksen task: marked differences or hidden similarities with the Simon task?

In conflict tasks, the irrelevant stimulus attribute needs to be suppressed for the correct response to be produced. In the Simon task, earlier researchers have proposed that this suppression is the reason that, after an initial increase, the interference effect decreases for longer RTs, as reflected by late, negative-going delta plots. This view has been challenged by observations of positive-going delta plots, even for long RTs, in other conflict tasks, despite a similar necessity for suppression. For late negative-going delta plots to be interpreted as reflecting suppression, a necessary, although maybe not sufficient, condition is that similar patterns should be observed for other conflict tasks. We reasoned that a similar suppression could be present, but hidden, in the Eriksen flanker task. By recording and analyzing electromyograms of the muscles involved in response execution, we could compute delta plots separately for trials that elicited a subthreshold incorrect response activation (partial error). Late negative-going delta plots were observable on partial-error trials, although they were weaker than for the Simon task, reducing the impact of this inversion on the overall distribution. We further showed that this pattern is modulated by time pressure. Those results indicate that mechanisms leading to negative-going delta plots, similar to those observed in the Simon task, are also at play in the Eriksen task. The link between negative-going delta plots and executive online control is discussed.     

HIV/AIDS and the family: a review of research in the first decade

Most studies of the psychosocial implications of HIV/AIDS have been focused on the individual. This paper reviews the small but growing body of research into the impact of HIV/AIDS on the family system. Special reference is made to definitions of the family, same-sex relationships and the African family. The impact of HIV/AIDS on the family is discussed in terms of social stigma, isolation and secrecy, stress and coping, social support, communication and disclosure, responses to illness, and changing structure and roles in families. It is anticipated that in the 1990s, the study of the family will become a dominant topic in HIV/AIDS-related research.