The role of temporal unpredictability for process interference and code overlap in perception-action dual tasks

Two experiments explore interference in dual tasks. The first task required perceptual judgment of the movement direction (left vs right) of a briefly presented stimulus; the second task was a tone-discrimination reaction-time (RT) task. Participants reported their judgment at leisure. In 50% of the trials they were told to ignore the stimulus (no report). The directions of stimulus movement and response in the RT task could either be the same or different, establishing cross-task compatibility (CTC) relations. We varied the degree of temporal unpredictability by using two stimulus-onset asynchronies (SOA, 100 ms vs 1200 ms) for the task stimuli. In Experiment 1, SOA was varied randomly within blocks of trials in one group and between blocks in another group. In Experiment 2, only the short SOA was used in one group and only the long SOA in another group. In both experiments, we observed substantially longer RTs with the short compared with the long SOA, regardless of whether there was temporal certainty (blocked or constant SOA) or uncertainty (random SOA) about stimulus onset. We assume that the process of encoding into short-term memory in one task interferes with concurrent retrieval processes (i.e., response selection) in the other task. This process interference effect was strongly reduced in no-report trials. Furthermore, we found shorter RT in compatible than in incompatible trials. This CTC effect diminished with long SOA but occurred even in no-report trials, implying that it refers to an automatically activated and then decaying code that primes response selection in the RT task.     

The role of external cues for endogenous advance reconfiguration in task switching

Most studies of task-set switching rely on cuing paradigms, in which external cues indicate the upcoming task. The present study used an entirely predictable task sequence in a variant of the alternating-runs paradigm of Rogers and Monsell (1995). Preparation effects with purely internal memory cues were compared with those in another experimental group with additional external cues presented prior to the stimulus. External cues led to strongly reduced shift costs with prolonged preparation time. However, this effect was much smaller with internal cues only. To account for this differential effect of preparation time as a function of cue type, it is suggested that internal cues select the next task set, which is sufficient to perform the task. External cues additionally facilitate preparatory retrieval of task-specific stimulus-response rules. This account may also explain why incidental task-sequence learning based on internal cues did not reduce shift costs.     

Latent inhibition disruption by MK-801 in a conditioned taste-aversion paradigm

N-Methyl-D-aspartate (NMDA) receptors appear to be involved in CS processing and memory consolidation. The present paper analyzed the effect of the non-competitive NMDA receptor antagonist Dizocilpine maleate (MK-801) on Latent Inhibition (LI)-retarded learning of a CS-US association after to-be-CS preexposures at time of testing, using Wistar rats as experimental subjects. If NMDA receptors are involved in CS processing, MK-801 administration should affect LI. In fact, previous experiments revealed that a 2.0mg/kg MK-801 dose, administered 20 h before preexposure and conditioning, abolished LI in a conditioned taste-aversion paradigm. In the present paper, MK-801 (0.2 mg/kg) was either injected after preexposure, after conditioning, or after both preexposure and conditioning stages. LI was abolished when MK-801 was injected after preexposure, but not when it was injected after conditioning. These results support the role of NMDA receptors in CS processing and memory consolidation.     

Pavlov in America: a heterodox approach to the study of his influence

This work presents a critical analysis of Pavlov's influence that goes beyond the conventional view: that which reduces his influence in American psychology to the behaviorism of Watson and Hull. In order to understand the nature of the Russian physiologist's influence in American psychology, we propose a distinction between three approaches to it: 1) the symbolic approach, on representing a model of the possibility of constructing an objective psychology; 2) the methodological approach, given the importance of the technique of conditional reflexes; and 3) the theoretical approach, which is derived from his theory of higher nervous activity. This perspective permits us to suggest that most of Pavlov's influence on behaviorism was of a symbolic and methodological nature--though the methodological influence also reached other authors that did not belong to the behaviorist traditions, as was the case of Mateer. As far as the theoretical influence is concerned, our work proposes that it is more visible in authors such as Gantt and Liddell, or even in authors such as Boldirev, Director of the Pavlovian Laboratory at the Battle Creek Sanitarium in Michigan. The case of Gantt is especially interesting because, in addition to his important contributions, he played an essential role in the foundation of the Pavlovian Society, and the journal Conditional Reflex. What our work proposes is that to understand the nature of Pavlov's influence in American psychology it is necessary to take into account the very characteristics of that psychology: its pragmatic interests, its methodological rigor, the dominant systems of neo-behavioral theory and the changes that occurred after the Second World War.     

Stereotype development in Andalusian children

Social psychologists have shown a profound interest in intergroup relationships, but there are very few papers focusing on the developmental aspects that explain the psychological mechanisms involved in the construction of group and cultural identity. Our research aims to explore how the self-categorization of Andalusian children evolves. We tried to assess the degree to which they self-identify as Andalusian, Spanish, and European, and how this identification changes with age. We were also interested in the affective evaluation of different groups (French, Italian, English, German, Spanish, Catalonian, and Andalusian) made by Andalusian children. Furthermore, we analyzed the relationship between self-categorization and the evaluation of these groups. Results show that the development of national (autonomous community) identity in these children is influenced by their cognitive development, as well as by the relationships among the regional communities of Spain and the relationships between Spain and other countries. The peculiarity of Andalusians as a group is that they assume both identities: Spanish and Andalusian, from a very early age. In-group favoritism is an extended phenomenon at all ages, and Andalusian children have a negative stereotype of the other Spanish groups and other European communities.     

Social psychology of mental health: the social structure and personality perspective

Previous research has revealed a persistent association between social structure and mental health. However, most researchers have focused only on the psychological and psychosocial aspects of that relationship. The present paper indicates the need to include the social and structural bases of distress in our theoretical models. Starting from a general social and psychological model, our research considered the role of several social, environmental, and structural variables (social position, social stressors, and social integration), psychological factors (self-esteem), and psychosocial variables (perceived social support). The theoretical model was tested working with a group of Spanish participants (N = 401) that covered a range of social positions. The results obtained using structural equation modeling support our model, showing the relevant role played by psychosocial, psychological and social, and structural factors. Implications for theory and intervention are discussed.     

Large-scale ensemble averaging of ambulatory impedance cardiograms

Impedance cardiography has been used increasingly to measure human physiological responses to emotional and mentally engaging stimuli. The validity of large-scale ensemble averaging of ambulatory impedance cardiograms was evaluated for preejection period (PEP), interbeat interval, and dZ/dt_(min) amplitude. We tested whether the average of “classical” 60-sec ensemble averages across periods with fixed activity, posture, physical load, social situation, and location could be accurately estimated from a single large-scale ensemble average spanning these entire periods. Impedance and electrocardiograms were recorded for about 24-h from 21 subjects. Recordings were scored by seven raters, using both methods for each subject. Good agreement (average intraclass correlation coefficient was .91) between both ensemble averaging methods was found for all three cardiac function measures. The results indicate that for unambiguous ambulatory impedance cardiograms, large-scale ensemble averaging is valid, which makes measuring prolonged changes in cardiac sympathetic activity by measuring ambulatory PEP feasible even in large epidemiological samples.     

Changes in executive control across the life span: examination of task-switching performance

A study was conducted to examine changes in executive control processes over the life span. More specifically, changes in processes responsible for preparation and interference control that underlie the ability to flexibly alternate between two different tasks were examined. Individuals (N = 152) ranging in age from 7 to 82 years participated in the study. A U-shaped function was obtained for switch costs (i.e., the time required to switch between tasks compared with a repeated-task baseline), with larger costs found for young children and older adults. Switch costs were reduced with practice, particularly for children. All age groups benefited from increased preparation time, with larger benefits observed for children and older adults. Adults benefited to a greater extent than children when the interval between the response to one task and the cue indicating which task to perform next was lengthened, which suggested faster decay of interference from the old task set for adults than for children. A series of hierarchical analyses indicated that the age-related variance in task-switching performance is independent, at least in part, from the age-related variance in other cognitive processes such as perceptual speed and working memory. The results are discussed in terms of the development and decline of executive control processes across the life span.     

Effect of inapplicable items in the factor structure of the Spanish version of the Ways of Coping Questionnaire

The aim of this work was to examine how the presence of inapplicable items might change the factor structure of the 1984 Ways of Coping Questionnaire by Lazarus and Folkman. The Spanish version of the Ways of Coping Questionnaire was administered to 156 subjects with university degrees. The 95 women and 61 men whose ages were from 18 and 45 years (M = 27.8, SD = 12.1) were of middle socioeconomic status. All were residents of Buenos Aires. To study whether relevant items modify the factor structure of the Ways of Coping Questionnaire, two factor analyses were carried out, one with items rated as not relevant (Item Mean) and the other with the same items rated as not chosen. In both factor analyses, principal axes method and oblimin rotation were performed, and five factors were considered. Congruence indexes were performed. Analysis showed that not choosing an item because it does not coincide with one's behavior or ideas is not the same as not selecting that item because it does not apply to the current threatening situation. Lack of discrimination between situations when analyzing data leads to a distorted interpretation of the way in which the subject actually behaves or copes with the situation.     

Quality of life before and after lung transplantation in patients with emphysema versus other indications

Whether lung transplantation improves Health-related Quality of Life in patients with emphysema and other end-stage lung diseases before and after lung transplantation was examined. Between 1992 and 1999, 23 patients with emphysema and 19 patients with other indications completed self-administered questionnaires before lung transplantation, and at 4, 7, 13, and 25 mo. after transplantation. The questionnaire included the Nottingham Health Profile, the State-Trait Anxiety Inventory, the Self-rating Depression Scale, the Index of Well-being, the self-report Karnofsky Index, and four respiratory-specific questions. Neither before nor after transplantation were significant differences found on most dimensions of Health-related Quality of Life between patients with emphysema and other indications. Before transplantation, both groups report major restrictions on the dimensions Energy and Mobility of the Nottingham Health Profile, low experienced well-being, depressive symptoms, and high dyspnea. About 4 mo. after transplantation, most Health-related Quality of Life measures improved significantly in both groups. These improvements were maintained in the following 21 mo.