The effects of marital status on episodic and semantic memory in healthy middle-aged and old individuals

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on memory, health and aging. The participants were grouped into two age cohorts, 35-60 and 65-85, and studied over a period of 5 years. Episodic memory tasks concerned recognition and recall, whereas semantic memory tasks concerned knowledge and fluency. The results showed, after controlling for education, some diseases, chronological age and leisure activity as covariates, that there were significant differences between married and single individuals in episodic memory, but not in semantic memory. Married people showed significantly better memory performances than singles in both subsystems of episodic memory, that is, recall and recognition. Also, the rate of decline in episodic memory was significantly larger for singles and widowed than other groups over the 5-year time period in both age groups. The findings demonstrate that the positive relation found between marriage and health can be extended to the relation between marriage and cognitive performance. This effect might be explained by the role played by cognitive stimulation in memory and cognition.     

An Investigation of the Associations Between Contingent Self-Worth and Aspirations Among Iranian University Students

This study investigated the novel associations between intrinsic and extrinsic aspirations and internal and external domains of contingent self-worth among a sample of 502 Iranian university students. We found a meaningful pattern showing that intrinsic aspirations were positively associated with internal domains, whereas extrinsic aspirations were positively associated with external domains. Our survey data also suggested that the factor structure of the Aspiration Index, as well as the factor structure of the Contingencies of Self-Worth Scale in our Iranian sample were consistent with factor structures of foreign samples. Finally, the types of aspirations and domains of contingencies of self-worth meaningfully predicted variables related to well-being, confirming previous research. We discuss the nature of the associations between the aspirations and the domains of contingent self-worth.     

Pragmatism,Bohr, and the Copenhagen Interpretation of Quantum Mechanics

In this article, we argue that although Bohr's version of the Copenhagen interpretation is in line with several key elements of logical positivism, pragmatism is the closest approximation to a classification of the Copenhagen interpretation, whether or not pragmatists directly influenced the key figures of the interpretation. Pragmatism already encompasses important elements of operationalism and logical positivism, especially the liberalized Carnapian reading of logical positivism. We suggest that some elements of the Copenhagen interpretation, which are in line with logical positivism, are also supported by pragmatism. Some of these elements are empirical realism, fallibilism, holism, and instrumentalism. However, pragmatism goes beyond logical positivism in espousing some other key elements of the Copenhagen interpretation, though imperfectly, such as the correspondence principle, complementarity, and indeterminism.     

Generalization as a behavioral window to the neural mechanisms of learning internal models

In generating motor commands, the brain seems to rely on internal models that predict physical dynamics of the limb and the external world. How does the brain compute an internal model? Which neural structures are involved? We consider a task where a force field is applied to the hand, altering the physical dynamics of reaching. Behavioral measures suggest that as the brain adapts to the field, it maps desired sensory states of the arm into estimates of force. If this neural computation is performed via a population code, i.e., via a set of bases, then activity fields of the bases dictate a generalization function that uses errors experienced in a given state to influence performance in any other state. The patterns of generalization suggest that the bases have activity fields that are directionally tuned, but directional tuning may be bimodal. Limb positions as well as contextual cues multiplicatively modulate the gain of tuning. These properties are consistent with the activity fields of cells in the motor cortex and the cerebellum. We suggest that activity fields of cells in these motor regions dictate the way we represent internal models of limb dynamics.     

The effect of retrieval enactment on recall of subject-performed tasks and verbal tasks

The effect of retrieval enactment on memory for nouns (objects) or verbal phrases describing simple actions (e.g., “lift the box”) was addressed in two experiments. In Experiment 1, the type of object involved in the actions was manipulated, with three different types of object being used (body parts, laboratory-related objects, and external objects). In Experiment 2, the integration between the verb-noun pairs was manipulated (well-integrated vs. poorly integrated). Results from both experiments showed that whereas encoding enactment (motor encoding and verbal test) substantially improved the memory performance compared with a verbal condition (verbal encoding and verbal test), retrieval enactment (verbal encoding and motor test) had no major impact on the number of recalled nouns or phrases. Moreover, there was no additional effect of dual enactment (motor encoding and motor test). The overall pattern of the results suggests that there is a fundamental difference between motor processing at encoding and motor processing at retrieval, and the lack of encoding specificity advantage for the motor modality contradicts the view that encoding enactment of verbal commands results in storage of motor representations.     

Control of Equilibrium Position and Stiffness Through Postural Modules

If muscles are viewed as spring-like torque generators, then the integral of torque with respect to joint angle is the potential energy of that muscle. An energy function for the musculoskeletal system can be defined by summing the energy contribution of each muscle and the potential energy stored in the limb. Any local minimum in this energy landscape is a possible equilibrium position for the limb. The gradient of this function with respect to joint angles is a torque field, and the task of postural control is to find a set of muscle activations to produce a desired field. We consider one technique by which this approximation may be achieved: A postural module is defined as a synergy of muscles that produce a class of torque functions that converge at a constant equilibrium position, but whose stiffness at this position varies as a function of activation of the postural module. For a single-joint system, we show that through control of two such modules it is possible to produce any stiffness at any desired equilibrium position. To extend this scheme to a multijoint system, we initially derive the mechanical constraints on the shape of the restoring force field when a multijoint limb is displaced from equilibrium. Next, we consider voluntary control of the force field when the human arm is displaced from equilibrium: Mussa-Ivaldi, Hogan, and Bizzi (1985) have suggested that subjects are unable to voluntarily change the shape and orientation of the field, although they can readily scale it. This suggests existence of a limitation on the independent recruitment of arm muscles. We show, through simulation, that the inability to voluntarily control the shape and orientation of the restoring force field can be attributed to an organization of postural modules that act as local stiffness controllers. We propose that through coactivation, postural modules coarsely encode the work space and serve as an intermediate control system in the motor control hierarchy.     

Electrocortical signs of arousal in response to darkness and the assessment of type A behavior in professional drivers with and without cardiovascular disease

Background and Aims  In night driving, the fatal accident rate is about four times that in daytime. There is a lack of published studies of the effect of darkness on electrocortical responses in professional drivers (PD). Aim: Assessing relations between electroencephalographic (EEG) reactions to enforced darkness reminiscent of night driving, and untoward behavioral response patterns, notably Type A behavior. Methods  PD: 13 with ischemic heart disease, 12 hypertensives (HTN), 10 borderline hypertensives and 34 normotensives, and 23 non-PD controls. Five minutes of electroencephalographic recording with eyes closed, and subsequently 3 minutes exposure to darkness. EEG parameters were: alpha abundance, amplitude and frequent. Type A behavior (TAB) was assessed by observation and by questionnaire. Results  Alpha abundance diminished significantly for darkness compared to spontaneous recording for all groups. No between-group differences were found for EEG. There were no significant differences in EEG between drivers with IHD or HTN taking versus not taking centrally active β-blockers. Drivers with IHD were the only group to show significant increase in dominant α frequency at darkness. The IHD group also had the highest TAB questionnaire scores and the heaviest exposure to professional driving. Type A scores were significantly correlated with dominantt alpha frequency during darkness. Low availability of attachment and special driving hazards best predicted TAB scores in driven. There was a significance between group difference with respect to Symbolic Aversiveness at the work place comparing each driver group with the non-PD control group. Conclusions  Exposure to darkness reminiscent of night driving can elicit central arousal, in conflict with circadian rhythm, and in combination with other driving hazards which contribute to symbolic aversiveness, the essence of driving. And low availability of social attachment could contribute to sustained, and in turn to the development of Type A behavior in professional drivers.     

The role of integration in recognition failure and action memory

In three experiments, we studied memory for action events with respect to exceptions from the Tulving-Wiseman function demonstrated in experiments on recognition failure of recallable words. In Experiment 1, we examined exceptions of poor integration in a regular recognition failure condition (i.e., recognition of targets without contextual cues, followed by recall of targets in the presence of contextual cues). In Experiment 2, we examined exceptions of cue overlap in which subjects also had access to the information of contextual cues at recognition test. In Experiment 3, we attempted to equate the levels of recognition across the action and verbal encoding. In addition, the cue overlap and no-cue overlap conditions were studied in a within-subjects design. Results from the three experiments indicated that encoding enactment (episodic integration) and conceptual integration (semantic integration) are related to each other. As a consequence of this relationship, there is a larger independence between recognition and recall of well-integrated items with encoding enactment. On the other hand, for the poorly integrated items without encoding enactment, there is a larger dependence between recognition and recall. Even in the cue overlap condition, where there is a case of large dependence between recognition and recall, the same pattern of data was observed. The results are discussed in terms of an episodic integration view of encoding enactment.