Force matching errors following eccentric exercise

During eccentric exercise contracting muscles are forcibly lengthened, to act as a brake to control motion of the body. A consequence of eccentric exercise is damage to muscle fibres. It has been reported that following the damage there is disturbance to proprioception, in particular, the senses of force and limb position. Force sense was tested in an isometric force-matching task using the elbow flexor muscles of both arms before and after the muscles in one arm had performed 50 eccentric contractions at a strength of 30% of a maximum voluntary contraction (MVC). The exercise led to an immediate reduction of about 40%, in the force generated during an MVC followed by a slow recovery over the next four days, and to the development of delayed onset muscle soreness (DOMS) lasting about the same time. After the exercise, even though participants believed they were making an accurate match, they made large matching errors, in a direction where the exercised arm developed less force than the unexercised arm. This was true whichever arm was used to generate the reference forces, which were in a range of 5-30% of the reference arm's MVC, with visual feedback of the reference arm's force levels provided to the participant. The errors were correlated with the fall in MVC following the exercise, suggesting that participants were not matching force, but the subjective effort needed to generate the force: the same effort producing less force in a muscle weakened by eccentric exercise. The errors were, however, larger than predicted from the measured reduction in MVC, suggesting that factors other than effort might also be contributing. One factor may be DOMS. To test this idea, force matches were done in the presence of pain, induced in unexercised muscles by injection of hypertonic (5%) saline or by the application of noxious heat to the skin over the muscle. Both procedures led to errors in the same direction as those seen after eccentric exercise.     

Activation of midbrain structures by associative novelty and the formation of explicit memory in humans

Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study, participants distinguished between familiar and novel configurations of pairs of items which had been studied together by either learning the location or the identity of the items. In the second study, participants studied words by either rating the words' pleasantness or counting syllables. The ventral tegmental area and medial substantia nigra showed increased activation by associative novelty (first study) and subsequent free recall performance (second study). In both studies, this activation accompanied hippocampal activation, but was unaffected by the study task. Thus midbrain regions seem to participate selectively in hippocampus-dependent processes of associative novelty and explicit memory formation, but appear to be unaffected by other task-relevant aspects.     

Late-associativity, synaptic tagging, and the role of dopamine during LTP and LTD

Protein synthesis-dependent, synapse input-specific late phases of long-term potentiation (LTP) and depression (LTD) may underlie memory formation at the cellular level. Recently, it was described that the induction of LTP can mark a specifically activated synapse by a synaptic tag to capture synapse non-specific plasticity-related proteins (PRPs) and thus maintaining input-specific LTP for prolonged periods. Here we show in rat hippocampal slices in vitro, that the induction of protein synthesis-dependent late-LTD is also characterized by synaptic tagging and that heterosynaptic induction of either LTD or LTP on two sets of independent synaptic inputs S1 and S2 can lead to late-associative interactions: early-LTD in S2 was transformed into a late-LTD, if late-LTP was induced in S1. The synthesis of process-independent PRPs by late-LTP in S1 was sufficient to transform early- into late-LTD in S2 when process-specific synaptic tags were set. We name this new associative property of cellular information processing 'cross-tagging.'     

Reliability and validity of the Spanish Version of the Crisis in Family Systems-Revised

Increasing the representation of Spanish-speaking study participants requires development and dissemination of reliable and valid translated scales. In the urrent study the construct validity was assessed of the Spanish version of the Crisis n Family Systems-Revised, a measure of contemporary life stressors, with a convenience sample of 377 parents interviewed in a study of childhood asthma, although over half of the respondents did not have children with asthma. Most respondents were foreign-born women between 20 to 60 years old (M=35, SD=7). 52% had not completed high school or its equivalent, and 55% reported a household income of dollar 15,000 or less. For a subsample of 25 respondents test-retest reliability was .86 over 2 wk. Reporting more life stressors was associated with greater depressive symptomatology, poorer physical and mental health function, and lower household income. These relationships support the construct validity of the test in Spanish. This study provided strong evidence that this version is a valid and reliable measure of life stressors for a Spanish-speaking population living in the United States.     

Attentional enhancement opposite a peripheral flash revealed using change blindness

We describe a new method for mapping spatial attentionthat reveals a pooling of attention in the hemifield opposite a peripheralflash. Our method exploits the fact that a brief full-field blank caninterfere with the detection of changes in a scene that occur during theblank. Attending to the location of a change, however, can overcome thischange blindness, so that changes are detected. The likelihood of detecting anew element in a scene therefore provides a measure of the occurrence ofattention at that element's location. Using this measure, we mappedhow attention changes in response to a task-irrelevant peripheral cue. Underconditions of visual fixation, change detection was above chance across theentire visual area tested. In addition, a "hot spot" ofattention (corresponding to near-perfect change detection) elongated alongthe cue-fixation axis, such that performance improved not only at the cuedlocation but also in the opposite hemifield.     

Being forgiven: toward a thicker description of forgiveness

The author describes the less frequently examined process of seeking forgiveness from others. Examples from the seminary classroom are used to describe the process. The examination of the seeking forgiveness process provides insight into the whole construct of forgiveness.     

The 'hard problem' and the quantum physicists. Part 1: the first generation

All four of the most important figures in the early twentieth-century development of quantum physics-Niels Bohr, Erwin Schroedinger, Werner Heisenberg and Wolfgang Pauli-had strong interests in the traditional mind-brain, or 'hard,' problem. This paper reviews their approach to this problem, showing the influence of Bohr's complementarity thesis, the significance of Schroedinger's small book, 'What is life?,' the updated Platonism of Heisenberg and, perhaps most interesting of all, the interaction of Carl Jung and Wolfgang Pauli in the latter's search for a unification of mind and matter.     

Health, wealth, and happiness: financial resources buffer subjective well-being after the onset of a disability

We examined the hypothesis that the relationship between financial status and subjective well-being, typically found to be very small in cross-sectional studies, is moderated by health status. Specifically, we predicted that wealth would buffer well-being after the onset of a disability. Using data from the Health and Retirement Study, a longitudinal study of people at and approaching retirement age, we employed within-subjects analyses to test whether wealth measured prior to the onset of a disability protected participants' well-being from some of the negative effects of a new disability. We found support for this hypothesis: Participants who were above the median in total net worth reported a much smaller decline in well-being after a new disability than did participants who were below the median. We also found some evidence that the buffering effect of wealth faded with time, as below-median participants recovered some of their well-being.