As Good as GOLD: Gram–Schmidt Orthogonalization by Another Name

Generalized orthogonal linear derivative (GOLD) estimates were proposed to correct a problem of correlated estimation errors in generalized local linear approximation (GLLA). This paper shows that GOLD estimates are related to GLLA estimates by the Gram–Schmidt orthogonalization process. Analytical work suggests that GLLA estimates are derivatives of an approximating polynomial and GOLD estimates are linear combinations of these derivatives. A series of simulation studies then further investigates and tests the analytical properties derived. The first study shows that when approximating or smoothing noisy data, GLLA outperforms GOLD, but when interpolating noisy data GOLD outperforms GLLA. The second study shows that when data are not noisy, GLLA always outperforms GOLD in terms of derivative estimation. Thus, when data can be smoothed or are not noisy, GLLA is preferred whereas when they cannot then GOLD is preferred. The last studies show situations where GOLD can produce biased estimates. In spite of these possible shortcomings of GOLD to produce accurate and unbiased estimates, GOLD may still provide adequate or improved model estimation because of its orthogonal error structure. However, GOLD should not be used purely for derivative estimation because the error covariance structure is irrelevant in this case. Future research should attempt to find orthogonal polynomial derivative estimators that produce accurate and unbiased derivatives with an orthogonal error structure.     

3-D eye movement analysis

This paper presents a novel three-dimensional (3-D) eye movement analysis algorithm for binocular eye tracking within virtualreality (VR). The user’s gaze direction, head position, and orientation are tracked in order to allow recording of the user’s fixations within the environment. Although the linear signal analysis approach is itself not new, its application to eye movement analysis in three dimensions advances traditional two-dimensional approaches, since it takes into account the six degrees of freedom of head movements and is resolution independent. Results indicate that the 3-D eye movement analysis algorithm can successfully be used for analysis of visual process measures in VR. Process measures not only can corroborate performance measures, but also can lead to discoveries of the reasons for performance improvements. In particular, analysis of users’ eye movements in VR can potentially lead to further insights into the underlying cognitive processes of VR subjects.     

Motion and rest in the Pensées – A note on Pascal's modernism

International Journal for Philosophy of Religion -     

How do women experience myocardial infarction? A qualitative exploration of illness perceptions, adjustment and coping

While UK Department of Health policy recognizes the importance of secondary prevention and rehabilitation following a cardiac event, there still appears a dearth of research addressing women's needs. This study aimed to explore adjustment in terms of women's perception of their cardiac event, impact on relationships and coping strategies employed. Five women suffering first time MI were interviewed, using a semi-structured format and were telephoned 2 months later. Data were analysed using Interpretative Phenomenological Analysis. Perceptions included: Making Sense of the Event, Cognitive and Emotional Responses and Self-beliefs. Relationships issues were: Others' Reactions and Change in Relationships and Roles. Cognitive and Behavioural strategies and Support from others (including cardiac rehabilitation) formed coping strategies. For most participants, the event was unexpected evoking uncertainty and later, emotions extending beyond the more widely accepted depression and anxiety. Women tended to minimize severity of symptoms and impact of event (perhaps as a way of coping and protecting others), displaying a strong sense of optimism and hope that life would soon return to "normal". However, it appeared this was difficult to maintain and the experience seemed to challenge relationships and roles. The findings suggest recommendations for further research with possible implications for clinical practice.     

Reaction time inconsistency in a spatial stroop task: age-related differences through childhood and adulthood

Age-related differences in inconsistency of reaction time (RT) across the life span were examined on a task with differing levels of demand on executive control. A total of 546 participants, aged 5 to 76 years, completed a spatial Stroop task that permitted observations under three conditions (congruent, incongruent, and neutral) according to the correspondence between the required response (based on stimulus direction) and stimulus location. An interference effect was observed across all ages. Analyses of neutral condition data replicated previous research demonstrating RT inconsistency follows a U-shaped developmental curve across the life span. The relationship between age and inconsistency, however, depended on condition: inconsistency in the congruent condition was higher than inconsistency in both the neutral and incongruent conditions across middle-aged groups. Reaction time inconsistency may reflect processing efficiency that is maximal in young adulthood and may also be sensitive to fluctuations in performance that reflect momentarily highly efficient responding.     

Visuospatial working memory in school-aged children exposed in utero to cocaine.

OBJECTIVE: Among the neurocognitive impairments reported as associated with prenatal cocaine exposure, slower response time, and less efficient learning in school-aged children are common to findings from several laboratories. This study presents performance data on a spatial working memory task in 75 prenatally cocaine exposed (CE) and 55 nondrug-exposed (NDE) 8- to 10-year-old children. METHODS: Children were administered a novel neuropsychological measure of immediate- and short-term memory for visuospatial information, the Groton Maze Learning Test (GMLT), a computer-based hidden maze learning test that consists of a "timed chase test" (a simple measure of visuomotor speed), eight learning trials followed by a delayed recall trial after an 8-minute delay and a reverse learning trial. Performance is expressed as correct moves per second and number of errors per trial. RESULTS: Across all trials, the cocaine-exposed group showed significantly slower correct moves per second and made significantly more errors. There were no significant main effects for amounts of alcohol, tobacco, or marijuana exposure. After an 8-minute delay and compared to the eighth trial, cocaine-exposed children showed less consolidation in learning compared to nonexposed children. When asked to complete the maze in reverse, cocaine-exposed children showed a greater decrement in performance (decreased correct moves per second and increased errors) compared to the eighth learning trial. CONCLUSIONS: Children exposed in utero to cocaine exhibit a possible impairment in procedural learning and diminished efficiency in creating and accessing an internal spatial map to master the hidden maze.     

Threatened by the unexpected: physiological responses during social interactions with expectancy-violating partners

Individuals who violate expectations increase uncertainty during social interactions. Three experiments explored whether expectancy-violating partners engender "threat" responses in perceivers. Participants interacted with confederates who violated or confirmed expectations while multiple measures were assessed, including cardiovascular reactivity, task performance, appraisals, and behavior. In Experiments 1 and 2, participants interacted with White or Latino confederates who described their family backgrounds as either high or low socioeconomic status. In Experiment 3, participants interacted with Asian or White confederates who spoke with expected accents or southern accents. Participants interacting with expectancy-violating partners (e.g., Asians with southern accents) exhibited cardiovascular responses consistent with threat, poorer task performance, and manifested negative and defeat-related behavior. Implications for decreasing prejudicial responses via uncertainty reduction are discussed.     

Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period.     

Stressor Controllability and Learned Helplessness Research in the United States: Sensitization and Fatigue Processes

Recent work in the learned helplessness paradigm suggests that neuronal sensitization and fatigue processes are critical to producing the behavioral impairment that follows prolonged exposure to an unsignaled inescapable stressor such as a series of electric tail shocks. Here we discuss how an interaction between serotonin (5-HT) and corticosterone (CORT) sensitizes GABA neurons early in the pretreatment session with inescapable shock. We propose that this process eventually depletes GABA, thus removing an important form of inhibition on excitatory glutamate transmission in the amygdala, hippocampus, and frontal cortex. When rats are re-exposed to shock during shuttle-escape testing 24 hrs later, the loss of inhibition (as well as other excitatory effects) results in unregulated excitation of glutamate neurons. This state of neuronal over-excitation rapidly compromises metabolic homeostasis. Metabolic fatigue results in compensatory inhibition by the nucleoside adenosine, which regulates neuronal excitation with respect to energy availability. The exceptionally potent form of inhibition associated with adenosine receptor activation yields important neuroprotective benefits under conditions of metabolic failure, but also precludes the processing of information in fatigued neurons. The substrates of adaptive behavior are removed; performance deficits ensue.     

The Development and Evaluation of a Statewide Training Center for Home Visitors and Supervisors

This paper informs practice in community‐based home visiting workforce development by describing the development and evaluation of a university‐based training certificate program for home visitors and supervisors. The Interactive Systems Framework for Dissemination and Implementation (ISF; Wandersman et al., 2008) guides our conceptualization and paper organization. The ISF describes the components involved in translating research findings into effective implementation of prevention programs. We describe implementation and lessons learned from seven development activities: (a) review of the literature, (b) survey of other training initiatives across the country, (c) focus groups with home visitors and supervisors, (d) consultation with individual home visitors, (e) creation of a state advisory board of home visiting providers and stakeholders, (f) evaluation of two pilot trainings, and (g) video development. We then present evaluation data from 49 home visitors and 23 supervisors who completed the training certificate program after the pilot trainings. Both home visitors and supervisors rated training satisfaction highly, reported significant increases in self‐efficacy related to the training topics, and reported extensive use of motivational communication techniques, which are the foundational skills of the training content. These and other favorable results reflect the benefits of building on advances in theory and science‐based practice and of involving providers and stakeholders repeatedly throughout the development process.