Linking cognitive and reaching trajectories via intermittent movement control

Theories of decision-making have traditionally been constrained by reaction time data. A limitation of reaction time data, particularly for studying the temporal dynamics of cognitive processing, is that they index only the endpoint of the decision making process. Recently, physical reaching trajectories have been used as proxies for underlying mental trajectories through decision space. We suggest that this approach has been oversimplified: while it is possible for the motor control system to access the current state of the evidence accumulation process, this access is intermittent. Instead, we demonstrate how a model of arm movements that assumes intermittent, not continuous, access to the decision process is sufficient to describe the effects of stimulus quality and viewing time in curved reaching movements.     

Preliminary Note on a General Purpose Recording Technique

The extent to which attitudes towards mental illness and the mentally ill were influenced by the respondent's own level of personal adjustment was studied for 77 female psychiatric aides. The data suggested that, for this sample, the two variables were relatively independent of each other.     

Emerging Worldviews: The Supplicate Order—Invocation of the Sacred

Approaches to supplication, such as faith and single-minded devotion to an ultimate value or deity, are proposed to constitute the human interface between the manifest and the unmanifest. A reciprocal, resonant interchange between the unmanifest and human summoning of the holy can bring the sacred to expression in cultural forms and personal experience. Addressing the boundaries between the human and the divine, this paper presents a cross-cultural model for spiritual supplication. This model utilizes the anthropological term ritual frame and provides an integrative worldview with which to examine the dynamics of sacred contact and invocation. This suggests that supplication is the universal and fundamental human orientation to invoke the reception of profound healings, as well as spiritual blessings, cross-cultural understandings and innumerable gifts of creativity.     

Centrality Preferences in Choices Among Similar Options

Three explanations were explored for the finding that people prefer the middle option rather than the extremes when choosing from an array of similar options. In Study 1, 68% chose the middle item from a set of three highlighters and three surveys, whereas 32% chose an item from either end, p < .0001. In Study 2, 71% selected the middle chair from a row of three chairs that were either all empty, or had a backpack occupying either one of the two end chairs, p < .0001. These results support a minimal mental effort principle rather than a preference for symmetry rule. In Study 3, 54.2% recalled more graphic items from the center poster of a 3-poster collage, whereas 31.3% and 14.5% recalled more items from the left and right posters, respectively, p < .004. These findings lend additional support to a focus of attention explanation.     

The Performance of Attention-Deficit-Disordered and Normal Children on Conservation Tasks

The present study was designed to investigate whether a specific subgroup of learning-disabled children (attention-deficit-disordered, ADD) differed from their normal counterparts on Piagetian tasks of conservation. The subjects were 34 third- and fourth-grade children. Seventeen children had been diagnosed as ADD; the remaining half were designated as normal. The two groups were equivalent in chronological age, mental age, and intelligence. The results indicated significant differences between the two groups on tasks tapping conservation of substance and number. These results may support the theory of a lag in the development of conservation in children with specific learning disabilities (ADD). Implications of the present research for therapeutic and remedial programs that serve ADD children are also discussed.     

Sentencing,severity, and social norms: A rank-based model of contextual influence on judgments of crimes and punishments

Context effects have been shown to bias lay people's evaluations of the severity of crimes and punishments. To investigate the cognitive mechanisms behind these effects, we develop and apply a rank-based social norms approach to judgments of perceived crime seriousness and sentence appropriateness. In Study 1, we find that (a) people believe on average that 84% of people illegally download software more than they do themselves and (b) their judged severity of, and concern about, their own illegal software downloading is predicted not by its amount but by how this amount is believed (typically inaccurately) to rank within a social comparison distribution. Studies 2 and 3 find that the judged appropriateness of a given sentence length is highly dependent on the length of other sentences available in the decision-making context: The same objective sentence was judged as approximately four times stricter when it was the second longest sentence being considered than when it was the fifth longest. It is concluded that the same mechanisms that are used to judge the magnitude of psychophysical stimuli bias judgments about legal matters.     

State-Space Analysis of Working Memory in Schizophrenia: An FBIRN Study

The neural correlates of working memory (WM) in schizophrenia (SZ) have been extensively studied using the multisite fMRI data acquired by the Functional Biomedical Informatics Research Network (fBIRN) consortium. Although univariate and multivariate analysis methods have been variously employed to localize brain responses under differing task conditions, important hypotheses regarding the representation of mental processes in the spatio-temporal patterns of neural recruitment and the differential organization of these mental processes in patients versus controls have not been addressed in this context. This paper uses a multivariate state-space model (SSM) to analyze the differential representation and organization of mental processes of controls and patients performing the Sternberg Item Recognition Paradigm (SIRP) WM task. The SSM is able to not only predict the mental state of the subject from the data, but also yield estimates of the spatial distribution and temporal ordering of neural activity, along with estimates of the hemodynamic response. The dynamical Bayesian modeling approach used in this study was able to find significant differences between the predictability and organization of the working memory processes of SZ patients versus healthy subjects. Prediction of some stimulus types from imaging data in the SZ group was significantly lower than controls, reflecting a greater level of disorganization/heterogeneity of their mental processes. Moreover, the changes in accuracy of predicting the mental state of the subject with respect to parametric modulations, such as memory load and task duration, may have important implications on the neurocognitive models for WM processes in both SZ and healthy adults. Additionally, the SSM was used to compare the spatio-temporal patterns of mental activity across subjects, in a holistic fashion and to derive a low-dimensional representation space for the SIRP task, in which subjects were found to cluster according to their diagnosis.     

An Introduction to Normalization and Calibration Methods in Functional MRI

In functional magnetic resonance imaging (fMRI), the blood oxygenation level dependent (BOLD) signal is often interpreted as a measure of neural activity. However, because the BOLD signal reflects the complex interplay of neural, vascular, and metabolic processes, such an interpretation is not always valid. There is growing evidence that changes in the baseline neurovascular state can result in significant modulations of the BOLD signal that are independent of changes in neural activity. This paper introduces some of the normalization and calibration methods that have been proposed for making the BOLD signal a more accurate reflection of underlying brain activity for human fMRI studies.