Modulation of N400 in chronic non-fluent aphasia using low frequency Repetitive Transcranial Magnetic Stimulation (rTMS)

Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates associated with the application of rTMS through measurement of the semantic based N400 Event-related brain potentials (ERP) component. Low frequency (1 Hz) rTMS was applied to the anterior portion of the homologue to Broca’s area (pars triangularis), for 20 min per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent persons with aphasia, 2-6 years post stroke were stimulated. Six participants were randomly assigned to receive real stimulation and six participants were randomly assigned to receive a blind sham control condition. ERP measures were recorded at baseline, 1 week and 2 months subsequent to stimulation. The findings demonstrate treatment related changes observed in the stimulation group when compared to the placebo control group at 2 months post stimulation indicating neuromodulation of N400 as a result of rTMS. No treatment related changes were identified in the stimulation group, when compared to the sham group from baseline to 1 week post stimulation. The electrophysiological results represent the capacity of rTMS to modulate neural language networks and measures of lexical-semantic function in participants with non-fluent aphasia and suggest that time may be an important factor in brain reorganization subsequent to rTMS.     

Vision and intelligence at age 83 in the Lothian Birth Cohort 1921

The extent to which visual function, measured as near and distant visual acuity and contrast sensitivity, is correlated with concurrently measured cognitive function and prior intellectual ability was investigated in a narrow age range group known as the Lothian Birth Cohort of 1921 (LBC1921). Participants were aged ~ 83 years at the time of testing (N = 321). A well-fitting structural equation model highlighted a significant contribution of a latent visual trait to a general fluid intelligence factor in old age, independent of the contribution from childhood intelligence. Additionally, childhood intelligence made a significant contribution to the general visual factor in old age. However, the model fitted equally well when the fluid intelligence factor is assumed to be a cause of the visual function latent trait, in which case childhood intelligence does not significantly influence vision in old age. We discuss these results with respect to four possible mechanisms by which vision and cognition can come to be correlated over the lifecourse.     

Aging as a Social Form: The Phenomenology of the Passage

If philosophers have discussed life as preparation for death, this seems to make aging coterminous with dying and a melancholy passage that we are condemned to survive. It is important to examine the discourse on aging and end of life and the ways various models either limit possibilities for human agency or suggest means of being innovative in relation to such parameters. I challenge developmental views of aging not by arguing for eternal life, but by using Plato’s conception of form in conjunction with Simmel’s work and Arendt’s meditation on intergenerational solidarity, to evoke a picture of the subject as having capacities that offer avenues for improvisational action. This paper proposes a method for analyzing any social form as a problem-solving situation where the real “problem” is the fundamental ambiguity that inheres in the mix between the finite characteristics of the action and its infinite perplexity. I work through the most conventional chronological view of aging to show how it dramatizes a fundamental ethical collision in life that intensifies anxiety under many conditions, always raising the question of what is to be done with respect to contingency, revealing such “work” as a paradigm of the human condition.     

Clinical Utility of Chromosomal Microarray Analysis of DNA from Buccal Cells: Detection of Mosaicism in Three Patients

Mosaic chromosomal abnormalities are relatively common. However, mosaicism may be missed due to multiple factors including failure to recognize clinical indications and order appropriate testing, technical limitations of diagnostic assays, or sampling tissue (s) in which mosaicism is either not present, or present at very low levels. Blood leukocytes have long been the “gold standard” sample for cytogenetic analysis; however, the culturing process for routine chromosome analysis can complicate detection of mosaicism since the normal cell line may have a growth advantage in culture, or may not be present in the cells that produce metaphases (the lymphocytes). Buccal cells are becoming increasingly utilized for clinical analyses and are proving to have many advantages. Buccal swabs allow for simple and noninvasive DNA collection. When coupled with a chromosomal microarray that contains single nucleotide polymorphic probes, analysis of buccal cells can maximize a clinician’s opportunity to detect cytogenetic mosaicism. We present three cases of improved diagnosis of mosaic aberrations using buccal specimens for chromosomal microarray analysis. In each case, the aberration was either undetectable in blood or present at such a low level it likely could have gone undetected. These cases highlight the limitations of certain laboratory methodologies for identifying mosaicism. We also present practice implications for genetic counselors, including clinic workflow changes and counseling approaches based on increasing use of buccal samples.     

Or cues knowledge of alternatives: Evidence from priming

Recent research has determined that word meanings can instantly influence the meaning and distribution of other words in the sentence. Here, we manipulated basic carrier sentences with the disjunction or linking two nouns that were either filling the same thematic role or not, and were either semantically related or not. Though previous research has shown that one word can prime a semantically related word even in a sentential context, we predicted that if or cues knowledge about contextually‐relevant alternatives, priming for semantic relatives will only obtain when those words also fill the same thematic role. These predictions were confirmed, as self‐paced reading times of the second alternative in the sentence were faster only when the two alternatives shared the same thematic role and semantic category, suggesting that disjunction words like or function similarly to verbs, which cue knowledge about expected argument structure and sense depending on sentential context. The relevance of these findings for basic reasoning phenomena (i.e., the subadditivity effect) is also discussed.     

Satan,Saint Peter and Saint Petersburg

We examine a distinctive kind of problem for decision theory, involving what we call discontinuity at infinity. Roughly, it arises when an infinite sequence of choices, each apparently sanctioned by plausible principles, converges to a ‘limit choice’ whose utility is much lower than the limit approached by the utilities of the choices in the sequence. We give examples of this phenomenon, focusing on Arntzenius et al.’s Satan’s apple, and give a general characterization of it. In these examples, repeated dominance reasoning (a paradigm of rationality) apparently gives rise to a situation closely analogous to having intransitive preferences (a paradigm of irrationality). Indeed, the agents in these examples are vulnerable to a money pump set-up despite having preferences that exhibit no obvious defect of rationality. We explore several putative solutions to such problems, particularly those that appeal to binding and to deliberative dynamics. We consider the prospects for these solutions, concluding that if they fail, the examples show that money pump arguments are invalid.     

Rotating With Rotated Text: A Natural Behavior Approach to Investigating Cognitive Offloading

Determining how we use our body to support cognition represents an important part of understanding the embodied and embedded nature of cognition. In the present investigation, we pursue this question in the context of a common perceptual task. Specifically, we report a series of experiments investigating head tilt (i.e., external normalization) as a strategy in letter naming and reading stimuli that are upright or rotated. We demonstrate that the frequency of this natural behavior is modulated by the cost of stimulus rotation on performance. In addition, we demonstrate that external normalization can benefit performance. All of the results are consistent with the notion that external normalization represents a form of cognitive offloading and that effort is an important factor in the decision to adopt an internal or external strategy.     

Catholic Social Teaching as a Framework for Research Ethics

The importance of having ethical oversight in research that is carried out on humans is well established. Research ethics, which is mainly influenced by a biomedical ethical framework, aims to ensure that the well-being and the rights of research participants are upheld and that any potential risks and harms are reduced. However, research is also considered to be a social activity with social effects. Therefore the principles of Catholic Social Teaching as a framework for research ethics may be significant. This paper outlines those principles and demonstrates how these principles may be used for: (1) reflecting ethically on research (i.e. before the project begins), (2) judging a research ethics proposal (i.e. the ethical review) and (3) providing guidelines for action in research (i.e. the implementation of the research project).     

Hide and seek: The theory of mind of visual concealment and search

Researchers have investigated visual search behavior for almost a century. During that time, few studies have examined the cognitive processes involved in hiding items rather than finding them. To investigate this, we developed a paradigm that allowed participants to indicate where they would hide (or find) an item that was to be found (or hidden) by a friend or a foe. We found that (i) for friends more than foes, participants selected the pop-out item in the display, and (ii) when the display was homogeneous, they selected nearby and corner items. These behaviors held for both hiding and finding, although hide and find behaviors were not identical. For pop-out displays, decision times were unusually long when hiding an item from a foe. These data converge on the conclusion that the principles of search and concealment are similar, but not the same. They also suggest that this paradigm will provide researchers a powerful method for investigating theory of mind in adults.