Predict or classify: The deceptive role of time-locking in brain signal classification

Several experimental studies claim to be able to predict the outcome of simple decisions from brain signals measured before subjects are aware of their decision. Often, these studies use multivariate pattern recognition methods with the underlying assumption that the ability to classify the brain signal is equivalent to predict the decision itself. Here we show instead that it is possible to correctly classify a signal even if it does not contain any predictive information about the decision. We first define a simple stochastic model that mimics the random decision process between two equivalent alternatives, and generate a large number of independent trials that contain no choice-predictive information. The trials are first time-locked to the time point of the final event and then classified using standard machine-learning techniques. The resulting classification accuracy is above chance level long before the time point of time-locking. We then analyze the same trials using information theory. We demonstrate that the high classification accuracy is a consequence of time-locking and that its time behavior is simply related to the large relaxation time of the process. We conclude that when time-locking is a crucial step in the analysis of neural activity patterns, both the emergence and the timing of the classification accuracy are affected by structural properties of the network that generates the signal.Comment: 23 pages, 5 figure

Mathematical difficulties as decoupling of expectation and developmental trajectories

Recent years have seen an increase in research articles and reviews exploring mathematical difficulties (MD). Many of these articles have set out to explain the etiology of the problems, the possibility of different subtypes, and potential brain regions that underlie many of the observable behaviors. These articles are very valuable in a research field, which many have noted, falls behind that of reading and language disabilities. Here will provide a perspective on the current understanding of MD from a different angle, by outlining the school curriculum of England and the US and connecting these to the skills needed at different stages of mathematical understanding. We will extend this to explore the cognitive skills which most likely underpin these different stages and whose impairment may thus lead to mathematics difficulties at all stages of mathematics development. To conclude we will briefly explore interventions that are currently available, indicating whether these can be used to aid the different children at different stages of their mathematical development and what their current limitations may be. The principal aim of this review is to establish an explicit connection between the academic discourse, with its research base and concepts, and the developmental trajectory of abstract mathematical skills that is expected (and somewhat dictated) in formal education. This will possibly help to highlight and make sense of the gap between the complexity of the MD range in real life and the state of its academic science

The role of expectations, hype and ethics in neuroimaging and neuromodulation futures

The production of expectations or future-goals for the development of techniques which “read” and modulate brain function, represent an important practical tool for neuroscientists. These visions-of-the-future assist scientists by providing focus for both individual and cross-disciplinary research programs; they encourage the development of new industrial sectors, are used to justify the allocation of government resources and funding, and via the media can help capture the imagination and support of the public. However, such expectations need to be tempered by reality. Over-hyping brain imaging and modulation will lead to disappointment; disappointment that in turn can undermine its potential. Similarly, if neuroscientists focus their attention narrowly on the science without concomitant consideration of its future ethical, legal and social implications, then their expectations may remain unrealized. To develop these arguments herein we introduce the theoretical concept of expectations and the practical consequences of expectations. We contextualize these reflections by referring to brain imaging and modulation studies on deception, which encompass the measurement-suppression-augmentation range

State estimation: direct state measurement vs. tomography

We compare direct state measurement (DST or weak state tomography) to conventional state reconstruction (tomography) through accurate Monte-Carlo simulations. We show that DST is surprisingly robust to its inherent bias. We propose a method to estimate such bias (which introduces an unavoidable error in the reconstruction) from the experimental data. As expected we find that DST is much less precise than tomography. We consider both finite and infinite-dimensional states of the DST pointer, showing that they provide comparable reconstructions.Comment: 4 pages, 4 figure

A systematic reflection upon dual career couples

Particularly among the highly educated, a persistent upward trend in female employment rates has characterized western industrialized countries in the last decades. Yet, strong gender inequalities persist in the career chances of equally highly qualified men and women. Women are still underrepresented in executive/ leading positions in both the private and public sector of the economy. We argue that such gender inequalities are also due to the fact that the majority of highly educated women lives with an equally highly educated partner. For these women the realization of dual careers becomes ever more important and represents an essential prerequisite for their own professional development. Following Phyllis Moen's 'linked lives' idea, we will argue that the achievement or failure of dual-career arrangements is a 'social-relational process' (Moen 2003a: 10) and that partners' lives are embedded with and influenced by each other. In particular, we will discuss how this entwining occurs, which processes at different levels play a role, and how these different processes interact with each other. Finally, we will give some suggestions on the direction for future research. -- Vor allem bei Hochqualifizierten charakterisiert ein andauernder Aufwärtstrend weiblicher Beschäftigungsraten die westlichen Industrieländer in den letzten Jahrzehnten. Jedoch herrscht bei den Karrierechancen von gleich qualifizierten Männern und Frauen noch immer eine große Geschlechterungleichheit vor. Frauen sind in führenden/leitenden Positionen sowohl im privatwirtschaftlichen als auch im öffentlichen Beschäftigungssektor noch immer unterrepräsentiert. Wir argumentieren, dass solche Geschlechterungleichheiten auf den Umstand zurückzuführen sind, dass die Mehrzahl hoch gebildeter Frauen mit gleichermaßen hoch gebildeten Partnern zusammenlebt. Für diese Frauen gewinnt die Realisierung von Doppelkarrieren an Bedeutung und stellt eine entscheidende Voraussetzung für ihre eigene professionelle Entwicklung dar. In Anlehnung an Phyllis Moens "linked lives" Idee werden wir diskutieren, dass der Erfolg oder das Scheitern von Doppelkarrierenarrangements ein "social- relational process" (Moen 2003a: 10) ist und dass die Lebensverläufe der Partner miteinander verwoben und voneinander abhängig sind. Im Einzelnen werden wir diskutieren, wie diese Verflechtung sich gestaltet, welche Prozesse auf verschiedenen Ebenen eine Rolle spielen und wie diese Prozesse miteinander interagieren. Zum Schluss werden wir Vorschläge für die Richtung zukünftiger Forschungen formulieren.

Should I Stay or Should I Go?: Gender Differences in Professional Employment

Occupational sex segregation is a persistent source of social inequalities. The increasing participation of women in tertiary education and rising female employment rates, however, have given hope that gender inequalities will decline as a result of growing female opportunities for high skill employment in the service sector, e.g. the professions. This paper asks whether such optimistic accounts are justified by comparing male and female professional career trajectories in Germany. Our main assumptions hold that, even today, strong gender differences continue to exist between public and private sector professions, which are further aggravated by different forms of family commitment. Overall, our analyses demonstrate that even among highly qualified men and women, important patterns of sex segregation are present. Aninitial horizontal segregation between public and private sectors brings about "equal, but different" career prospects, which in the phase of family formation turn into vertical segregation, promoting "different and therefore unequal" labor market chances.professions, sex segregation, labor market outcomes, family formation, tertiary education, German

XRIndex:a brief screening tool for individual differences in security threat detection in x-ray images

X-ray imaging is a cost-effective technique at security checkpoints that typically require the presence of human operators. We have previously shown that self-reported attention to detail can predict threat detection performance with small-vehicle x-ray images (Rusconi et al., 2012). Here, we provide evidence for the generality of such a link by having a large sample of naïve participants screen more typical dual-energy x-ray images of hand luggage. The results show that the Attention to Detail score from the autism-spectrum quotient (AQ) questionnaire (Baron-Cohen et al., 2001) is a linear predictor of threat detection accuracy. We then develop and fine-tune a novel self-report scale for security screening: the XRIndex, which improves on the Attention to Detail scale for predictive power and opacity to interpretation. The XRIndex is not redundant with any of the Big Five personality traits. We validate the XRIndex against security x-ray images with an independent sample of untrained participants and suggest that the XRIndex may be a useful aid for the identification of suitable candidates for professional security training with a focus on x-ray threat detection. Further studies are needed to determine whether this can also apply to trained professionals