Determination of H-Atom Positions in Organic Crystal Structures by NEXAFS Combined with Density Functional Theory: a Study of Two-Component Systems Containing Isonicotinamide

It is important to be able to identify the precise position of H-atoms in hydrogen bonding interactions to fully understand the effects on the structure and properties of organic crystals. Using a combination of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory (DFT) quantum chemistry calculations, we demonstrate the sensitivity of core-level X-ray spectroscopy to the precise H-atom position within a donor-proton-acceptor system. Exploiting this sensitivity, we then combine the predictive power of DFT with the experimental NEXAFS, confirming the H-atom position identified using single-crystal X-ray diffraction (XRD) techniques more easily than using other H-atom sensitive techniques, such as neutron diffraction. This proof of principle experiment confirms the H-atom positions in structures obtained from XRD, providing evidence for the potential use of NEXAFS as a more accurate and easier method of locating H-atoms within organic crystals

The relationship between sensory sensitivity and autistic traits in the general population.

Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p < .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties

Over-Selectivity is Related to Autism Quotient and Empathizing, But not to Systematizing

The relationships of autism quotient (AQ), systematizing (SQ), and empathizing (EQ), with over-selectivity were explored to assess whether over-selectivity is implicated in complex social skills, which has been assumed, but not experimentally examined. Eighty participants (aged 18–60) were trained on a simultaneous discrimination task (AB+CD−), and tested in extinction on the degree to which they had learned about both elements of the reinforced (AB) compound. Higher AQ and lower EQ scorers demonstrated greater over-selectivity, but there was no relationship between SQ and over-selectivity. These results imply that high AQ scorers perform similarly to individuals with ASD on this cognitive task, and that over-selectivity may be related to some complex social skills, like empathy

Event-related alpha suppression in response to facial motion

This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

Brief report: Perceptual load and the autism spectrum in typically developed individuals

A fundamental task of the cognitive system is to prioritize behaviourally relevant sensory inputs for processing at the expense of irrelevant inputs. In a study of neurotypical participants (n = 179), we utilized a brief flanker interference task while varying the perceptual load of the visual display. Typically, increasing perceptual load (i.e., with greater numbers of search items) reduces interference from a competing peripheral distractor. We show that individuals who score above average on the Autism Spectrum Quotient (AQ) show stronger interference at high perceptual load than individuals with below-average AQ scores. This is consistent with recent findings in individuals with autism spectrum conditions, and supports the idea that the cognitive style of the autistic brain is reflected in a broader phenotype across the population

The mere anticipation of an interaction with a woman can impair men's cognitive performance

Contains fulltext : 102966.pdf (publisher's version ) (Open Access)Recent research suggests that heterosexual men's (but not heterosexual women's) cognitive performance is impaired after an interaction with someone of the opposite sex (Karremans et al., 2009). These findings have been interpreted in terms of the cognitive costs of trying to make a good impression during the interaction. In everyday life, people frequently engage in pseudo-interactions with women (e.g., through the phone or the internet) or anticipate interacting with a woman later on. The goal of the present research was to investigate if men's cognitive performance decreased in these types of situations, in which men have little to no opportunity to impress her and, moreover, have little to no information about the mate value of their interaction partner. Two studies demonstrated that men's (but not women's) cognitive performance declined if they were led to believe that they interacted with a woman via a computer (Study 1) or even if they merely anticipated an interaction with a woman (Study 2). Together, these results suggest that an actual interaction is not a necessary prerequisite for the cognitive impairment effect to occur. Moreover, these effects occur even if men do not get information about the woman's attractiveness. This latter finding is discussed in terms of error management theory.6 p

Cognitive control of intentions for voluntary actions in individuals with a high level of autistic traits

Contains fulltext : 102383.pdf (publisher's version ) (Open Access)Impairments in cognitive control generating deviant adaptive cognition have been proposed to account for the strong preference for repetitive behavior in autism. We examined if this preference reflects intentional deficits rather than problems in task execution in the broader autism phenotype using the Autism-Spectrum Quotient (AQ). Participants chose between two tasks differing in their relative strength by indicating first their voluntary task choice and then responding to the subsequently presented stimulus. We observed a stronger repetition bias for the harder task in high AQ participants, with no other differences between the two groups. These findings indicate that the interference between competing tasks significantly contributes to repetitive behavior in autism by modulating the formation of task intentions when choosing tasks voluntarily.11 p