Modulating medial prefrontal cortex activity using real-time fMRI neurofeedback: Effects on reality monitoring performance and associated functional connectivity.

Neuroimaging studies have found 'reality monitoring', our ability to distinguish internally generated experiences from those derived from the external world, to be associated with activity in the medial prefrontal cortex (mPFC) of the brain. Here we probe the functional underpinning of this ability using real-time fMRI neurofeedback to investigate the involvement of mPFC in recollection of the source of self-generated information. Thirty-nine healthy individuals underwent neurofeedback training in a between groups study receiving either Active feedback derived from the paracingulate region of the mPFC (21 subjects) or Sham feedback based on a similar level of randomised signal (18 subjects). Compared to those in the Sham group, participants receiving Active signal showed increased mPFC activity over the course of three real-time neurofeedback training runs undertaken in a single scanning session. Analysis of resting state functional connectivity associated with changes in reality monitoring accuracy following Active neurofeedback revealed increased connectivity between dorsolateral frontal regions of the fronto-parietal network (FPN) and the mPFC region of the default mode network (DMN), together with reduced connectivity within ventral regions of the FPN itself. However, only a trend effect was observed in the interaction of the recollection of the source of Imagined information compared with recognition memory between participants receiving Active and Sham neurofeedback, pre- and post- scanning. As such, these findings demonstrate that neurofeedback can be used to modulate mPFC activity and increase cooperation between the FPN and DMN, but the effects on reality monitoring performance are less clear.

Cognitive styles and future depressed mood in early adulthood: the importance of global attributions.

BACKGROUND: Cognitive theories of depression suggest that beliefs of low self-worth and the tendency to attribute negative events to causes that are global (widespread rather than specific) and stable (will persist rather than change in the future) are associated with the development of depressed mood. Such theories are supported by evidence from prospective studies and have guided the development of successful treatment and prevention strategies such as CBT. However, the relative importance of different psychological constructs within cognitive theories is unknown. This is important to refine cognitive theories and develop more efficient prevention strategies. METHOD: We used prospective data from over 3500 young adults from the Avon Longitudinal Study for Parents and Children (ALSPAC) cohort in the UK to investigate the association between cognitive style, measured by short forms of the Dysfunctional Attitudes Scale (DAS) and Cognitive Styles Questionnaire-Short Form (CSQ-SF) at age 18, and future depressed mood at age 19. Structural equation modelling techniques were used to separate cognitive style constructs. RESULTS: Cognitive styles were associated with future depressed mood, independently of baseline mood, both as measured by the DAS-SF and the CSQ-SF. Of the different CSQ-SF constructs, only global attributions were associated with both baseline and future mood independently of other constructs. LIMITATIONS: The study was subject to attrition and the follow-up was relatively short (10 months). CONCLUSION: The findings suggest that the tendency to attribute negative events specifically to global causes could be particularly important for depression. Reducing global attributions is potentially important in the prevention and treatment of depression.

Mind-mindedness and maternal responsiveness in infant-mother interactions in mothers with severe mental illness.

BACKGROUND: Previous cross-diagnosis studies of interaction between mothers with severe mental illness and their babies have concluded that mothers with schizophrenia have deficits in interaction, but these studies have not included healthy controls. METHOD: In-patients on a mother and baby unit, with diagnoses of schizophrenia (n=15), depressive mood disorders with or without psychosis (n=23), or mood disorders where mania was the predominant feature, with or without psychosis (n=12), were observed interacting with their infants on admission and discharge. Mothers' mind-mindedness and other measures of the quality of maternal and infant behaviour were coded. Findings from this sample were compared with those from healthy mothers and their infants (n=49). RESULTS: Compared with healthy controls, on admission depressed mothers were marginally less likely to comment appropriately on their infants' mental states. Both the depressed and mania groups were more likely to touch their babies and engage in attention-seeking behaviours. Interactional behaviours of mothers in the schizophrenia group were not markedly different from healthy controls. On discharge there were fewer differences between the clinical and healthy groups, although the depressed group continued to engage in more attention-seeking and touching behaviour and the mania group continued to touch their infants more. Only mothers in the schizophrenia group showed changes in interactional behaviours between admission and discharge, talking more to their infants. CONCLUSIONS: The findings challenge previous conclusions that mothers with schizophrenia have deficits in their interactions with their babies, and demonstrate that mothers with severe mental illness are able to respond appropriately to their infants' cues.

The phenomenology of inner speech: comparison of schizophrenia patients with auditory verbal hallucinations and healthy controls.

BACKGROUND: Despite the popularity of inner-speech theories of auditory verbal hallucinations (AVHs), little is known about the phenomenological qualities of inner speech in patients with schizophrenia who experience AVHs (Sz-AVHs), or how this compares to inner speech in the non-voice-hearing general population. METHOD: We asked Sz-AVHs (n=29) and a non-voice-hearing general population sample (n=42) a series of questions about their experiences of hearing voices, if present, and their inner speech. RESULTS: The inner speech reported by patients and controls was found to be almost identical in all respects. Furthermore, phenomenological qualities of AVHs (e.g. second- or third-person voices) did not relate to corresponding qualities in inner speech. CONCLUSIONS: No discernable differences were found between the inner speech reported by Sz-AVHs and healthy controls. Implications for inner-speech theories of AVHs are discussed.

The efficiency of encapsulation within surface rehydrated polymersomes.

The key to the use of polymersomes as effective molecular delivery systems is in the ability to design processing routes that can efficiently encapsulate the molecular payload. We have evaluated various surface rehydration mechanisms for encapsulation, in each case characterizing the morphologies formed using DLS and confocal microscopy as well as determining the encapsulation efficiency for the hydrophilic dye Rhodamine B. In contrast to bulk methods, where the encapsulation efficiencies are low, we find that higher efficiencies can be obtained by the rehydration of thin films. We relate these results to the non-equilibrium mechanisms that underlie vesicle formation and discuss how an understanding of these mechanisms can help optimize encapsulation efficiencies. Our conclusion is that, even considering the good encapsulation efficiency, surface methods are still unsuitable for the massive scale-up needed when applied to commercial "mass market" molecular delivery scenarios. However, targeting more specialized applications for high value ingredients (like pharmaceuticals) might be more feasible.

The microrheology of polystyrene sulfonate combs in aqueous solution.

Video particle tracking (VPT) and diffusing wave spectroscopy were used to characterize the microrheology of polystyrene sulfonate combs in aqueous solutions. At low frequencies VPT demonstrated predominantly viscous behavior. The manner in which the viscosity scaled as a function of monomer concentration was a sensitive function of the comb architecture. Densely branched combs or combs with long side chains demonstrated entangled polyelectrolyte scaling above the overlap concentration, whereas sparsely branched combs had unentangled polyelectrolyte scaling. A dynamic scaling model was developed for the viscosity of unentangled semidilute solutions of comb polyelectrolytes. Diffusing wave spectroscopy demonstrated Rouse modes (G' approximately G" approximately omega12) for the high-frequency dynamics of the semidilute comb solutions. The form of the high-frequency viscoelasticity was independent of the chain architecture and the modulus scaled as expected for linear flexible polyelectrolytes.

Microrheology of polymeric solutions using x-ray photon correlation spectroscopy.

We demonstrate the technique of XPCS microrheology on opaque polymeric solutions (1-20% w/w) using colloidal silica probes. The short time decay of the intensity correlation function provides the mean square displacement (MSD) of the colloidal probes. The MSDs of the probes are subsequently transformed using the generalized Stokes-Einstein equation, allowing the linear viscoelastic spectra of a biopolymer (gellan) and a synthetic polyelectrolyte (polystyrene sulfonate, PSS) to be calculated over two decades of frequency. MSDs can be measured that are two orders of magnitude smaller than those possible with video particle tracking microrheology, with a sensitivity of ∼10 nm s(-1) for displacements of ∼nms. The XPCS data for water, glycerol and PSS combs are in agreement with video particle tracking microrheology experiments performed at lower polymer concentrations.

Surface energy of ethylene-co-1-butene copolymers determined by contact angle methods.

Wilhelmy plate measurements of contact angles with a series of test liquids are used to calculate the surface energies of two poly(ethylene-co-1-butene) random copolymers. Results from five methods of calculation are reported: one-liquid (Good-Girifalco and Neumann), two-liquid (harmonic mean and geometric mean), and three-liquid (Lifshitz-van der Waals acid-base) methods. We find that all five methods are sensitive to the choice of test liquids used for contact angle measurements, as previously reported, but consistent results are obtained if recommended combinations of liquids are used. The mean results of the three-liquid acid-base method are judged to be the most reliable and informative, leading to surface energies of 30.8 mJ/m2 for poly(ethylene-co-1-butene) copolymer composed of 92 mol% ethylene and 30.2 mJ/m2 for copolymer composed of 88 mol% ethylene.

Rethinking maternal sensitivity: mothers' comments on infants' mental processes predict security of attachment at 12 months.

This study investigated predictors of attachment security in a play context using a sample of 71 mothers and their 6-month-old infants. We sought to rethink the concept of maternal sensitivity by focusing on mothers' ability accurately to read the mental states governing infant behaviour. Five categories were devised to assess this ability, four of which were dependent on maternal responses to infant behaviours, such as object-directed activity. The fifth, mothers' Appropriate minded-related comments, assessed individual differences in mothers' proclivity to comment appropriately on their infants' mental states and processes. Higher scores in this fifth category related to a secure attachment relationship at 12 months. Maternal sensitivity and Appropriate mind-related comments were independent predictors of attachment security at 12 months, respectively accounting for 6.5% and 12.7% of its variance. We suggest that these findings are in line with current theorising on internal working models of attachment, and may help to explain security-related differences in mentalising abilities.