Task-load manipulation in the Symbol Digit Modalities Test: An alternative measure of information processing speed

ObjectiveTo evaluate the utility of an oral fMRI-adapted version of the Symbol Digit Modalities Test (SDMT) to assess information processing speed (IPS) using three different interstimulus intervals (ISI).MethodsNineteen right-handed healthy controls performed the adapted version of the SDMT, consisting of a block design that had a total of 6 control/activation block pairs with 3 different ISIs (1.5, 2 and 2.5 s) presented in two different runs: in ascending and descending orders. The brain activation patterns during different ISIs were assessed by effective functional connectivity analysis based on independent component analysis.ResultsAs expected, all conditions yielded activations in the fronto-parietal networks (FPNs) related to attention processes. Shorter ISIs (1.5 and 2 s) not only yielded greater patterns of connectivity within fronto-parietal and occipital regions such as the FPN and fronto-occipital network (FON), but also recruited more functional networks overall. Task performance at the shortest ISI was negatively correlated with connectivity at the FPN and activity of the pre-supplementary motor area extending to the cingulate gyrus.ConclusionIncreasing IPS demands due to shorter ISIs resulted in an increased level and number of functional networks required, increased connectivity within the FPN and FON, and enhancement of the prefrontal cortex. IPS does not arise from activity of a single b area but from affective information transfer among distant cortical regions of the frontal and parietal cortices. This adapted version of the SDMT may be useful for studying alterations of IPS in clinical and nonclinical populations.     

Brief pitch-priming facilitates infants’ discrimination of pitch-evoking noise: Evidence from event-related potentials

Pitch is derived by the auditory system through complex spectrotemporal processing. Pitch extraction is thought to depend on both spectral cues arising from lower harmonics that are resolved by cochlear filters in the inner ear, and on temporal cues arising from the pattern of action potentials contained in the cochlear output. Adults are capable of extracting pitch in the absence of robust spectral cues, taking advantage of the temporal cues that remain. However, recent behavioral evidence suggests that infants have difficulty discriminating between stimuli with different pitches when resolvable spectral cues are absent. In the current experiments, we used the mismatch negativity (MMN) component of the event related potential derived from electroencephalographic (EEG) recordings to examine a cortical representation of pitch discrimination for iterated rippled noise (IRN) stimuli in 4- and 8-month-old infants. IRN stimuli are pitch-evoking sounds generated by repeatedly adding a segment of white noise to itself at a constant delay. We created IRN stimuli (delays of 5 and 6 ms creating pitch percepts of 200 and 167 Hz) and high-pass filtered them to remove all resolvable spectral pitch cues. In experiment 1, we did not find EEG evidence that infants could detect the change in the pitch of these IRN stimuli. However, in Experiment 2, after a brief period of pitch-priming during which we added a sine wave component to the IRN stimulus at its perceived pitch, infants did show significant MMN in response to pitch changes in the IRN stimuli with sine waves removed. This suggests that (1) infants can use temporal cues to process pitch, although such processing is not mature and (2) that a short amount of pitch-priming experience can alter pitch representations in auditory cortex during infancy.     

Young women’s construction of their post-cancer fertility

Younger women diagnosed with cancer often face compromised fertility as a result of their treatment. However, previous research has adopted a biomedical model of fertility and utilised hypothetico-deductive research methods which have not allowed for full exploration of women’s subjectivity. This study explored younger women’s construction of their fertility post-cancer, and their discussions of fertility with healthcare professionals, from a social constructionist epistemology. Semi-structured one-to-one interviews were conducted with eight women aged 18–26, across a variety of cancer types. Foucaultian Discourse Analysis identified three subject positions associated with fertility concerns: ‘Inadequate woman: Accepting the motherhood mandate’; ‘Adequate woman: Resisting the motherhood mandate’; and ‘Survival of the fittest: Woman as genetically defective’. Implications of these subject positions included feelings of inadequacy, fear and devastation; feeling undesirable to romantic partners; and concern about passing on cancer-positive genes. In describing healthcare professional interactions, women adopted positions of ‘Satisfied patient’; ‘Passive recipient patient’; or ‘Resisting the passive patient position’. Accounts of inadequate information provision were associated with anger and frustration, whereas feeling adequately informed was associated with satisfaction at making decisions about fertility preservation. These results suggest that fertility is of importance to young women cancer survivors, and that compromised fertility can negatively impact subjectivity.     

Electrical conductivity of Nd and Ce co-doped Gd2Zr2O7 ceramics

In this study, (Gd_{1? x} Nd _x )₂(Zr_{1? x} Ce _x )₂O₇ (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5.     

High-temperature creep associated with the climb of extended dislocations subjected to chemical stresses

The effect of chemical stresses upon the relation between extended dislocations and high-temperature creep in a thin plate has been investigated. The critical stress needed for the contraction of extended jogs and its effect on the creep rate are obtained. The results indicate that the critical stress needed for the contraction increases with decreasing stacking fault energy (SFE). However, creep occurs more easily with increasing SFE and increasing angle of the Burgers vector to the dislocation line, as well as with the concentration of any diffusing atoms.     

Formation of FeNi with L10-ordered structure using high-pressure torsion

FeNi with the L1₀-ordered structure is formed over an astronomical timescale in meteorites. In this study, severe plastic deformation using high-pressure torsion (HPT) is employed for the production of the L1₀ structure in the laboratory. Its formation is confirmed by X-ray diffraction analysis and transmission electron microscopy. Processing of elemental nanopowders by HPT is an effective method for the formation of the L1₀ phase, which is enhanced by the addition of Co to FeNi or annealing after HPT. The formation of the phase must be associated with enhanced diffusion through HPT.     

Characterization of PLZT ceramics modified by isovalent (Ba,Sr), donor (Nb) and acceptor (Zn) dopants for piezoelectric applications

This article describes the influence of microstructure on the dielectric and piezoelectric properties of isovalent- donor- and acceptor-modified lead lanthanum zirconium titanate (PLZT) ceramics. The ceramic compositions, with formula: [Pb_0.954La_0.016Ba_0.01Sr_0.02][Zr_0.525Ti_0.475]_{0.981?( m /2)}Nb_0.012Zn _m O₃ where m =?0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol% Zn, were synthesized via a solid-state reaction method. X-ray diffraction studies are supported by tolerance factor and electronegativity difference measurements. Scanning electron microscopy studies reveal grain growth enhancement with increase of Zn concentration. As the Zn concentration increased from 0 to 0.8 mol%, the room-temperature dielectric constant increased while the Curie temperature decreased continuously. An increase in the Zn content had the most significant effect on the piezoelectric properties. The optimum piezoelectric properties were observed for 1 mol% Zn composition.     

What,and Where,Luck is: A Response to Jennifer Lackey

In ‘What Luck Is Not’, Lackey presents counterexamples to the two most prominent accounts of luck: the absence of control account and the modal account. I offer an account of luck that conjoins absence of control to a modal condition. I then show that Lackey's counterexamples mislocate the luck: the agents in her cases are lucky, but the luck precedes the event upon which Lackey focuses, and that event is itself only fortunate, not lucky. Finally I offer an account of fortune. Fortune is luck-involving, and therefore easily confused with luck, but it is not itself lucky.     

Mindfulness and acceptance-based group therapy versus traditional cognitive behavioral group therapy for social anxiety disorder: A randomized controlled trial

Recent research has supported the use of mindfulness and acceptance-based interventions for Social Anxiety Disorder (SAD).     

Changes in illness-related cognitions rather than distress mediate improvements in irritable bowel syndrome (IBS) symptoms and disability following a brief cognitive behavioural therapy intervention

Objective

A previous randomised controlled trial demonstrated that a cognitive behavioural therapy (CBT) self-management intervention significantly improved irritable bowel syndrome (IBS) symptoms and disability compared to treatment as usual (TAU). The current study analysed additional data to establish whether; 1) cognitive, behavioural and emotional factors hypothesized to perpetuate IBS symptoms and disability changed following CBT and, 2) ascertain if changes in these factors over the intervention period mediated treatment effects 6-months later.

Method

IBS patients (CBT = 31, TAU = 33) completed measures pre-and-post intervention including: Brief Illness Perception Questionnaire, Hospital Anxiety & Depression Scale and Cognitive and Behavioural Responses to Symptoms Questionnaire. Path models were evaluated to determine whether changes in cognitive and behavioural factors over the treatment period mediated treatment effects.

Results

Compared to TAU, CBT patients showed significant positive changes on several cognitive variables but not anxiety and depression following intervention. Positive change in illness perceptions following intervention mediated the treatment effect on improved IBS symptom severity and social adjustment six months later. Changes in damaging beliefs mediated the effect on social adjustment.

Conclusions

Change in cognition rather than mood mediated treatment related improvements. Changing negative perceptions of IBS appears to be a particularly important treatment mechanism.