Pilot investigation of the changes in cortical activation during facial affect recognition with lamotrigine monotherapy in bipolar disorder

Background: Bipolar disorder is associated with dysfunction in prefrontal and limbic areas implicated in emotional processing. Aims: To explore whether lamotrigine monotherapy may exert its action by improving the function of the neural network involved in emotional processing. Method: We used functional magnetic resonance imaging to examine changes in brain activation during a sad facial affect recognition task in 12 stable patients with bipolar disorder when medication-free compared with healthy controls and after 12 weeks of lamotrigine monotherapy. Results: At baseline, compared with controls, patients with bipolar disorder showed overactivity in temporal regions and underactivity in the dorsal medial and right ventrolateral prefrontal cortex, and the dorsal cingulate gyrus. Following lamotrigine monotherapy, patients demonstrated reduced temporal and increased prefrontal activation. Conclusions: This preliminary evidence suggests that lamotrigine may enhance the function of the neural circuitry involved in affect recognition.

Mask-less lithography for fabrication of optical waveguides

A flexible method for fabricating shallow optical waveguides by using femtosecond laser writing of patterns on a metal coated glass substrate followed by ion-exchange is described. This overcomes the drawbacks of low index contrast and high induced stress in waveguides directly written using low-repetition rate ultrafast laser systems. When compared to conventional lithography, the technique is simpler and has advantages in terms of flexibility in the types of structures which can be fabricated.

Fiber Bragg gratings inscribed using 800nm femtosecond laser and a phase mask in singleand multi-core mid-IR glass fibers

For the first time, Fiber Bragg grating (FBG) structures have been inscribed in single-core passive germanate and three-core passive and active tellurite glass fibers using 800 nm femtosecond (fs) laser and phase mask technique. With fs peak power intensity in the order of 10(11)W/cm(2), the FBG spectra with 2nd and 3rd order resonances at 1540 and 1033 nm in the germanate glass fiber and 2nd order resonances at approximately 1694 and approximately 1677 nm with strengths up to 14 dB in all three cores in the tellurite fiber were observed. Thermal responsivities of the FBGs made in these mid-IR glass fibers were characterized, showing average temperature responsivity approximately 20 pm/ degrees C. Strain responsivities of the FBGs in germanate glass fiber were measured to be 1.219 pm/microepsilon.

Recognition accuracy and response bias to happy and sad facial expressions in patients with major depression

Impaired facial expression recognition has been associated with features of major depression, which could underlie some of the difficulties in social interactions in these patients. Patients with major depressive disorder and age- and gender-matched healthy volunteers judged the emotion of 100 facial stimuli displaying different intensities of sadness and happiness and neutral expressions presented for short (100 ms) and long (2,000 ms) durations. Compared with healthy volunteers, depressed patients demonstrated subtle impairments in discrimination accuracy and a predominant bias away from the identification as happy of mildly happy expressions. The authors suggest that, in depressed patients, the inability to accurately identify subtle changes in facial expression displayed by others in social situations may underlie the impaired interpersonal functioning.

Producing facial composite sketches in remote cognitive interviews:a preliminary investigation

Justice systems around the world are increasingly turning to videoconferencing as a means to reduce delays and reduce costs in legal processes. This preliminary research examined whether interviewing a witness remotely - without physical co-presence of the witness and interviewer - could facilitate the production of quality facial composite sketches of suspects. In Study 1, 42 adults briefly viewed a photograph of a face. The next day they participated in Cognitive Interviews with a forensic artist, conducted either face-to-face or remotely via videoconference. In Study 2, 20 adults participated in videoconferenced interviews, and we manipulated the method by which they viewed the developing sketch. In both studies, independent groups of volunteers rated the likeness of the composites to the original photographs. The data suggest that remote interviews elicited effective composites; however, in Study 1 these composites were considered poorer matches to the photographs than were those produced in face-to-face interviews. The differences were small, but significant. Participants perceived several disadvantages to remote interviewing, but also several advantages including less pressure and better concentration. The results of Study 2 suggested that different sketch presentation methods offered different benefits. We propose that remote interviewing could be a useful tool for investigators in certain circumstances. © 2013 Taylor & Francis.

Look who's talking! Facial appearance can bias source monitoring

When we see a stranger's face we quickly form impressions of his or her personality, and expectations of how the stranger might behave. Might these intuitive character judgements bias source monitoring? Participants read headlines "reported" by a trustworthy- and an untrustworthy-looking reporter. Subsequently, participants recalled which reporter provided each headline. Source memory for likely-sounding headlines was most accurate when a trustworthy-looking reporter had provided the headlines. Conversely, source memory for unlikely-sounding headlines was most accurate when an untrustworthy-looking reporter had provided the headlines. This bias appeared to be driven by the use of decision criteria during retrieval rather than differences in memory encoding. Nevertheless, the bias was apparently unrelated to variations in subjective confidence. These results show for the first time that intuitive, stereotyped judgements of others' appearance can bias memory attributions analogously to the biases that occur when people receive explicit information to distinguish sources. We suggest possible real-life consequences of these stereotype-driven source-monitoring biases. © 2010 Psychology Press.

Dissociation of detection and evaluation of facial expressions in adolescence

Holistic face perception, i.e. the mandatory integration of featural information across the face, hasbeen considered to play a key role when recognizing emotional face expressions (e.g., Tanaka et al.,2002). However, despite their early onset holistic processing skills continue to improvethroughout adolescence (e.g., Schwarzer et al., 2010) and therefore might modulate theevaluation of facial expressions. We tested this hypothesis using an attentional blink (AB)paradigm to compare the impact of happy, fearful and neutral faces in adolescents (10–13 years)and adults on subsequently presented neutral target stimuli (animals, plants and objects) in a rapidserial visual presentation stream. Adolescents and adults were found to be equally reliable whenreporting the emotional expression of the face stimuli. However, the detection of emotional butnot neutral faces imposed a significantly stronger AB effect on the detection of the neutral targetsin adults compared to adolescents. In a control experiment we confirmed that adolescents ratedemotional faces lower in terms of valence and arousal than adults. The results suggest a protracteddevelopment of the ability to evaluate facial expressions that might be attributed to the latematuration of holistic processing skills.

Facial affect processing inbipolar disorder:a magnetoencephalography study

Background: Identifying biological markers to aid diagnosis of bipolar disorder (BD) is critically important. To be considered a possible biological marker, neural patterns in BD should be discriminant from those in healthy individuals (HI). We examined patterns of neuromagnetic responses revealed by magnetoencephalography (MEG) during implicit emotion-processing using emotional (happy, fearful, sad) and neutral facial expressions, in sixteen BD and sixteen age- and gender-matched healthy individuals. Methods: Neuromagnetic data were recorded using a 306-channel whole-head MEG ELEKTA Neuromag System, and preprocessed using Signal Space Separation as implemented in MaxFilter (ELEKTA). Custom Matlab programs removed EOG and ECG signals from filtered MEG data, and computed means of epoched data (0-250ms, 250-500ms, 500-750ms). A generalized linear model with three factors (individual, emotion intensity and time) compared BD and HI. A principal component analysis of normalized mean channel data in selected brain regions identified principal components that explained 95% of data variation. These components were used in a quadratic support vector machine (SVM) pattern classifier. SVM classifier performance was assessed using the leave-one-out approach. Results: BD and HI showed significantly different patterns of activation for 0-250ms within both left occipital and temporal regions, specifically for neutral facial expressions. PCA analysis revealed significant differences between BD and HI for mild fearful, happy, and sad facial expressions within 250-500ms. SVM quadratic classifier showed greatest accuracy (84%) and sensitivity (92%) for neutral faces, in left occipital regions within 500-750ms. Conclusions: MEG responses may be used in the search for disease specific neural markers.