Right Anterior Theta Hypersynchrony as a Quantitative Measure Associated with Autistic Traits and K-Cl Cotransporter KCC2 Polymorphism.

Our aim was to use theta coherence as a quantitative trait to investigate the relation of the polymorphisms in NKCC1 (rs3087889) and KCC2 (rs9074) channel protein genes to autistic traits (AQ) in neurotypicals. Coherence values for candidate connection regions were calculated from eyes-closed resting EEGs in two independent groups. Hypersynchrony within the right anterior region was related to AQ in both groups (p < 0.05), and variability in this hypersynchrony was related to the rs9074 polymorphism in the total group (p < 0.05). In conclusion, theta hypersynchrony within the right anterior region during eyes-closed rest can be considered a quantitative measure for autistic traits. Replicating our findings in two independent populations with different backgrounds strengthens the validity of the current study.

Comparison of the effects of open- and closed-skill exercise on cognition and peripheral proteins: A cross-sectional study.

Previous research indicates that different exercise modes might create different effects on cognition and peripheral protein signals. This study aimed to compare the effects of long-term participation in an open and closed-skill exercise on cognitive functions and Brain-derived neurotrophic factor and Cathepsin B levels. 18 fencers, 18 swimmers, 18 sedentary controls between 18-25 years old participated in the study. Participants performed visuospatial working memory, verbal fluency and selective attention tasks. Blood samples were tested for Brain-derived neurotrophic factor and Cathepsin B using ELISA. The results showed that fencers performed superiorly on some part of visuospatial working memory, verbal fluency, and selective attention tasks than swimmers and sedentary controls. Athlete groups showed higher scores on some subtests of visuospatial working memory and selective attention tasks than sedentary controls. The basal serum Brain-derived neurotrophic factor level was not significant between the groups, but Cathepsin B was higher in fencers than swimmers and sedentary controls. The peripheric protein signal response to acute exercise was significantly higher in athletes, particularly in the open-skill group for Cathepsin B. Our research provided noteworthy results that more cognitively challenging exercise may provide more benefits for some aspects of cognition. Since our findings suggest that open-skill exercise improves specific types of executive-control functioning, this exercise mode might be included in training programs to support cognition and prevent cognitive impairment.

Effect of Exercise on Major Depressive Disorder and Schizophrenia: A BDNF Focused Approach.

Psychiatric disorders are remarkable health problems that cause a massive social and economic burden, and the issue of their long-term and effective treatment is subjected to discussion. The effect of physical activity and exercise is under investigation in the treatment of the major depressive disorder (MDD) and schizophrenia which are accompanied by cognitive dysfunctions. Scientists focus on the positive effects of exercise on learning, memory and attention parameters while investigating the regulatory role of brain-derived neurotrophic factor (BDNF). In this review, the effect of aerobic exercise on peripheral BDNF levels in MDD and schizophrenia is examined by including human studies in which acute and chronic aerobic exercise are applied. The results showed that aerobic exercise caused different responses on BDNF levels, and some of the studies were accompanied by the improvement in cognitive functions in BDNF changes. In order to comprehend the effect of aerobic exercise in MDD and schizophrenia, it is understood that applying studies on larger and paired participant groups with different exercise frequencies and tensions in necessary.

Assessing Theory of Mind by Humor: The Humor Comprehension and Appreciation Test (ToM-HCAT).

Theory of Mind (ToM) may be defined as the ability to understand the mental states, such as beliefs, desires, intentions, and emotions, of others. Impairment of ToM ability leads to disorders with pathologies in social skills, such as autism spectrum disorder and schizophrenia. In addition to differences in ToM ability among patient populations, there is variation between neurotypical individuals. Unfortunately, ToM tasks are usually developed for children or patients with cognitive disorders and cannot detect variations in healthy adults. As an alternative tool, humor may be used. Humor plays a role in social communication and requires many different cognitive functions. Humor is believed to represent complex high-order cognitive processes. There are numerous types of humor; the most complex type is considered ToM humor, where an understanding of social/emotional content is necessary. Given the need for a ToM assessment test suitable for healthy adult populations, we developed a test for measuring humor comprehension and appreciation, with and without ToM content (ToM-HCAT). The present ToM-HCAT test is a performance test consisting of cartoons. The test measures perceived funniness, reaction time to perceived funniness decision, and meaning inference. Cartoons were selected after pilot studies involving 44 participants. Subscales were constituted according to expert views and confirmed by confirmatory factor analysis (N = 135). Goodness of fit values for the final 35-item test were acceptable to excellent: GFI = 0.97; AGFI = 0.97; NFI = 0.97; RFI = 0.97, and SRMR = 0.067. Both categories were internally consistent (α1 = 0.84, α2 = 0.94). External validity was assessed against autistic traits. One hundred and three participants completed the Autism Spectrum Quotient and were grouped by +0.5 standard deviations from the mean as high in autistic traits. The meaning-inference scores of the subscale with the ToM cartoons were significantly lower (p = 0.034) for the high autistic traits group, providing evidence of external validity. In conclusion, we developed and validated a test for assessment of ToM by humor comprehension and appreciation. We believe that the present test will be useful for the detection of variations in ToM ability in the healthy adult population.

Evaluation of cognitive slowing in OCD by means of creating incongruence between lexicon and prosody.

Studies indicate that patients with obsessive-compulsive disorder (OCD) have slowing in cognitive processing, especially in the presence of a conflict. This study aimed to determine whether decision and motor times in OCD patients were affected by manipulating the congruence/incongruence of lexical and prosodic aspects of commands. An experimental paradigm was designed to simulate a situation that can trigger anxiety and obsessions in OCD patients. Commands with or without a conflict, that is, an incongruence between lexical and prosodic aspects, were given to the participants. Decision time, motor time and errors were the main parameters of the experiment. The control group had significantly faster decision times than the OCD group in response to both conflicting and non-conflicting commands. The OCD patients demonstrated higher trait anxiety, while Stroop interference and state anxiety were not significantly different between the groups. These results suggest that OCD patients experience slowing in their response times, regardless of whether the stimuli are conflicting or not.

Corpus callosum has different channels for transmission of spatial frequency information.

Many studies suggest that separate retinocortical channels with different conduction speeds transmit the information about high and low spatial frequencies (SF). Similarly, separate callosal channels may be responsible for the transfer of different SFs. To test this hypothesis, interhemispheric transfer time (IHTT) was estimated using visual evoked potentials (VEPs) elicited by reversal of different SF checkerboard patterns, which were presented either in the right or left visual hemifield. VEPs were recorded from homologous occipital and parietal leads in 11 subjects. The P100 latencies obtained from directly stimulated hemispheres were defined as retinocortical conduction times. The difference in P100 latencies obtained from directly and indirectly stimulated hemispheres was defined as IHTT (i.e., contralateral P100 latency values subtracted from the ipsilateral latency values). The results, showing faster retinocortical transfer for low SF than for high SF, and the shortest transfer time at parietal leads only for low SF, indicate that the presented stimuli are transferred on separate retinocortical channels. Concerning the interhemispheric transfer (VEP-IHTT), faster right-to-left than left-to-right transfer for both low and high SF stimuli was found, which is in congruence with previous studies. Most important however, the VEP-IHTT was faster for low SF than high SF. These different interhemispheric transfer speeds support the hypothesis that transferring low SF, compared with high SF information, relies on larger callosal fibers. Thus, we conclude that indeed distinct callosal channels respond selectively to the SF content of visual stimuli.

Aspects of foot preference: differential relationships of skilled and unskilled foot movements with motor asymmetry.

In this research different aspects of foot preference were examined in 50 participants. The relationship between foot preference, hand preference, and hand/foot-tapping performance was analysed in detail. For foot preference, a practical behavioural test consisting of 14 daily foot movements was developed. After statistical analysis, five items were dropped. The test-retest reliabilities of the nine-item foot preference test and the foot-tapping task were found to be high. The factor analysis indicated a two-factor structure (skilled and unskilled foot movements). Foot preference in skilled and unskilled movements was correlated with hand preference and foot/hand-tapping speed. This correlation was found to be higher in skilled movements than in unskilled movements. Additionally, foot preference for skilled movements was strongly lateralised. The results indicate that the motor control of fine movements is similar for upper and lower limbs. The fact of lateralisation indicates that skilled and unskilled foot movements utilise different pathways. We propose that the asymmetrical lateral (corticospinal) pathway controls skilled movements while the medial pathways control unskilled movements. We therefore suggest that both skilled and unskilled foot tasks should be evaluated separately in order to assess foot preference.

Frontal and posterior ERPs related to line bisection.

The aim of this study was to investigate the dynamic nature of the cortical visuospatial attention processes during the line bisection test, which is sensitive to perceptual asymmetries. EEGs of 26 normal volunteers were recorded during the administration of a computerized line bisection test, which requires participants mark the midline of lines using a mouse. Two event-related potentials subsequent and time locked to the line presentations, namely, P300 and a positive slow wave, were obtained. Findings suggested that both potentials were related to the test performance, and the right hemisphere was more active. Analysis suggested a right parietotemporal and superior parietal locus for the P300 and right prefrontal activity for the positive slow wave. A dynamic asymmetrical activity was identified, such that after primary visual perception, spatial processing is then initiated in the right parietotemporal cortex and then proceeds to the right prefrontal cortex.

Directional preferences in turning behavior of girls and boys.

Turning biases in humans and animals are known to be related to dopaminergic asymmetry between the brain hemispheres. A laboratory method, in which turning preference was evaluated, was adapted based upon the turning of the subject toward a particular sound in a square room. One of the aims of this study was to investigate the reliability of this method with children, and the other aim was to research the turning preference in boys and girls. 31 children between 7 and 13 yr. old volunteered as subjects, and 17 subjects were retested. The subjects tended significantly to turn leftward (60.1%), and fewer girls (53.7%) turned to the left than boys (66.2%). The correlation between the test and the retest was significant (r=.79, p< .01). Most studies have indicated that humans in childhood and adulthood exhibit left-turning preference, but conflicts between the results obtained on different types of rotation tasks have suggested that hemispheric dopaminergic activity might affect preference. That needs study.

Time-frequency analysis of visual evoked potentials for interhemispheric transfer time and proportion in callosal fibers of different diameters.

This study is an extension of the experimental research of Nalçaci et al., who presented 16 subjects with a reversal of checkerboard pattern as stimuli in the right visual field or left visual field and recorded EEG at O1, O2, P3, and P4. They applied the chosen bandpass filters (4-8, 8-15, 15-20, 20-32 Hz) to the VEPs of subjects and obtained four different components for each VEP. The first aim of this study is to improve the previous report using some methods in time-frequency domain to estimate interhemispheric delays and amplitudes in a time window. Using the improved estimates of interhemispheric delays, the second aim is to estimate the proportion of callosal fibers of different diameters that are activated by visual stimuli by comparing amplitudes of VEPs in different frequency bands. If the relation between frequency components of VEP and delays for callosal fibers of different dimension were reliable, it would give us an opportunity to deal with amplitude of bandpass-filtered VEPs in order to see approximately the proportion of these fibers activated by a certain stimulus. By using frequency-dependent shifts in time and maximizing the cross correlation of direct VEP (DVEP-VEP obtained from contralateral hemisphere)-indirect VEP (IVEP-VEP obtained from ipsilateral hemisphere) pairs in the time-frequency domain, we examined the delay not only at P100 and N160 peaks but along a meaningful time interval as well. Furthermore, by shifting back the IVEP according to the delay estimated at each time window, both the amplitudes and energies of the synchronized DVEP-IVEP pairs were compared at the chosen frequency bands. The percentages of IVEPs at each band was then examined further in conjunction with the distribution of axon diameters in the posterior pole of the CC, questioning the relation between the distributions of the axon diameters and activations at each band. We established an energy definition to express the activation in the fibers. When the energy percentages of IVEPs in theta and alpha were totaled, they were found to be between 76.2% and 81.6%, which is close to the value 74-77% for fibers of 0.4-1 microm in diameter obtained from anatomical study of human CC. The sum of energy percentages in the beta1 and beta2 bands was between 20.1% and 24.2%, which probably reflects the proportion of activation of callosal fibers 1-3 microm in diameter.

[Reliability and validity of Turkish version of magical ideation scale in university students]. / Büyüsel düsünce olçegi'nin Türkçe formunun universite ogrencilerindeki geçerlik ve güvenilirligi.

OBJECTIVE: Schizoptypal disorder shares many clinical, neuropsychological and neurophysiological features with schizophrenia and is included in the schizophrenia spectrum. Patients with schizotypal disorder or individuals with mild schizotypal features are therefore highly valuable in the study of neuropsychological and neurophysiological characteristics of psychosis, and in particular schizophrenia, as they are likely to be free of the potential confounding factors of medication, chronic hospitalization and manifest psychosis. We report here the psychometric properties of the Turkish version of the Magical Ideation Scale (MIS), a self-report questionnaire that focuses on delusion-like beliefs and hallucination-like experiences and that has been used to quantify an important dimension of schizotypy. METHOD: Internal consistency and high cut-off scores were studied in 332 medical students. Forty-three students were readministered the scale 3 weeks later, and 96 received the Paranormal Belief Scale-R (PBS-R) along with the MIS, in order to measure test-retest reliability and convergent validity, respectively. RESULTS: The internal consistency of the scale is satisfactory with a Cronbach alpha coefficient of 0.78. Test-retest scores are highly correlated (r= 0.84). The high cut-off score is 21 for males, 23 for females, and 22 for the whole sample. Convergent validity was established by the significant correlation between the total MIS and PBS-R scores (r= 0.61). CONCLUSIONS: The scale is valid and reliable for studies that require a standard quantification of schizotypal signs and symptoms in young university students.

Line bisection task performance and resting EEG alpha power.

Neurologically normal subjects generally err to the left of veridical center when performing a line bisection task, a phenomenon termed "pseudoneglect." We hypothesized that resting electroencephalogram (EEG) alpha oscillations may show relationships with attentional mechanisms and give some clues about the underlying mechanisms of pseudoneglect. We recorded resting EEGs of 41 subjects and tested them with a paper-pencil line bisection task. Our results showed that line bisection scores of men (n=18) were less biased and their performance was higher compared to those of women (n=20), but these differences only approached significance. The eyes open resting EEG alpha power of women was significantly and positively correlated with their line bisection performance. In general, significant relationships were related to the left hand performance when the lines were presented in the left hemispace. Greater resting alpha power was correlated with lower absolute bisection score or, in other words, higher bisection performance. Greater alpha power also correlated with diminished leftward bisection bias (or reduced pseudo-neglect). The resting EEG alpha of men was weakly associated with bisection performance. Results discussed in terms of Kinsbourne's activation-orientation theory and Basar's view on brain oscillations.

[Reliability and validity of a handedness questionnaire]. / El tercihi anketinin geçerlik ve güvenilirligi.

OBJECTIVE: In this study, the validity and reliability of the hand preference item of a 13-item questionnaire adapted from Chapman and Chapman (1987) were investigated. METHOD: This questionnaire requires subjects to indicate which hand they usually use for various actions as follows: writing, drawing, throwing, using a hammer, using a toothbrush, using an eraser on paper, using scissors, holding a match when striking it, stirring a can of paint, using a spoon, using a screwdriver, twisting off the lid of a jar, and using a knife. Each item was scored as "1" for right, "2" for either, or "3" for left, and the handedness of subjects was scored from 13 (the strongest right-hand preference) to 39 (the strongest left-hand preference). In this study, 449 subjects filled in the questionnaire, and 43 subjects attended the test-retest study 3 weeks after the first examination. In order to determine the validity of the questionnaire, fine motor performance was measured using a finger tapping task, and the eye and foot preferences of the subjects were evaluated. RESULTS: The test-retest reliability (r=.993) and internal consistency (Cronbach's Alpha=.97) were found to be high. In item-total score analysis, the best single item was "using a hammer", while the worst item was "twisting off the lid of a jar". Factor analysis yielded two factors, skilled and unskilled activities. Handedness scores were found to show a significant correlation with foot preference scores and the dominance score of the finger tapping task. CONCLUSION: The results suggest that the handedness questionnaire is reliable and valid in measuring handedness.