scholarly journals In the eye of the beholder: visual mate choice lateralization in a polymorphic songbird

2012 ◽  
Vol 8 (6) ◽  
pp. 924-927 ◽  
Author(s):  
Jennifer J. Templeton ◽  
D. James Mountjoy ◽  
Sarah R. Pryke ◽  
Simon C. Griffith

Birds choose mates on the basis of colour, song and body size, but little is known about the mechanisms underlying these mating decisions. Reports that zebra finches prefer to view mates with the right eye during courtship, and that immediate early gene expression associated with courtship behaviour is lateralized in their left hemisphere suggest that visual mate choice itself may be lateralized. To test this hypothesis, we used the Gouldian finch, a polymorphic species in which individuals exhibit strong, adaptive visual preferences for mates of their own head colour. Black males were tested in a mate-choice apparatus under three eye conditions: left-monocular, right-monocular and binocular. We found that black male preference for black females is so strongly lateralized in the right-eye/left-hemisphere system that if the right eye is unavailable, males are unable to respond preferentially, not only to males and females of the same morph, but also to the strikingly dissimilar female morphs. Courtship singing is consistent with these lateralized mate preferences; more black males sing to black females when using their right eye than when using their left. Beauty, therefore, is in the right eye of the beholder for these songbirds, providing, to our knowledge, the first demonstration of visual mate choice lateralization.

2012 ◽  
Vol 71 (4) ◽  
Author(s):  
Z. Sardiwalla ◽  
D. Moodley ◽  
T. Ndawonde ◽  
A. Madikizela ◽  
N. Ngobese ◽  
...  

Thisstudy compared central corneal thickness (CCT) and intraocular pressure (IOP) of Black and Indian students from the University of Kwa-Zulu-Natal. Two hundred (100 Black and 100 Indi-an) participants of both genders aged 18-25 years (mean and standard deviation; 20.1±1.6 years) participated in this study. CCT and IOP were measured for the right eye of each participant using a Tono-Pachymeter (NT530P) and a Goldmann applanation tonometer (GAT) respectively. Data was analyzed with descriptive, t-test and Pearson’s cor-relation statistics. In the total sample (N = 200), the mean CCT value was 519.5 ± 38.6 μm and CCT was higher in the Indians (526.5 ± 37.2 µm) than in the Blacks (512.4 ± 38.9 µm) (p = 0.01).  Also, it was higher in the females (522.3 µm) than in males (516.7 µm), but the difference was insignificant (p = 0.07). The mean CCT was higher in the Indian males (520.1 µm) than in the Black males (513.2 µm), but the difference was insignificant (p=0.39).  However, it was significantly higher in the Indian females (533 µm) than in the Black females (511.6 µm) (p = 0.003). In the total sample, the mean IOP was 14.6 mmHg and IOP was greater in Indiansthan Blacks (mean = 15.3 ± 2.9 mmHg and 13.8 ± 2.6 mmHg respectively) (p = 0.01). Also, the mean IOP (N = 200) value was slightly higher in the females (14.7 mmHg) than in males (14.5 mmHg) (p = 0.51). The mean IOP was higher in the Indian males (15.0 mmHg) than in the Black males (14.0 mmHg) (p = 0.07) and the mean IOP value was higher in the Indian females (15.7 mmHg) than in the Black females (13.6 mmHg) (p < 0.001). The higher mean IOP value in the Indian than Black participants was attributed to the higher mean CCT values. A positive, but inconsistent association between CCT and IOP was found in this study, the coefficient in the total sample (r = 0.382, p = 0.000), in the Blacks (r = 0.196, p = 0.05) and in Indians (r = 0.498, p = 0.000). A national population study comparing CCT and IOP in the various South African ethnic groups is recommended. Cognizance of these differences should be taken in the diagnoses of glaucoma in these ethnic groups. (S Afr Optom 2012 71(4) 171-177)


2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.


Author(s):  
Elizabeth Schechter

This chapter defends the 2-agents claim, according to which the two hemispheres of a split-brain subject are associated with distinct intentional agents. The empirical basis of this claim is that, while both hemispheres are the source or site of intentions, the capacity to integrate them in practical reasoning no longer operates interhemispherically after split-brain surgery. As a result, the right hemisphere-associated agent, R, and the left hemisphere-associated agent, L, enjoy intentional autonomy from each other. Although the positive case for the 2-agents claim is grounded mainly in experimental findings, the claim is not contradicted by what we know of split-brain subjects’ ordinary behavior, that is, the way they act outside of experimental conditions.


2005 ◽  
Vol 93 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Jen-Tse Chen ◽  
Yung-Yang Lin ◽  
Din-E Shan ◽  
Zin-An Wu ◽  
Mark Hallett ◽  
...  

Transcranial magnetic stimulation (TMS) of the motor cortex can interrupt voluntary contralateral rhythmic limb movements. Using the method of “resetting index” (RI), our study investigated the TMS effect on different types of bimanual movements. Six normal subjects participated. For unimanual movement, each subject tapped either the right or left index finger at a comfortable rate. For bimanual movement, index fingers of both hands tapped in the same (in-phase) direction or in the opposite (antiphase) direction. TMS was applied to each hemisphere separately at various intensities from 0.5 to 1.5 times motor threshold (MT). TMS interruption of rhythm was quantified by RI. For the unimanual movements, TMS disrupted both contralateral and ipsilateral rhythmic hand movements, although the effect was much less in the ipsilateral hand. For the bimanual in-phase task, TMS could simultaneously reset the rhythmic movements of both hands, but the effect on the contralateral hand was less and the effect on the ipsilateral hand was more compared with the unimanual tasks. Similar effects were seen from right and left hemisphere stimulation. TMS had little effect on the bimanual antiphase task. The equal effect of right and left hemisphere stimulation indicates that neither motor cortex is dominant for simple bimanual in-phase movement. The smaller influence of contralateral stimulation and the greater effect of ipsilateral stimulation during bimanual in-phase movement compared with unimanual movement suggest hemispheric coupling. The antiphase movements were resistant to TMS disruption, and this suggests that control of rhythm differs in the 2 tasks. TMS produced a transient asynchrony of movements on the 2 sides, indicating that both motor cortices might be downstream of the clocking command or that the clocking is a consequence of the 2 hemispheres communicating equally with each other.


2006 ◽  
Vol 18 (11) ◽  
pp. 1789-1798 ◽  
Author(s):  
Angela Bartolo ◽  
Francesca Benuzzi ◽  
Luca Nocetti ◽  
Patrizia Baraldi ◽  
Paolo Nichelli

Humor is a unique ability in human beings. Suls [A two-stage model for the appreciation of jokes and cartoons. In P. E. Goldstein & J. H. McGhee (Eds.), The psychology of humour. Theoretical perspectives and empirical issues. New York: Academic Press, 1972, pp. 81–100] proposed a two-stage model of humor: detection and resolution of incongruity. Incongruity is generated when a prediction is not confirmed in the final part of a story. To comprehend humor, it is necessary to revisit the story, transforming an incongruous situation into a funny, congruous one. Patient and neuroimaging studies carried out until now lead to different outcomes. In particular, patient studies found that right brain-lesion patients have difficulties in humor comprehension, whereas neuroimaging studies suggested a major involvement of the left hemisphere in both humor detection and comprehension. To prevent activation of the left hemisphere due to language processing, we devised a nonverbal task comprising cartoon pairs. Our findings demonstrate activation of both the left and the right hemispheres when comparing funny versus nonfunny cartoons. In particular, we found activation of the right inferior frontal gyrus (BA 47), the left superior temporal gyrus (BA 38), the left middle temporal gyrus (BA 21), and the left cerebellum. These areas were also activated in a nonverbal task exploring attribution of intention [Brunet, E., Sarfati, Y., Hardy-Bayle, M. C., & Decety, J. A PET investigation of the attribution of intentions with a nonverbal task. Neuroimage, 11, 157–166, 2000]. We hypothesize that the resolution of incongruity might occur through a process of intention attribution. We also asked subjects to rate the funniness of each cartoon pair. A parametric analysis showed that the left amygdala was activated in relation to subjective amusement. We hypothesize that the amygdala plays a key role in giving humor an emotional dimension.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii44-ii44
Author(s):  
A T J van der Boog ◽  
S David ◽  
A M M Steennis ◽  
T J Snijders ◽  
J W Dankbaar ◽  
...  

Abstract BACKGROUND Surgical treatment of diffuse glioma is performed to reduce tumor mass effect and to pave the way for adjuvant (chemo)radiotherapy. As a complication of surgery, ischemic lesions are often found in the postoperative setting. Not only can these lesion induce neurological deficits, but their volume has also been associated with reduced survival time. Prior studies suggest areas with a singular vascular supply to be more prone to postoperative ischemic lesions, although the precise cause is yet unknown. The aim of this study was to explore the volumetric and spatial distributions of postoperative ischemic lesions and their relation to arterial territories in glioma patients. MATERIAL AND METHODS We accessed a retrospective database of 144 adult cases with WHO grade II-IV supratentorial gliomas, who received surgery and postoperative MRI within 3 days in 2012–2014. We identified 93 patients with postoperative ischemia, defined as new confluent diffusion restriction on DWI. Ischemic lesions were manually delineated and spatially normalized to stereotaxic MNI space. Voxel-based analysis (VBA) was performed to compare presence and absence of postoperative ischemia. False positive results were eliminated by family-wise error correction. Areas of ischemia were labeled using an arterial territory map, the Harvard-Oxford cortical and subcortical atlases and the XTRACT white matter atlas. RESULTS Median volume of confluent ischemia was 3.52cc (IQR 2.15–5.94). 23 cases had only ischemic lesion in the left hemisphere, 46 in the right hemisphere and 24 bilateral. Median volume was 3.08cc (IQR 1.35–5.72) in left-sided lesions and 2.47cc (1.01–4.24) in right-sided lesions. Volume of ischemic lesions was not associated with survival after 1, 2 or 5 years. A cluster of 125.18cc was found to be significantly associated with development of postoperative ischemia. 73% of this cluster was situated in the arterial territory of the right middle cerebral artery (MCA), limited by the border of the posterior cerebral artery (PCA), and the watershed area between the right MCA and the right anterior cerebral artery (ACA). Significant areas were located in the frontal lobes, spanning into the right temporo-occipital region, and predominantly included right and left thalamus, caudate nucleus, putamen, pallidum, as well as right temporal gyri and insular cortex, and parts of the right corticospinal tract, longitudinal fasciculi and superior thalamic radiation. CONCLUSION We found slightly more and larger ischemic lesions in the right than left hemisphere after glioma resection. A statistically significant cluster of voxels of postoperative ischemia was found in the territory of the right MCA and watershed area of the right ACA. Exploration of the spatial distribution of these lesions could help elucidate their etiology and form the basis for predicting clinically relevant postoperative ischemia.


Psihologija ◽  
2008 ◽  
Vol 41 (2) ◽  
pp. 195-211
Author(s):  
Jasmina Vuksanovic ◽  
Milena Djuric

Fluency tests are frequently used in clinical practice to asses executive functions. The literature data are not unequivocal although in a great number of papers is pointed out the importance of the left hemisphere, specially of the left frontal lobes in the mediation of phonological fluency and the right hemisphere in the mediation of nonverbal fluency. This paper considers the suitability of fluency tests for the detection of left versus right seizure laterality. The sample consisted of thirty-two epilepsy patients divided into two groups: LHF-participants with the seizure focus in the left hemisphere (n=16), and DHF-participants with the seizure focus in the right hemisphere (n=16), and K-the control group of t age-matched healthy children (n=50) aged 7-11 years. The qualitative and quantitative comparison of the phonological and nonverbal fluency performance was carried out in consideration of the seizure laterality as well as compared to the healthy controls. The results of phonological fluency performance revealed that the performance of the LHF group was significantly reduced as compared to both DHF and K group. The analysis of nonverbal fluency performance revealed that the performance of the DHF group was significantly reduced as compared to both LHF and K group The qualitative analysis obtained valuable data, which could additionally contribute to the neuropsychological evaluation of the left versus right seizure laterality.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Selene Schintu ◽  
Elisa Martín-Arévalo ◽  
Michael Vesia ◽  
Yves Rossetti ◽  
Romeo Salemme ◽  
...  

Rightward prism adaptation ameliorates neglect symptoms while leftward prism adaptation (LPA) induces neglect-like biases in healthy individuals. Similarly, inhibitory repetitive transcranial magnetic stimulation (rTMS) on the right posterior parietal cortex (PPC) induces neglect-like behavior, whereas on the left PPC it ameliorates neglect symptoms and normalizes hyperexcitability of left hemisphere parietal-motor (PPC-M1) connectivity. Based on this analogy we hypothesized that LPA increases PPC-M1 excitability in the left hemisphere and decreases it in the right one. In an attempt to shed some light on the mechanisms underlying LPA’s effects on cognition, we investigated this hypothesis in healthy individuals measuring PPC-M1 excitability with dual-site paired-pulse TMS (ppTMS). We found a left hemisphere increase and a right hemisphere decrease in the amplitude of motor evoked potentials elicited by paired as well as single pulses on M1. While this could indicate that LPA biases interhemispheric connectivity, it contradicts previous evidence that M1-only MEPs are unchanged after LPA. A control experiment showed that input-output curves were not affected by LPAper se. We conclude that LPA combined with ppTMS on PPC-M1 differentially alters the excitability of the left and right M1.


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