The defaultness hypothesis

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rachel Giora

Abstract This paper demonstrates that, when interpretation is at stake, it is only degree of defaultness that matters. Neither degree of Negation, nor degree of Affirmation, nor equal degree of Novelty, nor equal degree of Literalness/Nonliteralness, nor equal strength of Contextual support, whether linguistic or pictorial (see Heruti et al. 2019), makes a difference. Instead, it is only degree of defaultness that counts. Indeed, having established degree of defaultness of negatives and affirmatives (Experiment 1.1) and their processing cost when in isolation (Experiment 1.2), we further attested to the speed superiority of default negative interpretations, which seemed more pronounced in the Left Hemisphere rather than in the Right Hemisphere (Experiment 1.2; see Giora, Cholev et al. 2018).We then further attested to the speed superiority of these negatives, when embedded in equally strong supportive contexts. Here, we also show that default Negative Sarcasm is processed significantly faster than nondefault Affirmative Sarcasm (Experiment 2). And when embedded in equally strong sarcastically biasing contexts, both hemispheres reflect the superiority of default Negative Sarcasm over nondefault Affirmative Sarcasm (Experiments 2.1–2.2). However, given Affirmative Sarcasm’s nondefaultness, it is only nondefault Affirmative Sarcasmthat is expected and shown to rely on cueing for its derivation (Corpus-based Studies 1–2, Section 3). Still, when hedonic effects are considered (see Section 4), it is only utterances’ nondefault interpretations, whether in linguistic (Experiment 3) or pictorial contexts (Experiment 4), that are entertaining, given that they make up Optimal Innovations, while involving default interpretations in the process (see Giora et al. 2004, 2017). It is degree of defaultness, then, that affects both (i) processing speed (whether in or out of context), (ii) reliance on cueing, and (iii) hedonic effects. Finally, in Section 5, our results and conclusions are summarized.

2013 ◽  
Vol 20 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Nadia Scantlebury ◽  
Todd Cunningham ◽  
Colleen Dockstader ◽  
Suzanne Laughlin ◽  
William Gaetz ◽  
...  

AbstractWhite matter matures with age and is important for the efficient transmission of neuronal signals. Consequently, white matter growth may underlie the development of cognitive processes important for learning, including the speed of information processing. To dissect the relationship between white matter structure and information processing speed, we administered a reaction time task (finger abduction in response to visual cue) to 27 typically developing, right-handed children aged 4 to 13. Magnetoencephalography and Diffusion Tensor Imaging were used to delineate white matter connections implicated in visual-motor information processing. Fractional anisotropy (FA) and radial diffusivity (RD) of the optic radiation in the left hemisphere, and FA and mean diffusivity (MD) of the optic radiation in the right hemisphere changed significantly with age. MD and RD decreased with age in the right inferior fronto-occipital fasciculus, and bilaterally in the cortico-spinal tracts. No age-related changes were evident in the inferior longitudinal fasciculus. FA of the cortico-spinal tract in the left hemisphere and MD of the inferior fronto-occipital fasciculus of the right hemisphere contributed uniquely beyond the effect of age in accounting for reaction time performance of the right hand. Our findings support the role of white matter maturation in the development of information processing speed. (JINS, 2013, 19, 1–14)


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.


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.


2021 ◽  
Vol 23 (2) ◽  
pp. 107-112
Author(s):  
Elena B. Filippova ◽  
Elena M. Lesova ◽  
Natalya V. Murgaeva

We researched the dependence of cognitive abilities, mostly connected to functions of right and left hemispheres, and physical endurance on phases of sexual cycle. We discovered that on the first day of the cycle the number of correct tasks, connected with functions of the right hemisphere, was bigger than in the middle of the cycle, while no difference was detected in tasks, connected with functions of the left hemisphere. In the beginning of the cycle all test subjects correctly answered more "right hemisphere" questions, than during the ovulation phase, in the middle of the cycle the majority of test subjects correctly answered more "left hemisphere" tasks. We assume that sexual steroids moderate functional differences, connected with functions of right and left hemisphere. Precisely, low level of sexual steroids in the beginning of the cycle helps to activate functions of the right hemisphere, while steroids concentration in the middle of the cycle stops those functions. The level of heartbeat under the physical load was bigger in the luteal phase than before the ovulation; with the increase of load the heartbeat decreased before the ovulation and increase in the luteal phase. We assume that increased content of estrogens before the ovulations lead to decrease in physical endurance, while the decrease of concentration of estrogens in the luteal phase increased this endurance. Therefore, influence of sexual steroids helps to activate functions, which characterize specific psychological and physical status of women sex, particularly verbal abilities, lower abilities for visual analysis, and lower physical endurance of women.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Sana Somani ◽  
Melissa Gazi ◽  
Michael Minor ◽  
Joe Acker ◽  
Abimbola Fadairo ◽  
...  

Introduction: The Emergency Medical Stroke Assessment (EMSA) is a six point stroke severity scale with one point each for gaze preference, facial droop, arm drift, leg drift, abnormal naming, and abnormal repetition that was developed to help emergency medical services (EMS) providers identify acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). We hypothesized that the EMSA would detect left hemisphere LVO with a higher sensitivity than right hemisphere LVO. Methods: We trained 24 trauma system-based emergency communication center (ECC) paramedics in the EMSA. ECC-guided EMS in performance of the EMSA on patients with suspected stroke. We compared the sensitivity, specificity, area under the curve (AUC), and 95% confidence interval (CI) of ECC-guided prehospital EMSA for right versus left hemisphere ICA or M1 occlusion. Results: We enrolled 569 patients from September 2016 through February 2018, out of which 236 had a discharge diagnosis of stroke and 173 had a diagnosis of AIS. We excluded patients with bilateral (n=21) and brainstem (n=21) AIS. There were 64 patients with left hemisphere AIS including 19 with LVO. There were 67 patients with right hemisphere AIS including 22 with LVO. A score of ≥ 4 points yielded a sensitivity of 84.2 (95% CI = 60.4-96.6) and specificity of 66.7 (51.1-80.0) for left hemisphere LVO compared to a sensitivity of 68.2 (45.1-86.1) and specificity of 73.9 (58.9-85.7) for right hemisphere LVO. For predicting a left hemisphere LVO, the AUC was 0.77 (0.65-0.90) compared to 0.66 (0.50-0.82) for right-sided LVO. Assigning 2 points for abnormal gaze yielded an AUC of 0.78 (0.66-0.91) versus 0.67 (0.52-0.83) for left and right hemisphere LVO, respectively. Conclusions: The EMSA, like the National Institutes of Health Stroke Scale (NIHSS) upon which it is based, is more sensitive to left compared to right hemisphere LVO. More heavily weighting abnormal gaze did not improve the sensitivity of the EMSA for right hemisphere LVO. There is no comparable data on the right versus left hemisphere performance of other prehospital scales. There is a need to develop sensitive tests of right hemisphere dysfunction that are suitable for use in the field.


1978 ◽  
Vol 1 (2) ◽  
pp. 270-277 ◽  
Author(s):  
Michael J. Morgan ◽  
Michael C. Corballis

AbstractThis paper focuses on the inheritance of human handedness and cerebral lateralization within the more general context of structural biological asymmetries. The morphogenesis of asymmetrical structures, such as the heart in vertebrates, depends upon a complex interaction between information coded in the cytoplasm and in the genes, but the polarity of asymmetry seems to depend on the cytoplasmic rather than the genetic code. Indeed it is extremely difficult to find clear-cut examples in which the direction of an asymmetry is under genetic control. As one possible case, there is some evidence that the direction, clockwise or counterclockwise, of rotation of the abdomen in certain mutant strains of Drosophila is controlled by a particular gene locus, although there appears to be some degree of confusion on this point. By contrast, it is much easier to find examples in which the degree but not the direction of asymmetry is under genetic control. For instance, there is a mutant strain of mice in which half of the animals display situs inversus of the viscera. The proportion has remained at one half despite many years of inbreeding, suggesting that the mutant allele effectively cancels the normal situs and allows the asymmetry to be specified in random fashion.Although this account does not deny that the right hemisphere of humans may be the more specialized for certain functions, it does attribute a leading or dominant role to the left hemisphere (at least in most individuals). We suggest that so-called “right-hemisphere” functions are essentially acquired by default, due to the left hemisphere's prior involvement with speech and skilled motor acts; we note, for instance, that these right-hemisphere functions include rather elementary perceptual processes. But perhaps the more critical prediction from our account is that the phenomenon of equipotentiality should be unidirectional: the right (lagging) hemisphere should be more disposed to take over left-hemisphere functions following early lesions than is the left (leading) hemisphere to take over right-hemisphere functions. We note preliminary evidence that this may be so.


Sign in / Sign up

Export Citation Format

Share Document