Cortical locus of coherent motion deficits in deaf poor readers

Samar and Parasnis [Samar, V. J., & Parasnis, I. (2005). Dorsal stream deficits suggest hidden dyslexia among deaf poor readers: correlated evidence from reduced perceptual speed and elevated coherent motion detection thresholds. Brain and Cognition, 58, 300-311.] reported that correlated measures of coherent motion detection and perceptual speed predicted reading comprehension in deaf young adults. Because deficits in coherent motion detection have been associated with dyslexia in the hearing population, and because coherent motion detection is strongly dependent on extrastriate cortical area MT, these results are consistent with the claim that hidden dyslexia occurs within the deaf population and is associated with deficits in MT. However, coherent motion detection can also be influenced by subcortical deficits in both magnocellular and parvocellular pathways. To confirm the putative cortical locus of coherent motion perception deficits, we measured contrast thresholds for detecting the direction of movement of drifting sine wave gratings in the same participant group as [Samar, V. J., & Parasnis, I. (2005). Dorsal stream deficits suggest hidden dyslexia among deaf poor readers: correlated evidence from reduced perceptual speed and elevated coherent motion detection thresholds. Brain and Cognition, 58, 300-311.], under stimulus conditions that selectively biased for input from the subcortical magnocellular and parvocellular pathways, respectively. Contrast thresholds were not related to reading comprehension performance under either the magnocellular or parvocellular conditions. Furthermore, the previously reported correlations among reading comprehension, coherent motion thresholds, and perceptual speed remained significant even after contrast thresholds and non-verbal IQ were controlled in partial correlation analyses. In addition, coherent motion detection thresholds were found to correlate specifically with a reading-IQ discrepancy score, one commonly used indicator of dyslexia. These results provide direct psychophysical evidence that the previously reported deficit in coherent motion detection in deaf poor readers does not involve subcortical pathway deficits, but rather is associated with a cortical deficit likely involving area MT. They also strengthen the argument for the existence of hidden dyslexia in the deaf adult population.     

An exploratory assessment of cultural sensitivity in the practices of Lebanese researchers in the field of psychology: implications for national development efforts

The inclusion of the social and cultural characteristics of groups in the concept of national development highlights the contributions that culturally sensitive psychological research can make to development efforts. It also highlights the relevance of assessing and promoting such research, especially in majority world countries where development needs are pressing. In the current study, a content analysis was conducted to assess the degree to which Lebanese psychological researchers in post-civil war Lebanon have engaged in culturally sensitive research practices. The Cultural Sensitivity Measure for Published Research, which was inspired by Adair, Puhan, and Vohra's ( 1993 ) measure of indigenization, was applied to 54 peer-reviewed English- and French-language empirical studies conducted by Lebanese researchers on Lebanese samples within Lebanon. The results suggest that while cultural sensitivity levels were generally low, the sampled researchers engaged in more sensitive practices compared to researchers in the region. For example, they used qualitative methods more often, made more efforts to ensure the cultural compatibility of their methods, and engaged in more complex conceptualizations of culture and its relationship with psychological processes. Furthermore, certain practices, such as studying diverse groups or using findings to suggest real-life applications, were found to be predictive of higher general levels of cultural sensitivity in the sampled articles. These research practices could be fostered in institutional and intellectual contexts, and such initiatives would go a long way in supporting a locally appropriate research infrastructure that contributes to national development efforts.