Recent studies have made substantial progress in understanding the interactions between cognitive functions, from language to cognitive control, attention, and memory. However, dissociating these functions has been ha...Recent studies have made substantial progress in understanding the interactions between cognitive functions, from language to cognitive control, attention, and memory. However, dissociating these functions has been hampered by the close proximity of regions involved, as in the case in the prefrontal and parietal cortex. In this article, we review a series of studies that investigated the relationship between language and other cognitive functions in an alternative way - by examining their functional （co-）lateralization. We argue that research on the hemispheric lateralization of language and its link with handedness can offer an appropriate starting- point to shed light on the relationships between different functions. Besides functional interactions, anatomical asymmetries in non-human primates and those underlying language in humans can provide unique information about cortical organization. Finally, some open questions and criteria are raised for an ideal theoretical model of the cortex based on hemispheric specialization.展开更多
Interhemispheric disconnection syndrome (IDS), described by Sperry, Gazzaniga and Bogen, is characterized by the presence of visual and tactile anomia, absence of interhemispheric transference of unilateral somatosens...Interhemispheric disconnection syndrome (IDS), described by Sperry, Gazzaniga and Bogen, is characterized by the presence of visual and tactile anomia, absence of interhemispheric transference of unilateral somatosensory stimulation of both hands, hemialexia and unilateral left-side apraxia. Subsequently, changes were also observed in the sensory interhemispheric transfer and in tests of crossed motor control. In Marchiafava-Bignami disease (MBD) there have been descriptions of partial IDS. The aim is to describe the dissociations in IDS that are presented in a patient with MBD, using a specialized assessment methodology. Patient and Method: A 54-year-old patient, righthanded, with 11 years of schooling, presented with antecedent chronic alcoholism. Neuropsychological tests were administered for general assessment along with specific tests of interhemispheric transference. Results: Borderline changes were found in visual memory, visual-constructive abilities and attention and executive functioning. In tasks of interhemispheric transference the patient showed changes in: the imitation of hand poses;inter-manual pressure point localization (tactile stimulation);reading aloud of words by visual hemifield;and movement control. Conclusion: Our patient showed a wide lesion of the Corpus Callosum (CC) with relative preservation of the splenium, accompanied by partial disconnection syndrome in the context of a global cognitive deterioration from his chronic alcoholism.展开更多
Background:Classic dichotic listening tests using speech stimuli result in right ear advantage,due to the dominant crossed pathway for speech and language.It is presumed that similar crossed dominance could exist for ...Background:Classic dichotic listening tests using speech stimuli result in right ear advantage,due to the dominant crossed pathway for speech and language.It is presumed that similar crossed dominance could exist for non-speech stimuli too.Hence,this is an attempt to develop and validate the dichotic nonspeech test using environmental stimuli and explore the effect of focused attention on this test.Materials and method:Three lists of dichotic stimuli were created using these sounds with fifteen tokens in each list.Four professionals and non-professionals validated these materials.Normative estimation was obtained by administering the newly developed test on 70 adults and 70 children using a free-recall and forced-recall condition.Result:The results showed a significant difference between the left ear and right scores where the left ear score was better than the right,depicting left ear advantage(LEA)for free recall condition in both groups.In the forced recall condition,LEA was not seen;rather the mean score was significantly higher in the attended ear,irrespective of the stimuli presented to the right or left ear.The test-retest reliability in free recall was good in both the ears and moderate for forced right ear conditions.Conclusion:The novel test consistently showed LEA with good reliability and can be used to assess the hemispheric asymmetry in normal subjects and also in test batteries for the clinical population.展开更多
文摘Recent studies have made substantial progress in understanding the interactions between cognitive functions, from language to cognitive control, attention, and memory. However, dissociating these functions has been hampered by the close proximity of regions involved, as in the case in the prefrontal and parietal cortex. In this article, we review a series of studies that investigated the relationship between language and other cognitive functions in an alternative way - by examining their functional （co-）lateralization. We argue that research on the hemispheric lateralization of language and its link with handedness can offer an appropriate starting- point to shed light on the relationships between different functions. Besides functional interactions, anatomical asymmetries in non-human primates and those underlying language in humans can provide unique information about cortical organization. Finally, some open questions and criteria are raised for an ideal theoretical model of the cortex based on hemispheric specialization.
文摘Interhemispheric disconnection syndrome (IDS), described by Sperry, Gazzaniga and Bogen, is characterized by the presence of visual and tactile anomia, absence of interhemispheric transference of unilateral somatosensory stimulation of both hands, hemialexia and unilateral left-side apraxia. Subsequently, changes were also observed in the sensory interhemispheric transfer and in tests of crossed motor control. In Marchiafava-Bignami disease (MBD) there have been descriptions of partial IDS. The aim is to describe the dissociations in IDS that are presented in a patient with MBD, using a specialized assessment methodology. Patient and Method: A 54-year-old patient, righthanded, with 11 years of schooling, presented with antecedent chronic alcoholism. Neuropsychological tests were administered for general assessment along with specific tests of interhemispheric transference. Results: Borderline changes were found in visual memory, visual-constructive abilities and attention and executive functioning. In tasks of interhemispheric transference the patient showed changes in: the imitation of hand poses;inter-manual pressure point localization (tactile stimulation);reading aloud of words by visual hemifield;and movement control. Conclusion: Our patient showed a wide lesion of the Corpus Callosum (CC) with relative preservation of the splenium, accompanied by partial disconnection syndrome in the context of a global cognitive deterioration from his chronic alcoholism.
基金supported by the cognitive science research initiative of the Department of science and technologyGovernment of India Grant ID:DST/CSRI/2017/442.
文摘Background:Classic dichotic listening tests using speech stimuli result in right ear advantage,due to the dominant crossed pathway for speech and language.It is presumed that similar crossed dominance could exist for non-speech stimuli too.Hence,this is an attempt to develop and validate the dichotic nonspeech test using environmental stimuli and explore the effect of focused attention on this test.Materials and method:Three lists of dichotic stimuli were created using these sounds with fifteen tokens in each list.Four professionals and non-professionals validated these materials.Normative estimation was obtained by administering the newly developed test on 70 adults and 70 children using a free-recall and forced-recall condition.Result:The results showed a significant difference between the left ear and right scores where the left ear score was better than the right,depicting left ear advantage(LEA)for free recall condition in both groups.In the forced recall condition,LEA was not seen;rather the mean score was significantly higher in the attended ear,irrespective of the stimuli presented to the right or left ear.The test-retest reliability in free recall was good in both the ears and moderate for forced right ear conditions.Conclusion:The novel test consistently showed LEA with good reliability and can be used to assess the hemispheric asymmetry in normal subjects and also in test batteries for the clinical population.
