In addition, there’s less asymmetry of the planum temporale and Silvian fissure or lateral sulcus. Firstly, there’s a higher proportion of left-handers. Thus, several studies revealed that people affected by schizophrenia have several common characteristics. Schizophrenia alters some cognitive functions such as attention, working memory, and executive functions. Some of the suggested ones have been asymmetries in the interhemispheric activation or arousal, and memory and attentional effects, which are the most studied.ĭichotic listening applied to schizophrenia Such processes are different from those related to language lateralization. Several authors have proposed that the REA obtained under dichotic listening could reflect other cognitive processes. Influence of attention on dichotic listening

This affects the trace quality and results in responses with higher latency or with a greater number of errors. Then, they go through the transcellular pathway to the left hemisphere to be decoded from there. Meanwhile, the information received by the left ear must travel the contralateral pathways to get to the right hemisphere. Therefore, based on these conclusions, REA is due to the fact that the information received by the right ear travels a shorter and more direct path to the left hemisphere (contralateral pathways). Moreover, clinical and neurophysiological evidence indicates that the language is present in the left hemisphere. As a consequence, only the contralateral pathways remain functional. The first assumption is that, as mentioned above, the ipsilateral pathways inhibit. This advantage of the right ear is explained by Doreen Kimura under two assumptions. This is referred to as the right ear advantage (REA). It’s a common result for the subject to identify a greater number of syllables in the right ear than the left. All under a dichotic listening condition.Ī standard dichotic listening test consists of a relatively high number of dichotic syllables. It then happens that, if there’s an injury in any of the cerebral hemispheres, one can observe a deficit in the ear contralateral to the injury. Thus, the information received in one ear passes exclusively to the opposite cerebral hemisphere. During dichotic listening, the ipsilateral pathways inhibit. Thus, the information received by each ear projects on both cerebral hemispheres. In this technique, the projections of the auditory pathway to the motor cortex are ipsilateral and contralateral. In addition, other parameters might vary, such as the interval between and within stimuli, and the number of presentations and intensity. The stimuli presented can vary from words to syllables, to letters, and even to musical sounds. What exactly is dichotic listening?ĭichotic listening is a technique based on the simultaneous presentation of two different auditory stimuli, one in each ear. Meanwhile, the right hemisphere is responsible for visuospatial processing, the perception of objects and faces.

The left hemisphere specializes in language, and this hemisphere is responsible for grammatical processing and speech. That’s the relative predominance of one hemisphere or another for certain cognitive functions. This technique is used during research on functional hemispheric specialization. Dichotic listening is a behavioral technique based on perceptual laterality that’s commonly used in neuropsychology.

Selective listening