educed capacity to communicate with each other. This led to many interesting behavioral phenomena that allowed Gazzaniga and Sperry to study the contributions of each hemisphere to various cognitive and perceptual processes. One of their main findings was that the right hemisphere was capable of rudimentary language processing, but often has no lexical or grammatical abilities. Eran Zaidel also studied such patients and found some evidence for the right hemisphere having at least some syntactic ability.
Language is primarily localized in the left hemisphere. One of the experiments carried out by Gazzaniga involved a split-brain patient sitting in front of a computer screen while having words and images presented on either side of the screen and the visual stimuli would go to either the right or left visual field, and thus the left or right brain, respectively. It was observed that if a patient was presented with an image to his left visual field (right brain), he would report not seeing anything. If he was able to feel around for certain objects, he could accurately pick out the correct object, despite not having the ability to verbalize what he saw. This led to confirmation that the left brain is localized for language while the right brain does not have this capability, and when the corpus callosum is cut and the two hemispheres cannot communicate for the speech to be produced.
Popular psychology considers each hemisphere a unique brain that is called upon to serve their lateralized functions. This belief has led to ideas such as ‘right-brain and left-brain’ dominating popular belief. This stance, however, is rooted in the misinterpretation of studies done in the early 2000s and has since been fully disproven. Ironically these ideas held denote LHS as the 'logical brain' and RHS as the 'creative brain' which, even in the most generalized sense, is opposite the truth.
Significant differences between male and female hemispheric rivalry and dominance have been established. Male brains have significantly better global and rivalry efficiency between the hemispheres, whereas female brains possess considerably better local efficiency within the RHS.
Handedness has been implicated in determining which hemisphere is naturally dominant. Due to decussation the dominant hemisphere is opposite to the main hand/foot. Left-handed and ambidextrous individuals have been shown to have more efficient hemispheric interactions.
Damage to the RHS has been shown to drastically increase the likelihood of self-inflicted harm and suicide as calculative ideas such as the prospect of future are lost. RHS damage has also been shown to drastically decrease social performance and appropriateness as these behaviors stem from inhibition of boisterous activities which is no longer possible in these patients.
Lateralized cognitive processes
For example, structurally, the lateral sulcus generally is longer in the left hemisphere than in the right hemisphere, and functionally, Broca's area and Wernicke's area are located in the left cerebral hemisphere for about 95% of right-handers, but about 70% of left-handers.
Language functions such as grammar, vocabulary and literal meaning are typically lateralized to the left hemisphere, especially in right handed individuals. While language production is left-lateralized in up to 90% of right-handed subjects, it is more bilateral, or even right lateralized in approximately 50% of left-handers. In contrast, prosodic language functions, such as intonation and accentuation, often are lateralized to the right hemisphere of the brain.
The processing of visual and auditory stimuli, spatial manipulation, facial perception, and artistic ability are represented bilaterally. Numerical estimation, comparison and online calculation depend on bilateral parietal regions while exact calculation and fact retrieval are associated with left parietal regions, perhaps due to their ties to linguistic processing. Dyscalculia is a neurological syndrome associated with damage to the left temporo-parietal junction. This syndrome is assoc