For example, neuroimaging studies suggest that the two hemispheres might play different roles in emotion processing, with the left hemisphere showing somewhat greater activation for happy or positive emotions and the right hemisphere showing more activity during negative emotional processing. One particularly interesting insight that neuroimaging has given us is the finding that white matter tracts, or the wiring diagram of the two hemispheres, is different.
The wiring of the right hemisphere has been called more efficient because it has greater connectivity between regions. Think of a city with a really good subway system, like Manhattan, making it easy to get from one side of the city to another. The left hemisphere, in contrast, seems to be more modular. Learn more about how your brain works. Here, people are looking for evidence for the association between the right brain and creativity, and the left brain and logic point to these wiring differences.
If the right brain is more interconnected, does that make it easier for it to generate new ideas, finding new connections between remotely associated concepts? Not so fast. Neuroimaging research has also shown us just how communicative the two hemispheres are. Unless that connection between them is physically severed, information is zipping across the hemispheres during the vast majority of tasks that we ask our brains to accomplish. In many regions, signals pass from one hemisphere to the other more quickly than they do within a single hemisphere—that is, some signals from the left and right prefrontal cortex can be exchanged more efficiently than signals from the back to the front of the brain in the same hemisphere.
Common theory suggests that the left brain is needed for more logic-based skills such as learning a language and mathematics, while the right brain is needed for creative tasks such as art, as well as connecting to others on an emotional level. Supposedly, people whose left brain is more dominant tend to be more logical and better at science and mathematics than those who are more right-brain dominant.
A commonly-held belief is that analytical people think more with the left side of their brain while artistic or intuitive people lean more heavily on the right side of their brain for support. The two hemispheres communicate with one another through the corpus callosum. The corpus callosum is a wide, flat bundle of neural fibers beneath the cortex that connects the left and right cerebral hemispheres and facilitates interhemispheric communication.
The corpus callosum is sometimes implicated in the cause of seizures; patients with epilepsy sometimes undergo a corpus callostomy, or the removal of the corpus callosum. The brain is divided into four lobes, each of which is associated with different types of mental processes.
Clockwise from left: The frontal lobe is in blue, the parietal lobe in yellow, the occipital lobe in red, and the temporal lobe in green. The frontal lobe is associated with executive functions and motor performance. Executive functions are some of the highest-order cognitive processes that humans have. Examples include:. The frontal lobe is considered to be the moral center of the brain because it is responsible for advanced decision-making processes. It also plays an important role in retaining emotional memories derived from the limbic system , and modifying those emotions to fit socially accepted norms.
The temporal lobe is associated with the retention of short- and long-term memories. It processes sensory input including auditory information, language comprehension, and naming. It also creates emotional responses and controls biological drives such as aggression and sexuality.
The temporal lobe contains the hippocampus , which is the memory center of the brain. The hippocampus plays a key role in the formation of emotion-laden, long-term memories based on emotional input from the amygdala. Materials provided by Ruhr-University Bochum. Note: Content may be edited for style and length.
Science News. Left hemisphere language dominance Using a simple experiment, researchers can demonstrate just how superior the left hemisphere is when it comes to the processing of auditory speech: when playing two different syllables -- for example "Da" and "Ba" -- to a person's left and right ear via headphones, most people will state that they only heard the syllable in the right ear. Higher speed thanks to more neurites The result: test participants who were capable of processing auditory speech in the left hemisphere at a high speed possessed an extraordinarily high number of densely packed neurites in the left planum temporale.
Neurite architecture of the planum temporale predicts neurophysiological processing of auditory speech. Science Advances , ; 4 7 : eaar DOI: ScienceDaily, 12 July Ruhr-University Bochum. Why the left hemisphere of the brain understands language better than the right.
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