Split-brain research into hemispheric lateralisation -A-Level Psychology
Hemispheric lateralisation:
The idea that the two halves of the brain are functionally different and certain mental processes and behaviours are mainly controlled by one hemisphere e.g language
RIGHT SIDE-drawing,spatial tasks,facial recognition
LEFT SIDE-music,analytical tasks,language,viewing objects in the right field.
Split brain research:
Sperry (1968) observed the brains of those who had their corpus callosum surgically removed to deal with epileptic seizures.This meant that the main communication line between the two hemispheres was removed.From this Sperry was able to study the extent to which the two hemispheres are specialised for certain functions and whether the hemispheres performed tasks independently of one another.
Procedure:
Sperry devised a general procedure in which an image/word was projected to the right visual field(processed by the left hemisphere) or the left visual field(processed by the right hemisphere).
Normally,the corpus callosum would share the info between both hemispheres giving them a complete picture of the visual world.The patients were unable to convey info from one hemisphere to another.
Key findings:
Describing what you see-when an image was shown in the right visual field the patient could easily say what they saw.If the same image was shown in the left visual field the patient could not say what was seen.As language is processed in the left hemisphere,the patient’s inability to describe what they saw was due to this.The image was not able to be processed in the right hemisphere.
Although patients could not attach verbal labels to objects in the left visual field they could select a matching object with their left hand.
Composite words- when two words were presented simultaneously,the patient would select a key with their left hand and say the word ring.left visual field -key,right visual field-ring
Evaluation:
Issues with generalisation-unusual sample of people (11)who had a history of epileptic seizures.Findings may have been influenced by the unique changes in the brain instead and some patients experienced more disconnection of the two hemispheres as part of their surgical procedures than others.
Methodology-used high specialised and standardised procedures so experiment used a well-controlled procedure.Typically Pps stared at a fixation point where a image would flash for 1/10 of a second so there was no time for the eyes to be moved across both visual fields but by Sperry’s method of presenting visual info to one hemispheric field at a time was more useful at making sure only one hemisphere was receiving info at a time.
Hemispheric lateralization is the idea that the two halves (hemispheres) of the brain are specialized for different functions. The left hemisphere is typically associated with language, logic, and analytical thinking, while the right hemisphere is more involved in creativity, spatial awareness, and emotional processing.
Split-brain research is a type of study where the connection between the two hemispheres of the brain is surgically severed, typically to treat severe epilepsy. This allows researchers to study how the two hemispheres function independently and how they communicate with each other.
Split-brain studies have shown that the two hemispheres of the brain can operate independently and have different abilities. For example, the left hemisphere is better at language tasks, while the right hemisphere is better at tasks that involve spatial awareness and facial recognition.
Split-brain research is an important area of study in cognitive psychology, which is a core topic in A-Level Psychology. Understanding the functions of the two hemispheres of the brain and how they communicate is essential to understanding cognitive processes such as perception, memory, and language.
Yes, hemispheric lateralization can change over time, especially in response to environmental factors such as injury or training. For example, individuals who are blind from birth may develop enhanced abilities in auditory processing in their left hemisphere.
Split-brain research has led to important insights into the functions of the brain and has been used to develop treatments for conditions such as epilepsy. It has also been used to improve understanding of language processing, perception, and memory, which has implications for education, communication, and cognitive rehabilitation.
Yes, there are ethical concerns related to split-brain research, particularly regarding informed consent and the potential risks and benefits of the procedure. Researchers must ensure that participants fully understand the risks and benefits of the study and that they are not coerced into participating. Additionally, researchers must ensure that the procedure is performed in a safe and ethical manner.
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