Lesson 4 & 5 plasticity of the brain Presentation Transcript
Lesson 4&5: Plasticity of the brain
From the last lesson.....Identify and outline the role of three neurotransmittersinvolved in learning
From the last lesson.....Identify and outline the role of three neurotransmittersinvolved in learningNT’s involved in learning:Glutamate: Strengthens connections at the synapseduring learningDopamine: May be involved through rewarding‘pleasure’ experience.Acetylcholine: Present in some learning experiencesbut speciﬁc role unclear
Plasticity: The ability of the brain to change structure andfunction through experience
Developmental PlasticityDevelopmental Plasticity: changes in the brain’s neural structure inresponse to experience during its growth and developmentGenerally, an infant or a child’s brain will have more plasticity than anadult’s brain. This is referred to as developmental plasticity—the ability ofthese synapses to be modiﬁedDevelopmental plasticity refers to changes in the brain’s neural structure inresponse to experience during its growth and development. This type ofplasticity is predetermined and therefore inﬂuenced by the genes we inherit, butit is also subject to inﬂuence by experience.
Adaptive plasticity refers to changes occurring in the brain’s neuralstructure to enable adjustment to experience, to compensate for lost functionand/or to maximise remaining functions in the event of brain damage.
Case StudyThe case of a 25-year-old adult female who was an accomplishedpianist supports the idea of plasticity. The patient had a stroke that damaged the left hemisphere of her brain. Consequently, she was unable to speak and had lost complete use of her right hand. It was a devastating loss at a young age, and her inability to play the piano only added to the tragedy.She was placed in a rehabilitation program that involved repeated attempts toengage the right side of her body, including speech therapy and pianoplaying. After several months of rehabilitation, she regained nearly full use ofher right hand, and she was again able to speak.Furthermore, she also demonstrated exceptionally rapid ﬁnger movements inboth hands, displaying speed and coordination beyond those of the average(non-stroke-affected) person. Today she has resumed her piano playing and hasfully recovered her abilities to the virtuoso levelsattained before the stroke (Azari & Seitz, 2009).
Implications of Brain Plasticity
Sensitive or Critical PeriodsCertain periods in an individual’s development are particularly well suited tolearning certain skills and gaining knowledge. These periods are calledsensitive or critical periods. A sensitive period is a speciﬁc period of time indevelopment when an organism is more responsive (or ‘sensitive’) to certainenvironmental stimuli or experiences.
LanguageSensitive periods are sometimes described as ‘windows of opportunity forlearning’ because they are the optimal, or ‘best possible’, times for therelevant learning to occur.For example, certain skills and knowledge, such as those of languageacquisition, are believed to be more easily acquired during a sensitiveperiod in development. If these skills and knowledge are not acquiredduring the sensitive period, they may be acquired at a later time but it willusually take more time, be more difﬁcult and the learning may not be assuccessful. In relation to language learning, psychologists are not in complete agreement about the age limits for the sensitive period. Generally, the sensitive period for our native language is up to the age of about 12 years, with the window gradually closing from about age seven.
The use of imaging TechnologiesNeuroimaging technologies, particularly MRI, PET, fMRI, and TMSenable researches to study changes in the brain associated with learning.Research by Elbert (1995) used MRI recordings to reveal that experienced violinists whodo elaborate movements on the strings with their left hands had a larger righthemisphere somatosensory area devoted to these ﬁngers than did non-musicians.