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Effects of Deprivation on Neuroplasticity. BY: Tamsin, Celina, Rosie and Romi. Neuroplasticity. The brains ability to develop and change in response to the environment The brain rearranges connections between the neurons which means that the structure of the brain is changed
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Effects of Deprivation on Neuroplasticity BY: Tamsin, Celina, Rosie and Romi
Neuroplasticity • The brains ability to develop and change in response to the environment • The brain rearranges connections between the neurons which means that the structure of the brain is changed • It can change the functional qualities of various brain structures • Plasticity occurs wherever neuro-processing happens
Factors that affect neuroplasticity • The changes that occur in the structure of the brain during neuroplasticity is a result of either: • Learning • Experience • New situations • Changes in the environment • High levels of stimulation
Sensory Deprivation • The intentional removal of stimuli affecting one or all of the 5 human senses • Vision, hearing, smell, taste and touch • Can be used as a form of relaxation and meditation • Can also be used for interrogation or torture
Sensory Deprivation • Just 15 minutes of near-total sensory deprivation can bring on hallucinations in many otherwise sane individuals.
“Total Isolation” • Six ordinary people are taken to a nuclear bunker and left alone for 48 hours. • Three subjects are left alone in dark, sound-proofed rooms, while the other three are given goggles and foam cuffs, while white noise is piped into their ears.
“Total Isolation” • Prior to isolation, the volunteers underwent tests of visual memory, information processing, verbal fluency and suggestibility • After, they spent two days and two nights in isolation the subjects noted that their inability to sense time and the hallucinations and visions that they experienced made the 48 hours inside the cell very difficult on their mind.
Strengths • Same test were conducted before and after the experiment. • Supports the hypothesis that sensory deprivation affects neuroplasticity. • Experiment was conducted on humans. • Each person was put through the same conditions.
Weaknesses • 2 women and 4 men • Age not specified • Demand characteristics • The participant variables could not controlled (e.g. personal experiences) • Can’t look at the brains of the humans (not ethical) • Not repeated • We don’t know what they mean by ‘ordinary’ people • Cannot be generalized to the population due to the small sample size
Hallucinations in sensory deprivation after 15 minutes • Sensory deprivation lasting only 15 minutes is enough to trigger hallucinations in healthy members of the public • This was proven during a new study published in the Journal of Nervous and Mental Disease.
Hallucinations in sensory deprivation after 15 minutes • In this study a large number of participants were used • They were given a questionnaire that asked them about hallucinatory experiences in everyday life • On the basis of this, they recruited two groups: one of ‘high’ hallucinators and another of ‘low’ hallucinators.
Hallucinations in sensory deprivation after 15 minutes • They then put the participants, one by one, in a dark Anechoic chamber which shields all incoming sounds and deadens any noise made by the participant. The room had a ‘panic button’ to stop the experiment but no-one needed to use it.
Hallucinations in sensory deprivation after 15 minutes • They asked participants to sit in the chamber for 15 minutes and then, immediately after, used a standard assessment to see whether they’d had an unusual experiences. • After a twenty minute break, they were asked again about any changes in their perception to see if there were any difference when normal sensation was restored.
Hallucinations in sensory deprivation after 15 minutes • Hallucinations, paranoid thoughts and low moods were reported more often after sensory deprivation for both groups • People who already had a tendency to have hallucinations in everyday life had a much greater level of perceptual distortion after leaving the chamber than the others. • One subject's memory capacity fell 36% and all the subjects had trouble thinking of words beginning with the letter "F". All four of the men (neither of the two women) had markedly increased suggestibility
Strengths • It was ethical as it went for 15 minutes • The participants could press the ‘panic button’ if they wanted to end the experiment which shows that there were withdrawal rights • They consented
Weaknesses • There is no specific number of people that took part in the experiment • We don't know if there were both males and females • We don’t know their ages
References • http://memoryzine.com/2010/07/02/introduction-to-neuroplasticity/ • http://www.wisegeek.com/what-is-sensory-deprivation.htm • http://www.medterms.com/script/main/art.asp?articlekey=40362 • http://mindhacks.com/2009/10/19/hallucinations-in-sensory-deprivation-after-15-minutes/ • http://www.wired.com/wiredscience/2009/10/hallucinations/