P&B 4

1. P&B 4 Amber Gerdman & Alyssa Reck

2. Discuss two effects of the environment on physiological processes.

3. Neuroplasticity • Neuroplasticity: a neuroscience term that refers to the ability of the nervous system and the brain in all species to change functionally and structurally as a result of input from the environment. • Your brains ability to change itself is called neuroplasticity • During neuroplasticity there are changes that occur in the structure of the brain due to new situations, experiences, changes in the environment, etc.)

4. Neuroplasticity • When you focus and practice activities the brain morphs to grow new connections between cells, and to create new motor and sensory-motor maps for each new activity (neuroplasticity). • Neuroplasticity allows brain cells and nerves to change their appearance and function in new ways. • Sensory deprivation: where a person is deprived of normal external stimuli (like sound or sight) for a long period of time (experimental technique). • http://www.youtube.com/watch?v=84rP844SssY&feature=channel_video_title

5. Paul Bach-y-Rita • Bach-y-Rita believed in sensory susbtitution: if one sense is damaged, other senses can sometimes take over. • He thought skin and its touch receptors could act as a retina (using one sense for another). • “We see with our brains, not with our eyes.”

6. Paul Bach-y-Rita • 1960s, Paul Bach-y-Rita invented device that allowed blind people to read, perceive shadows, and distinguish close and far objects. • The patient sat in an electrically stimulated chair that had a large camera behind it that scanned the area, sending electrical signals of the image to stimulators on the chair on the patient’s skin. • The six participants of the experiment were eventually able to recognize a picture of a supermodel. • For the brain to interpret the sense of touch and convert it into visual information, it has to learn something new and adapt to the new signals. The brain's capacity to adapt implies that it possessed plasticity.

7. Meditation and Neuroplasticity • Aim: to see whether the brain can change in response to only internal, mental signals. • Davidson, a neuroscientist at the University of Wisconsin, has led experiments in cooperation with the Dalai Lama on effects of meditation on the brain. • They compared brain activity in volunteers who were novice meditators to Buddhist monks who had spent more than 10,000 hours in meditation. • The results suggest that long-term, or short-term practice of meditation results in different levels of activity in brain regions associated with the qualities attention, anxiety, depression, anger, the ability of the body to heal itself, etc.

8. Rosenzweig & Bennett (1972) experiment on sensory deprivation • The aim of the study was to investigate the effect of deprivation for rats on the development of neurons in the cerebral cortex. • Procedure: The rats were placed in either a deprived environment or a stimulating environment. The rats spent about 30-60 days in their environment that was chosen for them, and then they were dissected. • Rosenzweig and Bennett found out that the rats that were in the stimulating environment showed an increase thickness in the cerebral cortex.

9. Jet Lag • Jet lag: physiological condition caused by disturbance to the body’s natural circadian rhythm (internal clock). • Jet lag is usually caused by air travel across one or more time zones. • Jet lag can also be caused by shift work. • The effects usually only lasts a few days, but the effects could last longer depending on the disturbance.

10. Jet Lag continued • Circadian rhythm refers to the natural tendency of all living things to operate on a 24 hour cycle. The cycle is based on and influenced by the cycles of darkness and sunlight. • Symptoms of jet lag: fatigue, disorientation, loss of appetite, headaches, insomnia, mild depression, and nausea. • You can take Melatonin supplements to help with jet lag. • Melatonin plays a role in your ‘body clock’ (which regulates various functions). is present in the bloodstream in different amounts depending on the time of day. • Melatonin is produced by the pineal gland (which affects wake/sleep pattern) in darkness; secretion stops when there is light to the eyes.

11. Jet-Lag Experiment • The University of Virginia (2006) • Aim: To see if jet lag and shift work is dangerous • Results: A six-hour shift in time schedule once a week, for up to 8 weeks hastens death in elderly mice. • 53% of elderly mice put on an advanced-time schedule were dead after 8 weeks (it didn’t have much effect on younger mice). • The University of Virginia concluded that internal clock can have serious health consequences

12. SADS • Seasonal Affective Disorder (SAD) is a mood disorder with depressive symptoms: difficulty waking up, morning sickness, overeating and sleeping, and craving for carbohydrates. • Occurs during the dark times of the year when there is relatively little sunshine (sunshine=vitamin D). • Studies indicate that symptoms of SAD may be due to changing levels of vitamin D3, which may affect serotonin levels in the brain. • There are multiple studies to prove this: • Study in the Netherlands found that low levels of Vitamin D correlated with major depression.