Biopsychology Year 2

What is plasticity?

• This is the theory that the Bain is always changing and developing

  • although slower with age the brain can change development and learn at any age.

What is functional recovery?

• Functional recovery refers to the process of regaining lost abilities or skills after an illness, injury, or disability.

• The brain does the by forming new neural connections

What were Sperry’s method?

• Quasi experiment

• 11 ppts who had their corpus callosum cut due to severe epilepsy

• In the visual tests, images were flashed into their left or right visual field for a 1/10 of a second and they were asked to name, describe or draw the objects.

• In the tactile test, objects were placed in either their left or right hand behind a screen

Explain Sperry’s findings

• information in the right visual field (LH) could be described in speech and writing

• if the same information was presented to the left visual field (RH) it could not be described in speech or writing

• Objects placed in the right hand (LH) could be described in speech or writing.

• If the same objects were placed in the left-hand (RH), participants guessed and sometimes seemed unaware they were holding anything.

What was Sperry’s conclusion?

Language is processed in the left hemisphere of the brain

Evaluate Sperry’s research?

• Strengths:

  • Controlled and standardised - reliable

• Limitations:

  • small sample

  • individual differences

  • Lack of ecological validity

What’s was Maguire’s procedure?

• A natural experiment.

• Using an MRI scanner, the researchers calculated the amount of grey matter in the brains of taxi drivers and a set of control participants

What was the findings and the conclusion?

• Results

  • The hippocampi of taxi drivers were significantly larger relative to those of controls and hippocampal volume was positively correlated with the amount of time they had spent taxi driving.

• Conclusion.

  • This demonstrates brain plasticity. The structure of the brain can change in response to the demands placed upon it

What is a Magnetic Resonance Imaging (MRI) scan?

• Your body is placed inside a large magnet, which makes the hydrogen atoms in your body line up in a certain way.

• The machine sends radio waves into your body, knocking the hydrogen atoms out of alignment.

• As the atoms return to their original positions, they send out signals.

• A computer processes these signals and creates highly detailed images of your organs, tissues, and bones

What is a Functional Magnetic Resonance Imaging (fMRI) scan?

• Detects changes in oxygen levels in the blood

• Areas in the brain that are more active require more oxygenated blood and this can be identified by the fMRI

What are advantages of the fMRI?

• It has good spacial resolution which means it can detect differences in structure and functions of the brain

  • e.g fMRI can distinguish within the millimetre range

What are the advantages of fMRI?

• poor temporal resolution cannot detect changes in the brain resolution over time

• expensive

• patients have to sit still in an enclosed space for long periods of time

What is an Electroencephalogram (EEG)?

• Useful for overall brain activity

• Electrodes are placed on the scalp

• waves patterns are generated

  • different wave patterns are created as a result of different stimuli

  • They are often used in sleep studies

What are advantages of EEG?

• High temporal resolution - shows changes in brain over time

• subtle differences across seconds can be recorded

what are disadvantages of EEG?

• poor spatial resolution meaning they cannot show brain activity in specific parts of the brain

What is an event related potential scan (ERP)?

• Electrical activity in the brain is generated as a result of a stimuli

  • an EEG is used to study these waves

What is a post mortem?

• This is when the brain is examined after death

What are advantages of post mortem examinations?

What are the disadvantages of a post mortem

What are infradian rhythms?

• occur over a time period longer than 24 hour

  • e.g. menstrual cycle

What are Ultradian rhythms?

• rhythms that happen more than once over a 24 hour period

  • pulse, heart rate, blood circulation

What are circadian rhythms?

• rhythms that happen in a 24 hour time period

  • sleep wake cycle

  • core body temperature

Endogenous pacemaker (sleep cycle)

• Internal factors which effect the sleep wake cycle