Methods in biological psychology

• Invasive methods are techniques that directly interact with or manipulate the brain or nervous system for research purposes such as surgeries, electrical stimulation, and the use of invasive electrodes to study neural activity and behaviour.
• Hypothesis: Alternating exchange of information between hippocampus and cortex during sleep, modulated by acetylcholine, a neurotransmitter that plays a role in regulating sleep and memory.
• Non-invasive methods are techniques that do not require direct physical interaction with the brain or nervous system such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and transcranial magnetic stimulation (TMS).
• Single-cell recordings involve placing electrodes in the brain to directly measure the activity of individual neurons.
• The action potential is directly measured in the single-cell recording method.
• Single-cell recordings can be obtained by implanting a very small electrode into the axon itself or outside the membrane.
• In single-cell recordings, the number of action potentials produced in response to a stimulus is counted.
• Single-cell recordings are used to study neural activity and understand how specific cells contribute to brain function and behaviour.
• Electroencephalography (EEG) is used to measure electrical activity of the brain.
• Electrodes are placed on the scalp to detect and record the brain’s electrical signals in EEG.
• The EEG signal reflects the sum of electrical events throughout the head, including action potentials and post-synaptic potentials.
• A very small signal is amplified many times before it is fed through to a monitor and seen as an EEG wave.
• Electroencephalography (EEG) is a non-invasive method.
• When we're awake and alert, EEG recordings show desynchronized activity, meaning that neurons are firing independently.
• REM sleep follows a regular 90 min cycle of REM sleep alternating with slow-wave sleep.
• REM sleep is when we experience vivid dreams.
• EEG is commonly used in research and clinical settings to study brain activity and diagnose certain neurological conditions.
• When wakened from REM sleep, subjects report that they have been dreaming.
• When we're resting or asleep, EEG recordings show synchronized activity, meaning that neurons fire together in waves.
• This pattern of synchronized activity creates different patterns that correspond to different stages of sleep.
• The desynchronized EEG during REM sleep is associated with the rapid eye movements that occur during REM sleep.
• During REM sleep, the EEG shows desynchronized activity, meaning that the brain waves become irregular, similar to when we're awake.
• During REM sleep, there is a loss of muscle tone, causing our muscles to become relaxed, a protective mechanism that prevents us from acting out our dreams.
• Rapid eye-movements are associated with dreaming during REM sleep.
• REM sleep is paradoxical because even though the body is in a state of deep sleep, the brain shows high levels of activity, similar to when we're awake.
• This pattern of desynchronized activity reflects the active and dynamic state of the brain during wakefulness.
• REM sleep, also known as paradoxical or D sleep, was first discovered by Kleitman and Dement in the late 1950s.
• Sleep plays a crucial role in the consolidation of memories.
• During sleep, our brain processes and strengthens the memories we formed while awake.
• When the hippocampal-cortical network is reactivated during sleep, it can lead to the progressive strengthening of cortico-cortical connections.
• Event-related potentials (ERPs) are electrical brain responses that are measured using electroencephalography (EEG).
• ERPs reflect the brain's activity in response to specific events or stimuli.
• ERPs provide valuable information about cognitive processes, such as attention, perception, and memory.
• ERPs measured at 6-10 months of age can potentially predict shifts in eye gaze associated with autism at 36 months.
• ERPs differed between the two gaze conditions in typically developing infants, but not in infants who later developed autism.
• Understanding these differences can help in early identification and intervention.
• MEG is a technique used to measure the magnetic fields produced by electrical activity in the brain.
• All electrical currents have a magnetic field, including the electrical currents in the brain.
• MEG uses superconducting devices called SQUIDS to detect very small changes in the magnetic field.
• MEG has very good temporal resolution (like EEG), but better spatial resolution than EEG (allows researchers to pinpoint brain activity with more precision).