Cognitive neuroscience Flashcards
Lesion studies
Allows for causality inferences. De-activate a brain area believed to be involved in a task and see if person can still complete task. Disadvantages in generalising from animals to humans and from individuals to groups.
PET and fMRI
Positron Emission Tomography and functional Magnetic Resonance Imaging allow for localisation of processes in the brain. Rely on the assumption that blood flow in the brain indicates which parts of the brain are being used. Therefore PET and MRI are able to quantify the blood flow in specific brain regions during psychological tasks. Requires subtraction of control from task to ensure no irrelevant stimuli are contributing to brain activity. Advantages: Good spatial resolution. Disadvantages: poor temporal resolution.
EEG
Electroencephalography measures electrical activity in the brain using electrodes. Greater number of electrodes = greater accuracy. Advantages: Good temporal resolution. Disadvantage: noisy as measuring activity on surface of scalp and hair. Poor spatial resolution.
Types of brain waves
Delta - unconscious - instinct, survival and deep sleep
Theta - unconscious - emotion, dreamlike state, sleepy
Alpha - conscious - consciousness, awareness of body, integration of feelings
Beta - conscious - thought, perception, concentration and mental activity
Gamma - conscious - will - extreme focus, energy and ectasy
MEG
Magnetoencephalography records magnetic waves on surface of brain generated by small intracellular electrical currents in neurons of the brain. Conducted using a sensitive device called a SQUID (superconducting quantum interference device). Better at locating site of brain activity than EEG.
TMS
Transcranial magnetic stimulation involves stimulating the brain with a magnetic impulse to disrupt cortical processing. Involved in diagnosis and therapy. Magnetic coil either excites or inhibits neurons.
