Methods of Cognitive Neuroscience Flashcards

Question

Who discovered the EEG and what else did he discover?

Answer 1

Hans Berger in search of "psychic energy" -measured first cerebral blood flow, then electrical potentials -discovered robust alpha and beta EEG waves

Answer 2

Magnetoencephalography (MEG) is an advanced brain scanning technique which can measure brain activity millisecond by millisecond. It specifies the timing and location of neurons’ signals. MEG is helpful in studying and identifying perceptual and cognitive mechanisms and locating brain tissues prior to surgery. For instance, this technique has been used in knowing more about the unique neurological responses of patients with schizophrenia.

Answer 3

Divided into ”classical” frequency bands (i.e. how many ”waves” per second visible in the ongoing EEG) : - delta < 4 Hz - theta 4 8 Hz - alpha 8 12 Hz - beta 12 20 Hz - gamma 20 70 Hz

Answer 4

Event-related potential (ERP) is the measured brain response that is the direct result of a specific sensory, cognitive, or motor event. More formally, it is any stereotyped electrophysiological response to a stimulus. ERPs are measured by means of electroencephalography (EEG).

Answer 5

Transmagnetic cranial stimulation (TMS) is a procedure that uses electromagnetism to stimulate nerve cells in the brain. It is a non-invasive technique which means no surgery or cutting occurs. A large metal coil that has electromagnetic components is placed on the scalp over particular regions of the brain. The electric currents stimulate neural connections in the brain and can help with multiple medical issues. TMS can be used to help with major depression, sclerosis diseases, migraines, neuropathic pain, and schizophrenia. It can also be used to determine the extent of brain damage after a stroke. There are very rare side effects that can occur from TMS such as fainting and seizures.

Answer 6

Transcranial Direct-Current Stimulation (tDCS) is a portable, wearable brain stimulation technique that delivers a low electric current to the scalp. A fixed current between 1 and 2 mA is typically applied1. tDCS works by applying a positive (anodal) or negative (cathodal) current via electrodes to an area. tDCS is a neuromodulation technique that produces immediate and lasting changes in brain function. The position of the anode and cathode electrodes on the head is used to set how current flows to specific brain regions. The current delivered by tDCS is NOT strong enough to trigger an action potential in a neuron; instead its “sub-threshold” changes the pattern of already activity neurons. Think of the brain as active, trying to do or learn something, and tDCS coming along to boost this ongoing activity. At the cellular level2, tDCS changes neuronal firing and by strengthening synaptic transmission between neurons by augmenting synaptic plasticity3 which is, in turn, the cellular basis of learning. tDCS is often combined with training. Training in itself produces learning (synaptic plasticity), and concurrent tDCS amplifies these effects (enhances synaptic plasticity). Some clinical applications tDCS is currently being explored for are depression, schizophrenia, aphasia, addiction4, epilepsy, chronic pain (migraine, fibromyalgia), attention, and motor rehabilitation. tDCS is also used for non-medical wellness applications, for example accelerated learning5, focus, relaxation, and meditation.6

Answer 7

Transcranial Alternating Current Stimulation (tACS) is a device that applies a low-intensity sinusoidal electrical current to the brain through electrodes on the scalp. The technique can be painless and is thought to boost the brain's own oscillations, which can be used to treat disease or enhance brain function. In many ways tACS is similar to tDCS as a neuromodulatory technique, but instead of applying a direct electrical current, tACS oscillates a sinusoidal current at a chosen frequency to interact with the brain’s natural cortical oscillations. Generally, a large electrode is placed over an area of interest which applies stimulation while a reference electrode is placed in a neutral location. When a single, low frequency (< 100 Hz) frequency is applied the exogenous oscillation can synchronize with the brain’s endogenous frequency. This is typically what tACS is. When several oscillations are pulsated, desynchronization of cortical oscillations can occur. As such, tACS effects are contingent on the frequency, amplitude, and phase applied. tACS applied in the EEG frequency range (0.1-80Hz) can entrain neural oscillations, augmenting them. In higher ranges (1-5 kHz), oscillation interaction is unlikely to occur, but cortical excitability has been suggested1. tACS has recently become more popular with more clinical trials and even consumer devices, but it has a history that dates back decades2.

Answer 8

in order to obtain an accurate image of the reality... The resolution of the instrument should be at the same level with the elements of the reality! "seeing is believing" - if we see it we can believe it. But dont get fooled: What do we really see when we look at the results or the colorful images? No technique or method is yet good enough to see the bigger picture or the complete reality of the brain.

Answer 9

Temporal resolution refers to the accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain activity The method or the instrument itself may be slow : it generates or picks up signals at a slow rate (PET) -> low temporal resolution The reality being imaged may be slow to react to changes in neural activity -> low temporal resolution AND questionable validity (fMRI)

Answer 10

Spatial resolution is a term that refers to the number of pixels utilized in construction of a digital image. Images having higher spatial resolution are composed with a greater number of pixels than those of lower spatial resolution.

Methods of Cognitive Neuroscience Flashcards

(34 cards)