Lecture 2 - Neuroimaging
A lot of neuroscientists proclaim that there can be no free will → everything you do, perceive, etc, is
grounded in the brain.
- This is a debatable philosophical standpoint.
Cognitive neuroscience
A field that specifically interested in mind-brain
relations is the field of cognitive neuroscience. This
is a branch of both cognitive psychology and
neuroscience.
- Especially interested in the biological
processes that underlie cognition.
Neuroimaging
- Non-invasive methods
- EEG: Electroencephalography
- Active electrodes on the scalp.
- When neurons fire, they produce tiny electrical currents. EEG measures
electrical activity of large groups of neurons in the cortex. It reflects the
activity of neurons that fire simultaneously.
- Pyramidal cells (neurons) → when a group of these cells fire, there is
a large enough current to be detected
by an EEG.
- The distance between the channels is either 10 or 20% of the total distance
(ear to ear). All the channels are labeled.
- Frontal
- Temporal
- Parietal
- Occipital
- EEG waveforms reflect some type of psychological state.
- Gamma waves are associated with problem solving and
concentration
- Beta waves are associated with active behavior, but less so than
gamma waves
- Alpha waves are more reflective, restful.
- Theta waves are associated drowsiness
- Delta waves are associated actual sleeping and dreaming.
- You want to see the response to a certain stimulus.
- The electrical potential is related to an event
→ event related potential
- You have to present a stimulus
repeatedly, because there is a lot of
noise in the data (muscle activity,
eye movements). By averaging a
large number of trials, the
background noise is cancelled.
- ERP:
- P1 - first positive peak
- N1 - first negative peak
A lot of neuroscientists proclaim that there can be no free will → everything you do, perceive, etc, is
grounded in the brain.
- This is a debatable philosophical standpoint.
Cognitive neuroscience
A field that specifically interested in mind-brain
relations is the field of cognitive neuroscience. This
is a branch of both cognitive psychology and
neuroscience.
- Especially interested in the biological
processes that underlie cognition.
Neuroimaging
- Non-invasive methods
- EEG: Electroencephalography
- Active electrodes on the scalp.
- When neurons fire, they produce tiny electrical currents. EEG measures
electrical activity of large groups of neurons in the cortex. It reflects the
activity of neurons that fire simultaneously.
- Pyramidal cells (neurons) → when a group of these cells fire, there is
a large enough current to be detected
by an EEG.
- The distance between the channels is either 10 or 20% of the total distance
(ear to ear). All the channels are labeled.
- Frontal
- Temporal
- Parietal
- Occipital
- EEG waveforms reflect some type of psychological state.
- Gamma waves are associated with problem solving and
concentration
- Beta waves are associated with active behavior, but less so than
gamma waves
- Alpha waves are more reflective, restful.
- Theta waves are associated drowsiness
- Delta waves are associated actual sleeping and dreaming.
- You want to see the response to a certain stimulus.
- The electrical potential is related to an event
→ event related potential
- You have to present a stimulus
repeatedly, because there is a lot of
noise in the data (muscle activity,
eye movements). By averaging a
large number of trials, the
background noise is cancelled.
- ERP:
- P1 - first positive peak
- N1 - first negative peak
