Lecture 1 – Adolescent development from a neuroscience perspective
The lecture started with a quiz to test our basic knowledge. The answers:
1. The following methods were the first that studied the brain, and were established in +/- the 19 th century:
1) post-mortem studies, 2) phrenology, and 3) lesion studies. Which method(s) yielded valuable
knowledge about the brain that is still valid/being used? Answer: 1 and 3
2. What is the blue lobe called? Answer: the parietal lobe
3. The brain consists of gyri and sulci to increase the surface of the cortex. What are 1 and 2 called?
Answer: 1 = gyrus and 2 = sulcus
4. For each of the following statements, indicate whether it applies to white matter (WM) or grey matter
(GM) in the brain:
a. Connections between brain areas
b. Consists of neuronal cell bodies
c. Surface of cerebral cortex & cerebellum
d. Is myelinated
e. In subcortical structures
Answer: WM = a + d; GM = b + c + e
5. Which part of a neuron enables enhanced/optimal neurotransmission? Possible options: axon, synapse,
glia, myoline, neurotransmitter, myelin, dendrite, soma. Answer: myelin.
6. Which part of a neuron conducts electrical impulses? Possible options: axon, synapse, glia, myoline,
neurotransmitter, myelin, dendrite, soma. Answer: axon.
7. “With age, there are changes in brain function but no changes in brain structure”. Is this statement correct
or incorrect? Answer: incorrect.
8. Who has more brain cells, an 11 year old or an adult? Answer: an11 year old.
9. What happens with grey matter during adolescence? Answer: it decreases.
10. What’s the global pattern of structural brain development? Options:
a. From back to front
b. From front to back
c. That is currently unknown
Answer: From back to front. See the image below. Purple is less gray matter (means maturation):
11. Functional Magnetic Resonance Imaging (fMRI) technique is based on which signal? Answer: the BOLD
level.
12. What is the advantage of fMRI compared to EEG? Answer: after fMRI participants do not need to wash
their hair (EEG used a sticky substance on the head).
13. How would you refer to the different directions in the brain (shown in the picture)
Answer:
1=dorsal
2=posterior
,3=ventral
4=anterior
14. Which image displays the medial PFC (mPFC) and which image the lateral PFC (LPFC)?
Answer: A = LPFC, B = mPFC
15. Which image marks the subcortical structure ‘striatum’?
Answer: B (A shows the insula)
16. Which brain area is the temporoparietal junction (TPJ) and which is the superior temporal sulcus (STS)?
Answer: A = STS, C = TPJ
17. Which of the following brain regions is readily associated with behavior regulation? Options: temporal
cortex, parietal cortex, prefrontal cortex, subcortical regions. Answer: the PFC.
18. Which of the following brain regions is readily associated with processing of rewards? Options: striatum,
nucleus accumbens, ventromedial PFC, all of the above. Answer: all of the above.
19. Which of the following brain regions plays an important role in processing of emotions? Options: nucleus
accumbens, amygdala, caudate, fusiform gyrus. Answer: amygdala
20. Which of the following brain regions is considered to be an important part of the ‘social brain’ network?
Options: posterior superior temporal sulcus (pSTS), dorsomedial prefrontal cortex (dmPFC), the TPJ, all
of the above. Answer: all of the above.
21. During adolescence the connectivity between which brain regions is important for the regulation of
emotions like fear? Answer: the amygdala and the PFC
22. “We do not use our brain 100%”. True or false? Answer: false.
How to study the brain?
Around the 1800s phrenology was a method that was used to assess brain function. It was proposed by Frans
Joseph Gall. He argued that every mental function had its own place in the brain. Someone’s character and
qualities/weaknesses could be measured by studying the skull. The idea of localization of function is a very
important idea that is still very relevant.
Post-mortem studies have led to great discoveries. Post-mortem studies give the ability to link certain
disfunctions to certain brain areas. Three examples:
Paul Broca discovered that language production is linked to the left inferior frontal cortex.
Carl Wernicke discovered that language understanding is linked to the left posterior temporal cortex.
Case study of Phineas Gage: a large iron rod was driven through his head and destroyed much of his
medial prefrontal cortex (mPFC) and orbitofrontal cortex (OFC). He survived the accident, but his
personality changed a lot. He started showing impulsivity, gambling and inappropriate social behavior.
Brain lesions also tell us a lot about the brain.
Brain size
The size of the brain of an 8 year old is about 80% of the size of an adult brain. One of the biggest brain changes is
the increase in connections between neurons and there is an increasing amount of white matter (due to
myelination of the cortex). The increase in white matter is linear. Grey matter increases till adolescence and
, decreases after adolescence. This decrease might be due to the balance between synaptogenesis (making of new
synapses) and pruning (eliminating excess synapses).
fMRI
Magnetic Resonance Imaging (MRI) pictures brain structure and functional MRI (fMRI) pictures brain function.
fMRI is an indirect measure of brain activity. As soon as a certain part of the brain is active, more oxygen is
needed. More blood goes to the area to supply blood. BOLD stands for “Blood Oxygenation Level Dependent”. The
changing hemoglobin in red blood cells can be measured.
It is important to keep in mind that the BOLD signal is not an absolute measure of brain activation, it is relative. It
is important to know what the control condition is in an experiment. Many trials are need per condition (at least
20 trials). Fixation between trials is also important. And last: the experimenter should engage the participants so
that they don’t get bored or fall asleep while in the scanner.
fMRI versus EEG
Electroencephalography (EEG) and fMRI are both non-invasive techniques. fMRI had a high spatial resolution, but
has a low temporal resolution (because its an indirect measure). EEG has a high temporal resolution, but has a low
spatial resolution.
The paper by Nelson et al. (2005)
Adolescence is the period in which you grow up to be an adult. It is the period between childhood and adulthood.
Puberty is seen as the start of adolescents. Puberty starts when hormones start changing. Girls start puberty
around 8-9 years of age and boys generally start one year later. Adolescence ends around 25 years of age.
However, the age at which you become an adult is thought of differently across cultures. For example, in the US
you can drive when you are 16, in the Netherlands you have to be 18.
Social information processing network (SIPN)
There are 3 different nodes:
The detection node: perceptual processing
o Face perception
o Facial expressions / emotions
o Biological motion
o Other sensory modes
The affective node: emotional response
o Positive and negative emotional arousal (amygdala)
o Negative emotions, anything that goes against your norms (disgust, fear, unfairness) (insula)
o Reward (nucleus accumbens / striatum)
The cognitive-regulation node: regulation and monitoring of perception and affection
o Self-referential processing, self-reflection, mentalizing (mPFC)
