Emotion Psychology

This axis is the first step of stress reaction amygdala and hypothalamus start this cascade even before the

brain's visual centers have had a chance to fully process what is happening.

N.B. Cortisol has receptors also in brain for instance, it is able to modulate the activity of neurons involved

in the storage of info and memory related to aversive and traumatic events. This mechanism is activated in

order to be able to remember which situations can be dangerous to our survival (evolution developed strong

system for survival).

The hypothalamus is a structure deep within your brain. Your hypothalamus keeps your body in a balanced

state regarding body temperature, hunger, mood and many other functions. It does this by directly

influencing your autonomic nervous system or managing hormones.

The pituitary gland is a small gland located at the base of the brain below the hypothalamus. It is the center

of our endocrine system since it produces several essential hormones and regulates other endocrine glands.

The adrenal glands are small glands on top of each of your kidneys producing hormones that regulate

several important bodily functions. The adrenal cortex is part of the HPA axis.

HPA axis dysfunction may also play a role in memory loss and neurodegenerative conditions such as

Alzheimer disease therefore the axis still represent a complex physiological concept.

MAOA gene

Polymorphism = different form of genes that may have low or high activity

The gene encodes an enzyme involved in the metabolism of excitatory neurotransmitters as serotonin,

noradrenaline and dopamine that are linked to behavior and mood. The mutation of the gene causes reduction

in their metabolic activity (leading to excitatory behaviors) and it is statistically associated with an increased

likelihood of committing serious crime or violence.

The first study on the topic was made by Brunner (1993) in which was found that a complete deficiency of

MAOA activity was correlated with impulsive aggressive behavior (known as “Brunner syndrome”). The

second study, by Caspi (2002), found that childhood maltreatment coupled with low levels of MAOA

activity was correlated with antisocial behavior.

Brunner syndrome is a rare genetic disorder associated with a mutation in the MAOA gene. It is

characterized by lower-than-average IQ (typically about 85), problematic impulsive behavior (pyromania,

hypersexuality and violence), sleep disorders and mood swings.

It was firstly identified in fourteen males from one family in 1993.

It is caused by a monoamine oxidase A deficiency, for which the regular function of the gene (breaking

down monoamines) is disrupted, leading to an excess of monoamines in the brain (serotonin, dopamine,

norepinephrine on which monoaminergic systems are based on).

This gene has also been associated with a variety of other psychiatric and neurological disorders,

including antisocial behavior such autism, Alzheimer's disease, aggression, panic disorder, bipolar disorder,

major depressive disorder, attention deficit hyperactivity disorder. For instance, drugs used to increase or

reduce the effect of monoamine neurotransmitters are used to treat these type of patients (depression, anxiety,

schizophrenia, Parkinson's disease)

Caspi and al. used large population of males participants: one with long form of the gene with a high MAOA

activity and the other with a short form of the gene with a low MAOA activity.

He showed that if one has a long form of the gene, independently from a positive or negative

environment, does not have any alteration of the behavior while, if one has a small form of the gene and

is subjected to an aversive environment during childhood and adolescence, it results in abnormal and

antisocial behavior (the gene is not protected from the environmental aversity). This argument is admitted

in Courts as justifications for crimes.

In this sense, it has been shown that abused children with the normal variant of the gene do not develop

antisocial behavior as adults while children who have the MAOA mutation as adults are at greater risk of

developing aggressive behavior towards the community.

The distinctive traits of these individuals are high testosterone levels, low IQ…

N.B. The interesting thing about the MAO-A gene is that it is placed on the X chromosome. Therefore,

males have only one copy of it while women have two. If a male has an allele of the MAO-A gene that is

related to violence, there is no other one that can counterbalance it.

Females have two copies and therefore if they have one risk allele, they have another that can compensate for

it. This is why the majority of MAOA research has focused on males, and that the effects of MAOA have

been observed in general only in males.

First sentence on MAOA in Italy



1 October 2009 the Court of Appeal of Trieste used genetic investigations and instrumental brain imaging

to determine the defendant’s ability to understand and act. This groundbreaking ruling granted the offender

of murder a reduced sentence, because he was affected by "genetic vulnerability" because in his genetic

heritage there was the presence a mutated MAO-A allele capable of making him particularly reactive in

terms of aggressiveness and consequently vulnerable in the presence of stress situations.

Mechanisms underlining memory formation

1879 in Lipsia wound founded first experimental laboratory of psychology based on the first paradigm of

psychology thus structuralist school. This work was focused on behavior and mind and in which way they

work and how one could quantify them (i.e. by studying the reaction time intended as the interval between



the stimulus and the reaction to it = longer the reaction longer the mental process) mind as complex

ensemble of cognitive functions

William James is the founder of functionalism and proposed the existence of two systems of memory

(primary and secondary memory).

Years later memory was not so crucial in studies and research. This lack of interest was due to the fact that,

th

from the 20 century, psychology was influenced by behavioralist. They introduced a scientific method in

psychology by studying the behavior and the relation between stimuli-reaction even though they had a

significant limitation: they studied behavior only connected in response to something else (SR = stimulus

and response) and left aside all the other cognitive functions and processes (brain and mind were defined as

‘black box’).

Historical evolution in the study of memory and where it is stored (Henry Molaison)

Previously there was the assumptions that memories were stored in the hippocampus (supported by several

cases in which patients having lesions in that area were affected in the recalling of memories).



1953 HM was a famous patient that illustrated the localization of a memory deficit.

He was epileptic thus he was subjected to surgery to isolate the area in which there was the epileptic focus

which typically triggered the crisis and seizures (= medial temporal lobe which included hippocampus,

amygdala and parahippocampal gyrus. Milner wrote “I have never claimed that the memory loss was solely

attributable to the hippocampal lesions”).

N.B. Epilepsy is due to a group of neurons that suddenly start to fire ap in a non-organized nor systematic

way and affects the nearby areas of the brain which are then targeted by several stimulations, start not to

function properly and produces seizure.

After the neurosurgery, Neurosurgeon Scoville and Brenda Milner submitted him to a memory test

discovering that he became affected by retrograde amnesia from the moment that he was unable to recall

memories, typically those happened before the aversive or traumatic event (opposed to anterograde amnesia

= unable to form new memories).

In this sense, he had a deficit of declarative memory and was unable to form new long-term memory

however he still had an intact procedural memory (= residual capacity of learning motor skills).

This finding illustrated the existence of multiple memory systems of the mammalian brain.

Subsequently, the terms declarative and non-declarative were introduced: declarative memory refers to the

kind of memory that is impaired in H.M. which is dependent on the medial temporal lobe V. non-declarative

memory is an umbrella term referring to additional memory systems (support skill learning, habit learning,

simple conditioning, emotional learning, priming and perceptual learning) which are dependent on the basal

ganglia, the cerebellum, the amygdala, and the neocortex.

These studies allowed the understanding of the connection between the areas of the brain and their

related cognitive functions on the storage and formation of memory.

In the 70s/80s, the multiple memory system categorization proposed two types of memory:

1. Declarative is a memory related to consciousness thus voluntary recall of info based on facts or

memories of past events that can be ‘declared’ rather than performed.

It can be divided in other sub-types: semantic (related to facts and events as part of general

knowledge) connected with spatial (location); episodic (involving an info which is exactly located

in space and time) connected with autobiographical (typically combining semantic and episodic

memories and contribute to your sense of self based on one’s own life history and identity).

N.B. Retrieval of episodic and autobiographical memories is highly reconstructive: extra bits of

information that weren’t there when the memory was originally stored can get added in during the

process of remembering (= accurate eyewitness testimony become very difficult).

Two key areas of the brain involved in forming and storing declarative memories are the prefrontal

cortex and the hippocampus. The prefrontal cortex, located at the very front of the brain, is

responsible for our working memory thus processing new incoming information and manipulating

any existing memories that we might be consciously thinking about at any given time.

2. Procedural is a memory referred to our knowledge of

skills and performance of tasks which one mostly

remember automatically without using consciousness

(i.e. play instrument). Its main component is emotional

memory which is a form of long-term memory strongly

influenced by the emotional experience of aversive

events. Multiple parts of the brain are involved in the

formation of procedural memories. Once a skill has been

learned, the basal ganglia is responsible for processing

and coordinating the muscle movements and habitual

actions. Also the cerebellum is responsible for executing

learned motor movement and the amygdala responsible

for emotional memory. 

People having dysfunctions concerning declarative memory can still use their procedural one these

systems of memory depend on the integrity and function of different brain structures.

Moreover, if procedural and declarative memories are the what of memory, implicit and explicit are the how:

1. Implicit memories are those that we remember unconsciously and are expressed in our behaviors in

some way (procedural