Brain Structure and Aggression Flashcards
(19 cards)
What is localisation?
The brain tends to be organised according to function- regions devoted to different roles. Psychologists study the CNE to study the functions of the brain.
EG
Hippocampus- memory
Medulla- breathing
Cerebellum- balance, movement, coordination.
What is brain lateralisation?
Refers to the structural and functional differences between the left and right hemispheres (sides) of the brain. Some brain functions seem to be evenly spread across the brain such as those connected with sensorimotor functions (connecting movement of limbs with the senses), however others seem to be concentrated in one side of the brain more than the other.
EG language. For right handed people language function is mainly found in the left hemisphere- same for 60% of left-handed people.
What tends to happen in the left hemisphere?
What does it recognise?
Speech
Analysis
Time
Sequences
Words
Letters
Numbers
What tends to happen in the right hemisphere?
What does it recognise?
Creativity
Patterns
Spatial awareness
Context
Faces
Places
Objects
What is trepanning?
Surgical intervention in which a hole is drilled into the skull to treat problems related to the surface of the brain
What is phrenology?
The practice of mapping the bumps on a persons skull and using these deduce aspects of their character (now discredited).
What are lobes?
What are the different areas?
How many are there in each hemisphere?
Specific locations in each hemisphere of the brain.
Frontal- front part.
Temporal- side and behind ears.
Parietal- top area.
Occipital- back of brain.
8 lobes, 4 in each hemisphere.
What are the different things to happen to the brain?
(Aphasia, lesion, ablation)
Aphasia- a disturbance in the comprehension and production of language caused by brain dysfunction or damage (eg a stroke).
Lesion- accidental or deliberate (eg experimental, damage to the brain, incision or cut).
Ablation- removing part of the brain.
What is the cortex?
Cortex (Latin for cover/bark)- the last part of the brain to evolve and most developed.
It covers the rest of the brain like a cap and is made of large, convoluted folds of tissue that make the brain appear like a wrinkled sheet.
What is the case study of Phineas Gage?
A 25 year-old railway worker who, in 1848, experienced a horrific accident that severely damaged his prefrontal cortex. His language and intellectual capabilities & movement were entirely unaffected by his brain injury, however his personality underwent a significant change.
Before the accident, he was a considerate, loyal, friendly and regarded as one of the best and most efficient workers. However after the accident, he had bursts of anger, became impertinent, aggressive and impulsive and lost his capacity to judge the social acceptability of certain ways of behaving. He became unreliable, offensive and irresponsible. He lost friends and jobs, never worked again, became isolated and died alone 11 years later.
What happens to people with damage in Broca’s area?
They have normal speech comprehension but cannot articulate a reply; they may show deficits with prepositions, word endings & other grammatical devices. Those with less extensive damage speak slowly and inarticulately. (They know what things are but can’t say the words).
What is Wernicke’s area?
Describe what damage to it does.
Located at the rear of the left temporal lobe as it joins the parietal lobe.
Damage to the Wernicke’s area is linked to severe impairment in language comprehension, patients can produce speech but it is meaningless, in less severe cases people may have difficulty finding the right word, make up names or substitute one name for another, or use vague or roundabout expressions.
What does the frontal lobe do?
Planning of movements, some aspects of memory(semantic), inhibition of inappropriate behaviours, reward, attention (contains most of dopamine sensitive neurons in the brain).
What does the temporal lobe do?
Hearing- understanding spoken language, advanced visual processing- recognition of faces.
Kluver-Bucy syndrome linked to this area (previously wild and aggressive monkeys fail to display normal fears and anxieties after temporal lobe damage).
What does the parietal lobe do?
Body sensations, integrating sensory information and some parts are linked to language processing.
What does the occipital lobe do?
Vision
Whst is the limbic system?
Forms a border around the brain stem. Comprises a serious of interlinked structures particularly important for motivated and emotional behaviours, such as eating, drinking, sexual activity, anxiety and aggression. The larger structures of the limbic system are: olfactory bulb, hypothalamus, hippocampus, amygdala, cingulate gurus of the cerebral cortex.
What is the midbrain?
Contains an area called the periaqueductal grey matter (PAG), which links the amygdala & hypothalamus with the PFC. The PAG plays a role on the modulation of pain & in defensive behaviour; it co-ordinates and integrated behavioural responses to perceived internal and external stressors, such as pain and threat.
Lobstering and Stern 1998- Lesions in the PAG of rats show an increase in aggression when these rats are confronted with potential threat in the form of unfamiliar male rats being introduced to the cage.
What is the amygdala?
The centre for primitive emotional behaviour, emotions and motivation. It integrates internal and external stimuli and every sensory modality input, which when combined gives us an instinctive feeling or reaction to the environment that will include aggression. The PFC also connects to the amygdala & it is this connect that may lead to the expression of aggression.
