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Biological Psychology - Coggle Diagram

- - - - Key structure involved in aggression is the amygdala and has a central role in how organisms assess and respond to environmental threats and challenges.
      - The evidence of Emil Coccaro et al. (2007) which studied people with Intermittent Explosive Disorder were scanned with fMRI showed that an angry facial expression is an ecologically valid sign of threat.
    - - The amygdala works alongside the orbitofrontal cortex, which plays a big part in cognitive functions like rational thinking and decision-making. Involved as well in self-control, impulse regulation and aggressive behaviours.
      - Adrian Raine et al. (1997) used PET scans to study murderers who commited aggressive crimes and found a greater glucose metabolism in the amygdala but abnormally low metabolism in the prefrontal cortex compared to a group of controls.
    - - Neurotransmitter with widespread inhibitory effects on transmission between neurons in the brain. Slows down and dampens neuronal activity. Decreased serotonin may well disturb the link, reducing self control and leading to impulsive behaviour including aggression.
      - Matti Virkkunen et al. (1994) compared levels of serotonin breakdown in the cerebrospinal fluid of violent impulsive and non-impulsive offenders. Levels were significantly lower in impulsive offenders. Serotonin helps to regulate sleep patterns. Disturbance of sleep strongly implies some disruption of serotonin functioning.
    - - Neurotransmitter that has inhibitory effects in some areas of the brain and excitory effects in others. Regulates motivated behaviour and experience of reward.
      - Main influence comes through interactions with serotonin. Dongju Seo et al. (2008) found serotonin hypofunction stimulates dopamine hyperfunction and both are linked with impulsivity and aggression so serotonin hypofunction is the primary cause of impulsive aggression and dopamine hyperfunction makes an additional contribution
  - - - Individuals who possess characteristics that help them stay alive and reproduce the ones who pass their genes on to the next genetration
      - The process of natural selection
        
        The selection of genes done by the environment, of individuals who can survive and reproduce successfully.
        
        Due to the survival of genes, the most useful ones are retained in the population and become more frequent. The outcome of selection is adaption.
    - - Influence of evolution acting on the success of reproduction. Characteristics are retained in offspring due to advantages being gained over them.
    - - Guarding partners
        
        Mate retantion are often aggressive to prevent them from straying.
      - Guarding offspring
        
        Human parents will direct aggressive acts against other people that threaten their children. This aggression is adaptive because each child is a valuable genetic comodity.
  - - - Expressing aggression releases psychic energy reduces the sex drive and makes further aggression less likely. Preventing catharsis creates a build-up of energy which will eventually produce a destructive aggressive outburst either inwards via self harm/suicide or outwards via violent assault.
    - - The id and the pleasure principle
        
        The id exists from birth and is the most primitive element in the whole unconscious mind. It motivates all behaviour including aggression and aggressive drives. The id demands immediate gratification with no consideration to other factors. We cannot eradicate it so must direct it which is the role of the ego
      - The ego and the reality principle
        
        The ego is the logical, rational and mostly conscious part of personality and begins development soon after birth. It is the interface between the is and social reality so the eho doesn't directly fulfil the id urges but satisfies it indirectly and symbolically. The ego has no moral sense.
      - The superego
        
        The superego fulfils the moral role and emerges later in development at about 5-6 years. It shows our conscience and moral sense of right or wrong, as well as the ideal image of ourselves. The superego opposes the id's aggressive drive through guilt and shame. The superego is just as irrational and punishing in its demands as the id.
  - - - Endocrine glands manufacture a variety of hormones and secrete them directly into the bloodstream.
      - Have a crucial role in fight or flight response or percieved stressors, helping to fuel the aggressive response that may be needed to respond to a threat
      - Hormones act much more slowly than the NS but have widespread and powerful effects.
    - - Regulates social behaviour through its influence on areas of the brain implicated in aggression.
      - Testosterone are related to more aggressive behaviour in the males of several species.
      - Mairead Dolan et al. (2001) found a positive correlation between testosterone levels and aggressive behaviours in a sample of 60 male offenders in UK maximum secutrity hospitals.
    - - Hormonal causes of aggression are much more complex than the role of a single hormone implies
      - Cortisol secreted in the adrenal glands protect the body against stress - Suggests there's an interaction between the systems responsible for regulating aggression and the stress response.
      - Justin Carré and Pranjal Mahta (2011) clain high levels of testosterone lead to aggressive behaviour when cortisol is low.
      - According to Dual-Hormone Hypothesis the combined activity of the two hormones are may be a better predictor of human aggression than either hormone alone.
    - - Female aggressive behaviour may still be enhanced by testosterone.
      - Cristoph Eisenegger et al. (2011) found women given a dose of testosterone behaved more generously and sociably in a negotiating game. Non-biological factors may be important because of the findings of this lab experiment.
- - - - Brains relay system
      - Passes on info to appropriate areas for higher-level processing
      - Acts as a gate or filter
    - - Controls motivational behaviours - hunger, thirst, sex
      - Has control of 'fight or flight' - body stress response
      - regulates activity of endocrine system and secretes hormones of its own
    - - Consists of several structures
        
        Amygdala
        
        Hypocampus
        
        Thalamus
        
        Hypothalamus
    - - Coordinates posture, balance and movement
      - Integrates information form the spinal cord and motor cortex
    - - Allows communication between hemispheres by passing signals
      - Integrates activities from both sides of the body
- - - - Carry messages from sensory receptors
      - Long dendrites and short axons
    - - Carry messages from the CNS, along nerves in the PNS to effectors in the body
    - - connect sensory and motor neurons
      - connect to other relay neurons
      - short dendrites and short axons
      - only found in the cns
- - - - Cocaine blocks the reuptake of dopamine by binding with dopamine teleporter molecules on the terminal buttons of the presynaptic neuron. These recycle dopamine back into the neuron. With this blocked the synapse floods with surplus quantities of dopamine, all available for binding with postsynaptic receptors. This is the main cause of the euphoric high with cocaine use.
    - - Dopamine receptors become downregulated because fewer receptors are active and the quantity of dopamine declines which explains withdrawal and higher dosages.
  - - - Agonist drug because mimics action of another natural biochemical.
    - - Downregulation means opioid receptors on postsynaptic neurons are constantly binding with morphine molecules, which desensitises then to the effects of the drug.
- - - - Aim
        
        Brain scanning technology to identify brain impairments in people charged with murder who had pleaded not guilty by reason of identity.
        
        Hypothesis was brain scans show dysfunctions in prefrontal cortex, angular gyrus, amygdala, hippocampus, thalamus and corpus callosum
      - Method
        
        Looked at differences between two groups - 41 murderers and 41 non-murderers. IV = murderer or non-murderer. DV = glucose metabolism in specific brain areas.
      - Procedure
        
        PET scans used to spot brain metabolism, completed a continuous performance task - identifying targets on a screen and pressing a button during a 32 minure period.
      - Findings
        
        Cortical Regions
        
        Murderers had significantly less activity in lateral and medial prefrontal areas, left angular gyrus and left and right superior parietal areas.
        
        Subcortical Regions
        
        Murderers had lower glucose metabolism in the corpus callosum, left amygdala, and left medial temporal lobe. Murderers had greater activity in the right amygdala, the right medial temporal lobe and the right thalamus.
      - Conclusions
        
        Hypothesis was supported and shows murderers pleading NGRI have different brain activity from people who are not violent offenders. Murderers had impaired functioning in areas of the brain previously involved with violent behaviour.
        
        Raine et al. also concluded we should be very cautious in interpreting the findings because other brain areas are known to be involved in violence that ther were unable to scan. However the study is reliable because it provides useful preliminary evidence and signposts several directions for future research.