Limbic system Flashcards

Question

Theories of aggression in humans

Answer 1

Basic instinct/innate drive (Freud): Death instinct – aggression, self-destructive acts Modified by positive emotional attachments, substitute outlets e.g. sports Frustration-aggression hypothesis: Frustration leads to aggressive drive – aggression leads to reduction in drive (does it?) Aggression is usual response but there may be others if aggression doesn’t work Social Learning theory: Aggression is a learned response to frustration or other unpleasant emotional arousal – learned through observation and imitation (vicarious learning) Positive reinforcement increased the likelihood of occurrence Evidence supports social learning theory Young children imitate aggression observed in adults, films and cartoons If aggression is a drive, then expression should result in decreased aggression (drive-reduction) In fact, aggression increases with positive reinforcement (victim’s response!)

Answer 2

Positive correlation between amount of viewing of violence in childhood and aggressiveness in later life? WHY? Imitation Arousal (increased if frustrated or annoyed) Desensitisation to effects of violence Decreased inhibition of aggressive behaviour Distorted views of conflict resolution Cognitive factors: guilt, self control, influence the expression of aggression Disinhibition by alcohol

Answer 3

A powerful motivator, necessarily for the survival of the species. Hypothalamus controls sexual arousal, and more complex behaviours: Sexually dimorphic nucleus (SDN): larger in male brains 2:1. Differentiation occurs ~ age 2 to 4 in humans (corresponds to Freud’s ‘phallic stage’). Suprachiasmatic nucleus (SCN) - sexual and reproductive behaviour: Larger in female compared to male brains, 2:1 Larger in homosexual male brains as compared to heterosexual male brains Amygdala: stimulation leads to complex sexual activity, lesion lead to inappropriate hypersexuality

Answer 4

Hormonal control of sexual behaviour decreases from lower to higher vertebrates: Male Rats: castration leads to greatly decreased sexual activity. Primates: little or no decline Humans: complicated by emotional, social factors, most studies report little or no decline. Female Oopherectomy: complete cessation of sexual activity in all animals from reptiles to monkeys. Human is the only exception: most studies report no decrease in sexual motivation after menopause, may in fact increase (due to lack of fear of pregnancy). Ovulatory cycle: Most female animals are receptive only during period of ovulation i.e. when ‘in heat’. Primates: all phases of cycle, but most intense during ovulation.

Answer 5

learning plays n increasingly important role from lower to higher mammals. Humans: secure attachment to primary care-giver leads to the development of trust and good relationships with peers, which are essential for healthy adult sexual relationships Cultural variations in acceptable sexual activity e.g. incest –taboo in most cultures, premarital sex etc.

Answer 6

In many species the most powerful motivator of all. Regulated in the hypothalamus Preoptic area, VMH, mesolimbic DA pathway. Hormones vs environment: Virgin rats presented with pups take ~1 week to develop maternal behaviours, but if given plasma from a post-natal rat, it happens in 1 day Maternal behaviour is induced by gonadal steroids and increased by oxytocin, prolactin and environmental stimuli Maternal behaviour pattern is innate

Answer 7

Like other motivated behavior, maternal behavior is dependent on the hypothalamus Medial preoptic area (MPOA) Lesions of MPOA will abolish maternal behavior Regulated by the POA, VMH, DA pathway

Answer 8

Primates Experience is much more important Monkeys reared in isolation make very poor first-time mothers, if they mate at all They need to practice the movements of mating in play with other young monkeys to mate efficiently as adults They need to form an affectionate bond with mother in order to develop maternal behaviour in adulthood Humans Experience far overrides whatever influence hormones may have E.g. parents who abuse their children and often victims of abuse themselves

Answer 9

Harlow evaluated whether feeding or contact comfort was more important to infant attachment. The young animals were “raised” by two kinds of surrogate monkey mother machines. One ‘mother’ was made of soft terry cloth, the other made of wire mesh Harlow's research showed that the need for affection created a stronger bond between mother and infant than did physical needs (food). Monkeys raised without their mothers or other monkeys were socially maladjusted for the rest of their lives. When confronted with fear, they displayed institutionalized behaviors-throwing themselves on the floor, clutched themselves, rocked back and forth, and screamed in terror. They were incapable of having sexual relations and they were also unable to parent their offspring, either abusing or neglecting them. Harlow’s work suggested that the development of a child’s love for their caregiver was emotional rather than physiological Harlow showed that the development of attachment was closely associated with critical periods in early life. It is difficult or impossible to compensate for the loss of initial emotional security

Answer 10

Curiosity is a motive in itself We are motivated to seek stimulation, to actively explore the environment, even when it satisfies no biological need – e.g. 3 month old infants have learnt to shake a rattle and to turn on a musical toy There is enormous individual variation in need for stimulation Sensation-seeking scales: wide individual variation but good consistency across different situations Compatibility on sensation-seeking is a good predictor of marital adjustment, incompatibility leads to marital discord, especially if female is higher than male!

Answer 11

Just think: The challenges of the disengaged mind – Wilson et al, Science 2014 People are unhappy in their own company and some prefer painful experiences to their own thoughts! Nearly half the subjects gave themselves mild electric shocks during 15 minutes of quiet time 18 of 42 people, more of them men than women, chose to give themselves at least one mild shock on the ankle when left alone for 15 minutes. These were all people who had experienced the same shock already and declared that, if given $5, they would part with some of it in order not to be zapped again. People who didn't think they'd pay to avoid the shock were excluded - as was one man who pushed the button 190 times!

Answer 12

Exploration and manipulation leads to a variety in sensory input: Sensory deprivation leads to visual hallucinations, difficulty in thinking, feelings of unreality, disorientation in time and place Most subjects refuse to continue with experiment after a few days, no matter what reward they’ve been promised Variety in sensory input is necessary for proper mental functioning.