Animal Studies

Weiskrantz et al - date

1956

Weiskrantz et al - aim

To study the role of the amygdala in behavior

Weiskrantz et al - procedure

4 monkeys with bilateral amygdalae lesions, 4 with lesions in other part of temporal lobe

Weiskrantz et al - results

damaged amygdala -> tame behavior, no fear towards human researchers

Sapolsky et al - Date

1990

Sapolsky et al - Aim

To study the effect of stress on hippocampal volume

Sapolsky et al - Procedure

Experiment group: Monkeys with implanted cortisol pellets Control group: Monkeys with implanted cholesterol pellets

Sapolsky et al - Results

Monkeys with cortisol implants had significant damage to neurons in the hippocampus, including dendritic atrophy.

Albert et al - Date

1986

Albert et al - Aim

To study the effects of testosterone levels on aggression in rats

What were the 4 conditions in Albert et al's study?

1. Castrated

2. Castrated + implanted testosterone tube

3. Castrated + implanted empty tube

4. 'Sham' castration

What happened when alpha male rats were castrated?

They displayed decreased levels of aggression towards rats in the same cage.

What happened when castrated rats had testosterone replaced?

Their aggression levels turned to normal levels.

How did the social dynamics change among the rats after castration?

Subordinate males rose in status, and the castrated rats lost their alpha position.

Mosienko et al - Date

2012

Mosienko et al - Aim

To study the effect of the TPH-2 gene on aggression

Mosienko et al - Procedure

Knockout mice - ablated TPH-2 gene Used Resident-Intruder Paradigm

Mosienko et al - Results (Attack Latency)

100% of knockout mice attacked in 5 minutes 22% of control mice attacked in 5 minutes

Van Oortmessen and Bakker - Date

1981

Van Oortmessen and Bakker - Aim

To study the effect of genetics on aggression

Van Oortmessen and Bakker - Procedure

Identified the most aggressive mice and selectively bred them

How many generations were involved in Van Oortmessen and Bakker's study?

11 generations

How were the mice tested in Van Oortmessen and Bakker's study?

All tested with Resident-Intruder Paradigm - attack latency of mice

Van Oortmessen and Bakker - Results

Attack latency of experiment group decreased with each generation -> genetics affect aggression in mice