Maguire et al (2000)

Correlational study.
No variables were manipulated.
Magnetic Resonance Imaging (MRI) doesn't have low ecological validity since it's only looking at structure.
Sample is gender biased.

Milner et al (1968)

HM Longitudinal Case study-50 years+

HM suffered from anterograde and retrograde amnesia.
Surgery removed the medial temporal lobe and the hippocampus, full of acetylcholine.
HM had spatial, procedural and working memory but he could not acquire semantic or episodic knowledge.

Sharot et al (2007)

Sample: 24 adults who were in NYC during 9/11. This sample is small and culturally biased (individualist cultures tend to show more flashbulb memories).

Amygdala.
Functional MRI

Weissman et al (2005)

Kinship studies. 20 years+

Sample: 161 grandchildren, their parents and grandparents. Both high and low risk families. Depressed participants were chosen from a clinic and the rest from the same community.

Cadoret et al (1995)

Adoption study

Sample: 95 males adopted at birth in Iowa. This sample is highly biased.

Ethical considerations.

Antanova et al (2011)

Sample: 20 male adults. Gender biased and small sample.

Without the fMRI, differences couldn't have been significantly observed.

Participants reported being stress. Researcher bias and participant variability were avoided.

Kendler et al (2006)

Twin study.
Correlational.

Sample: 15,493 twin pairs in Sweden, all whose zygotic could be verified. Twins born between 1886 and 1958.

Rogers and Kesner (2003)

Sample: 30 rats.
Not generalisable for humans.

Hebb Williams Maze

Establishes cause and effect.
Reductionist approach.

Draganski et al (2004)

Sample: 21 females and 3 males. Small sample.

MRI

Low internal validity.
Cause and effect established.