IB Psychology HL

Aim: To investigate if schema processing influences both encoding and retrieval Procedure: The participants were given one schema at the encoding stage and one schema at the retrieval stage, to see if they were influenced by the last schema when they had to recall the information. The participants heard a story that was based on 72 points. Half of the participants were asked to read the story for the point of view of a house-buyer and the other half from the point of view of a burglar. After a break, half of the participants were given a different schema, so the burglars switched to the buyers and vice versa. The other half were tested on their original schema again. Results: The researchers found that the group of participants in the changed schema group were able to recall 7 percent more points on the second test than on the first one. Recall of points that were directly linked to the new schema increased by 10 per cent, whereas recall of points that were important to the pr...

Rogers and Kesner (2003) Aim: To investigate the role of acetylcholine on memory encoding and memory retrieval. Method: It was a laboratory experiment using rats. Rats were trained to learn a simple maze, but before the memories could be learned well-enough to be transferred from short-term memory to long-term memory, the rats were divided into groups and injected with drugs: Group 1 was injected with scopolamine, which is known to block the reception of acetylcholine by the post-synaptic neurons. This means that acetylcholine, a neurotransmitter expected to help form memories, cannot travel from one neuron to another. This was the no acetylcholine condition. Group 2 was injected with physostigmine, a drug that blocks cholinesterase, which is what cleans up the acetylcholine from receptor proteins on the post-synaptic neurons, returning the neurons to their resting potential, where no nerve impulse is being sent. Therefore the acetylcholine continued to act. This was the h...

Bouchard et al. (1990) Aim:  To investigate the relative influence of environment and genetic factors on human characteristics and behaviours, including intelligence. Method: A cross-cultural correlational study of more than 100 pairs of reared-apart twins and siblings whose data was compared with twins and siblings reared together. The participants comprised identical (monozygotic/MZ) twins and non-identical (dizygotic/DZ) twins, with an average age of 41 years. MZ twins are often used in genetic research because they have identical or almost identical genes. Each participant underwent over 50 hours of psychological testing and interviews. In twin research, the correlation found between each twin and therefore presumable between genetic inheritance and a particular behaviour is called the concordance rate. Results: The concordance rates for IQ were: MZ twins reared together: 86% (0.86) MZ twins reared apart: 76% (0.76) DZ twins reared together: 55% (0.55) Biologi...