Steyvers and Hemmer 2012

Steyvers and Hemmer (2012)

Hotel Avante 127 1200x800 (image/jpeg)

Caption: : Hotel Scene

Idt065 1 (image/jpeg)

Caption: : Dining Scene

Extraordinary Home Office Design Ideas Interior Cool Modern Office Decor Ideas Then Cool Modern Office Decor Decorations Picture Modern Office Decor Have Office Decor (image/jpeg)

Caption: : Office Scene

Aims

To investigate the interaction between episodic and semantic memory in naturalistic environments.To see how prior knowledge (semantic memory) is used to reconstruct memory for photographs of normal everyday settings (episodic recall), such as kitchen, office, dining room, hotel and urban scenes.

Procedure - initial testing

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Caption: : Kitchen Scene

First prior knowledge was assessed, as this would show participants expectations about naturalistic scenes. A random sample of 22 participants was recruited from a University experimental participant pool. To assess prior expectations, the group was asked to list objects they would expect to find in 5 naturalistic scenes (dining, urban, kitchen, hotel, office). The frequency of objects named was recorded as a measure of prior expectation.Secondly, a second group of 25 participants was shown 25 images of the 5 types of scene (DUKHO), five of each type, and asked to name all the objects they could see as a measure of perception. This was important to ensure objects were not overlooked because they were not perceptible in the scene.These initial tests showed that people have good prior knowledge of these naturalistic environments and that each scene was largely representative of each type of naturalistic environment.

Procedure - experimental condition

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Caption: : Urban Scene

49 participants from the same experimental pool (but who had not been part of the initial testing - meaning 96 participants in total were used in the study) were randomly selected. 10 of the stimulus images from the prior tests were selected to be used in the experiment (2 of each scene type ). From these 2 sets of 5 images were formed (1 of each type of scene in each set). Participants were only shown one set of images (to avoid carry-over effects from seeing 2 images of the same scene type) and were either shown the images for 2 seconds or 10 seconds. This meant there were 4 possible trial time orderings and participants were allocated randomly to one of these. Exposure duration was manipulated to alter the extent to which participants used prior knowledge in episodic memory retrieval. It was thought that recall from the 2 second exposure duration would rely more heavily on prior knowledge as there was little opportunity for it to be encoded. It was also thought that recall of objects not consistent with the scene could only be recall from episodic memory and recall of objects missing from the scene could only be recalled using semantic memory. Participants were asked to recall objects in their own time.

Results and Conclusions

ResultsMean number of objects recalled:2 second exposure duration: 7.7510 second exposure duration: 10.05When participants are presented with naturalistic scenes, memory is quite accurate. Where scenes do not represent real-life context accurately, the error rate increased.The effect of prior knowledge was assessed by comparing the correct number of objects guessed in the expectation test to those actually recalled in the experimental conditions. The results suggested that episodic memory plays a significant role in recall.

ConclusionsIn recall of naturalistic scenes, prior knowledge drawn from semantic memory can contribute to accurate recall in episodic memory tasks, when scenes are unmanipulated/naturalistic.Prior knowledge contributes greatly to recall of naturalistic environments, but we are more likely to notice novel items than previous research has suggested.

Evaluation

The sample, while large, may not be representative of or generalisable to the rest of the population because they were all taken from a University participant pool, meaning they were mainly psychology students of similar age and social class. Being psychology students they also may have guessed that purpose of the experiment, reducing the validity as they may have changed their behaviour or tried harder in order to 'please' the experimenter. However, the standardised procedure would be easy to replicate, making the study reliable. The scenes were naturalistic, meaning they were ecologically valid.