Tulving's Gold Memory Study

What is Memory?

Cognitive psychologists have faced the challenging task of explaining memory in theoretical terms and empirically. One of the main figures researching this topic is Endel Tulving. Before we understand the Tulving model of memory, let's review some basic memory definitions.

Memory refers to the ability to store information that we have learned or experienced.¹ But that's not all; memory can be further subdivided into short- or long-term memory.

On the other hand...

Multi-Store Model of Memory (Atkinson & Shiffrin, 1968)

The mentioned definitions originated from the pioneering ideas of Atkinson & Shiffrin (1968). They developed a memory model in which they identified three memory storage systems. The sensory register is meant to contain information that comes from the senses. Such information would then be transferred into short-term memory (STM), a memory system with limited capacity and duration.

When information in STM is rehearsed and repeated over time, it is consolidated in the long-term memory (LTM) system. This memory system has an unlimited capacity. The model also suggested that retrieval allows accessing information already stored in LTM.

Although this model is widely acknowledged, it's not considered totally accurate these days. It was a great pioneering work and motivated other researchers to study memory further.

Long-Term Memory: Tulving (1989)

Tulving's contribution to our understanding of memory centres on long-term memory. It was back in 1972 when Tulving first described the distinction between semantic and episodic memory. This distinction is still used in psychology today.

Tulving's model suggests that episodic and semantic memory essentially involve two different mental processes in the brain. Tulving described episodic memory as long-term memories associated with time and in relation to a specific context.

Conversely, Tulving described semantic memory as the long-term knowledge of facts and concepts.

Put simply; episodic memory can be described as the recollection of events, while semantic memory refers to the recollection of facts,

Tulving Experiment: Tulving's Gold Memory Study (1989)

As with any model in experimental fields, Tulving needed to prove his model through experiments. The study Tulving conducted is today referred to as Tulving's "Gold" Memory Study (1989).

The study was designed to provide neuropsychological evidence that episodic and semantic memory are two different cognitive processes.

To determine if the two types of memory are different cognitive processes, we expect to see different brain activity when doing tasks that rely on the different types of memory. Essentially, Tulving aimed to identify patterns of brain activity related to episodic and semantic memories.

Tulving Experiment: Procedure

Tulving used the functional brain-imaging technique PET (Positron Emission Tomography) scans to test this. In the scan, a radioactive isotope of gold was used to detect the potential differences in brain activity.

Six individuals volunteered to participate in the study, Tulving and his wife included. The study used a repeated measures design as each participant took part in each condition of the experiment.

During the experimental phase, volunteers were asked to lay down and recall episodic and semantic memories, one at a time. Brain activity was recorded during the recollection of the two types of memories.

The data from three volunteers presented inconsistencies. Therefore, only the data from the remaining three volunteers were considered for analysis.

Tulving Experiment: Results

The results supported Tulving's model of long-term memory. When volunteers recalled episodic memories, there was higher activity in the frontal and temporal lobes. On the other hand, when volunteers recalled semantic memories, the parietal and occipital lobes showed greater activity.

From the Tulving experiment, it can be concluded that episodic and semantic memory are two distinct cognitive processes as different networks are activated when recalling the different types of memory.

Research has identified that one brain region does not perform a specific function. Instead, multiple areas (a network) work together to perform a function.

Tulving's Gold Study Evaluation

Strengths:

• The study was one of the first ones that distinguished cognitive processes with a brain imaging technique.
• Using a PET scan allows researchers to measure brain activity in the different brain regions empirically.
• Informed consent was collected from the volunteers who took part in the study. Therefore, the researchers took into account ethical considerations.

Weaknesses:

• Data from three participants were inconsistent and could not be analysed; this suggests there may have been potential confounding/ extraneous variables that had not been accounted for, which may have affected these cases. The issue with confounding/ extraneous variables is that they lower the internal validity of an experiment.
• The study lacks generalisability. Given that PET scans of three individuals were analysed, this sample does not represent the general population. Therefore, the study does not account for individual differences.
• Since researchers were only able to ask volunteers to think of memories, the researchers can't control if participants have intrusive thoughts unrelated to the type of memory being investigated, suggesting the study may lack internal validity.

• As with any other study in a laboratory setting, the results lack ecological validity. Lab settings are artificial (lacking mundane realism) that are not representative of real-life settings and may cause participants to act unnaturally.

Tulving Model : Procedural memory

After Tulving had established that semantic and episodic memory are distinguishable, Tulving realised that there was another type of LTM, procedural memory.

Procedural memory is a form of LTM that is used when we perform an action. However, unlike semantic and episodic memories, procedural memories do not rely on us consciously attending to them; instead, they're automatic.