Decision-making and memory: an investigation on the recollection of a moral dilemma

Abstract

Individuals inevitably face situations where they have to choose between several options with uncertain future outcomes. This decision-making process can occur in various contexts such as getting the COVID vaccine, voting in a referendum, changing electricity provider, buying or renting a house, etc. It is, therefore, not surprising that decision-making has been the focus of a wide range of fields, including economics, philosophy, marketing, neurosciences and psychology (Johnson & Busemeyer, 2010).

In cognitive psychology, there is a consensus around the idea that decision-making is highly related to memory (Fellows, 2018). The relationship between decision-making and memory is thought to be bi-directional, where both cognitive functions have a mutual impact (Tremel et al., 2018). However, empirical research has mainly investigated the effect of memory on decision-making. The impact of decision-making on memory has yet to be fully characterised (Murty et al., 2015).

Previous research has suggested that decision-making may influence specific aspects of memory, such as learning and forgetting (Murty et al., 2015; Murty et al., 2019). This thesis investigates the effect of decision-making on memory through the lens of learning and forgetting. Chapter 1 presents the development of a longitudinal experimental paradigm eliciting decision-making and memory in a set of three experiments - Experiments 1a, 1b, 2 and 3. Experiment 1 describes the retention of a standardised piece of prose (Logical memory Story C subtest from Wechsler Memory Scale -- fourth edition; Wechsler, 2009) under normal forgetting and retrieval practice (a learning strategy that enhances long-term retention) with a delay of up to one month. Experiment 1a illustrates the forgetting curve of Story C over time. Experiment 1b shows how the retention of Story C is enhanced under retrieval practice.

Experiment 2 analyses the benefit of retrieval practice on the retention of Story C and a dilemma story. These results suggest that the dilemma story is more difficult to encode, as it has lower immediate and delayed retention than Story C. However, the difference in retention between the two stories remains constant over time - the stories are forgotten to the same extent. Experiment 3 compares the percentage of moral decision types (i.e., deontological or utilitarian) provided for a set of popular dilemma stories. The results reveal that the Nobel Prize dilemma has the most even split in chosen option for decision. From these three studies, I developed an experimental paradigm that concomitantly manipulates decision-making and measures memory retention.

Chapter 3 presents two experiments focusing on the effect of decision-making and moral decision types on forgetting. Experiment 4 focuses on the retention of the dilemma story following a deontological decision, a utilitarian decision, or an unrelated choice (control). The results suggest that decision-making and moral decision types do not influence memory retention after a day.

Experiment 5 further investigates the impact of moral decision types on memory retention over a month. The results replicate the absence of an effect found in Experiment 4. Chapter 3 concludes that decision-making may not systematically influence memory, regardless of moral decision types.

Chapter 4 explores the role of learning in the relationship between decision-making and memory. Experiment 6 focuses on the effect of decision-making and moral decision types on memory retention as a function of retrieval practice and forgetting.

This experiment aims to test whether learning can change the impact of decision-making on memory. The results revealed that decision-making does not impact forgetting regardless of moral decision types and retrieval practice.

Chapter 5 concludes and discusses the research findings. Overall, my research does not provide evidence of an impact of decision-making on episodic memory. The discussion acknowledges the limitations of the current thesis. Then, explanations for the consistent lack of effects observed in the thesis are considered. Finally, I discuss theoretical and methodological implications and future directions.