Browsing by Author "De Brigard, Felipe"

Working memory—the mental capacity to “hold on to” information after it ceases to be perceptually available—is one of the most discussed topics in psychology and neuroscience. Despite the importance of working memory in the sciences, however, there is only a small amount of philosophical research on the topic. The aim of my dissertation is to provide a philosophically-informed account of working memory, and to assess its relationship to other mental phenomena, including attention and consciousness.

In chapter one, I provide a broad historical overview of working memory. I begin by outlining William James’ original distinction between “primary” and “secondary” memory, and work my way up to present-day neuroscientific investigations of working memory. One of the main conclusions of this chapter is that there is no single working memory “module” in the brain. Instead, working memory is best conceptualized as a functionally-defined process that is potentially realized by multiple neural mechanisms.

In chapter two, I explore the link between working memory and attention. Recent evidence from psychology and neuroscience indicates that attention is (to some extent) involved in the process of working memory maintenance. However, it remains unclear whether the contents of working memory are always attended, or if working memory representations can be dynamically shifted in and out of the focus of attention. Drawing on empirical and phenomenological data, I argue that the second view is correct. Although attention plays an important role in working memory maintenance, working memory representations can persist—at least temporarily—outside the focus of attention.

Chapter three addresses a related question: namely, how working memory relates to consciousness. I distinguish three possible positions on this score: (i) working memory representations are always conscious; (ii) working memory representations can be either conscious or unconscious, but they are all accessible to consciousness; and (iii) working memory representations can be either conscious or unconscious, and some are inaccessible to consciousness. Based on the available empirical data, I argue in favor of position (ii). Evidence suggests that working memory representations can be unconscious, but such unconscious representations still appear to be consciously accessible, in the sense that they can be brought to consciousness at will.

Finally, in chapter four, I provide a critique of Peter Carruthers’ recent sensory-based account of working memory. According to Carruthers, attention only targets “mid-level” sensory areas, and thus the representations held in working memory will necessarily be sensory based in nature. I disagree. I point out that there is some evidence for attentional modulation outside of modality-specific sensory areas. I also highlight several empirical studies which provide preliminary support for the existence of non-sensory (i.e., amodal) working memory representations.

Emotions play a fundamental role in how we remember the past. Decades of neuroscience research have uncovered the neural mechanisms that help explain why we selectively remember emotional experiences, often at the expense of more neutral ones. What remains less understood, however, are the factors that govern biased access to certain emotional memories over others. Discerning such effects can provide insight to aberrant memory biases that perpetuate psychopathological symptoms in a wide range of clinical disorders. Here I present three different routes to emotional memory bias, stemming from factors at encoding, consolidation, or retrieval that selectively influence what we remember from the past and how we remember it. First, I tested the influence of spatial proximity during initial exposure to threatening stimuli, finding that threats encountered in near space activate a distinct neural fear circuit that predicts enhanced reinstatement the next day. Second, I tested the influence of mood during consolidation, finding that mood after encoding retroactively strengthens mood-congruent content into long-term memory. Third, I tested how memories can be modified at retrieval by manipulating conceptual and perceptual features of the remembered event, finding that these two forms of reconstruction recruit distinct neural profiles. Finally, I summarize how these studies inform memory biases in mood disorders, while also discussing related work on emotion representation and dispositional biases in retrieval tendencies.

The human capacity for causal judgment has long been thought to depend on an ability to consider counterfactual alternatives: the lightning strike caused the forest fire because had it not struck, the forest fire would not have ensued. To accommodate psychological effects on causal judgment, a range of recent accounts of causal judgment have proposed that people probabilistically sample counterfactual alternatives from which they compute a graded index of causal strength. While such models have had success in describing the influence of probability on causal judgments, among other effects, we show that these models make further untested predictions: probability should also influence people's metacognitive confidence in their causal judgments. In a large (N=3020) sample of participants in a causal judgment task, we found evidence that normality indeed influences people's confidence in their causal judgments and that these influences were predicted by a counterfactual sampling model. We take this result as supporting evidence for existing Bayesian accounts of causal judgment.

Why did the car accident occur? How do we stop the recent rise in inflation? Which player is responsible for the team winning the game? In daily life, we are constantly presented with a variety of questions such as these about the causes of events. Given its prevalence and importance, we should hope to understand how people make causal judgments. But driven by a longstanding debate in philosophy, the psychology of causal judgment is fragmented between two concepts of causation. Productive concepts follow the intuition that causes interact with their effects through a chain of transmissions of quantities like force and energy. On the other hand, dependence concepts assume that causes make a difference to their effects in that if the cause had been different, the effect would also have been different. In this dissertation, I present six experiments demonstrating that causal judgment has a modal and metacognitive character, and I argue that dependence concepts alone can explain both of these characters. Specifically, in Chapter 2 and Chapter 3, I find that people make causal judgments in ways that are consistent with the idea that they do so by imagining alternative possibilities, and they even move their eyes to visually imagine these possibilities. In Chapter 4 and Chapter 5, I find that people qualify their causal judgments by their confidence in these judgments in systematic ways. Throughout these six experiments, these patterns in causal judgments are well-described by a particular dependence concept of causation known as counterfactual sampling models. Moreover, productive concepts of causation are unable to make similar predictions. I conclude by suggesting that people make causal judgments by imagining alternative possibilities and by discussing the implications of this result for psychology and philosophy.

Counterfactual thinking is a spontaneously occurring process that involves imagining alternative versions of events that have already transpired. By creating “what if” and “if only” scenarios, people use the emotions of these new simulations to alter their perception of what actually occurred. These emotional changes then influence later behavior. While this process is largely automatic, counterfactual thinking can be intentionally utilized to alter the emotional response to a memory. By examining counterfactual thinking as an emotion regulation technique, we can begin to use this method to combat behaviors such as worry and rumination that are associated with maladaptive mental simulation. In my dissertation, I first provide a process model of counterfactual thinking, complete with the emotional consequences of each step, that is then compared to the existing process model of emotion regulation. I then present a series of experiments utilizing counterfactual thinking in a variety of emotion regulation contexts. Using self-report, psychophysiology, and functional magnetic imaging, this research begins to integrate the fields of counterfactual thinking and emotion regulation. Through this work, I find that creating alternative versions of events can effectively reduce the negativity of an emotional response to a memory. Importantly, intentional counterfactual thinking is especially effective for people who report higher levels of trait anxiety symptomology. Possible mechanisms and future implications of regulatory counterfactual thinking are discussed with suggestions on how to better integrate the areas of counterfactual thinking and emotion regulation.