As we go about our daily lives, we are constantly exposed to new information―news reports from a foreign country, politicians’ statements about domestic policy, a friend’s description of a new restaurant, and celebrity gossip. Some of that information is true and some is false.
How do we remember which statements are true and which are false? Modern psychologists frame this debate around the writings of two long dead philosophers, Baruch Spinoza and René Descartes. These 17th century European philosophers helped establish the philosophical tradition of rationalism.
Both philosophers wrote extensively about the nature of truth and how we come to understand the world around us. In particular, Spinoza wrote that “will and understanding are one and the same.” Modern philosophers have taken this to mean that all information is initially believed. Thus, according to the Spinozan model, in order to comprehend a statement, we first assume that it is true. Then, only if we have the mental energy, we mark false statements as “false”. Therefore, anything we retrieve from memory is assumed to be true, unless it is explicitly labelled as false.
In contrast, Descartes believed in free will and that we can “withhold our assent in doubtful matters and hence avoid error.” Thus, the Cartesian model assumes newly learned statements are initially untagged by default, and that with knowledge and mental energy we label true statements as “true” and false statements as “false”.
One way to test these two models is to examine what happens when people learn information while they are distracted by a second task. In the Spinozan model, all statements are initially believed to be true and then, with effort, some statements are labelled as false. Thus, if people are distracted while learning which statements are true or false, it should only affect their memory for what’s false. In contrast, in the Cartesian model it takes effort to mark a statement as true or false. Therefore, distraction should impair memory for both true and false statements.
Initial studies supported the Spinozan model of the mind. Distraction impaired people’s ability to label the false statements as “false”, but had no effect on accuracy for true statements. However, more recent studies have placed limits on that account. The Spinozan view of the mind does not hold when people have strong background knowledge. For example, people are able to quickly and easily recognize statements like “soft soap is edible” as false, even with distraction. The Spinozan model also fails for statements that are informative when false such as “Amy is liberal”. Instead of remembering the statement plus a “false” tag, people remember that “Amy is conservative”.
A recent article in the Psychonomic Society’s journal Memory & Cognition shines new light on the debate between Spinoza and Descartes. The authors, Lena Nadarevic and Edgar Erdfelder, hypothesized that prior work supporting the Spinozan model may have been contaminated by guessing biases. When people are unsure if a statement is true or false, they have a bias to guess that it is true. (Most things that most people tell us are true). This bias can lead to responding that looks like it was produced by a Spinozan model, even if both true and false statements are labelled in memory.
In their Experiment 1, participants were asked to imagine that they would be participating in a trivia game show. In preparation, they would have to memorize whether a series of statements were true or false. The participants would then see a trivia statement (e.g., “Manamas is the capital of Bahrain”) followed by whether that statement was “true”, “false” or of “uncertain” veracity. Importantly, all of the statements were relatively obscure and participants had no prior knowledge of whether they were true or false.
Participants in the interruption group were told that while they were studying they would be interrupted by their mother or little brother. Every time that the true/false/uncertain feedback was presented, a picture would appear (simulating the interruption) and participants had to decide whether it was a woman or a boy. Participants in the control group were not interrupted.
On a final memory task, participants were shown new and old statements and were asked to indicate whether each statement was old or new, and if it was old, whether it was labelled as true, false, or uncertain at the first presentation.
Consistent with the Cartesian model, interruption impaired memory for both the true and false feedback. This pattern appeared both with typical measures of source memory accuracy (left panel in the figure below) and when the authors modeled the effects of statement memory, feedback memory, and guessing on responses (right panel).
In Experiment 2, the authors used stimuli more similar to those from the original studies supporting the Spinozan model. Participants were told to imagine that they were travelling and needed to learn a new language. They then saw a series of translations (e.g., “A monishna is a star”) and were told if each translation was correct (i.e., true, false or uncertain). Again, some participants were interrupted while viewing the feedback and others were not.
Replicating prior work, interruption impaired memory for false statements, but did not affect memory for true statements. This is the pattern that would be expected given a Spinozan model. (See the figure below).
However, when the authors modeled the contributions of statement memory, feedback memory and guessing, a different picture emerged. Interruption impaired memory for true statements, but not for false or uncertain statements. Participants were more likely to guess that statements were “true” in the interruption condition. This pattern contradicts both the Spinozan and Cartesian models.
So who was right, Descartes or Spinoza? Likely neither. Nadarevic and Erdfelder propose that we use both true and false tags as proposed by Descartes, but that those tags are optional.
We only tag information when it would be informative to do so. When trying to learn a new language, learning that a translation is false is not informative, and therefore we may not devote mental energy to remembering that information. In contrast, with a trivia quiz, it is useful both to know what answers are correct and which answers are incorrect, and hence we get busy tagging in those circumstances.
Perhaps it’s time to leave Descartes and Spinoza in their graves. Depending on the context, our minds focus on remembering the most useful and relevant information. There are no absolutes.
Psychonomics article considered in this blog post:
Nadarevic, L., & Erdfelder, E. (2019). More evidence against the Spinozan model: Cognitive load diminishes memory for “true” feedback. Memory & Cognition, 1-15. DOI: 10.3758/s13421-019-00940-6.