Vividness as the similarity between generated imagery and an internal model

The relevancy of the relevance: Different aspects of relevancy during emotional episodes evaluations

The present research investigates the effect of relevance on our subjective experience while generating alternative events in our mind. To accomplish this aim, we asked participants to read and visualize 280 situations outlined in concise scripts. During each trial, they evaluated the relevance of the situation and other aspects of their metacognitive and emotional experience using a Likert scale ranging from 1 to 9. We employ PLS-SEM (partial least squares structural equation modelling) to investigate a potential causal sequence among three tiers of latent components. Specifically, the situational level consists of relevancy and plausibility factors, the metacognitive level consists of an imaginability factor, and the subjective experience level consists of feeling and thought suppression factors. Our analysis indicates that the effect of the plausibility of alternative scenarios on subjective experience is mediated by both the relevance and imageability factors, regardless of whether events are negative or positive. Furthermore, we successfully replicated the negativity rejection bias shown in our prior work. This bias refers to the tendency of participants to perceive bad events as less likely to occur than good events, independent of the precise details of those events.

A Systematic Review of Aphantasia: Concept, Measurement, Neural Basis, and Theory Development

People with aphantasia exhibit the inability to voluntarily generate or form mental imagery in their minds. Since the term "aphantasia" was proposed to describe this, it has gained increasing attention from psychiatrists, neuroscientists, and clinicians. Previous studies have mainly focused on the definition, prevalence, and measurement of aphantasia, its impacts on individuals' cognitive and emotional processing, and theoretical frameworks synthesizing existing findings, which have contributed greatly to our understanding of aphantasia. However, there are still some debates regarding the conclusions derived from existing research and the theories that were constructed from various sources of evidence. Building upon existing endeavors, this systematic review emphasizes that future research is much needed to refine the definition and diagnosis of aphantasia, strengthen empirical investigations at behavioral and neural levels, and, more importantly, develop or update theories. These multiple lines of efforts could lead to a deeper understanding of aphantasia and further guide researchers in future research directions.

Behavioral and Neural Correlates of Visual Working Memory Reveal Metacognitive Aspects of Mental Imagery

Mental imagery (MI) is the ability to generate visual phenomena in the absence of sensory input. MI is often likened to visual working memory (VWM): the ability to maintain and manipulate visual representations. How MI is recruited during VWM is yet to be established. In a modified orientation change-discrimination task, we examined how behavioral (proportion correct) and neural (contralateral delay activity [CDA]) correlates of precision and capacity map onto subjective ratings of vividness and number of items in MI within a VWM task. During the maintenance period, 17 participants estimated the vividness of their MI or the number of items held in MI while they were instructed to focus on either precision or capacity of their representation and to retain stimuli at varying set sizes (1, 2, and 4). Vividness and number ratings varied over set sizes; however, subjective ratings and behavioral performance correlated only for vividness rating at set size 1. Although CDA responded to set size as was expected, CDA did not reflect subjective reports on high and low vividness and on nondivergent (reported the probed number of items in mind) or divergent (reported number of items diverged from probed) rating trials. Participants were more accurate in low set sizes compared with higher set sizes and in coarse (45°) orientation changes compared with fine (15°) orientation changes. We failed to find evidence for a relationship between the subjective sensory experience of precision and capacity of MI and the precision and capacity of VWM.