The transliminal brain at rest: baseline EEG, unusual experiences, and access to unconscious mental activity.

Transliminality reflects individual differences in the threshold at which unconscious processes or external stimuli enter into consciousness. Individuals high in transliminality possess characteristics such as magical ideation, belief in the paranormal, and creative personality traits, and also report the occurrence of manic/mystic experiences. The goal of the present research was to determine if resting brain activity differs for individuals high versus low in transliminality.

A brain mechanism for facilitation of insight by positive affect.

Previous research has shown that people solve insight or creative problems better when in a positive mood (assessed or induced), although the precise mechanisms and neural substrates of this facilitation remain unclear. We assessed mood and personality variables in 79 participants before they attempted to solve problems that can be solved by either an insight or an analytic strategy. Participants higher in positive mood solved more problems, and specifically more with insight, compared with participants lower in positive mood.

Hemispheric differences in processing the literal interpretation of idioms: converging evidence from behavioral and fMRI studies.

The present study examined the role of the left (LH) and right (RH) cerebral hemispheres in processing alternative meanings of idiomatic sentences. We conducted two experiments using ambiguous idioms with plausible literal interpretations as stimuli. In the first experiment we tested hemispheric differences in accessing either the literal or the idiomatic meaning of idioms for targets presented to either the left or the right visual field.

Inferences during story comprehension: cortical recruitment affected by predictability of events and working memory capacity.

Although it has been consistently shown that readers generate bridging inferences during story comprehension, little is currently known about the neural substrates involved when people generate inferences and how these substrates shift with factors that facilitate or impede inferences, such as whether inferences are highly predictable or unpredictable. In the current study, functional magnetic resonance imaging (fMRI) signal increased for highly predictable inferences (relative to events that were previously explicitly stated) bilaterally in both the superior temporal gyri and the inferior frontal gyri. Interestingly, high working memory capacity comprehenders, who are most likely to generate inferences during story comprehension, showed greater signal increases than did low working memory capacity comprehenders in the right superior temporal gyrus and right inferior frontal gyrus.

The origins of insight in resting-state brain activity.

People can solve problems in more than one way. Two general strategies involve (A) methodical, conscious, search of problem-state transformations, and (B) sudden insight, with abrupt emergence of the solution into consciousness. This study elucidated the influence of initial resting brain-state on subjects' subsequent strategy choices.

Methods for investigating the neural components of insight.

The authors describe how they have used visual-hemifield and event-related neuroimaging approaches to study their theory specifying some of the neural components of insight. A set of problems developed by the authors, and the use of solvers' self reports of insight, are presented to argue that advances in our understanding of insight are being unnecessarily stifled by over reliance on traditional insight problems and a widespread failure to determine whether insight has occurred on a solution-by-solution basis.

The prepared mind: neural activity prior to problem presentation predicts subsequent solution by sudden insight.

Insight occurs when problem solutions arise suddenly and seem obviously correct, and is associated with an "Aha!" experience. Prior theorizing concerning preparation that facilitates insight focused on solvers' problem-specific knowledge. We hypothesized that a distinct type of mental preparation, manifested in a distinct brain state, would facilitate insight problem solving independently of problem-specific knowledge.

Neural activity of inferences during story comprehension.

In this event-related functional magnetic resonance imaging (fMRI) study, participants listened to and comprehended short stories implying or explicitly stating inference events. The aim of this study was to examine the neural mechanisms that underlie inference generation, a process essential to successful comprehension. We observed distinct patterns of increased fMRI signal for implied over explicit events at two critical points during the stories: (1) within the right superior temporal gyrus when a verb in the text implied the inference; and (2) within the left superior temporal gyrus at the coherence break or when participants need to generate an inference to understand the story.

Bilateral brain processes for comprehending natural language.

Comprehension of natural language--stories, conversations, text--is very simple for those doing the comprehending and very complex for cognitive neuroscientists. It also presents a paradox: the advantage of the left hemisphere (LH) for most language tasks is one of the best-established facts about the brain; yet, when it comes to comprehending complex, natural language, the right hemisphere (RH) might play an important role. Accumulated evidence from neuropsychology, neuroimaging, and neuroanatomy suggests at least three roughly separable (but highly interactive) components of semantic processing.

New approaches to demystifying insight.

After a person has become stuck on a problem, they sometimes achieve a clear and sudden solution through insight--the so-called Aha! experience. Because of its distinctive experience, the origins and characteristics of insight have received considerable attention historically in psychological research. However, despite considerable progress in characterizing insight, the underlying mechanisms remain mysterious.

Neural activity when people solve verbal problems with insight.

People sometimes solve problems with a unique process called insight, accompanied by an "Aha!" experience. It has long been unclear whether different cognitive and neural processes lead to insight versus noninsight solutions, or if solutions differ only in subsequent subjective feeling. Recent behavioral studies indicate distinct patterns of performance and suggest differential hemispheric involvement for insight and noninsight solutions.

Normative data for 144 compound remote associate problems.

We have developed and tested 144 compound remote associate problems. Across eight experiments, 289 participants were given four time limits (2 sec, 7 sec, 15 sec, or 30 sec) for solving each problem. This paper provides a brief overview of the problems and normative data regarding the percentage of participants solving, and mean time-to-solution for, each problem at each time limit.

Aha! Insight experience correlates with solution activation in the right hemisphere.

In one experiment, we tested for an association between semantic activation in the right hemisphere (RH) and left hemisphere (LH) and the Aha! experience when people recognize solutions to insight-like problems. The compound remote associate problems used in this experiment sometimes evoke an Aha! experience and sometimes do not. On each trial, participants (N = 44) attempted to solve these problems and, after 7 sec, named a target word, made a solution decision, and rated their insight experience of recognizing the solution.