I mind
Functional connectome fingerprinting: Identifying individuals using patterns of brain connectivity
Emily Finn et al.
Nature Neuroscience, November 2015, Pages 1664-1671
Abstract:
Functional magnetic resonance imaging (fMRI) studies typically collapse data from many subjects, but brain functional organization varies between individuals. Here we establish that this individual variability is both robust and reliable, using data from the Human Connectome Project to demonstrate that functional connectivity profiles act as a 'fingerprint' that can accurately identify subjects from a large group. Identification was successful across scan sessions and even between task and rest conditions, indicating that an individual's connectivity profile is intrinsic, and can be used to distinguish that individual regardless of how the brain is engaged during imaging. Characteristic connectivity patterns were distributed throughout the brain, but the frontoparietal network emerged as most distinctive. Furthermore, we show that connectivity profiles predict levels of fluid intelligence: the same networks that were most discriminating of individuals were also most predictive of cognitive behavior. Results indicate the potential to draw inferences about single subjects on the basis of functional connectivity fMRI.
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Physical Activity Benefits Creativity: Squeezing a Ball for Enhancing Creativity
JongHan Kim
Creativity Research Journal, Fall 2015, Pages 328-333
Abstract:
Studies in embodied cognition show that physical sensations, such as touch and movement, influence cognitive processes. Two studies were conducted to test whether squeezing a soft versus a hard ball facilitates different types of creativity. Squeezing a malleable ball would increase divergent creativity by catalyzing multiple or alternative ideas, whereas squeezing a hard ball would increase convergent creativity by facilitating only a single correct response. In Study 1, participants squeezed either a hard ball or a soft ball while completing the Torrance Test of Creative Thinking (TTCT), a divergent creativity test. The same procedures were used in Study 2 except that the TTCT was replaced with the Remote Associates Test, a convergent creativity test. Participants who squeezed a soft ball generated more original and diverse ideas (Study 1), whereas participants who squeezed a hard ball were better at coming up with a single correct answer (Study 2).
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Taylor Hayes & Alexander Petrov
Journal of Cognitive Neuroscience, forthcoming
Abstract:
The ability to adaptively shift between exploration and exploitation control states is critical for optimizing behavioral performance. Converging evidence from primate electrophysiology and computational neural modeling has suggested that this ability may be mediated by the broad noradrenergic projections emanating from the locus coeruleus (LC) [Aston-Jones, G., & Cohen, J. D. An integrative theory of locus coeruleus-norepinephrine function: Adaptive gain and optimal performance. Annual Review of Neuroscience, 28, 403-450, 2005]. There is also evidence that pupil diameter covaries systematically with LC activity. Although imperfect and indirect, this link makes pupillometry a useful tool for studying the locus coeruleus noradrenergic system in humans and in high-level tasks. Here, we present a novel paradigm that examines how the pupillary response during exploration and exploitation covaries with individual differences in fluid intelligence during analogical reasoning on Raven's Advanced Progressive Matrices. Pupillometry was used as a noninvasive proxy for LC activity, and concurrent think-aloud verbal protocols were used to identify exploratory and exploitative solution periods. This novel combination of pupillometry and verbal protocols from 40 participants revealed a decrease in pupil diameter during exploitation and an increase during exploration. The temporal dynamics of the pupillary response was characterized by a steep increase during the transition to exploratory periods, sustained dilation for many seconds afterward, and followed by gradual return to baseline. Moreover, the individual differences in the relative magnitude of pupillary dilation accounted for 16% of the variance in Advanced Progressive Matrices scores. Assuming that pupil diameter is a valid index of LC activity, these results establish promising preliminary connections between the literature on locus coeruleus noradrenergic-mediated cognitive control and the literature on analogical reasoning and fluid intelligence.
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Language and Memory Improvements following tDCS of Left Lateral Prefrontal Cortex
Erika Hussey et al.
PLoS ONE, November 2015
Abstract:
Recent research demonstrates that performance on executive-control measures can be enhanced through brain stimulation of lateral prefrontal regions. Separate psycholinguistic work emphasizes the importance of left lateral prefrontal cortex executive-control resources during sentence processing, especially when readers must override early, incorrect interpretations when faced with temporary ambiguity. Using transcranial direct current stimulation, we tested whether stimulation of left lateral prefrontal cortex had discriminate effects on language and memory conditions that rely on executive-control (versus cases with minimal executive-control demands, even in the face of task difficulty). Participants were randomly assigned to receive Anodal, Cathodal, or Sham stimulation of left lateral prefrontal cortex while they (1) processed ambiguous and unambiguous sentences in a word-by-word self-paced reading task and (2) performed an n-back memory task that, on some trials, contained interference lure items reputed to require executive-control. Across both tasks, we parametrically manipulated executive-control demands and task difficulty. Our results revealed that the Anodal group outperformed the remaining groups on (1) the sentence processing conditions requiring executive-control, and (2) only the most complex n-back conditions, regardless of executive-control demands. Together, these findings add to the mounting evidence for the selective causal role of left lateral prefrontal cortex for executive-control tasks in the language domain. Moreover, we provide the first evidence suggesting that brain stimulation is a promising method to mitigate processing demands encountered during online sentence processing.
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Sharon Zmigrod, Lorenza Colzato & Bernhard Hommel
Creativity Research Journal, Fall 2015, Pages 353-360
Abstract:
Creativity has been conceptualized as involving 2 distinct components; divergent thinking, the search for multiple solutions to a single problem, and convergent thinking, the quest for a single solution either through an analytical process or the experience of insight. Studies have demonstrated that these abilities can be improved by cognitive stimulation, mood, and meditation. This investigation examined whether convergent and divergent thinking can be enhanced by noninvasive transcranial direct current stimulation (tDCS). In different sessions, participants received bilateral stimulation over the dorsolateral prefrontal cortex-DLPFC (Experiment1) and over the posterior parietal cortex-PPC (Experiment2), while performing the Compound Remote Associative task (CRA) assessing convergent thinking and the Alternative Uses Task (AUT) assessing divergent thinking. In Experiment1, anodal-left cathodal-right stimulation over the DLPFC significantly enhanced CRA performance. In Experiment2, stimulations over the PPC significantly increased insight solutions and decreased analytical solutions compared to the no stimulation condition. These findings provide direct evidence for the role of the left DLPFC in convergent and divergent thinking and a mediating role of the PPC in problem-solving behavior, presumably through attentional processes. From a methodological perspective, brain stimulation can be used as a tool to modulate and to explore components of creativity.