Michael W. O'Boyle

Enhanced brain connectivity in math-gifted adolescents: An fMRI study using mental rotation

Mathematical giftedness is a form of intelligence related to enhanced mathematical reasoning that can be tested using a variety of numerical and spatial tasks. A number of neurobiological mechanisms related to exceptional mathematical reasoning ability have been postulated, including enhanced brain connectivity. We aimed to further investigate this possibility by comparing a group of mathematically gifted adolescents with an average math ability control group performing mental rotation of complex three-dimensional block figures. Functional magnetic resonance imaging (fMRI) data were collected and differences in intrahemispheric and interhemispheric connectivity between the groups were assessed using structural equation modeling (SEM). The math-gifted showed heightened intrahemispheric frontoparietal connectivity, as well as enhanced interhemispheric frontal connectivity between the dorsolateral prefrontal and premotor cortex. These enhanced connectivity patterns are consistent with previous studies linking increased activation of the frontal and parietal regions with high fluid intelligence, and may be a unique neural characteristic of the mathematically gifted brain.

How Sex, Native Language, and College Major Relate to the Cognitive Strategies Used during 3-D Mental Rotation.

Eighty college students mentally rotated 3-D shapes while maintaining a concurrent verbal or spatial memory load to investigate how sex, native language, and college major relate to the cognitive strategies employed during mental rotation (MR). Males were significantly better than females at MR, whereas native language was not related to MR ability or preferred strategy. A significant Sex × Major × Load interaction was found such that males majoring in the physical sciences performed better when primed by a concurrent spatial load as compared with a no-load or verbal load, suggesting their use of a spatially mediated MR strategy. In contrast, males majoring in the social sciences performed better when primed by a concurrent verbal load as compared with a no-load or spatial load, suggesting their use of a verbal/analytic MR strategy. The potential origins of these differences in strategy are discussed in the context of individual differences in brain organization.

Attentional network deficits in children with autism spectrum disorder.

Abstract Statement of purpose: Individuals with autism spectrum disorder (ASD) often demonstrate deficient attentional ability, but the specific nature of the deficit is unclear. The Attention Networks model provides a useful approach to deconstruct this attentional deficit into its component parts. Method: Fifty-two neurotypical (NT) children and 14 children with ASD performed the child version of the Attention Network Test (ANT). The latter requires participants to indicate the direction of a centre target stimulus, which is presented above/below fixation and sometimes flanked by either congruent or incongruent distractor stimuli. Results: Relative to NT children, those with ASD were: (1) slower to react to spatially cued trials and (2) more error prone on executive (conflict) attention trials. Conclusions: Young children with ASD have intact alerting attention, but less-efficient orienting and executive attention.

Differences in Mental Rotation Strategies for Native Speakers of Chinese and English and How They Vary as a Function of Sex and College Major.

In this study we examine how native language, sex, and college major interact to influence accuracy and preferred strategy when performing mental rotation (MR). Native monolingual Chinese and English speakers rotated 3-D shapes while maintaining a concurrent verbal or spatial memory load. For English speakers, male physical science majors were more accurate than social science majors and employed a spatial/holistic strategy; male social science majors used a verbal/analytic strategy. Regardless of college major, English-speaking females were not consistent in MR strategy. A small overall advantage in accuracy was found for Chinese speakers, and both male and female Chinese-speaking physical science majors relied on a combined spatial/holistic and verbal/analytic strategy; Chinese-speaking social science majors did not show a strategy preference. Our results suggest that acquiring a logographic language like Chinese may heighten spatial ability and bias one toward a spatial/holistic MR strategy.

Neural Correlates of Nature Stimuli: An fMRI Study

OBJECTIVE: Examine whether there are unique patterns of brain activation associated with exposure to photographic sky compositions (representing nature stimuli) as compared with other positive, negative, and neutral images. BACKGROUND: The positive impact of nature images on health outcomes traditionally has been measured using behavioral and physiological indicators. However, there is a lack of understanding of the underlying neural mechanism that explains this positive influence. METHODS: A combination of behavioral responses and functional magnetic resonance imaging (fMRI) technology was used to address research questions. Ten participants belonging to five age groups were subjected to short (25 seconds) exposures of 32 images while their brain activation was monitored via the BOLD response. In a separate run, participants were subjected to extended exposures (12 minutes) of a sky composition and an image of a traditional ceiling. RESULTS: The results show that the activation patterns produced by sky compositions and positive images were quite similar as compared to negative or neutral images. However, sky compositions also produced some unique areas of activation, including those associated with spatial cognition, the expanse of space, circadian rhythm, and perceived motion. In the extended exposure condition, sky compositions tended to activate regions associated with dreaming, while traditional ceiling images activated regions that are related to face processing and potentially visual hallucinations. CONCLUSIONS: Nature stimuli, with a combination of vegetation and sky, may produce unique beneficial effects not present in general positive stimuli.

Connectivity in math-gifted adolescents: Comparing structural equation modeling, granger causality, and dynamic causal modeling

Major challenges in brain research include understanding how the brain retrieves, processes, and transmits information along with understanding how information is stored. Therefore, connectivity analyses are vital in exploring information flow and temporal interactions between particular brain regions. This paper presents the results of two different types of connectivity analysis on previously acquired fMRI data of mathematically gifted adolescents and control subjects performing a mental rotation task. It has been hypothesized that mathematically gifted children rely on the parietal region and right hemisphere, along with utilizing inter-hemispheric interactions that may be a more efficient network during mental rotation tasks. Granger causality and dynamic causal modeling (DCM) were used to model the connectivity in the two groups. The model outputs are compared with connectivity paths determined from structural equation modeling (SEM) in a previous study [1]. Although these methods can be used as confirmatory and/or exploratory tools, they may provide complementary, rather than redundant, information about connectivity networks within the brain.

A Model of Alzheimer's disease and mild cognitive impairment based on EEG coherence

EEG coherence was used to model the integrity of neural connectivity in patients with Alzheimers Disease (AD), Mild Cognitive Impairment (MCI), and age-matched controls. Our model was derived from the EEG data of 16 AD patients, 24 MCI patients and 16 age-matched controls. We computed the coherence of the relevant channel pairs believed to represent fiber pathways. Coherence values were compared across groups of AD patients, MCI patients, and controls, and the Kruskal-Wallis test was used to determine those channel pairs that exhibited significant differences between MCI or AD patients and controls. Because increased and decreased EEG coherence (relative to controls) has been found to be associated with fiber damage, channel pairs showing significant differences in EEG coherence were rated as damaged. The data show that while AD patients have more damaged pathways than MCI patients, the areas of damage are similar for both groups. The significance of this model is its future application (perhaps in conjunction with white matter imaging techniques) to the development of connectivity models of cognitive decline in AD and MCI patients.

Clustering and modeling of EEG coherence features of Alzheimer's and mild cognitive impairment patients

Using multiple discriminant analysis (MDA) and k-means clustering, coherence features extracted from the EEGs of a group of 56 subjects were analyzed to assess how feasible an automated coherence-based pattern recognition system that detects Alzheimers disease (AD) would be. Sixteen of the subjects were AD patients, 24 were mild cognitive impairment (MCI) patients while 16 were age-matched controls. With MDA, an overall classification rate (CR) of 84% was obtained for AD vs. MCI vs. Controls classifications. The high CR implies that it is possible to distinguish between the three groups. The coherence features were also statistically analyzed to derive a neural model of AD and MCI, which indicated that patients with AD may have a greater number of damaged cortical fibers than their MCI counterparts, and furthermore, that MCI may be an intermediary step in the development of AD.

Mirror neuron activation of musicians and non-musicians in response to motion captured piano performances

HighlightsMusicians/non‐musicians viewed “stick‐like” motion captured piano performances.Musicians activated more mirror neurons to pieces played in an “enjoyment” mode.Greater mirror neuron activity in response to “enjoyment” to “correct mode”.Mirror neuron activation is modulated by musical expertise.Activation in musicians may stem from imagining themselves playing the piece. Abstract Mirror neurons (MNs) activate when performing an action and when an observer witnesses the same action performed by another individual. Functional magnetic resonance imaging (fMRI) and presentation of motion captured piano performances were used to identify differences in MN activation for musicians/non‐musicians when viewing piano pieces played in a “Correct” mode (i.e., emphasis on technical correctness) or an “Enjoyment” mode (i.e., simply told to “enjoy” playing the piece). Results showed greater MN activation in a variety of brain regions for musicians, with these differences more pronounced in the “Enjoyment” mode. Our findings suggest that activation of MNs is not only initiated by the imagined action of an observed movement, but such activation is modulated by the level of musical expertise and knowledge of associated motor movements that the observer brings to the viewing situation. Enhanced MN activation in musicians may stem from imagining themselves actually playing the observed piece.

fMRI activation patterns in an analytic reasoning task: consistency with EEG source localization

Functional magnetic resonance imaging (fMRI) is used to model brain activation patterns associated with various perceptual and cognitive processes as reflected by the hemodynamic (BOLD) response. While many sensory and motor tasks are associated with relatively simple activation patterns in localized regions, higher-order cognitive tasks may produce activity in many different brain areas involving complex neural circuitry. We applied a recently proposed probabilistic independent component analysis technique (PICA) to determine the true dimensionality of the fMRI data and used EEG localization to identify the common activated patterns (mapped as Brodmann areas) associated with a complex cognitive task like analytic reasoning. Our preliminary study suggests that a hybrid GLM/PICA analysis may reveal additional regions of activation (beyond simple GLM) that are consistent with electroencephalography (EEG) source localization patterns.