Stimulus Complexity and Chunk Tightness Interact to Impede Perceptual Restructuring During Problem Solving

The mutual influence of stimulus complexity and chunk tightness on perceptual restructuring was examined using a chunk decomposition task (CDT). Participants attempted to remove components of Chinese characters in order to produce new, valid characters. Participants had their electroencephalogram recorded while completing a CDT in conditions of low or high stimulus complexity, crossed with two levels of chunk tightness. Tight chunks overlapped spatially whereas loose chunks did not. Both increasing chunk tightness and increasing stimulus complexity impaired performance (lower accuracy, longer reaction times), and these factors interacted such that highly complex, tight chunks produced the worst performance. These factors also had interacting effects on the late positive complex (LPC). The LPC amplitude was reduced by increasing chunk tightness, but this effect was attenuated for highly complex stimuli. These results suggest that though chunk tightness and stimulus complexity impair performance in the CDT, they have dissociable neural underpinnings

Acute Exercise and Creativity: Embodied Cognition Approaches

This dissertation manuscript is the culmination of three years of research examining several unique, exercise-induced mechanisms underlying creativity. This collection of work addresses historical and current empirical concepts of creativity in a narrative review, providing recommendations for future research. Several reviews follow this introduction, highlighting the proposed effects of exercise on creativity, putative mechanisms for creativity, and the effects of exercise and embodied manipulations on creative behavior. Multiple experiments utilizing moderate-intensity exercise as a theoretical stimulus for higher-order cognitions were conducted to investigate associations between exercise and creativity, which lead to the final dissertation experiment. The dissertation experiment was the first to provide statistically significant evidence for acute, moderate-intensity treadmill exercise coupled with anagram problem-solving to prime subsequent RAT completion compared to a non-exercise, priming only condition. We emphasize that the additive effects of exercise plus priming may be a viable strategy for enhancing verbal convergent creativity. Future research is warranted to explore a variety of priming effects on the relationship between exercise, embodied interventions, and creativityThis dissertation manuscript is the culmination of three years of research examining several unique, exercise-induced mechanisms underlying creativity. This collection of work addresses historical and current empirical concepts of creativity in a narrative review, providing recommendations for future research. Several reviews follow this introduction, highlighting the proposed effects of exercise on creativity, putative mechanisms for creativity, and the effects of exercise and embodied manipulations on creative behavior. Multiple experiments utilizing moderate-intensity exercise as a theoretical stimulus for higher-order cognitions were conducted to investigate associations between exercise and creativity, which lead to the final dissertation experiment. The dissertation experiment was the first to provide statistically significant evidence for acute, moderate-intensity treadmill exercise coupled with anagram problem-solving to prime subsequent RAT completion compared to a non-exercise, priming only condition. We emphasize that the additive effects of exercise plus priming may be a viable strategy for enhancing verbal convergent creativity. Future research is warranted to explore a variety of priming effects on the relationship between exercise, embodied interventions, and creativit

Source Modelling of the Human Hippocampus for MEG

Magnetoencephalography (MEG) is a neuroimaging technique which gives direct non-invasive measurements of neuronal activity with high temporal resolution. Given its increasing use in cognitive and clinical research, it is important to characterize, and ideally improve upon, its advantages and limitations. For example, it is conventionally assumed to be insensitive to deep structures because of their distance from the sensors. Consequently, knowledge about their signal contribution is limited. One deep structure of particular interest is the hippocampus which plays a key role in memory and learning, and in organising temporal flow of information across regions. A large body of rodent studies have demonstrated quantifiable oscillatory underpinnings of these functions, now waiting to be addressed in humans. Due to its high temporal resolution, MEG is ideally suited for doing so but faces technical challenges. Firstly, the source-to-sensor distance is large, making it difficult to obtain sufficiently high signal-to-noise ratio (SNR) data. Secondly, most generative models (which describe the relationship between sensors and signal) include only the cortical surface. Thirdly, errors in co-registering data to an anatomical image easily obstruct or blur hippocampal sources. This thesis tested the hypotheses that a) identification and optimisation of acquisition parameters which improve the SNR, b) inclusion of the hippocampus in the generative model, and c) minimisation of co-registration error, together enable reliable inferences about hippocampal activity from MEG data. We found the most important empirical factor in detecting hippocampal activity using the extended generative model to be co-registration error; that this can be minimised using flexible head-casts; and that combining anatomical modelling, head-casts, and a spatial memory task, allows hippocampal activity to be reliably observed. Hence the work confirmed the overall hypothesis to be valid. Additionally, simulation results revealed that for a new generation of MEG sensors, ~5-fold sensitivity improvements can be obtained but critically depend on low sensor location errors. These findings set down a new basis for time-resolved examination of hippocampal function

Typical and atypical functional specialisation within human prefrontal cortex

The prefrontal cortex (PFC) plays an important role in a range of higher-level cognition including decision-making, social cognition, executing delayed intentions, and creative thinking. Previous studies have proposed a functional specialisation of the PFC region, and that this heterogeneity is associated with both structural and functional typicality between individuals. In order to examine this possibility, a reverse engineering approach was used to develop a PFC battery measuring behaviours relating to gambling, referential judgment, mentalizing, and faux pas detection. 107 typical-developing (TD) adults were recruited to establish the behavioural baseline, and identify the neural correlates of the measures in the PFC battery using voxel-based morphometry (VBM). The VBM analysis revealed significant relationships between different mental abilities and the size of different PFC sub-regions. Subsequently, 34 adults with autism spectrum disorder (ASD; a pathological group diagnosed with deficits on decision-making and social cognition) were tested on the new PFC battery. The results show that it provides new tools for detection of the ASD phenotype, and demonstrated the atypicality of ASD subjects when using single-case analysis. The thesis then turned to the functional specialisation of rostral PFC. A dissociation between lateral vs. medial rostral PFC activation was revealed when executing delayed intentions (the ability referred as prospective memory, or PM), compared with baseline ongoing activities. A novel PM paradigm for use with fMRI was designed to examine the specificity of PM cues. The results demonstrated the role that BA9/46 region plays in the detection of certain vs. uncertain future intentions. The final study examined cross-cultural differences in creativity, a cognitive ability thought to be substantially underpinned by frontal lobe structures. Matched adults from the UK and Taiwan were compared on adapted version of standard measures of creativity. Cross-cultural differences were found on the novelty aspect of the creativity, but not on the usefulness aspect, which seemed to reflect different Eastern vs. Western self-construal. Altogether, the thesis used a range of approaches to highlight functional and structural variation within the PFC region and the mental abilities it supports, demonstrating some principles of organisation that exist across individuals, but also differences between individuals, and between populations of individuals

Multivariate pattern analysis of input and output representations of speech

Repeating a word or nonword requires a speaker to map auditory representations of incoming sounds onto learned speech items, maintain those items in short-term memory, interface that representation with the motor output system, and articulate the target sounds. This dissertation seeks to clarify the nature and neuroanatomical localization of speech sound representations in perception and production through multivariate analysis of neuroimaging data. The major portion of this dissertation describes two experiments using functional magnetic resonance imaging (fMRI) to measure responses to the perception and overt production of syllables and multivariate pattern analysis to localize brain areas containing associated phonological/phonetic information. The first experiment used a delayed repetition task to permit response estimation for auditory syllable presentation (input) and overt production (output) in individual trials. In input responses, clusters sensitive to vowel identity were found in left inferior frontal sulcus (IFs), while clusters responsive to syllable identity were found in left ventral premotor cortex and left mid superior temporal sulcus (STs). Output-linked responses revealed clusters of vowel information bilaterally in mid/posterior STs. The second experiment was designed to dissociate the phonological content of the auditory stimulus and vocal target. Subjects were visually presented with two (non)word syllables simultaneously, then aurally presented with one of the syllables. A visual cue informed subjects either to repeat the heard syllable (repeat trials) or produce the unheard, visually presented syllable (change trials). Results suggest both IFs and STs represent heard syllables; on change trials, representations in frontal areas, but not STs, are updated to reflect the vocal target. Vowel identity covaries with formant frequencies, inviting the question of whether lower-level, auditory representations can support vowel classification in fMRI. The final portion of this work describes a simulation study, in which artificial fMRI datasets were constructed to mimic the overall design of Experiment 1 with voxels assumed to contain either discrete (categorical) or analog (frequency-based) vowel representations. The accuracy of classification models was characterized by type of representation and the density and strength of responsive voxels. It was shown that classification is more sensitive to sparse, discrete representations than dense analog representations

Eye quietness and quiet eye in expert and novice golf performance: an electrooculographic analysis

Quiet eye (QE) is the final ocular fixation on the target of an action (e.g., the ball in golf putting). Camerabased eye-tracking studies have consistently found longer QE durations in experts than novices; however, mechanisms underlying QE are not known. To offer a new perspective we examined the feasibility of measuring the QE using electrooculography (EOG) and developed an index to assess ocular activity across time: eye quietness (EQ). Ten expert and ten novice golfers putted 60 balls to a 2.4 m distant hole. Horizontal EOG (2ms resolution) was recorded from two electrodes placed on the outer sides of the eyes. QE duration was measured using a EOG voltage threshold and comprised the sum of the pre-movement and post-movement initiation components. EQ was computed as the standard deviation of the EOG in 0.5 s bins from –4 to +2 s, relative to backswing initiation: lower values indicate less movement of the eyes, hence greater quietness. Finally, we measured club-ball address and swing durations. T-tests showed that total QE did not differ between groups (p = .31); however, experts had marginally shorter pre-movement QE (p = .08) and longer post-movement QE (p < .001) than novices. A group × time ANOVA revealed that experts had less EQ before backswing initiation and greater EQ after backswing initiation (p = .002). QE durations were inversely correlated with EQ from –1.5 to 1 s (rs = –.48 - –.90, ps = .03 - .001). Experts had longer swing durations than novices (p = .01) and, importantly, swing durations correlated positively with post-movement QE (r = .52, p = .02) and negatively with EQ from 0.5 to 1s (r = –.63, p = .003). This study demonstrates the feasibility of measuring ocular activity using EOG and validates EQ as an index of ocular activity. Its findings challenge the dominant perspective on QE and provide new evidence that expert-novice differences in ocular activity may reflect differences in the kinematics of how experts and novices execute skills

Creative problem solving and automated discovery : an analysis of psychological and AI research

Since creativity is the ability to produce something novel and unexpected, it has always fascinated people. Consequently, efforts have been made in AI to invent creative computer programs. At the same time much effort was spent in psychology to analyze the foundations of human creative behaviour. However, until now efforts in AI to produce creative programs have been largely independent from psychological research. In this study, we try to combine both fields of research. First, we give a short summary of the main results of psychological research on creativity. Based on these results we propose a model of the creative process that emphasizes its information processing aspects. Then we describe AI approaches to the implementation of the various components of this model and contrast them with the results of psychological research. As a result we will not only reveal weaknesses of current AI systems hindering them in achieving creativity, but we will also make plausible suggestions - based on psychological research - for overcoming these weaknesses

Queensland teachers' conceptions of creativity : a phenomenographic investigation

This study investigated conceptions of creativity in a group of Queensland teachers. The analysis of interview data produced precise descriptions of seven categories of meanings of creativity, delimiting the range and variance of meanings expressed. The study provides evidence of two distinct ways of experiencing and defining creativity. As a result the researcher was able to propose further research directions to extend educational understanding of creativity and recommended using the present study findings to strengthen policy and training measures for the Australian Curriculum focus on building creative capital