Aljoscha C. Neubauer

Intelligence and neural efficiency.

We review research on the neural efficiency hypothesis of intelligence, stating that brighter individuals display lower (more efficient) brain activation while performing cognitive tasks [Haier, R.J., Siegel, B.V., Nuechterlein, K.H., Hazlett, E., Wu, J.C., Paek, J., Browning, H.L., Buchsbaum, M.S., 1988. Cortical glucose metabolic rate correlates of abstract reasoning and attention studied with positron emission tomography. Intelligence 12, 199-217]. While most early studies confirmed this hypothesis later research has revealed contradictory evidence or has identified some moderating variables like sex, task type, task complexity or brain area. Neuroscientific training studies suggest that neural efficiency also seems to be a function of the amount and quality of learning. From integrating this evidence we conclude that neural efficiency might arise when individuals are confronted with tasks of (subjectively) low to moderate task difficulty and it is mainly observable for frontal brain areas. This is true for easier novel cognitive tasks or after sufficient practice allowing participants to develop appropriate (efficient) strategies to deal with the task. In very complex tasks more able individuals seem to invest more cortical resources resulting in positive correlations between brain usage and cognitive ability. Based on the reviewed evidence we propose future empirical approaches in this field.

The creative brain: Investigation of brain activity during creative problem solving by means of EEG and FMRI

Cortical activity in the EEG alpha band has proven to be particularly sensitive to creativity‐related demands, but its functional meaning in the context of creative cognition has not been clarified yet. Specifically, increases in alpha activity (i.e., alpha synchronisation) in response to creative thinking can be interpreted in different ways: As a functional correlate of cortical idling, as a sign of internal top‐down activity or, more specifically, as selective inhibition of brain regions. We measured brain activity during creative thinking in two studies employing different neurophysiological measurement methods (EEG and fMRI). In both studies, participants worked on four verbal tasks differentially drawing on creative idea generation. The EEG study revealed that the generation of original ideas was associated with alpha synchronisation in frontal brain regions and with a diffuse and widespread pattern of alpha synchronisation over parietal cortical regions. The fMRI study revealed that task performance was associated with strong activation in frontal regions of the left hemisphere. In addition, we found task‐specific effects in parietotemporal brain areas. The findings suggest that EEG alpha band synchronisation during creative thinking can be interpreted as a sign of active cognitive processes rather than cortical idling. Hum Brain Mapp, 2009.

Superior performance and neural efficiency : The impact of intelligence and expertise

Superior cognitive performance can be viewed from an intelligence perspective, emphasising general properties of the human information processing system (such as mental speed and working memory), and from an expertise perspective, highlighting the indispensable role of elaborated domain-specific knowledge and acquired skills. In exploring its neurophysiological basis, recent research has provided considerable evidence of the neural efficiency hypothesis of intelligence, indicating lower and more focussed brain activation in brighter individuals. The present EEG study investigates the impacts of intelligence and expertise on cognitive performance and the accompanying cortical activation patterns in the domain of tournament chess. Forty-seven tournament chess players of varying intelligence and expertise level worked on tasks drawing on mental speed, memory, and reasoning. Half of the tasks were representative for chess, while the other half was not. The cortical activation was quantified by means of event-related desynchronisation (ERD) in the upper alpha band. Independent effects of expertise and intelligence emerged at both, the performance and the neurophysiological level. Brighter participants performed better than less intelligent ones which was associated with more efficient brain functioning (lower ERD) across all tasks. Additionally, a high expertise level was beneficial for good task performance but exerted a topographically differentiated influence on the cortical activation patterns. The findings suggest that superior cognitive performance and the underlying cortical activation are not only a function of knowledge and domain-specific competences but also of the general efficiency of the information processing system.

Brain correlates underlying creative thinking: EEG alpha activity in professional vs. novice dancers

Neuroscientific research on creativity has revealed valuable insights into possible brain correlates underlying this complex mental ability domain. However, most of the studies investigated brain activity during the performance of comparatively simple (verbal) type of tasks and the majority of studies focused on samples of the normal population. In this study we investigate EEG activity in professional dancers (n=15) who have attained a high level of expertise in this domain. This group was compared with a group of novices (n=17) who have only basic experience in dancing and completed no comprehensive training in this field. The EEG was recorded during performance of two different dancing imagery tasks which differed with respect to creative demands. In the first task participants were instructed to mentally perform a dance which should be as unique and original as possible (improvisation dance). In the waltz task they were asked to imagine dancing the waltz, a standard dance which involves a sequence of monotonous steps (lower creative demands). In addition, brain activity was also measured during performance of the Alternative Uses test. We observed evidence that during the generation of alternative uses professional dancers show stronger alpha synchronization in posterior parietal brain regions than novice dancers. During improvisation dance, professional dancers exhibited more right-hemispheric alpha synchronization than the group of novices did, while during imagining dancing the waltz no significant group differences emerged. The findings complement and extend existing findings on the relationship between EEG alpha activity and creative thinking.

Intelligence and Spatiotemporal Patterns of Event-Related Desynchronization (ERD)

Abstract Recently, several studies have reported negative associations between brain activity under cognitive load and psychometric intelligence. The position emission tomography (PET) used in these studies allows a high spatial resolution, but it does not permit an assessment of the temporal course of cerebral activation. Therefore, this study examined the relationship between psychometric intelligence (determined by Ravens Advanced Progressive Matrices) and spatiotemporal patterns of cortical activation. Seventeen university students performed an elementary cognitive task, the Sentence Verification Test (SVT), during which the electroencephalogram (EEG) was recorded. In the EEG, the event-related desynchronization (ERD) was quantified, which can be interpreted as a correlate of cortical activation. Lower IQ participants displayed a comparatively unspecific cortical activation increasing with time, whereas higher IQ participants were characterized by a temporal development of activation in those cortical regions that are required for task performance, resulting in less overall activation as compared to the lower IQ participants. These findings support the hypothesis of a more efficient use of the brain in higher IQ individuals.

To create or to recall? Neural mechanisms underlying the generation of creative new ideas

This fMRI study investigated brain activation during creative idea generation using a novel approach allowing spontaneous self-paced generation and expression of ideas. Specifically, we addressed the fundamental question of what brain processes are relevant for the generation of genuinely new creative ideas, in contrast to the mere recollection of old ideas from memory. In general, creative idea generation (i.e., divergent thinking) was associated with extended activations in the left prefrontal cortex and the right medial temporal lobe, and with deactivation of the right temporoparietal junction. The generation of new ideas, as opposed to the retrieval of old ideas, was associated with stronger activation in the left inferior parietal cortex which is known to be involved in mental simulation, imagining, and future thought. Moreover, brain activation in the orbital part of the inferior frontal gyrus was found to increase as a function of the creativity (i.e., originality and appropriateness) of ideas pointing to the role of executive processes for overcoming dominant but uncreative responses. We conclude that the process of idea generation can be generally understood as a state of focused internally-directed attention involving controlled semantic retrieval. Moreover, left inferior parietal cortex and left prefrontal regions may subserve the flexible integration of previous knowledge for the construction of new and creative ideas.

Intelligence and Neural Efficiency: The Influence of Task Content and Sex on the Brain-IQ Relationship.

In studying physiological correlates of human intelligence, new brain imaging techniques like positron emission tomography (PET) and electroencephalography (EEG) mapping methods focus on the level and topographical distribution of cortical activation. Actually, there is strong empirical evidence that more intelligent individuals display a more focused cortical activation during cognitive performance resulting in lower total brain activation than in less intelligent individuals (i.e., neural efficiency hypothesis). Former studies have used only single, homogeneous tasks and most of the studies have been performed using males. Therefore, here the influence of different task content and of sex on the relationship between intelligence and cortical activation has been tested. In a sample of 26 males and 25 females, we administered verbal, numerical, and figural versions of a well-known elementary cognitive task, the so-called Posner task. Our results suggest a comparatively low cortical activation in brighter as compared to less intelligent individuals but this expected neural efficiency pattern interacted with sex and task content: In the verbal Posner task, the females were more likely to produce cortical activation patterns in line with the neural efficiency hypothesis, whereas in the figural task, primarily the males displayed the expected inverse relationship between IQ and cortical activation.

Psychometric comparison of two circadian rhythm questionnaires and their relationship with personality

Abstract Two questionnaires for the measurement of individual differences in circadian phase position (morningness-eveningness) were psychometrically evaluated and compared: the widely used Morningness-Eveningness Questionnaire (MEQ) by Horne and Ostberg (International Journal of Chronobiology, 4, 97–110, 1976) and the Marburger questionnaire by Moog (Night and shift work: biological and social aspects. Oxford: Pergamon Press, 1981). Further instruments given to the sample (113 undergraduate students) were the EPI and a 2-week sleep/waking diary. In addition, two groups of extreme morning and evening types measured their own oral temperature throughout several days. Both circadian rhythm questionnaires proved reliable and valid (with respect to sleep/waking behaviour and oral temperature), although some deficiences were found for the MEQ with regard to its multidimensionality, skewness of distributions and a negative correlation with neuroticism. In line with previous research, a weak negative relationship of morningness-eveningness with extraversion was observed for both questionnaires. Impulsivity, rather than sociability, seemed to be the component responsible for this association. Effects of sex and age were only partially in line with previous findings.

EEG alpha synchronization is related to top-down processing in convergent and divergent thinking

Highlights ► The functional meaning of EEG alpha synchronization was investigated. ► An experimental manipulation of internal processing demands was achieved. ► Frontal alpha synchronization is related to top-down processing. ► Alpha desynchronization is related to bottom-up processing. ► Alpha synchronization in creative thinking is attributed to top-down processing.

Sensitivity of human EEG alpha band desynchronization to different working memory components and increasing levels of memory load

Event-related alpha band desynchronization is frequently used to analyze spatiotemporal cortical activation patterns during the performance of cognitive tasks. In the present paper the sensitivity of alpha band desynchronization to increasing levels of cognitive load and to different cognitive working memory components is investigated. A 27-channel electroencephalogram of 62 participants while solving (a) a short-term memory and (b) a working memory task (dual task), each with five levels of memory load, was analyzed. We found (a) a linearly increasing desynchronization in the upper alpha band with ascending cognitive load, and (b) evidence of the involvement of distinguishable cognitive components (storage and controlled attention) in the memory tasks.