Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neural efficiency hypothesis confirmed

28.07.2015

The brains of more intelligent people are capable of solving tasks more efficiently, which is why these people have superior cognitive faculties, or as Elsbeth Stern, Professor for Research on Learning and Instruction at ETH Zurich, puts it: "when a more and a less intelligent person are given the same task, the more intelligent person requires less cortical activation to solve the task."

Scientists refer to this as the neural efficiency hypothesis, although it ceased being a hypothesis quite some time ago and is now accepted by experts as an undisputed fact, with ample evidence to support it.


A subject solves a facial recognition task while EEG measurements of electrical activity in his brain are measured.

Credit: Fabio Bergamin / ETH Zurich

While working on her doctoral thesis in Stern's work group, Daniela Nussbaumer also found evidence of this effect for the first time in a group of people possessing above-average intelligence for tasks involving what is referred to as working memory.

"We measured the electrical activity in the brains of university students, enabling us to identify differences in brain activity between people with slightly above-average and considerably above-average IQs," explained Nussbaumer. Past studies conducted to identify the effect of neural efficiency have generally used groups of people that exhibit extreme variations in intelligence.

Facial memory tested

Psychologists define working intelligence as a person's ability to associate memories with new information as well as to adapt to changing objectives by filtering out information that has become irrelevant. The frontal lobe plays a pivotal role in these processes. In order to test these abilities, the ETH researchers asked 80 student volunteers to solve tasks of varying complexity on a computer.

One task, for example, was to determine whether individual letters or faces were part of a selection of letters or faces that had been shown to the subjects immediately beforehand. An especially difficult task involved identifying letters and faces shown to the subjects during past runs of the test within a time limit.

While the students were completing the tests, the researchers used electroencephalography (EEG) to measure their brain activity. For the results analysis, the researchers had the subjects take a conventional IQ test and then split them into two groups: one with slightly above-average IQs and another with well above-average IQs.

Neural efficiency for moderately difficult tasks

The researchers found no differences in brain activity in either group of subjects when they performed very easy or very difficult tasks. They did, however, see clear differences in the case of moderately difficult tasks. Stern attributes this to the fact that none of the subjects had any trouble whatsoever with the simple tasks and that the difficult tasks were cognitively demanding even for the highly intelligent subjects. In contrast, all subjects succeeded in solving the moderately difficult tasks, but the highly intelligent subjects required fewer resources to do so.

Stern uses the analogy of a more and less efficient car: "When both cars are travelling slowly, neither car consumes very much fuel. If the efficient car travels at maximum speed, it also consumes a lot of fuel. At moderate speeds, however, the differences in fuel consumption become significant."

Intelligence is not a muscle

So is it possible to use EEG measurements to draw any direct conclusions about intelligence? Stern qualifies the findings: "If you want to learn something about intelligence, you have to perform a conventional IQ test, because these tests still provide the most reliable results," she says. EEG and other brain activity readings are not precise enough to assess the intelligence of an individual. Still, using these methods may be an interesting way to study how different levels of intelligence are manifested in the brain.

The ETH researchers' intelligence study also suggests that it is impossible to "exercise" working memory. This has been a controversial issue among scientists in recent years because of contradictory findings in different studies. If subjects practise a certain task for a prolonged period, they improve with time. As Stern and her peers have now shown in their study, people who have practised certain tasks do not have any advantage over their unpractised counterparts when confronted with new, yet similar tasks.

###

Literature reference

Nussbaumer D, Grabner RH, Stern E: Neural efficiency in working memory tasks: The impact of task demand. Intelligence 2015. 50: 196-208, doi: 10.1016/j.intell.2015.04.004 [http://dx.doi.org/10.1016/j.intell.2015.04.004]

Media Contact

Elsbeth Stern
elsbeth.stern@ifv.gess.ethz.ch
41-446-325-366

 @ETH_en

http://www.ethz.ch/index_EN 

Elsbeth Stern | EurekAlert!

Further reports about: EEG ETH ETH Zurich IQ test Intelligence activity working memory

More articles from Life Sciences:

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>