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.
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.
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.
Elsbeth Stern | EurekAlert!
Here comes the long-sought-after iron-munching microbe
25.10.2016 | Max-Planck-Institut für marine Mikrobiologie
Novel method to benchmark and improve the performance of protein measumeasurement techniques
25.10.2016 | Johannes Gutenberg-Universität Mainz
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Life Sciences
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences