Categories
Cognitive Health Nootropics

Can We Really Increase Our Intelligence?

According to the psychological literature available, there are two general prospects of intelligence: the uniform one, evaluated in school, which basically addresses linguistic & logical-mathematical intelligence; and the Pluralistic View of Mind, proposed by Howard Gardner in his acclaimed theory of Multiple Intelligences. Two different theories that demand two very different -and eventually opposed- answers to the inquiry of intelligence enhancement.

Intelligence Quotient (IQ) is a certain type of measurement of intellectual ability that came in due to devotion to universal formal education. Thus, IQ tests have been shown to be moderately correlated with grades in elementary, primary, and high school; job performance; professional status; and number of years in school[1]. In this way, the prevalence of IQ tests imply a certain Hereditarian Theory of Intelligence that is rather invariable and stable across time among healthy individuals. According to this approach, intelligence is a unitary entity, an abstraction of an all-purpose system that permeates uniformly in all intellectual activity. Therefore, according to this prospect, the primary basis of intelligence is primarily genetically determined.

Indisputably, IQ tests are limited in some of its applications and have interpretation problems. They do not appropriately assess the role of motivation (it is likely that motivated individuals put more effort in IQ tests and hence score higher), creativity, social skills, practical intelligence, or wisdom, just for mentioning some relevant variables. Nevertheless, Charles Spearman has demonstrated[2], interestingly, that the various subsets that conform the IQ inventory are positively correlated, labeled as the factor G to stand for the general factor that underlies all intellectual ability. This generic problem solving system is what is popularly called “fluid intelligence”, an empirical argument that  rather supports a hereditarian or genetic theory of intelligence.

Indeed, available data from twins research suggest that genes are a primary determinant of this view of intelligence[3]. Thus, there is an important group of psychologists and brain & mind scientists who do not think that it is possible to modify your factor G, even though it is not completely clear how this factor and the environment interact with each other[4]. For instance, Jack Naglieri, an intelligence expert from University of Virginia, prevents us to not confuse ability with knowledge. The right way of measuring intelligence, he argues, is to quantify those abilities that underlie the acquisition of knowledge, independently from the knowledge itself. Thus, this psychologist is implying that intelligence is something relatively independent of the learning experience.

Nonetheless, a renowned article published in the journal Nature by Price and her colleagues challenged this immutable view of intelligence[5]. The study had 33 adolescents, who were 12 to 16-years-old when the study initiated. Price and her team gave them IQ tests, tracked them for four years, and then tested them again with the same measurement tools. The fluctuations in IQ were outstanding: not about a couple points, but 20-plus IQ points. These changes in IQ scores, according to the researchers, were not random — they tracked elegantly with structural and functional brain imaging. Thus, there is also an important group of scientists that maintain that many of the changes in IQ are correlated to changes in the environment, particularly schooling.

It’s analogous to fitness. A teenager who is athletically fit at 14 could be less fit at 18 if they stopped exercising. Conversely, an unfit teenager can become much fitter with exercise.

Furthermore, there is also a certain number of studies that have shown brain changes after several kinds of educational regimens. The study about Tokyo taxi drivers is a especially distinguished one[6]. Scientists conducted memory, visual and spatial information tests and took brain scans using MRI of 79 male trainee Tokyo taxi drivers at the beginning of their training regimen. At the beginning of the study, no variance was found in their brain structure or memory. Three to four years later, however, scientists found a considerable increase in grey matter in the posterior hippocampi, among the 39 trains who performed as taxi drivers. Naturally, this change was not observed in the non-taxi drivers. Thus, this kind of studies suggest that the brain can change to accommodate new knowledge, so future programs for lifelong learning are possible[7].

To sum up, it is not fully clear What intelligence is[8], and hence How to directly increase it.[9] Nonetheless, we can consider intelligence, for practical purposes, as a starting point in life. Naturally, we are born with certain capacities and particular features, but it is later in life when we discover and develop them, regardless of our individual  genetic background. Thus, instead of frustratingly trying to increase your “G” factor (since we do not have a general consensus and determinant scientific evidence yet), what you can do is focus in your multiple crystallized intelligences: the ability to use skills, knowledge, and experience. If you are a scientist, observe and analyze information; if you are a philosopher, organize it and turn it into knowledge; if you are an artist, interpret it. Different areas of intelligence have different weights of importance in each person’s occupational life, and you can definitely get better at specific activities through practice and discipline.

References   [ + ]

1, 8. Intelligence and Achievement: Just how Correlated are they?
2, 9. Summary of Psychology topic Intelligence g Factor
3. McGue , M. Bouchard , T. J. , Jr Iacono , W. G. Lykken , D. T. (1993). Behavioral genetics of cognitive ability: A life-span perspective. In R. Plomin G. E. McClearn (Eds.), Nature, nurture, and psychology (pp. 59-76). Washington, DC: American Psychological Association
4. Nature-nurture and intelligence.
5. Brain scans support findings that IQ can rise or fall significantly during adolescence
6. The Use of Geospatial Information and Spatial Cognition of Taxi Drivers in Tokyo
7. Nurture net of nature: Re-evaluating the role of shared environments in academic achievement and verbal intelligence
Categories
Cognitive Health

Why Do I Find Stimulants Calming?

ADHD drugs enhance human focus by expanding the levels of neurotransmitters from the prefrontal cortex of the brain which coordinate attention and behavior: norepinephrine and dopamine. Psychostimulants like methylphenidate (Ritalin) amphetamines (Adderall) encourage focus and attention, both in ADHD-diagnosed and non-ADHD-diagnosed people[1], regardless of one’s initial intellectual baseline.

Thus, giving stimulants to a person with a learning disability is like giving more time on a test: an advantage that might help anybody, but assists especially the ones in need (rather than fixing their brains).

In spite of the positive evidence[2], stimulant users do report different subjective realities: while ones get anxiety, others remain calm and relaxed. From a psychological point of view, it is assumed that part of the problem in ADHD is that the patient’s environment doesn’t stimulate their brains enough as it does in people without the disorder. As a result, ADHD-sufferers feel constantly bored and hence look for various ways to stimulate themselves by rapidly shifting their attention to something new. Therefore, in theory, by providing the missing excitement to the brain, these medicines allow ADHD people calm down and stay focused in a single activity.

Despite this highly plausible explanation, the neurological mechanism by which psychostimulants act as calming agents in humans with attention-deficit hyperactivity disorder or hyperkinetic disorder is currently unknown. Mice lacking the gene encoding the plasma membrane dopamine transporter (DAT) have elevated dopaminergic tone and are hyperactive[3], particularly when facing a novel environment. Furthermore, these mice are appreciably impaired in spatial cognitive function, and they display a decrease in locomotion in response to psychostimulants[4]. The behavioural resemblance between the DAT knockout mice and individuals with ADHD bring to mind that common mechanisms may underlie some of their conducts and responses to psychostimulants, and that dopamine D4 receptor gene might be abnormal on these individuals.[5]
In contrast to the classical dopamine transporter (DAT)-dependent enhancement of the dopaminergic signal observed at concentrations of cocaine lower than 3 μM, the inhibitory effect of cocaine was found at concentrations higher than 3 μM. The paradoxical inhibitory effect of cocaine and methylphenidate was associated with a decrease in synapsin phosphorylation [] Interestingly, a cocaine-induced depression of DA release was only present in cocaine-insensitive animals (DAT-CI). Similar effects of cocaine were produced by methylphenidate in both wild-type and DAT-CI mice. On the other hand, nomifensine only enhanced the dopaminergic signal either in wild-type or in DAT-CI mice. Overall, these results indicate that cocaine and methylphenidate can increase or decrease DA neurotransmission by blocking reuptake and reducing the exocytotic release, respectively. The biphasic reshaping of DA neurotransmission could contribute to different behavioural effects of psychostimulants, including the calming ones, in attention deficit hyperactivity disorder.[6]
Thus, SUNY’s researcher David Erlij and his group of researchers sustain to have recognized a network of nerve terminals where stimulation of dopamine D4 receptors exhaust motor activity.[7] This network seem to be localized deep in the brain, in the basal ganglia and the thalamus and its responses may explain the reduction in motor activity caused by psychostimulants. In this way, these results suggest that enhancing dopamine D4 transmission in the basal ganglia and the thalamus is likely part of the mechanism of the therapeutic effects of psychostimulants on ADHD patients.
In conclusion, because of genetic anomalies, people with ADHD might encounter stimulants antagonistically. While further research is required to clear up the mechanisms behind the cognitive enhancement itself (why does it also works for the healthy ones then?) at a neurological level, taking into account the subjective outcome of the individual -calm vs. nervous- becomes significant when choosing a treatment.

References   [ + ]

Categories
Cognitive Health Nootropics

Contraceptives: a Nootropic for Women?

As you might already know, the nervous system uses neurotransmitters as its chemical signals; the endocrine system, hormones. In this way, the pituitary gland secretes factors into the blood that operate on the endocrine glands to either raise or drop hormone production, establishing a major communication system between the body and the brain. This process is known as a feedback loop, and it involves chemical transmission from the brain to the pituitary to an endocrine gland, and back to the brain. When this process is comprehended, it does not become a surprise that hormonal medication may rapidly change the structure and function of our brains.

Birth control pills are on the market now for more than five decades, used by more than one hundred million of women who report high levels of contentment. However, the repercussions of the synthetic steroids contained in the pill on brain and cognition have scarcely been studied. Thus, 2014 has been a year in which neuroscientists just found the topic particularly appealing.[1] Here we summarize for you the latest findings, which might be of special interest among female nootropic users.

According to a new UC Irvine research[2], women who take contraceptives may experience memory changes. These changes are not from a quantitative nature, but rather a qualitative one: women who are taking the pill were found to be more effective at recalling the gist of an emotional event, while the women who were not using it performed better at retaining details. This cognitive change makes perfect sense, argues researcher Nielsen, since contraceptives suppress sex hormones such as estrogen and progesterone to prevent pregnancy, and these hormones were previously linked to women’s strong “left brain”.

Thus, birth control medication is nowadays presumed of being “masculinizing” brain patterns activation. In this trial[3], women’s number processing was analyzed and male-like brain activation patterns were recognized in women who were taking the pill, and a small but significant enhancement in processing social cues[4]. Nevertheless, the most consistent finding was the sustained improvement of verbal memory with birth control use, and a statistically significant enhancement in visuospatial ability as well. Interestingly, these cognitive changes seem to present a long-term nature, which results predict better cognitive outcomes later in life, even years after discontinued use. In this line of thought, this study[5] found that contraceptive ever users performed significantly better than never users in the domain of visuospatial ability, and speed & flexibility, with duration-dependent increases in performance, especially in ever users with ≥ 15 years of use.

Furthermore, an apparent effect of oral contraceptives on emotion recognition was observed, strengthening the theory of brain masculinization. While it is well known in neuropsychology that females tend to score higher at recognizing faces and emotions; in this clinical trial[6], users of oral contraceptives detected significantly fewer facial expressions of sadness, anger and disgust than non-users.

A few years back, a study discovered that users of oral contraceptives had larger volumes of grey matter[7] in certain areas of the brain. Thus, these past neuroatomical findings seem to correlate pretty well with the neurobehavioral changes recognized nowadays in the cited studies.

In conclusion,  the mechanisms in which the brain responds to hormones point out that the organ is capable of responding effectively, in a flexible manner, to environmental signals from the endocrine system. This creates a strong demand for additional studies about how the pill affects indirectly & directly the nervous system from a molecular to a behavioural level.

References   [ + ]