#cerebral cortex

This also applies to comparing cognitive ability. Trying to infer from brains and their structures which animals are “better” at cognition and ranking animal brains in order of “intelligence” is as treacherous as it is tempting. Stan Kuczaj, who spent his lifetime studying the cognition and behavior of different animals, put it bluntly: “We suck at being able to validly measure intelligence in humans. We’re even worse when we try to compare species.” Intelligence is a slippery concept and perhaps unmeasurable. As mentioned earlier, many biologists conceive of it as an animal’s ability to solve problems. But because different animals live in different environments with different problems, you can’t really translate scores of how well their brains perform. A brain attribute is not simply “good” or “bad” for thinking, but rather varies depending on the situation and the thinking that brain needs to undertake. Intelligence is a moving target.

What confounds this dilemma further is that individual animals within a species have varying cognitive abilities. To quote the Yosemite National Park ranger who, when asked why it was proving so hard to make a garbage can that bears couldn’t break into, said, “There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists.”

Understanding the neural network

The brain, our body's conductor, is a complex network of billions of interconnected neurons. These neurons communicate with each other via specialized pathways known as nerve tracts. These pathways are essential for transmitting sensory, motor and cognitive information throughout the body.

Main brain pathways

1. The pyramidal pathway

- Role: The pyramidal pathway is primarily responsible for the voluntary control of movement. It connects the primary motor cortex to the motor neurons in the spinal cord, enabling the initiation and control of precise skeletal muscle movements.

- Components: It comprises the corticospinal bundle and the corticobulbar bundle.

- How it works: Nerve signals from the motor cortex travel down this pathway to activate the muscles concerned.

2. Sensory pathways

- Role: These pathways transmit sensory information from the body to the brain.

- Types of sensitivity:

o Tactile sensitivity: Allows us to perceive touch, pressure and vibration.

o Thermal sensitivity: Allows us to perceive heat and cold.

o Deep sensitivity: Allows us to perceive the position of limbs in space (proprioception) and joint movements.

o Pain sensitivity: Allows us to perceive pain.

- Pathway: Sensory information is transmitted by peripheral nerves to the spinal cord, then back to the brain via various ascending pathways.

3. Specific sensory pathways

- Visual: transmits visual information from the retina to the occipital lobe.

- Auditory: Transmits auditory information from the inner ear to the temporal lobe.

- Olfactory pathway: transmits olfactory information from olfactory receptors to the olfactory bulb.

- Taste pathway: transmits taste information from the taste buds to the taste cortex.

4. Proprioception pathway

- Role: Proprioception is the sense that enables us to know our body's position in space.

- How it works: Proprioceptive receptors in muscles, tendons and joints constantly send information to the brain about the state of muscle contraction, joint angle and limb position.

- Importance: Proprioception is essential for movement coordination, balance and posture.

Nerve pathway disorders

Damage to or dysfunction of these pathways can lead to a variety of neurological disorders, such as :

- Hemiplegia: Paralysis of one side of the body.

- Paresthesia: Sensation of numbness or tingling.

- Ataxia: Loss of coordination of movements.

- Blindness: Loss of vision.

- Deafness: Loss of hearing.

In conclusion

Brain pathways are complex networks that ensure communication between the brain and the body. Understanding how they work is essential for grasping the mechanisms underlying many physiological and pathological processes.

Frontal Lobe Activity in Executive Functions.

In this post, I will briefly outline what is meant by the term 'executive functions' and I will highlight some interesting literature pertaining to the debate surrounding frontal lobe activity in executive functions. This post may be useful for anyone studying psychology at university, or if you just fancy an interesting read!

Executive functions refer to the integrated cognitive processes determining goal directed and intentional behaviour. Executive functions are responsible for initiating behaviour; anticipating consequences of actions; formulating goals and organising and planning behaviour according to spatial, temporal, logical or topical sequences. Research suggests that the frontal lobes of the brain, are most directly associated with executive functions.

In the frontal lobes of the brain, you will discover the 'prefrontal executive' and 'motor' areas. The motor cortices consists of the primary motor cortex (generates signals to initiate and direct movement), secondary motor cortices (preparation and sequencing of actions) and the frontal eye-fields (eye movements). *Fun fact: the area of the brain actually responsible for processing visual information is located in the occipital lobe, which is located posterior (behind) to the parietal and temporal lobes, at the back of the skull!*. The prefrontal cortex is responsible for many cognitive functions, such as attention, memory, cognitive flexibility and cognitive control. The prefrontal cortex contains lateral surfaces (dorsolateral prefrontal cortex, anterior prefrontal cortex and ventrolateral cortex). This area also includes medial surfaces (ventral anterior cingulate, anterior prefrontal cortex and orbitofrontal cortex).

There is a myriad of data suggesting the association between frontal lobe activity and executive functions. One way that researchers are able to understand this relationship, is through 'frontal lobe measures'. One example, is the Wisconsin Card Sorting Task (WCST). This is a neuropsychological test which involves two packs of cards, which contain four stimulus cards and 64 response cards, all 7x7 cm. The cards are also in numerous shapes, colours and numbers. Participants are asked to accurately arrange every response card with one of the four stimulus cards.

Typically, researchers may find that in a group of participants who have lesions to their frontal lobes, performance on the WCST is poor, compared to the average person. Therefore, as the test is a measure of executive function proficiency and the scores amongst participants with frontal lobe lesions is very poor, the logical assumption would be that frontal lobe activity is the most intrinsically involved area of the brain associated with performing executive functions.

Yet, in Alvarez and Emory's (2006) meta-analysis of lesion neuroimaging studies, they observed mixed results. The findings did not support the theory of a one-to-one association between frontal lobes and executive functions. Their results seemed to suggest that both frontal and non-frontal regions of the brain were implicated. This evokes two questions: are there multiple brain regions responsible for executive functions as shown in this meta-analysis? Or, are the measures utilised unreliable? One study by Nelson (1976), noticed that their elderly patients found the WCST to be distressing and highly difficult. As such, they produced the Modified Card Sorting Test (MCST) to make the task simpler and less ambiguous. Interestingly, they found that when they compared the two groups (one with patients who have frontal lobe lesions, and another group with unilateral lesions), patients with frontal lobe lesions performed less well than those with lesions elsewhere!

So, why does research into frontal lobe activity in executive functions produce such mixed results? One issue could be due to the fact that it is difficult for researchers to find participants with damage to a specific area of interest, as lesions to the brain are a naturally occurring incidence. Moreover, once participants with frontal lobe lesions have been obtained, researchers cannot control for the potentiality that the damage may also extend to other areas of the brain, which would confound the experiment and ultimately produce unreliable data and questionable ecological validity. One way in which researchers attempt to navigate around this obscurity is through the use of Transcranial Magnetic Stimulation (TMS). This method is able to invokes virtual lesions to the brain (albeit with limited spatial resolution) by using a strong electromagnet which can temporarily disrupt information processing in a particular brain region. Despite it being a non-invasive method, participants have reported feeling discomfort due to feelings of tingling, spasms and headaches. Therefore, there are clear limitations to this method regarding its efficacy and safety.

Meditation can change your brain structure, increasing your ability to respond vs react. 

Meditating isn’t just a way to calm down, quiet your mind, and relax. We’re talking about shrinking and increasing the volume of parts of the brain that regulate your consciousness, decision making, impulsivity, behavior, and trauma responses. Check out this breakdown for some of the ways that meditation may change the brain. - How does meditation change the brain? - Processing and Reacting/Responding - What is the amygdala? - What is the hippocampus? - What is the cerebral cortex? Learn more & practice with our program, available online as a 10 week course or 3 week intro course: https://transmuteenergy.com/shop

Neurons in a culture dish trying to form connections with each other. Sped up to show 8 hours in 1 second. Bright spots are the neuron nuclei. We have 100 billion of these in our brain. Amazing.