Introduction
Cognition is a state of mind that enables brain to perceive and process sensory functions like touch, smell, taste, hearing and vision. Its requirement is essential for all living beings to adapt to various environmental conditions. To better understand this neurological task there is a need to focus on the connection between brain and awareness. Awareness is a state of mind that determines the individual’s ability to perceive environmental changes by attention.
The levels of attention may vary between individuals and in certain cases its defect could also lead to attention–deficit hyperactivity disorder (ADHD).This neurological illness particularly affects children or young adolescents by causing a decline in their attention levels and ultimately leading to poor educational outcomes (Loe & Feldman, 2007).
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Awareness is believed to have strong link with working memory (WM) which gets activated in patterns from representations. If a person is allowed to visualize the color, movement and shading of an object keenly, he might easily perceive them. This may be because in the visual system there may be representations of these tasks constructed from the native pattern of cell activation in the retina (Charlton, 2000). Previous studies have reported that awareness could be better studied by measuring the performance of various memory tasks while monitoring gaze direction, delaying responses, and recording brain activity (Charlton, 2000).
Individuals having memory retention problems may fall victim to a condition of ‘unawareness when they fail to perceive and interpret the changes different from those visualized earlier (Silva, Groeger & Bradshaw, 2006).
Individuals with Alzheimer’s disease (AD) have memory impairment and defects in self-awareness (Mimura, 2008).These reports indicate that awareness defects are having strong pathological connection with diseases.
Next, awareness of body states constitutes consciousness. Although, both are related they seem to differ on the grounds that awareness is found in all the animals of animal kingdom and consciousness is found in only socially adapted primates such as chimpanzees and bonobos and other mammals like elephants and dolphins. Both these animal members were believed to evolve recently (Charlton, 2000).
This was further strengthened by a report that described that many animals come across simple levels of consciousness when they were found to show a comparable awareness of certain similarly conditioned human tasks (Griffin & Speck, 2004).
Since, consciousness was earlier found in specific primates, it could have also evolved in other primate members including human beings and developed over the time. Therefore, it may indicate that consciousness found in present-day human beings may have its evolutionary linkage with their primate ancestors.
Further, it is reasonable to connect the relationship between awareness and memory with the concept of feeling of knowing. Spehn and Reder (2000) highlighted that feelings of knowing are generated through the monitoring of one’s knowledge and such process could enable behavior to search memory for an answer. To consider an example, in an earlier clinical study, questionnaires were conducted to obtain information about past history of drugs and illnesses from patients. To better assist them, researchers also revealed the brand names of drugs to make the identification process easier. (Carol Louik et al., 2007). The collected information was later evaluated in assessing the connection between previous drug exposure and birth defects.
The reliability of this questionnaire would surely depend on the patient’s ability to recall the relevant past events. Here, a feeling of knowing will be only perceived by the patient when he monitors his previous drug knowledge by searching the memory.
In reality, the patient may not know that he has enough drug knowledge. But it is the questionnaire initiated monitoring and memory search process that enabled a feeling in the patient that he knows about the drugs used.
This process of possessing the knowledge without knowing could be explored by a variety of experiments.Dienes (2008) described a method of confidence ratings after making judgments in order to show that the person has knowledge, but does not know that he has it.
Therefore, unconscious awareness may appear hidden but may have some benefits when it becomes apparent. From the above example, it was understood that memory has played vital role in driving the conscious and unconscious awareness.
It is essential to know the neuroanatomy of the brain for better understanding the evolutionary aspects of consciousness.
Earlier workers described a hypothesis stating that evolutionary origin of consciousness is
- Neuroanatomical,
- in accord with biological evolution,
- utilizes the most highly evolved structures of the cerebral cortex with their ultramicrosite operation and
- based on quantum physics (Eccles, 1992).
This hypothesis may indicate that evolution has influenced the anatomical wiring of the brain to get adapted to different biological conditions. This anatomical setting might have reinforced the cognition properties of brain to execute normal biological functions. So, keeping in view of the hypothesis, some of the structural elements of brain that are believed to affect consciousness are apical dendrites, dendrons and psychons.
It was described that consciousness is microgranular in nature and composed of mental units called psychons whereas dendrons, the collection of apical dendrites possess the potential to interact with psychons which came into existence to form the mental world and give the mammal conscious experience (Eccles, 1992).This has ultimately lead to evolutionary advantage in mammals over other members of the animal kingdom such as reptiles.
To further strengthen this evolutionary concept of consciousness and the much-related perception, it is reasonable to highlight about the cerebral cortex, also known visual cortex. Vision may be considered as the most important function which is controlled by the cerebral cortex of brain that is divided into dorsal and ventral streams. Both these streams start in primary visual cortex V1, and extend to posterior parietal cortex and extrastriate cortical regions, respectively. Dorsal stream is mainly involved in spatial consciousness, location of objects in space and regulation of actions. Ventral stream is involved in identification of objects and representation of structure.
The dorsal stream provides a thorough map of the visual field, precise body image, awareness and understanding of spatial relationships, noticing and examining the movements, gaining knowledge of tasks that involve coordination of the body in space. The ventral stream is influenced by factors known as extra retinal such as attention, working memory and stimulus salience.
Previously, the role of primary visual cortex in contributing to visual experience was considered controversial, but subsequent studies have provided better insights that V1 might be necessary for conscious perception (Tong, 2003).This report was further confirmed by a study that not only highlighted the importance of V1 in consciousness but also described an association between visual processing and the perceptual delaying (Lin, 2008).These studies may indicate that cerebral cortex has evolved specifically to perform environmentally adapted functions.
Very often, unconsciousness may interfere during the visual perception of the outside world by blocking the information from getting processed in the visual cortex. This could also form the basis for poor memory. Since awareness is related with thinking and memory, it can be inferred that unconscious awareness may arise due to abnormal thinking behavior.
For example, daydreaming is recognized as one of the symptoms of ADHD.Individuals with this disorder may develop unconsciously awareness when they enter into dreaming initiated deep thinking, which affects their daytime activities. In adult’s age-related disorders like dementia or Alzheimer’s may create awareness problems.
Hence, individuals with conscious awareness may have better memory because of no unconscious interference or blockage of information in any form. Therefore, it is clear that learning behavior might greatly vary among people with different levels of conscious or unconscious awareness.
Further, the existence of awareness may facilitate an animal or human being to perform environmentally adapted activity. For example, the highly evolved cerebral cortex in mammals concerned with spatial consciousness may not only enable animals to locate their prey in their vicinity but also guides a search behavior.
These highly adapted biological functions that require intelligence are common in every living being indicating a strong evolutionary connection. Hence, consciousness was modified as an important meaningful aspect of intelligence for social situations. Therefore, this kind of mechanism, where internal body states are regulated in response to environment may be better described as the somatic marker mechanism (SMM) (Charlton, 2000).
This mechanism was believed to evolve with the objective of determining social information and promote well planned social intelligence. In addition, SMM is also considered as a crucial phase of theory of mind mechanism (Tomm) that is essential for definite behavior and its interpretation from the mental inferences (Charlton, 2000).
Most animals choose a definite behavior of searching for their prey. This learning attitude may be obtained from inferences that tell the presence or absence of prey and direct them to a specific location. These instances of spatial learning could support the SMM.
In certain situations, conscious awareness may not enable a patient to perceive changes in body states such as fatigue. Mostly, all sportsmen are prone to fatigue after a strenuous exercise. They would not perceive any changes unless they experience the feeling of tiredness. Previously, it was described that the feeling of fatigue is derived subconsciously from the differences in homeostatic control systems of brain (Clair Gibson Alan et al., 2003).
It may indicate that an internal unconscious or subconscious state of mind may be regulating the behavior that would enable him to perceive the changes, making him consciously aware of situation. In other words, a week feeling or stimuli of tiredness would be perceived subliminally without his awareness. This process is termed as subliminal perception which can be considered as another form of unconscious awareness. It generally occurs when stimuli presented below a constraint for awareness are found to influence thoughts, feelings, or actions and reported to occur in people with neurological disorders (Kazdin, 2000).
Prosopagnosia is a disorder that makes patients to forget familiar faces.Here, irrespective of previous interactions, patients will be in a condition to question that person as if they have not seen him earlier. It indicates that people with prosopagnosia have lost the ability to perceive information regardless of faces they are viewing (Kazdin, 2000).
Further, unconscious bias is another form where individuals exhibit prejudice towards females, more commonly known as gender bias. Many people while casting votes may support female contestants in elections and elevate to higher positions regardless of their character or behavior. Here, while perceiving women people are unable to evaluate themselves. People also show unconscious bias in their tendency to favor white men while neglecting black men.
In some cases, unconscious bias may also play role in fame judgment. Because, some individuals tend to prefer the name of a famous person just by considering his or her previous records irrespective of any present circumstances. Banaji and Greenwald (1995) reported a fame judgment study that when famous names of both male and female were pronounced, there was greater assignment of fame to famous male than famous female names, by the participants. These examples indicate that people are consciously aware but show a kind of ‘subliminal perception’ in their decision that would influence their actions.
Kiesel et al. (2006) described that actions that are experienced as freely chosen are controlled without the conscious awareness and manipulation of individuals. Therefore, it can be inferred that decision making which is vital in our daily lives is most prominently influenced by interplay between conscious and unconscious awareness. Hence, it may also appear reasonable to associate unconscious bias with the concept of subliminal perception which suggests that peoples’ thoughts, feelings and actions are influenced by stimuli that are perceived without any awareness of perception (Kazdin, 2000).
Conscious perception enables a person to better focus on problem-solving skills and perform a given job through the aid of visual memory. Earlier workers described that individuals were found to have better visual working memory when they remembered the objects grouped bottom-up compared to ungrouped objects, according to gestalt grouping principles (Woodman, Vecera & Luck, 2003).
Finally, in order to consider how the neural activity gives rise to human thought it is imperative to focus on the previous section of this description that highlighted the role of cerebral cortex in visual processing.
Steven Yantis et al. (2002) described that the activation of parietal cortex is associated with a discrete signal to change spatial attention. According to the most favored transient hypothesis, activity of parietal lobes might be related to the act of shifting attention from one location to another. This hypothesis may appear supporting to the concept of spatial learning in animals and human beings that guides search behavior.
In view of the above information it is clear that neurocognition is largely influenced by conscious and unconscious awareness. Conscious feeling has wide role to play in performing various environmentally adapted activities. But this process was found to get hindered by the interference of unconsciousness or inattention in certain situations. Deep thinking and feeling of knowing have clues related to unconscious awareness. Therefore, the function of working memory (WM) may be considered vital in assessing the degree of perceived and processed information.
Summary
Evolutionary studies have centered their focus in linking the neuroanatomical structures such as cerebral cortex with visual perception indicating its highly adapted biological role.
The importance of cerebral cortex was also understood in the light of neural activity that is essential for attention shifts as evident from the transient hypothesis. Two mechanisms SMM and ToMM have been hypothesized that underscored the importance of evaluating social interactions with intelligence. Unconscious bias was found to influence actions of prejudice by providing a possible link to subliminal perception.
The concept of subliminal perception may seem to have better implications for studying a wide range of awareness problems associated with neurological syndromes. However, with the available literature it is obvious that further studies may be required to better evaluate all important facets of neurocognition.
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