I. Brain and cognition.
Cognition refers to the process of acquiring, encoding, manipulating, extracting and using sensory input information in the process of knowing objective things, and is an internal mental process that occurs between input and output; this process includes perception, attention, memory, thinking and language. The processing of cognition is realized through the brain, a special substance.
(i) Joint cortex of the brain
Cognitive functions are closely related to the cortical structures of the brain. Somatomotor centers, somatosensory centers, and other sensory centers occupy only a small part of the cerebral cortex, and most of it is occupied by the association areas. Many of the brain’s “real” actions occur in the association areas. Various cognitive acquisitions that are considered major brain functions such as superimposing two numbers, recognizing a parent or an acquaintance, organizing a sentence, planning a meal, etc., occur in the association cortical areas.
The association cortex is the most phylogenetically advanced structure in the brain and the least mature in individual development. The association areas are not involved in purely sensory or motor functions. For example, the joint sensory area receives multiple information from the sensory cortex and processes and integrates it, calling concrete and intuitive perceptual processing abstract thinking or concepts; the joint somatomotor area is involved in the formation of ideas for various complex movements, planning and programming motor programs, and then transmitting information to the motor cortex, i.e., transforming abstract thinking into concrete behavior. Thus, the combined cortical areas of the brain play a “joint” role in sensory input and motor output. The process of cognition is a higher brain function activity.
(B) Brain structure and cognitive function
1.Frontal lobe
The frontal lobe is responsible for the sequencing of information and the integration of stimuli after categorization (attention and concentration, abstract concepts, reasoning and judgment, concept formation, problem solving, and speech). Idea generation, concept formation, organization and sequencing of action steps, timing, initiation of action, judgment, abstract thinking, memory, verbal-motor programming, intelligence, emotion.
2.Parietal lobe
The functions of the parietal lobe include the reception, processing, and integration of fine touch, proprioception, and kinesthesia. Recognition of visual, tactile, and auditory input. Storage of visuomotor memory traces or programs required for motor sequencing; human postural patterns, body parts and their spatial location; word comprehension, tone decoding, word intensity and temporal sound modulation.
3. Temporal lobe
The temporal lobe is associated with memory, higher-level operations and auditory patterns of learning, emotion, motivation, personality, speech comprehension, sound modulation, music perception, memory, and auditory reception.
4.Occipital lobe
The functions of the occipital lobe are synthesis and integration of visual information, perception of visuospatial relations, formation of visual memory traces, comprehension of language and verbal antecedent structures, formation of visuomotor memory traces, and visual reception.
5. Limbic lobe
The limbic lobe plays an integrative role in emotional activity. Complex and flexible behavior patterns are based on experience, with the addition of emotional elements, and finally expressed through the motor system. There is a close connection between the limbic system and the cortical association areas, and information from the temporal, parietal, and occipital association areas is threaded through the cingulate gyrus of the limbic system to the frontal association areas.
6.Thalamus and hypothalamus
The thalamus is the liaison station that transports all sensory information to the cortex. The thalamus is closely associated with complex intellectual processing, emotion and memory. The hypothalamus plays an important role in maintaining the stability of the internal environment, regulating and controlling endocrine through direct or indirect pathways, regulating and controlling body temperature, feeding, emotions and related behaviors.
7. Corpus callosum
The corpus callosum is the fiber that links the left and right cerebral hemispheres and is responsible for transmitting motor plans and programs prepared by the premotor cortex to the right hemisphere. Intentional motor disuse of unilateral limbs can occur after corpus callosum injury.
Second, the impact of cognitive impairment on the ability to perform activities of daily living
Numerous clinical observations have shown that cognitive impairment will have an impact on patients’ ability to perform activities of daily living, such as inability to execute commands in patients with attention disorders. Patients with severe cognitive impairment will require more specialized care in their daily life. Therefore, if cognitive impairment can be detected in time, correct treatment plan and discharge plan can be formulated, which is not only beneficial to the rehabilitation of cognitive impairment, but also has positive practical significance to promote the rehabilitation of physical dysfunction and improve the independence of daily life.