There is lateralization of sensory processing and motor output. The contralateral control of movement for the motor cortex is not absolute. Proximal muscle control is largely bilateral and distal muscle control is largely contralateral. The lateralization of language can be tested by using the WADA-test (temporarily anaesthetize left hemisphere). Lateralization of language can be left, right or bilateral. The following anatomical differences between the two hemispheres can be observed: a flatter Sylvian fissure on the left (1), difference in size in Heschl’s gyrus (2), difference in size in Planum Temporale (3), larger pyramidal cell bodies in the left Heschl’s gyrus (4) and more distance between patches in Wernicke’s area (5). Connections between cells are organized in patches. Anatomical differences do not correlate with language lateralization. Macroscopic and microscopic anatomical differences and functional differences exist between the two hemispheres, but are not absolute.The two hemispheres cooperate because the corpus callosum connects the two hemispheres, together with the anterior commissure and the posterior commissure. There is interhemispheric synchrony between neurons that respond to the same stimulus that activates cells with receptive fields in both hemifields. For split-brain patients, stimuli that are only presented to the right hemisphere cannot be verbally reported if there is a full split of the corpus callosum. When the posterior part of the callosum is sectioned, higher order, abstract information about the stimulus can be reported, but not the stimulus itself. Two hemispheres can search for a visual target independently if the corpus callosum is cut. Search time increases with half the slope of regular subjects when items are presented to two hemispheres simultaneously. There are differences between the left- and the right hemisphere. The right-hemisphere: is better at spatial and geometrical tasks (1), is...

The final common pathway of all motor output is the ventral horn in the spinal cord. The dorsolateral part of the ventral horn is involved in distal muscles and fine movements. The ventromedial part of the ventral horn is involved in proximal muscles and posture. Muscles make use of alpha neurons. It involves alpha neurons. There are different reflexes of the human body:Stretch reflex (posture)Activation of one muscle leads to the relaxation of the other muscle. The muscle spindle senses stretching, which activates the alpha motor neurons which leads to the muscle contracting.Golgi tendon reflex (protection from overload)Excessive weight on a muscle causes the neuron from the Golgi tendon to fire, inhibiting the motor neuron which leads to relaxation of the muscle.Withdrawal reflex (protection from damage)Activation of pain receptors on the skin causes the muscle to contract and withdraw.Crossed extensor reflexThe flexing of one muscle leads to the relaxation of another.The central pattern generator is the mechanism in the spinal cord that enables patterns (e.g., walking, breathing, swallowing) to be generated and is activated by a higher brain command or by proprioceptive feedback. Reflexes are processed and generated in the spinal cord. Reciprocal inhibition of antagonistic muscles refers to the relaxation of the flexor as the extensor contracts.Pyramidal tracts are axons that travel directly from the cortex to the spinal cord. The extrapyramidal tracts are axons that travel through another cortical structure to the spinal cord. There are several extrapyramidal tracts:Rubrospinal tractFrom the upper motor neurons in the red nuclei to the spinal cord. It controls muscle tone and distal limb muscles that perform more precise movements.Tectospinal tractFrom the upper motor neurons in the superior- and inferior colliculi to the spinal cord. It receives auditory and visual information and controls the orienting-response....

Emotions consist of a physiological response to the stimulus (1), a behavioural response (2) and a feeling (3). The function of emotions is activating the fight/flight response (1), making quick decisions based on emotional value (2) and anticipating the consequences of a decision (3) Basic emotions (anger, sadness, happiness, disgust, surprise, fear) are innate and universal emotions that correspond to facial expressions. Complex emotions are learned emotions, shaped by the culture and the environment. Emotions can differ on arousal (subjective intensity of emotion) and valence (positive/negative experience). Emotions are not traceable to specific brain regions.The James-Lange theory states that emotion has three components: cognition (1), readiness for action (2) and feeling (3). Emotion is a label to our responses. This theory is a flawed, as the autonomous nervous system is not differentiated enough to account for all emotions (1), hormonal feedback from the body is too slow to induce emotions (2) and hormone injections can cause different emotions (3).The hypothalamus is responsible for the readiness for action component of emotion. The sympathetic nervous system is involved in action. Cortical processing is involved in experiencing feelings. The anterior insula is involved in the awareness of bodily responses. The ventromedial prefrontal cortex is involved in using emotions for decision making. If the ventromedial prefrontal cortex is damaged, there is emotional perseverance (e.g., no fear extinction). The somatic marker theory states that the ventromedial prefrontal cortex starts an internal simulation to evaluate the emotional outcomes of decisions and these emotional outcomes (somatic markers) are used to guide decision making.The amygdala receives information from the entire brain and can influence the entire brain. It responds to emotional stimuli and neutral stimuli predicting motivating stimuli. It judges the emotional value...

Sleepwalking involves typically automated behaviour and occurs most often in young children. It occurs more frequently after sleep deprivation and the prevalence is 1%-5%. It typically occurs during the deepest stages of sleep and the frontal cortex is deactivated during sleepwalking.In normal sleep, there are successive sleep stages. Cycles last ±90 minutes. Deep sleep stages occur in the early part of the night. It includes high amplitude, low-frequency EEG. REM-sleep stages occur towards the end of the night. Sleep paralysis refers to the muscle tone remaining flat because of muscle paralysis, but the person is awake. This is also shown on EEG. Sleep violence refers to REM-sleep without muscle paralysis. Narcolepsy is the sudden onset of REM-sleep. There are several disorders of consciousness:Brain deathNo pupil response, no reflexes, no EEG.ComaNo reactions, no sleep-wake cycle. It is often short-lived and either results in death, vegetative state or waking up. Life support is often needed.Vegetative stateA sleep-wake cycle, breathing, autonomous reactions, eye movements, orienting, no reactions, no communication. Minimally consciousThe same as the vegetative state, but the person sometimes regains consciousness and communication.Locked-in syndromeBeing fully awake, but being unable to respond, except for a single muscle (e.g., eyelid).The reticular activation system (RAS) is critical for maintaining consciousness. It either projects directly to the cortex or via the thalamus. Easy problems of consciousness include problems of consciousness that are very difficult to understand and explain, but it is possible to envision a solution. Hard problems of consciousness refer to explaining qualia. There is an explanatory gap, explaining the function of consciousness does not explain the experience of that part of consciousness. Blindsight refers to not being able to consciously report stimuli in the visual field, but act appropriately...