Parts of the brain

Corpus Callosum

consists of a large bundle of fibers connecting the right and left hemispheres of the brain. Each hemisphere controls movement in the opposite (contralateral) side of the body and can also specialize in performing specific cognitive and perceptual functions. It allows information to move between hemispheres and is therefore a very important integrative structure.

premotor cortex

consists of a narrow region between the prefrontal and motor cortices. It is involved in preparing and executing limb movements and uses information from other cortical regions to select appropriate movements. it's also important for learning (imitation) and social cognition (empathy) - mirror neurons in this area of the macaque brain fire when the animal observes an action in others.

Ventricles

interconnected fluid-filled spaces that are extensions of the spinal cord. They have no unique function but provide cushioning against brain damage and are useful landmarks for determining the location of other brain structures.

Pons

the region in the brain most closely associated with breathing and with circuits that generate respiratory rhythms. It forms a bridge between the cerebrum and cerebellum and is involved in motor control, posture, and balance. It is also involved in sensory analysis and is the site at which auditory information enters the brain.

Hippocampus

the structure in the brain most closely aligned to memory formation. It is important as an early storage place for long-term memory, and it is involved in the transition of long-term memory to even more enduring permanent memory. The hippocampus also plays an important role in spatial navigation.

prefrontal cortex

thought to play an important role in "higher" brain functions. It is a critical part of the executive system, which refers to planning, reasoning, and judgment. It is also involved in personality and emotion by contributing to the assessment and control of appropriate social behaviors.

dentate gyrus

The hippocampal formation has three regions, which are highly interconnected: the dentate gyrus, CA3, and CA1. It is one of the very few regions in the brain where adult neurogenesis (development of new neurons) has been confirmed. The dentate gyrus may play an important role in translating complex neural codes from cortical areas into simper code that can be used by the hippocampus to form new memories.

amygdala

a complex structure adjacent to the hippocampus. It is involved in processing emotions, and fear-learning. It links areas of the cortex that process "higher" cognitive information with hypothalamic and brainstem systems that control "lower" metabolic responses (e.g. touch, pain sensitivity, and respiration). This allows it to coordinate physiological responses based on cognitive information - the most well-known example being the fight-or-flight response.

Broca's area

a functionally defined structure in the left frontal lobe of about 97% of humans (including a large majority of left-handers). Broca's area is involved mainly in the production of spoken and written language and also in language processing and comprehension. It takes its name from the French scientist whose work with language-impaired patients led him to conclude that we speak with our left-brain.

Wernicke's area

a functionally defined structure that is involved in language comprehension. In about 97% of humans (including a large majority of left-handers) major language functions are contained in the left hemisphere of the brain and for most people, Wernicke's area is lateralized to the left side. It takes its name from Carl Wernicke, who worked with language-impaired patients to distinguish separate regions for language comprehension from production.

limbic system

a group of brain structures including the amygdala, hippocampus, and hypothalamus that are involved in processing and regulating emotions, memory, and sexual arousal. it is an important element of the body's response to stress and is highly connected to the endocrine and autonomic nervous systems. it is also responsible for processing the body's response to odors.

Basal Ganglia

comprise a group of structures that regulate the initiation of movements, balance, eye movements, and posture. They are strongly connected to other motor areas in the brain and link the thalamus with the motor cortex. It's also involved in cognitive and emotional behaviors and play an important role in reward and reinforcement, addictive behaviors and habit formation.

temporal lobes

contain a large number of substructures, whose functions include perception, face recognition, object recognition, memory acquisition, understanding language, and emotional reactions. Damage to the temporal lobes can result in intriguing neurological deficits called agnosias, which refer to the inability to recognize specific categories (body parts, colors, faces, music, smells).

Superior Temporal Gyrus

contains the primary auditory cortex, which is responsible for processing sounds. Specific sound frequencies map precisely onto the primary auditory cortex. This auditory (or tonotopic) map is similar to the homunculus map of the primary motor cortex. Some areas of the superior temporal gyrus are specialized for processing combinations of frequencies, and other areas are specialized for processing changes in amplitude or frequency. The superior temporal gyrus also includes the Wernicke's area, which (in most people) is located in the left hemisphere. It is the major area involved in the comprehension of language.

primary motor cortex

critical to initiating motor movements. Areas of the motor cortex correspond precisely to specific body parts. For example, leg movements map to the part of the motor cortex closest to the midline. Not all body parts are equally represented by surface area or cell density - representations of the arm hand motor area occupy the most space in the motor cortex (unsurprising given their importance to human behavior). Similarly, representations in the motor cortex can become relatively large or small with practice/training.

Thalamus

heavily involved in relaying information between the cortex and brain stem and within different cortical structures. Because of this role in corticocortical interactions, the thalamus contributes to many processes in the brain including perception, attention, timing, and movement. It plays a central role in alertness and awareness.

cingulate gyrus

helps regulate emotions and pain. It is thought to directly drive the body's conscious response to unpleasant experiences. In addition, it is involved in fear and the prediction (and avoidance) of negative consequences and can help orient the body away from negative stimuli. Learning to avoid negative consequences is an important feature of memory.

Middle and Inferior Temporal Gyri

involved in a number of cognitive processes, including semantic memory processing, language processes (middle temporal gyrus), visual perception (inferior temporal gyrus), and integrating information from different senses. These structures have been implicated in recognizing and interpreting information about faces and are a part of the ventral visual pathway, which identifies "what" things are. The inferior-temporal gyrus also participates in some forms of mental imagery.

Cerebellum

monitors and regulates motor behavior, particularly automatic movements. Some recent studies have associated the cerebellum with cognitive functions, such as learning and attention. Although it accounts for roughly 10% of total brain weight, it contains more neurons than the rest of the brain combined. It also one of the few mammalian brain structures where adult neurogenesis (the development of new neurons) has been confirmed.

Frontal lobe

part of the cerebral cortex and are the largest of the brain's structures. They are the main site of so-called 'higher' cognitive functions. The frontal lobes contain a number of important substructures, including the prefrontal cortex, orbitofrontal cortex, motor and premotor cortices, and Broca's area. These substructures are involved in attention and thought, voluntary movement, decision-making, and language.

Entorhinal Cortex

plays a major role in memory formation. Two major connections from the entorhinal area (lateral and medial) provide the main input to the hippocampus and are important to pre-processing memorable information. The lateral input stream is thought to convey spatial information to the hippocampus, while the medial input stream conveys nonspatial information. The stream of information from the entorhinal cortex, through the dentate gyrus, to the hippocampus is called the perforant path.

parietal lobes

plays an important role in integrating information from different senses to build a coherent picture of the world. It integrates information from the ventral visual pathways (which process what things are) and dorsal visual pathways (which process where things are). This allows us to coordinate our movements in response to the objects in our environment. It contains a number of distinct reference maps of the body, near space, and distant space, which are constantly updated as we move and interact with the world.

Perirhinal Cortex

plays an important role in object recognition and in storing information (memories) about objects. It is highly connected to other brain structures, including the amygdala, basal ganglia, and frontal cortex. These extensive connections allow the perirhinal cortex to specialize in associating objects with sensory information and potential consequences (e.g. reward).

somatosensory cortex

receives tactile information from the body. Sensory information is carried to the brain by neural pathways to the spinal cord, brainstem, and thalamus, which project to the somatosensory cortex (which in turns has numerous connections with other brain areas). It integrates sensory information (e.g. touch, pressure, temperature, and pain, spatial attention), producing a "homunculus map", similar to that of the primary motor cortex. Sensory information about the feet, for example, map to the medial somatosensory cortex.

Hypothalamus

regulates a wide range of behavioral and physiological activities. It controls many autonomic functions such as hunger, thirst, body temperature, and sexual activity. To do this, the hypothalamus integrates information from many different parts of the brain and is responsive to a variety of stimuli including light (it regulates circadian rhythms), odors (e.g. pheromones), stress, and arousal (hypothalamic neurons release oxytocin directly into the bloodstream). Other functions controlled by the hypothalamus include parenting behavior, perspiration, blood pressure, and heart rate.

Subiculum

the main output region of the hippocampus and is therefore important to learning and memory. It also plays a role in spatial navigation, mnemonic (symbol) processing, and regulating the body' response to stress by inhibiting the HPA axis.

occipital lobes

the primary visual area of the brain. It receives projections from the retina (via the thalamus) from where different groups of neurons separately encode different visual information such as color, orientation, and motion. Pathways from the occipital lobes reach the temporal and parietal lobes and are eventually processed consciously. Two important pathways of information originating in the occipital lobes are the dorsal and ventral streams. The dorsal stream projects to the parietal lobes and processes where objects are located. The ventral stream projects to structures in the temporal lobes and processes what objects are.