Final answer:
The outer layer of the cerebral hemispheres that plays a key role in higher brain functions is known as the cerebral cortex. It is highly folded and subdivided into four lobes, each responsible for different complex processes.
Step-by-step explanation:
The outer layer of the cerebral hemispheres involved in higher brain functions is called the cerebral cortex. This part of the brain encompasses the outermost layer of gray matter and contributes to complex processes such as consciousness, thought, emotion, reasoning, language, and memory. The cerebral cortex is characterized by wrinkles and folds known as gyri and sulci, which increase its surface area, allowing for a greater number of neurons within a limited space. Each cerebral hemisphere is subdivided into four lobes (frontal, parietal, temporal, and occipital), with each being responsible for different functions of the brain. Together, the cerebral cortex and associated subcortical structures like the thalamus, hypothalamus, pituitary gland, and limbic system form the forebrain, playing a pivotal role in the higher-level processes that define human cognition and emotion.