5 Steps to a 5 AP Psychology 2019

Biological Bases of Behavior ❮ 81

brainstem the hindbrain. The old mammalian brain roughly corresponds to the limbic

system that includes the septum, hippocampus, amygdala, cingulate cortex, hypothalamus,

and the thalamus, which are all important in controlling emotional behavior, some aspects

of memory, and vision. The new mammalian brain or neocortex, synonymous with the

cerebral cortex, accounts for about 80 percent of brain volume and is associated with the

higher functions of judgment, decision making, abstract thought, foresight, hindsight and

insight, language and computing, as well as sensation and perception. Developmental psy-

chologists call the structures of the “mammalian brains” the forebrain. The surface of your

cortex has peaks called gyri and valleys called sulci, which form convolutions that increase

the surface area of your cortex. Deeper valleys are called fissures. The last evolutionary

development of the brain is the localization of functions on different sides of your brain.

Localization and Lateralization of the Brain’s Function

Although multiple representations of information can be located within different areas of

your brain, specific regions of your brain seem most critical in handling particular func-

tions. This localization of structure and function has been identified for numerous regions

(see Figure 7.1). Association areas are regions of the cerebral cortex that do not have

specific sensory or motor functions, but are involved in higher mental functions, such as

thinking, planning, remembering, and communicating. In general, crossing over of nerves

sending information from one side of your body to the other side of your brain results in

contralaterality, control of one side of your body by the other side of your brain.

Corpus callosum

Thalamus

Pituitary gland Hypothalamus

Hippocampus

Pons

Medulla

Reticular formation

Brainstem

Cerebellum

Amygdala

Cerebrum

Figure 7.1 Major structures of the brain in medial view.