Psychology in Action (8e) PowerPoint  Lecture Notes Presentation Chapter 2: Neuroscience and Biological Foundations

Lecture Overview Neural Bases of Behavior Nervous System Organization A Tour Through the Brain Our Genetic Inheritance

Neural Bases of Psychology Neuroscience: interdisciplinary field studying how biological processes relate to behavioral and mental processes

Neural Bases of Psychology The nervous system consists of neurons (cells responsible for receiving and transmitting electrochemical information).

Figure 2.2 A motor neuron Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

Neural Bases of Psychology: The Structure of a Neuron

Neural Bases of Psychology: Neural Communication Within a neuron, communication occurs through an action potential (neural impulse that carries information along the axon of a neuron).

Neural Bases of Psychology: Neural Communication (Continued) Between neurons, communication occurs through transmission of neural information across a synapse by neurotransmitters (chemicals released by neurons that alter activity in other neurons).

Neural Bases of Psychology: Neural Communication (Continued) Receiving neurons receive multiple messages from other neurons, and these messages determine if an action potential occurs or not.

Neural Bases of Psychology: Neural Communication (Continued) Note how the axon terminals of sending neurons almost completely cover the cell body of the receiving neuron.

Neural Bases of Psychology: Applying Psychology to Everyday Life Major Neurotransmitters: Serotonin Acetylcholine (ACh) Dopamine (DA) Norepinephrine (NE) Epinephrine (adrenaline) GABA (gamma aminobutyric acid) Endorphins

Table 2.1 Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

Neural Bases of Psychology: Receptor Sites normal message blocked message (wrong shape) agonistic drugs mimic shape and enhance neurotransmitter antagonistic drugs fill the site and block neurotransmitter

Neural Bases of Psychology: How Hormones Affect Us Endocrine System: collection of glands that manufacture and secrete hormones

Nervous System Organization Central Nervous System (CNS): includes the brain and spinal cord Peripheral Nervous System (PNS): includes all nerves and neurons connecting CNS to the rest of the body (subdivided into the somatic and autonomic nervous systems)

Nervous System Organization

Nervous System Organization: Central Nervous System (CNS) Brain Spinal Cord (transmits information into and out of the brain )

Nervous System Organization: Central Nervous System (CNS) The spinal cord is also responsible for involuntary, automatic behaviors called reflexes.

Nervous System Organization: Subdivisions of the Peripheral Nervous System Somatic Nervous System (SNS): connects to sensory receptors and controls skeletal muscles. Autonomic Nervous System (ANS): controls involuntary bodily functions ANS is subdivided into: Sympathetic Nervous System (arouses) and the Parasympathetic Nervous System (calms)

Nervous System Organization: Parasympathetic and Sympathetic Nervous Systems

A Tour Through the Brain

A Tour Through The Brain: Hindbrain Three key structures of the hindbrain: Medulla: life survival functions Pons: respiration, movement, waking, sleeping, and dreaming Cerebellum: coordination of fine muscular movements, balance, and some aspects of perception and cognition

A Tour Through The Brain (Continued) Midbrain: collection of brain structures in the middle of the brain that coordinates movement patterns, sleep, and arousal (Reticular formation: runs through the hindbrain, midbrain, and brainstem and screens incoming information and controls arousal

A Tour Through The Brain (Continued) Forebrain: collection of upper-level brain structu24res, including the thalamus, hypothalamus, and limbic system Thalamus: relays sensory messages to the cerebral cortex Hypothalamus: responsible for emotions, drives, and regulating the body’s internal environment

Figure 2.18 The limbic system Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

A Tour Through The Brain (Continued) Limbic System: interconnected group of forebrain structures involved with emotions, drives, and memory

A Tour Through The Brain: Cerebral Cortex Cerebral Cortex: thin surface layer on the left and right cerebral hemispheres regulating most complex behavior, including sensations, motor control, and higher mental processes

A Tour Through The Brain: Lobes of the Cerebral Cortex (Cont.)

A Tour Through The Brain: Lobes of the Cerebral Cortex The frontal Lobes- receive and coordinate messages from other lobes and are responsible for motor control, speech production, and higher functions, such as thinking, personality, emotion, and memory.

A Tour Through the Brain: The Importance of the Frontal Lobes Phineas Gage’s mining accident sent a 13-pound tamping iron through his frontal lobes. How did this affect his short- and long-term behavior and mental processes?

A Tour Through The Brain: Lobes of the Cerebral Cortex (Cont.) Parietal Lobes: located at the top of the brain directly behind the frontal lobes and responsible for interpreting bodily sensations Temporal Lobes: located on each side of the brain above the ears and responsible for audition, language comprehension, memory, and some emotional control Occipital Lobes: located at the back of the brain responsible for vision and visual perception

Figure 2.32 Specialization and integration in language Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

Figure 2.33 Brain activity when hearing, seeing, and speaking words Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

Figure 2.23 Brain structures and their functions Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

The Motor Cortex and The Sensory Cortex The motor cortex, an arch-shaped region at the rear of the frontal lobes, controls voluntary muscle movements on the opposite side of the body. Body parts requiring the most precise control occupy the greatest amount of cortical space. In an effort to find the source of motor control, researchers have recorded messages from brain areas involved in planning and intention, leading to the testing of neural prosthetics for paralyzed patients.

The Motor Cortex and The Sensory Cortex The sensory cortex, a region at the front of the parietal lobes, registers and processes body sensations. The most sensitive body parts require the largest amount of space in the sensory cortex.

The association areas are not involved in primary motor or sensory functions. Rather, they interpret, integrate, and act on information processed by the sensory areas. They are involved in higher mental functions, such as learning, remembering, thinking, and speaking. Association areas are found in all four lobes. Complex human abilities, such as memory and language, result from the intricate coordination of many brain areas.

Describe the five brain areas that would be involved if you read this sentence aloud. Language depends on a chain of events in several brain regions. When we read the sentence aloud, the words (1) register in the visual area (2) are relayed to the angular gyrus which transforms the words into an auditory code, which is (3) received and understood in the nearby Wernicke’s area and (4) sent to Broca’s area, which (5) controls the motor cortex as it creates the pronounced word.

Depending on which link in this chain is damaged, a different form of aphasia occurs. For example, damage to the angular gyrus leaves the person able to speak and understand but unable to read. Damage to Wernicke’s area disrupts understanding. Damage to Broca’s area disrupts speaking

The Brain’s Plasticity Research indicates that some neural tissue can reorganize in response to injury or damage. When one brain area is damaged, others may in time take over some of its function. For example, if you lose a finger, the sensory cortex that received its input will begin to receive input from the adjacent fingers, which become more sensitive.

New evidence reveals that adult humans can also generate new brain cells. Our brains are most plastic when we are young children. In fact, children who have had an entire hemisphere removed still lead normal lives.

A Tour Through The Brain: The Motor Cortex and Somatosensory Cortex

A Tour Through The Brain: Motor and Somatosensory Cortex (Cont.) Why are the hands and face on this drawing so large? What do they represent?

A Tour Through The Brain: Split-Brain Research Severing the corpus callosum provides data regarding the functions of the brain’s two hemispheres.

Figure 2.35 The corpus callosum Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

A Tour Through The Brain: Split-Brain Research (Continued)

A Tour Through The Brain: Lateralization The left and right hemispheres of the brain each specialize in particular operations.

Our Genetic Inheritance To answer questions about the influence of nature versus nurture, psychologists use behavioral genetics research. Behavioral Genetics: studies the relative effects of nature (heredity, genes, and chromosomes) and nurture (environment) on behavior and mental processes.

Our Genetic Inheritance: Genes & DNA The nucleus of every cell in our body contains genes, which carry the code for hereditary transmission. These genes are arranged along chromosomes (strands of paired DNA).

Our Genetic Inheritance: Genes & DNA Tongue-curling is one of the only traits that depends on a specific dominant gene.

Our Genetic Inheritance: Twin Research

Our Genetic Inheritance Evolutionary Psychology: studies how natural selection and adaptation help explain behavior and mental processes

Our Genetic Inheritance Sex differences in lateralization. Note how activation is confined to only one hemisphere in the male brain on the left, and how it occurs on both hemispheres in the female brain on the right.

Our Genetic Inheritance: Better Living Through Neuroscience Neuroplasticity: brain’s lifelong ability to reorganize and change its structure and function Neurogenesis: the division and differentiation of non-neuronal cells to produce neurons Stem cells: Precursor (immature) cells that give birth to new specialized cells