PSYCH001 Week 4

Announcements and Deadlines

  • Quiz 3 & Ch 2 Inquizitives

    • Due: Thursday 8 am (01/29)

    • Note: No ZAPS due this week.

  • Navigating the Quiz Page

    • Important: Do not navigate away from the quiz page while taking it; doing so will reduce the grade as stated in the syllabus.

  • Midterm Exam

    • Date: 02/12 (Thursday)

    • Content: Covers material up to the week of the exam.

  • Upcoming Content

    • Next week’s lecture will cover Evolution, which will be part of the Final, not the Midterm.

Chapter 3: Biology and Behavior

Overview

  • This section covers:

    • Divisions and function of the Neocortex

    • Human Brain Imaging

The Neocortex Underlies Complex Mental Activity

  • Cerebral Cortex

    • Definition: The outer layer of brain tissue; responsible for complex thoughts, perceptions, and behaviors.

    • Structure: Each cerebral hemisphere is divided into four lobes:

    • Occipital Lobe

    • Parietal Lobe

    • Temporal Lobe

    • Frontal Lobe

Four Lobes of the Cerebral (Neo)Cortex

  • Frontal Lobe

    • Functions: Associated with thought, planning, and movement.

  • Temporal Lobe

    • Functions: Responsible for hearing and memory.

  • Parietal Lobe

    • Functions: Responsible for touch and spatial relations.

  • Occipital Lobe

    • Functions: Specialized for vision.

Functions of the Frontal Lobe

  • Contains the primary motor cortex.

  • Features the prefrontal cortex (PFC):

    • Involved in planning behavior, attention, and judgment.

  • Includes orbitofrontal cortex:

    • Role: Significant in olfaction (smell) and emotion.

Functions of the Occipital Lobe

  • Contains the primary visual cortex.

  • Connects to the temporal and parietal lobes for detailed processing of visual stimuli (identification, position, and motion).

Functions of the Temporal Lobe

  • Contains the primary auditory cortex.

  • Specializes in complex, multi-modal functions:

    • Recognition of objects.

    • Recognition of familiar faces.

Functions of the Parietal Lobe

  • Houses the primary somatosensory cortex:

    • Helps localize touch, pain, skin temperature, and body position.

    • Posterior areas handle complex processing of visual information.

The Prefrontal Cortex in Close-Up

  • Case Study: Phineas Gage

    • Incident: His accident resulted in significant personality changes, highlighting the role of the prefrontal cortex in behavior.

Historical Perspective: Lobotomy

  • Definition: Deliberate damaging of the prefrontal cortex.

  • Developed by Egas Moniz, who earned a Nobel Prize in 1949.

  • Use: Treated psychological disorders in the late 1940s and early 1950s.

  • Outcome: Patients often became lethargic, emotionally flat, and disconnected from their social environments.

Somatosensory and Motor Functions in the Neocortex

  • Diagram: Represents various body parts and their corresponding regions in the primary somatosensory and motor cortex.

    • Includes Thumb, Neck, Brow, Eye, Nose, Face, Lips, Gums, Teeth, Jaw, Arm, Shoulder, Trunk, Hip, Knee, Leg, Ankle, Foot, Toes, Genitals.

Smell and Taste in the Neocortex

  • Frontal Lobe: Responsible for taste (gustatory cortex).

  • Temporal Lobe: Associated with smell (olfactory cortex).

  • Parietal Lobe: Contributes to sensory integration.

  • Occipital Lobe: Involved in visual processing.

Auditory Functions in the Neocortex

  • Primary Auditory Cortex: Corresponds to various frequencies in the cochlea (e.g., 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, 8000 Hz, 16000 Hz).

  • Secondary Auditory Cortex: Supports complex auditory processing.

Visual Functions in the Neocortex

  • Visual Processing:

    • Left visual field processed by the right hemisphere (better with spatial relationships).

    • Right visual field processed by the left hemisphere (better with language).

  • Visual Areas: Including V1 (Primary), V2, V3, V3A, V4, and MT/V5 areas specialized for visual processing.

Human Brain Imaging and Assessment

  • Modern techniques have enhanced our understanding of the brain.

  • Electroencephalograph (EEG):

    • Measures electrical activity in the brain.

    • Good temporal resolution but poor spatial resolution.

Positron Emission Tomography (PET)

  • Method of brain imaging assessing metabolic activity through radioactive substance.

  • Offers good spatial but poor temporal resolution.

Magnetic Resonance Imaging (MRI)

  • Produces high-quality images of the brain using a powerful magnetic field.

Functional Magnetic Resonance Imaging (fMRI)

  • Examines changes in brain activity by measuring blood oxygen levels.

  • Good spatial but poor temporal resolution.

Transcranial Magnetic Stimulation (TMS)

  • Employs strong magnets to briefly disrupt normal brain activity to study brain regions.

Overview of Brain Imaging Techniques

  • TMS: Used to explore brain function.

  • Comparison of fMRI and PET data for activities like seeing, hearing, speaking, and thinking.

Chapter 3: Biology and Behavior

Endocrine System

  • Definition: Composed of glands releasing hormones to communicate with the body.

  • Response: Reacts to nervous system input, particularly from the hypothalamus.

  • Functions: Involved in arousal, metabolism, growth, and sexual functions.

The Pituitary Gland

  • Known as the master gland.

  • Regulates other glands through hormones it releases.

  • Controlled by the hypothalamus, positioned directly above it.

Endocrine Glands

  • Pineal Gland: Regulates sleep cycles and body rhythms.

  • Pituitary Gland: Influences growth and lactation; regulates other glands.

  • Thyroid Gland: Maintains metabolism rate.

  • Adrenal Glands: Secrete hormones affecting arousal and stress response.

  • Pancreas: Releases insulin for blood sugar regulation.

Sex Differences in Endocrine Function

  • Males:

    • Testes: Main reproductive glands secreting testosterone.

    • Role: Influences sexual function and critical in puberty.

  • Females:

    • Ovaries: Main reproductive glands secreting estrogen.

    • Role: Influences sexual function, puberty, and menstruation.

Nature vs. Nurture

  • Nature:

    • Contributions of genetic inheritance.

  • Nurture:

    • Contributions of learning and environment.

Genetics in Psychological Science

Definitions

  • Genetics: Study of how traits are passed to offspring and gene expression.

  • Gene: Units of heredity that influence traits.

  • Gene Expression: Process of genes being turned on or off in specific body locations.

The Genome

  • Definition: The comprehensive blueprint for organism development.

  • Quote: “The genome provides the option, and the environment determines which option is taken.”

  • Chromosomes: Structures made of DNA within cells that contain genes.

DNA Structure

  • DNA: A double-stranded helix comprising 4 nucleotide bases: A, T, G, C.

  • Discovery: Elucidated by Crick and Watson in 1953.

Alleles and Genetic Variation

Definition of Alleles

  • Allele: Alternate forms of the same gene, leading to individual differences.

  • Impact: Certain alleles, like those affecting hemoglobin, influence physical characteristics (e.g., sickle-shaped red blood cells).

Definitions of Gene Types

  • Dominant Gene: Expressed in offspring whenever present.

  • Recessive Gene: Expressed when matched with a similar gene from the other parent.

Homozygous vs. Heterozygous Gene Pairs

  • Homozygous: Having two identical alleles (e.g., CC, cc).

  • Heterozygous: Having two different alleles (e.g., Cc).

Patterns of Inheritance

  • Example: Explanation of eye color inheritance using genotypes (BB, Bb, bb) among parents of different phenotypes.

Genetic Drift

  • Definition: Change in allele frequencies due to chance.

  • Example: Loss of orange beetles due to accidental stepping on certain individuals.

Founder Effect

  • Description: Occurs when a small population settles separately from the larger group, leading to reduced genetic variation.

  • Outcome: Rare parental alleles may become more prevalent in the new population.

  • Example: The Amish community and the occurrence of certain genetic traits.

Consequences of Reduced Genetic Variation

  • Inbreeding can lead to genetic disorders.

  • Example: The Blue People (Blue Fugates) of Kentucky, resulting from inbreeding.

Sexual Reproduction and Genetic Variation

Importance of Sexual Reproduction

  • Enhances genetic diversity, which is crucial for adaptation and survival in changing environments.

  • Provides variability necessary for evolutionary processes.

Genes Affect Behavior

  • Interaction of genes and environment influences psychological traits and abilities.

  • Behavioral Genetics: Study of how genetics and environment interact to shape behavior.

Research Methods in Behavioral Genetics

  • Twin Studies: Evaluate genetic influence by comparing identical (monozygotic) and fraternal (dizygotic) twins.

  • Adoption Studies: Examine the effects of genetic and environmental factors by comparing biological and adoptive relatives.

Understanding Heritability

  • Heredity: Transmission of traits through genes.

  • Heritability: Statistical estimation of trait variation within a population attributable to genetics rather than environment.

  • Clarification: Heritability is about populations, not individuals; it assesses how much of the variation in a trait can be linked to genetic differences among individuals in a group.