Chapter 2: Cognitive Neuroscience

I. THE BRAIN

• A. Viewing the structures and functions of the Brain
  • 1. Postmortem Studies
    • Identify disorder and then examine after death
      • Young, Holcomb, Yazdani, Hicks & German (2004)Found that depression is associated with a greater number of nerve cells in the Thalamus being devoted to emotional regulation. Supported idea that structural abnormality may lead to depression
  • 2. Animal studies
    • Monitor activity of a single neuron
      • Animal Study: Single Neuron Monitoring
        • Disterhoft & Matthew (2003) Young versus old rabbits compared in learning of eyeblink conditioning. Hippocampal pyramidal neurons were monitored. Typically aging animals cannot learn the task. Metrifonate, galanthamine, and CI-1017 injected into the aging rabbits. This led aged rabbits to learn as quickly as young controls
  • 3. Electrical Recordings
    • a) Electroencephalograms (EEGs)
• 4. Static Imaging Techniques
• a) Magnetic resonance imaging (MRI) scan
  • Strong magnetic field passed through the skull
  • Uses the detection of radio frequency signals produced by displaced radio waves in a magnetic field
  • Creates a detailed anatomical image of the brain
• 5. Metabolic Imaging
  • a) Positron emission tomography (PET)
    • Radioactive material is injected or inhaled
    • Participant is then scanned to produce an image of the brain's activity
• b) Functional magnetic resonance imaging (fMRI)
  • fMRI imaging takes a series of images of the brain in quick succession and then statistically analyzes the images for differences among them
  • Brain areas with more blood flow have been shown to have better visibility on MRI images
  • Better visibility is thought to be correlated with brain activation
  • fMRI in Research
    • Gauthier, Skudlarski, Gore & Anderson (2000) fMRIs demonstrate that expertise for cars and birds uses areas involved in face recognition

II. COGNITION IN THE BRAIN: CEREBRAL CORTEX AND OTHER STRUCTURES

• A. Gross Anatomy of the Brain Forebrain, Midbrain, Hindbrain
  • 1. Forebrain
    • a) Limbic system
      • Controls Mood and attitude
      • Stores highly charged emotional memories
      • Controls appetite and sleep cycles
    • b) Amydgala
      • Involved in anger, & fear
    • c) Septum
    • d) Hippocampus
      • Is important in the formation of memories
    • e) Korsakoff's syndrome
      • Alcohol abuse can lead to it and to anterograde amnesia
    • f) Thalamus
      • Relay station
    • g) Hypothalamus
      • Important to metabolic behaviors, eating, drinking, sexual behaviors, and regulating emotions
  • 2. Midbrain (The midbrain extends from the pons to the lower portion of thalamus)
    • a) Reticular activating system (RAS)
      • Controls respiration, cardiovascular function, digestion, alertness, and sleep
    • b) Brain Stem
      • Vital in basic attention, arousal, and consciousness
  • 3. Hindbrain
    • a) Medulla oblongata
      • Breathing, swallowing and digestion
    • b) Pons
    • c) Cerebellum
      • Motor co-ordination, posture, and maintaining balance
• B. Cerebral Cortex and Localization of Function
  • 1. Cerebral Cortex
    • 'Thinking Cap' of brain
  • 2. Contralateral
    • Right side of brain controls left side of body
    • Left side of brain controls right side of body
  • 3. Ipslateral (opposite of contralateral)
  • 4. Corpus Callosum
    • Neural fibers connecting left and right lobes
    • Allows communication between right and left sides of the brain
  • 5. Cerebral Hemispheres
• C. Hemispheric Specialization
  • 1. Aphasia
    • Speech is affected in some way
  • 2. Broca's Area
    • Can understand everything said
    • Patient can only respond in monosyllabic words
  • 3. Wernicke's area
    • Speaks fluently but nonsensically
    • Not coherent, contains lexical and grammatical errors
  • 4. Split-brain patients
    • Corpus callosum severed for MEDICAL reasons
      • Sperry (1960 - 1998)
        • First to study patients with a split corpus callosum
        • Two lobes function independently
      • Gazzaniga (1980's- current)
        • Two lobes function complimentarily
    • Left Lobe
      • Language functions (speech, song)
      • Logical thought (writing, logic)
    • Right Lobe
      • Spatial-relation functions
      • Perception of rhythm, abstract or intuitive thought
  • 5. Apraxia
• D. Lobes of the Cerebral Hemispheres
  • 1. Lobes
  • 2. Frontal lobe
    • Reasoning & Planning
  • 3. Parietal lobe
    • Touch, Temperature, Pain, & Pressure
  • 4. Temporal lobe
    • Auditory & Perceptual processing
  • 5. Occipital lobe
    • Visual processing
  • 6. Primary motor cortex
    • At rear of frontal lobe
  • 7. Primary somatosensory cortex
    • At front of parietal lob
• E. Association Areas
  • Areas that show no specific function
• F. Male - Female Cognitive Differences
  • Intellectual differences (Kimura, 1992)
    • females better at:
      • tests of perceptual speed
      • object displacement tests
      • ideational fluency (i.e., list objects of same color)
      • verbal fluency (i.e., list words that start with a particular letter)
      • precise fine motor tasks
      • mathematical calculation
    • males better at:
      • spatial tasks--i.e., mental rotations of objects
      • target directed skills--i.e., guiding or intercepting projectiles
      • disembedding tests--i.e., telling foreground from background
      • tests of mathematical reasoning