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Questions and Answers
Which disorder is characterized by the death of dopamine-producing cells in the substantia nigra?
What is the first symptom that typically presents in Alzheimer's Disease?
What is the primary goal of the Posner task?
What significant change occurred in Phineas Gage's personality after the accident?
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In the Sternberg task, what are the hypothesized stages involved in processing?
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Which two structures are affected in Huntington's disease due to reduced levels of a specific neurotransmitter?
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What does the word superiority effect indicate about letter recognition?
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Which type of tumor is named after the type of cell it originates from, such as astrocytoma?
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What does the Stroop effect demonstrate about cognitive processing?
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What is a key principle of the lesion method in cognitive neuroscience?
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What is a characteristic of the intracellular single unit recording method?
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What effect does memory set size have on response times in the Sternberg task?
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How does the Posner task approach letter categorization?
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What does Electroencephalography (EEG) primarily measure?
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What is the primary function of a PET scan?
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What is the main principle behind functional MRI (fMRI)?
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What kind of resolution does EEG have?
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How are structural and functional MRI different?
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What is neurogenesis primarily defined as?
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Which layer of the neural plate develops into the nervous system?
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What results from the radial migration of neural precursor cells?
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What disruption is observed in Reeler mice as a consequence of genetic manipulation?
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Which concept is integral to Rakic's 'protomap' hypothesis?
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At what approximate age do the prefrontal regions of the brain fully develop?
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What is one method used to track developmental timecourse in embryos?
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Which of the following defines the role of radial glial cells during neural development?
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Which developmental stage in Jean Piaget's theory is characterized by abstract thinking and logical reasoning?
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What structure is primarily formed from the ectoderm during development?
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What defines the process of assimilation in cognitive development?
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At what stage do children begin to develop object permanence according to Piaget?
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What is a key limitation in Piaget's theory according to Neo-Piagetians?
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What discovery did Rene Baillergeon make regarding object permanence?
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During which developmental stage do children primarily engage in imaginative play?
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What cognitive ability typically develops during the concrete operations stage?
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What is the main contribution of Judy DeLoache’s research in cognitive development?
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What characterizes the formal operations stage in Piaget’s framework?
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Study Notes
Long Term Memory
- Long term memory is involved in the Posner and Sternberg tasks
- The Posner test is designed to show that multiple representations are activated by a single stimulus
- The Sternberg test is meant to show that memory retrieval is a serial comparison process
Posner Task
- Participants are presented with letter pairs
- They are instructed to determine if the letters are the same – determined by size and vowel/consonant or capital/lowercase
- Results show multiple representations of a single stimulus are activated
Sternberg Task
- Participants memorize a set of letters
- Then they are presented with a new letter and determine if it is part of the set
- Response time increases with the size of the set - indicating the process is serial - each response takes a fixed amount of time
Word Superiority Effect
- The word superiority effect is shown in the Sternberg task
- This effect occurs when target letters are faster to identify when they are within a word, rather than a random string of characters
Stroop Task
- Participants name the color of ink that a word or string of letters are presented with
- The Stroop Effect occurs when the word presented is a color name, but in a different colored ink
- For example, the word "RED" printed in blue ink - this increases the time it takes to name the color
- This is thought to be because of competing representations - the color in reality and the color the word represents
The Lesion Method
- This was the foundation for cognitive neuroscience
- Missing brain regions can be inferred from the patient’s inability to perform certain tasks
Single Unit Recording
- This method involves attaching electrodes to the skull
- A micropipette penetrates single cells
- This requires fine control within 1 micron
- Three basic types:
- Extracellular: the strongest signal is from the closest cell, filters are used to minimize weaker signals, repetition is required to determine if the signal is typical
- Intracellular: a pipette penetrates the cell
- Microiontophoresis: combines recording with the deposition of chemicals onto a neuron - this is difficult because it’s hard to know what to manipulate
Electroencephalography (EEG)
- EEG does not measure individual neuron activity, it measures the summed activity across the scalp
- High temporal resolution, low spatial resolution
- Trial averaging is needed for reliable data
- Signal varies with states of consciousness
Position Emission Tomography (PET)
- Useful for evaluating brain diseases - it can capture a variety of processes
- It can acquire the activity of neurotransmitters
- Different tracers emit different gamma rays, which are detected by the machine
- Positrons emit two gamma rays that have equal energy but move in opposite directions
- The PET scanner detects the gamma rays and produces an image
Functional Magnetic Resonance Imaging (fMRI)
- Radiofrequency pulses make hydrogen protons spin and release energy
- The energy is different for different types of tissue
- Structural MRI shows anatomical images
- Functional MRI shows maps of blood oxygen level changes, this is how we infer neural activity
- This method allows the visualization of "active" brain regions during cognitive performance
- Active neurons require more oxygen, which is provided by an increase in blood flow
- fMRI detects the changes in oxygen levels across the brain
Naturally Occurring Lesions
- Tumors:
- An abnormal mass of growing tissue
- Named after the region they grow in
- Degenerative Disorders
- Infections
- Head Trauma
- Contra coup: closed head injuries result in frontal and parietal damage
- Epilepsy
Degenerative Disorders
- Parkinson’s disease:
- Death of dopamine-producing cells in the substantia nigra
- Results in motor control issues
- Huntington’s disease:
- Degeneration of the caudate and putamen due to a reduction in GABA
- Alzheimer’s disease:
- Progressive deterioration from the posterior to the anterior cortex
- Memory loss is the first symptom
- Pick’s Disease:
- Rarer than Alzheimer’s disease, progresses in the opposite direction (anterior to posterior)
- Characterized by cortical “pick’s bodies”
- Personality disorders are the first symptom to present
Phineas Gage
- A tamping iron severely damaged his left frontal lobe
- This shows the importance of the prefrontal cortex in personality, executive function, and impulse control
- He went from a diligent and polite individual to irreverent, impatient, aggressive, profane, etc.
Development of the Nervous System
- Gross development:
- Multicellular blastula: the first structure after the egg is penetrated by the sperm
- Contains precursor cells (undifferentiated cells) that become neurons, glial cells, and ependymal cells
- Precursor cells divide in 3 ways: dividing into brain cells, into brain cells and precursor cells, into only precursor cells
Development of the Nervous System
- Developmental Sequence of Multicellular Blastula:
- Gastrulation: invagination and cell migration within the blastula to form the ectoderm
- Neurulation: ectodermal cells form the neural plate, which then invaginates and folds to form the neural groove
- The 3 layers of the neural plate:
- Ectoderm: forms the nervous system and outer skin
- Endoderm: forms the gut and digestive organs
- Mesoderm: forms the skeletal system and voluntary muscles
Development of the Nervous System
- Neurogenesis:
- This is the creation of neurons
- This continues after embryonic development
- The brain is changing across the lifespan - there is the formation and pruning of synapses and myelination
- The prefrontal cortex is not fully developed until adulthood - around age 25
Human Embryo
- The primitive brain consists of 3 cavities that form the ventricles
- Ependymal cells stay behind to form the ventricular walls
- Gross brain structures are formed by bends called flexures
- The cortex forms from the inside out
- The 3H-thymidine labeling technique is radioactive and injected into the embryo and labels the cells that are dividing
Rakic’s Evidence for Hypotheses
- The type of neuron a cell becomes is determined by its point of genesis
- Evidence:
- Correlational- determination of cell type is correlated with the time of creation during gestation
- Experimental- cells transplanted from one animal to another migrate to the location based off their creation time
- Transplantation does not affect connectivity
Consequences of Radial Migration
- Cells migrate along radial glia
- Cells born next to each other stay together in the adult brain
- Cells born far apart stay far apart in the adult brain
- This creates a topographic relation of cells in the ventricular zone
- This leads to the columnar/laminar organization of the cortex
- Cortical column is a key unit of cortical organization
- Radial cells become astrocytes after migration is complete
- Radial unit hypothesis
Reeler Mice Experiment
- Genetically manipulated radial glia
- Disrupted neuronal organization
- Laminar organization is reversed
- This leads to:
- Reduced cerebellar volume
- Ataxic gait
- Dystonia
- Tremors
Rakic’s “protomap” hypothesis
- Genetic predisposition for organization
- Brain organization is determined in the ventricular zone
- Neurons in the ventricular zone attract function-specific afferent fibers according to the protomap (a type of “blueprint”)
Rakic’s Hypothesis: radiations and protomaps
- The final role of cells is determined by a complex mix of genetic and environmental factors
- This interplay is studied with microsurgical experimental techniques
Jean Piaget
- Knowledge develops in 4 stages:
- Sensorimotor
- Pre-operational
- Concrete operations
- Formal operations
- Cognitive structures are patterns of physical or mental actions that support intellect
- 3 processes that develop these structures:
- Adaptation: infants try to adapt to the world
- Assimilation: interpreting events through existing cognitive structures
- Accommodation: changing cognitive structures to make sense of the world
Piaget’s Theory of Developmental Stages
- Sensorimotor stage:
- Ages birth to 2 years
- unconnected intelligence, sensation, and thought
- poor concepts of objects and no object permanence
- Pre-operational stage:
- Ages 2 to 7 years
- Conservation of quantity, imagination, and imitation develop
- Concrete Operations stage:
- Ages 7 to 11 years
- Logical problem-solving, classification, and categorization abilities develop
- Concrete concepts and reversibility develops
- Formal Operations stage:
- Ages 12 and on
- Abstract thought, problem-solving, scientific thought
- Social issues and identity are of concern
Neo-Piagetians
- Challenged the rigidity of Piaget’s theory
- They believed cognitive abilities developed earlier than Piaget believed
- Neo-Piagetians discussed in class:
Rene Baillergeon
- Studied object permanence
- Methodology:
- An object is presented, then hidden behind a screen that is dropped
- Sometimes the object is there, sometimes it is not
- Findings:
- Infants 3.5 months old show surprise if the object appears to disappear
- Object permanence may occur earlier than Piaget said
Judy DeLoache
- Studied symbol use
- Methodology:
- A child sees a prize in a model of a room
- The child then searches the actual room for the prize
- Findings:
- 2.5-year-olds have trouble and search randomly
- 3-year-olds have a much higher rate of success
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Description
This quiz explores the concepts of long term memory, focusing on the Posner and Sternberg tasks. Participants will learn how these tasks illustrate multiple representations activated by stimuli and the serial comparison process in memory retrieval. Test your knowledge on the word superiority effect and its relation to these memory tasks.
