cognition neuro

Hypothalamus and Pathways in Sexual Behavior

  • Major Pathway Concepts

    • Sexually Dimorphic Nucleus (SDN)

    • Part of the male pathway influencing sexual behavior.

    • Ventromedial Nucleus

    • Associated with female sex behavior circuit.

  • Key Insight:

    • The sexually dimorphic nucleus is crucial for understanding these pathways in male behavior.

Student Interaction and Quizzes

  • Instructor's Offer:

    • Questions about quizzes; clarity on right or wrong answers.

    • Encourage reaching out after class or via email with queries.

Functional Magnetic Resonance Imaging (fMRI)

  • Basic Operation:

    • Patient placed in strong magnetic field.

    • Magnetic molecules align according to the field.

    • Radio waves applied to brain, causing magnetic molecules to emit energy.

    • Detectors capture emitted radio waves to locate brain activity.

  • Molecular Variability:

    • Different magnetic properties yield varied signals from molecules (e.g., oxygenated vs deoxygenated hemoglobin).

    • Enables distinction between different types of molecules, such as blood and water in the brain.

  • Tracking Brain Activity:

    • Concerned with levels of oxygenated blood in specific brain areas during tasks.

    • Activity detected by changes in blood flow tied to oxygen use during cognition.

    • Astrocytic response leads to blood vessel dilation, increasing oxygen supply upon neural activation.

Experimental Design on Humor Processing

  • Background of the Study:

    • Investigates brain areas processing humor across human cultures.

  • Pre-Study Phase:

    • Collection of cartoon images rated by participants for humor (scale 0-10).

    • Selection of highly humorous (9-10) and non-humorous (0-1) images for the main experiment.

  • Experiment Execution:

    • Random presentation of humor and non-humor images during the fMRI scan.

    • Data sorted by conditions for brain activity analysis.

  • Observational Methodology:

    • Humor-related brain activity derived from subtracting activity during non-humor conditions.

    • Critical for isolating humor responses amidst other mental stimuli.

  • Significance of Design:

    • Helps ensure no extraneous factors influence interpretation of humor-related brain signals.

Neuroimaging Technologies

  • Positron Emission Tomography (PET):

    • Utilizes positrons, which are anti-electrons with identical mass but opposite charge.

    • Mechanism of Action:

    • Annihilation Event: Positrons and electrons annihilate, emitting gamma rays detectable by sensors.

    • Applicability:

    • High glucose uptake indicates active neurons.

    • PET allows for tracking of specific biomolecules and can detect conditions like cancer through labeled antibodies.

  • Comparison with fMRI:

    • fMRI excels in spatial and temporal resolution of brain activity.

    • PET is better for confirming BOLD signal (blood oxygen level dependency) related to brain activity.

Understanding Deja Vu and Cognitive Processing

  • Definition of Deja Vu:

    • The sensation that an experience feels like a recalled memory, despite having no actual prior occurrence.

  • Phenomenon in Epilepsy:

    • Some individuals with temporally focused epilepsy experience deja vu moments prior to seizures.

  • Investigative Approach:

    • Research examined brain activity differences in patients with epilepsy who experience deja vu to identify affected areas.

  • Functional Findings:

    • The hippocampus emerges as a central brain structure involved in the experience of deja vu—suggestive of memory processing anomalies.

Language Development Insights

  • Infant Sound Discrimination:

    • Infants can differentiate sounds from birth, linking them to sensory experiences and actions in their environment.

  • Language Acquisition Process:

    • Crucial experiences during early years enable associations between sounds and meanings, necessary for spelling, grammar, and vocabulary formation.

  • Sensitive Period for Language Development:

    • Early exposure to language influences capacity for learning. Without it, children may lose the ability to acquire language later, as seen in cases of neglect.

  • Complexity of Language Learning:

    • Older learners face challenges retaining learned languages, suggesting varied neurological processes between early and late language acquisition.

Neurodevelopment and Aphasia

  • Localized Brain Functions:

    • Identification of key brain areas (Broca's and Wernicke's) involved in language based on neurological damage.

  • Broca's Aphasia:

    • Damage in the frontal lobe impairs speech production but retains comprehension.

    • Results in limited speech fluency, with preserved functions for automatic speech like cursing.

  • Wernicke's Aphasia:

    • Found in temporal lobe damage, causing nonsensical output that lacks meaning, coupled with comprehension difficulties.

  • Cerebral Lateralization:

    • Language processing is typically localized in the left hemisphere for most individuals, though some exhibit right hemisphere lateralization.

Attention Mechanisms in Cognition

  • Types of Attention:

    • Endogenous Attention:

    • Voluntary focus on specific stimuli; prone to distraction. Broken into:

      • Overt Attention: Focus aligned with visual gaze.

      • Covert Attention: Mental focus not aligned with visual gaze, often unnoticed.

    • Exogenous Attention:

    • Reflexive response to external stimuli; automatic reorienting of focus, such as reacting to a loud noise or movement.

Conclusion

  • Knowledge Integration:

    • Emphasis on various cognitive processes and their neurobiological underpinnings promoting a comprehensive understanding of psychological functions and conditions.