1. Introduction to the Human Brain
17 Nov 2023 (10 months ago)
Retrospective Cortex
- A postdoc named Russell Epstein, specializing in computer vision, aimed to understand human vision by simulating brain algorithms.
- Epstein was skeptical about the emerging brain imaging techniques and was persuaded to conduct an imaging experiment to aid his job prospects.
- The experiment, which involved scanning people as they looked at images of scenes, unexpectedly identified a brain area highly responsive to scenes, not faces or objects.
- This discovery of the parahippocampal place area spurred significant research in the field of vision and cognition.
- A personal anecdote revealed the slow growth of a non-cancerous meningioma tumor found in a friend's brain, first observed in past research data.
Medical Incident and Neuropsychological Insights
- The discovery that the tumor, initially unseen in earlier data, was growing slowly suggested it wasn't as aggressive as some brain tumors.
- The friend's tumor was later identified as a non-cancerous meningioma.
- During a hospital visit, a resident acknowledged the author's expertise in brain studies.
- Urged by a neurosurgeon friend, the author used connections to find a top neurosurgeon for their friend's surgery.
- A pre-surgery test revealed the friend had difficulties with spatial tasks, such as drawing a floor plan, but not with drawing objects like a bicycle or lobster, indicating a specific impairment in spatial reasoning related to places.
Surgical Outcome and Reflection [Not in the provided text]
- Details concerning the surgical outcome and any further reflections were not included in the provided text.
Navigational Abilities
- Bob's navigational abilities did not recover following brain damage.
- Relies on iPhone GPS for navigation, indicating technology's role in compensating for lost brain functions.
- Recovery of such specific brain functions is less likely in adults, compared to children.
- Left-right distinction and recognition of familiar places remain intact, but the ability to navigate or orient spatially to travel to those places is impaired.
- Can follow memorized routes but cannot form new routes or alternate pathways.
- Can estimate distances but struggles with creating mental maps of surroundings.
- Difficulty with navigation persists even in familiar environments and within buildings.
The Organization of the Brain Echoes the Architecture of the Mind
- The organization of the brain reflects the architecture of the mind, indicating specific mental functions.
- Brain structure corresponds to specific mental abilities; not all brain parts are equally specialized.
How Do Brains Change
- Changes in the brain due to normal development, learning, experience, and injury vary with age.
- Children’s brains are more plastic and able to adjust after injury.
- The study of how brains change can involve a variety of methods, from behavioral observations to anatomical and functional imaging.
Why How and What of Exploring the Brain
- Various methods are used to explore the brain's structure and functions, each providing different insights.
Why Should We Study the Brain
- Studying the brain is essential for understanding the essence of what makes us who we are.
- The brain is a unique organ responsible for our identity, distinct from other vital organs.
- Understanding the brain can help us grasp the limits of human knowledge.
Understand the Limits of Human Knowledge
- Recognizing the limits of human understanding can help gauge the quality of the knowledge we possess.
- Ungraspable scientific theories might exist.
- Studying the mind serves as empirical epistemology to understand the knower.
- The development of AI has rapidly evolved, especially in vision, challenging the human visual system's superiority.
- The landmark Krizhevsky paper in 2012 on deep nets drastically improved visual object recognition approaching human performance.
- Despite advancements, deep nets still struggle with more variable and realistic sets of images compared to humans.
Image Understanding
- AI can label images but struggles with understanding the dynamic situations within them.
- Image captioning algorithms can accurately describe some images but often fail with complex scenes.
- Deep neural networks (deep nets) are proficient in pattern recognition but not in comprehending nuanced real-world scenarios.
- AI lacks human capabilities like navigating new situations, understanding beliefs, communication, and creativity.
- AI systems have dramatically advanced but still have much to learn from human brain functionality to fully replicate human cognition.
Fourth Reason To Study the Human Brain
- The human brain is considered the greatest intellectual quest of all time.
- The brain has multiple levels of organization offering various approaches to its study.
- This course will not focus on any single method but rather explore how the brain gives rise to the mind.
How Does the Brain Give Rise to the Mind
- Understanding the brain requires starting with the concept of the mind.
- Identifying what the mind is and how it functions is critical.
Mental Functions
- The course will examine various mental functions, such as perception and cognition.
- For each function, specialized neural machinery and brain region interactions will be explored.
- Cognitive science methods such as psychophysics and studying perceptual illusions are fundamental to the course.
- Functional MRI, neuropsychological studies, EEG, neurophysiology, and other methods will be used to understand the brain basis for mental functions.
- The instructor addresses previous course feedback and clarifies that the focus is on cognitive science, not just the brain's biology.
- Recent progress has greatly expanded knowledge about specific brain region functions related to mental processes.
- The course will concentrate on functions with well-understood brain bases, like color, shape, motion perception, face recognition, language understanding, and others.
- The discussions will include developmental aspects, species comparisons, and what is unique to the human brain.
- Broader questions like knowledge acquisition, brain plasticity, and thinking without language will be considered.
- The course will omit topics such as motor control due to time constraints.
Awareness
- The course will also touch upon the role of awareness in thinking, perceiving, and understanding.
Subcortical Function and Related Sections
- The course primarily focuses on the cerebral cortex, important for conscious thinking and cognition.
- Comparative under-coverage of subcortical function and decision-making due to course's scope.
- Understanding circuit-level mechanisms of high-level mental functions, such as comprehending sentences, is currently beyond our scientific grasp.
- Detailed neuron-level understanding of less complex functions, like fear conditioning in mice, has been achieved.
- Lack of focus on memory is due to the instructor's desire to avoid uninteresting lectures.
- Reinforcement learning and reward systems, as well as attention, are mentioned but won't be major focuses.
- The course is aimed at students who have taken prerequisites (900 or 901) but is accessible to others willing to put in extra effort.
- Some overlap is inevitable with prerequisite courses due to the nature of the material.
The Goals of this Course
- The course aims to help students appreciate major questions and theoretical stakes in the field.
- Understanding rather than memorization is emphasized.
- Instruction on methods in human cognitive neuroscience, their strengths, and limitations.
- Students will learn about domains of cognition with significant advancements at both the cognitive and brain level, such as face recognition and language understanding.
- A major goal is to enable students to read and interpret current scientific papers in the field, with course readings advancing to recent publications.
Why no Textbook
- No textbook is used because the field progresses too rapidly for textbooks to keep up.
- The course emphasizes reading current original research articles over outdated textbooks or review articles.
- The approach is designed to empower students to engage directly with the most recent studies in the discipline.
Details on the Grading
- Grading is straightforward, with a midterm and final exam each constituting 25% of the grade.
- The final exam is cumulative but focuses more on the latter part of the course material.
Reading and Writing Assignments
- Students will have reading and writing assignments, with two papers to read weekly and a short written assignment on one paper.
- Understanding the paper is critical for answering questions.
- Assignments and submissions will be managed via Stellar, with the first paper response due February 12 at 6 PM.
- Assignments are due the night before the class to allow TAs to assess comprehension.
Scene Perception and Navigation
- The course will explore scene perception and navigation, using various methods to understand how these processes work.
- Lectures will address development, how brains are wired, and the roles of genes and learning, focusing on navigation and face recognition systems.
- Additional topics include the brains of blind people, number cognition, pleasure, pain, reward, neuroeconomics, uniquely human capabilities, and the differencse between human and animal cognition.
Brain Machine Interface and Theory of Mind
- Guest lecturer Michael Cohen will cover brain-machine interfaces.
- The course will also delve into language comprehension and production, and the concept of theory of mind, which involves interpreting others' mental states.
Brain Networks
- Brain function involves multiple regions working together.
- Studies aim to identify which sets of regions collaborate.
- The quest is to understand broader networks of brain regions.
- The course will include a longer written assignment for students to design their own experiments.
- Group sessions will refine experiment designs.
- Katherina Dobbs will give a guest lecture on deep nets and their relation to cognition and brains.
- Topics of attention and awareness will be discussed.
- The final class might feature TAs presenting their research, pending confirmation.
- The structure and content of the remaining classes were clarified to the students.
Reading and Understanding Academic Papers
- This course isn't focused on statistics or MRI physics.
- Students should understand basic concepts like P levels, T-tests, ANOVAs, and correlations.
- Reading papers is not about mastering the statistics but understanding the study's substance.
- When reading, identify the main question of the paper, ideally found in the abstract.
- Ascertain the key findings from the paper.
- Understand the interpretation of the findings, such as why they are significant.
- The course will not cover the intricacies of statistical details in experiments due to time constraints.