Summary
Highlights
Nancy Kanwisher welcomes students to 913, 'The Human Brain,' and outlines the day's agenda: a personal story, discussion of 'why, how, and what' to study the brain, and course mechanics. She emphasizes the interactive nature of the class and her enthusiasm for the subject.
Kanwisher shares a true story about her friend, Bob, who experienced unexplained navigational deficits. Despite other intellectual strengths, Bob's increasing difficulty with directions worried her, unconsciously linking to her research on brain modularity and navigation. This foreshadows key themes of the course: brain organization, recovery after damage, and the distinction between various mental abilities.
After an incident at her home, Bob is taken to the ER. Kanwisher, sensing a neurological issue, suggests checking his brain, despite the ER doctor thinking it was a heart issue. Later, a lime-sized tumor is discovered in Bob's brain, near the parahippocampal place area—a region her lab previously discovered to be involved in navigation. Earlier scans from her lab, initially unnoticed, confirm the tumor's slow growth.
Before Bob's surgery, Kanwisher conducts informal tests, asking him to draw floor plans of his house and hers. He produces disorganized, unrecognizable maps, indicating a severe deficit in spatial layout. However, he can draw multi-part objects like bicycles and lobsters perfectly, demonstrating a specific impairment in spatial navigation, not general object representation. Despite a successful surgery, Bob's navigational abilities do not recover, highlighting the brain's limited plasticity in adults and the specific nature of certain cognitive functions.
Kanwisher extracts several core themes from Bob's story: the brain's structured organization and modularity, the specificity of some brain functions, how brain architecture mirrors the mind's architecture, and insights into how brains change from development, experience, and injury. She also highlights the diverse methods used to study the brain, from behavioral observations to anatomical and functional imaging.
Kanwisher presents four reasons for studying the human brain: 1) 'Know thyself' – the brain is central to identity. 2) To understand the limits of human knowledge – using cognitive science for empirical epistemology. 3) To advance AI – where the human brain still outperforms current AI in complex tasks despite recent deep learning advancements. 4) The brain represents the greatest intellectual quest of all time.
While deep nets have revolutionized AI, particularly in vision, challenging new datasets demonstrate their limitations compared to human object recognition. Furthermore, current AI systems struggle with rich image understanding, humor, and constructing world models, skills that humans excel at. This shows AI still has much to learn from human cognition.
Studying the human brain involves understanding its multiple levels of organization, from molecules to neural networks. The course will focus on how the brain gives rise to the mind, starting with mental functions and then exploring their brain bases. Key questions include identifying specialized neural machinery, understanding information representation, and how it is processed. Methods include psychophysics, neuropsychology, fMRI, neurophysiology, EEG, and MEG.
Kanwisher clarifies that the course emphasizes cognitive science alongside neurobiology, treating the brain as the physical substrate of the mind. The curriculum will cover mental functions with well-understood brain bases, such as visual perception, face and place recognition, language, numbers, and understanding other people. This approach prioritizes areas of recent progress and high-level cognitive functions.
The course will delve into questions regarding the unique aspects of the human brain that enable complex achievements like science, engineering, and art. It will explore the origins of knowledge—innate versus learned—and the extent to which minds and brains can change through development, learning, training, or after injury. The relationship between language and thought, and perception without awareness, will also be discussed.
Topics not covered extensively include motor control, subcortical functions (except during the brain dissection), decision-making, and circuit-level mechanisms for complex cognition, as such detailed explanations are largely unavailable in the field today. Memory will also receive limited attention, as Kanwisher seeks more engaging ways to teach it.
The course involves a midterm (25%), final exam (25%), and reading/writing assignments (50%). Students will read approximately two scientific papers per week, with one short written response per paper. There will also be around eight short in-class quizzes and one longer experimental design assignment. The course schedule prioritizes recent articles over textbooks due to the rapid pace of the field.
The course begins with basic neuroanatomy, followed by a live human brain dissection. Subsequent lectures will cover high-level vision, debates on visual cortex organization, scene perception, and navigation, drawing from patient studies and animal physiology. Developmental aspects of brain wiring, brains in blind individuals, number cognition, pleasure/reward systems, language, and theory of mind will also be explored. Towards the end, guest lectures on brain-machine interfaces and deep nets will be featured.
Kanwisher provides guidance on efficiently reading scientific papers, advising students to focus on key questions: the research question, findings, interpretation ('who cares?'), and experimental design. She encourages starting with the abstract and then selectively navigating the paper for answers, emphasizing that understanding takes time and active engagement, rather than a linear read.