Class notes PSY324 Reading & Lecture Notes Week 1 Notes (PSY324 Reading & Lecture Notes Week 1 Notes)

PSY324: Cognition & Memory Week 1 Notes Chapter 2 Notes: Eyes and ears are important to cognitive psychology. Brain is only 2% of body weight but claims 20% of blood supply. Specific cognitive mechanisms are associated with specific brain areas. cognitive neuroscience is the area of research concerned with this relationship (pg. 25) The Brain as the organ of the mind Brain is composed of specific parts or modules modules: different parts of the brain, each of which is responsible for particular cognitive operations Gall and Spurzheim: Phrenology: the study of the shape, size and protrusions of the cranium in an attempt to discover the relationships between parts of the brain and various mental activities and abilities. Phrenological charts purport to show where various psychological functions are located in the brain. 3 Basic principles The brain is the sole organ of the mind Basic character and intellectual traits are innately determined. Since there are differences in character and intellectual traits among individuals as well as differences in various intellectual capacities within a single individual, there must exist differentially developed areas on the brain, responsible for those differences. Where there is variation in function, there must be variation in the controlling structures. believed that the more highly developed a function was, the larger it would be. The larger the function, it would manifest as a protrusion on the skull. Localization of function: Shepherd Ivory Franz: the idea that there is a direct correspondence between specific cognitive functions and specific parts of the brain. Franz was an expert in ablation, a technique that destroyed parts of the cortex and consequences for behavior are observed. neither learning nor memory was dependent upon the properties of individual cells, rather both were functions of the total mass of tissue (pg 28) these results came to be formulated as two laws: law of mass: learning and memory depend on the total mass of brain tissue remaining rather than the properties of individual cells. law of equipotentiality: even though some areas of the cortex may become specialized for certain tasks, any part of an area can (within limits) do the job of any other part of that area The relation between mind and brain consciousness: narrower concept; often taken to mean what we are aware of at any point in time (pg 28) mind: is a broader concept, it includes consciousness, but also encompasses processes that may take place outside of our awareness 4 classic efforts toward understanding mind and brain Interactionism: associated with Descartes mind and brain are separate substances that interact with and influence each other Epiphenomenalism: “mind” is superfluous by-product of bodily functioning a by product of brain functions and has no causal role in determining behavior belief that consciousness is irrelevant to an understanding of behavior steam from a steam whistle to a coal-powered locomotive Parallelism: “mind” and brain are two aspects of the same reality and flow in parallel every event in the mind is accompanied by a corresponding event in the brain Isomorphism: mental events share the same structure traced to Gestalt psychologists Gestalt means form or configuration argued that consciousness tends to be organized into a coherent whole an experience and its corresponding brain process share the same pattern difference between isomorphism and parallelism is that the latter envisions more than a simple point for point correspondence between mental events and brain events external stimulus is constant but the internal subjective experience varies. Methods in Cognitive Neuroscience Animal Models an indirect route to investigating brain mechanisms in humans is provided by animal models almost everything we currently know about the micro-organization of brain structure and function is derived from the study of animal brains (pg 30) differences across species in terms of structure and function place strong limitations on our ability to generalize from one species to another and from animal models to humans Behavioral Studies combines our knowledge of normal sensory systems with precise stimulus presentation and response recording The study of brain injuries brain injuries can serve as a kind of substitute for experiments that provide evidence for the localization of one or more functions. Broca’s aphasia: a deficit in the ability to produce speech as a result of damage to Broca’s area Broca’s area: the area of the brain’s left hemisphere that is responsible for how words are spoken Wernicke’s area: area of the brain’s left hemisphere that is responsible for processing the meaning of words Wernicke’s aphasia: A deficit in the ability to comprehend speech as a result of damage to Wernicke’s area Surgical Intervention Roger Sperry, research on inter hemispheric transfer inter hemispheric transfer: communication between the brain’s hemispheres, enabled in large part by the corps callosum conducted on cats and involved severing the optic chasm (area in the brain where the optic nerves that transmit information from the eyes to the visual cortex cross) when the corpus callosum is severed, information transfer between hemispheres is disrupted each hemisphere appeared to be a separate mental domain operating with complete disregard, indeed with a complete lack of awareness of what went on in the other. split brain: a condition created by severing the corpus callosum the animal behaved as if it had entirely separate brains. Perry argued that consciousness was an emergent property of the brain emergent property: in Sperry’s sense, a property that “emerges” as a result of brain processes, but is not itself a component of the brain. In the case of the mind, this means that consciousness is neither reducible to, nor a property of, a particular brain structure or region. emergent causation: in Sperry’s sense, causation brought about by an emergent property. Once the “mind” emerges from the brain, it has the power to influence lower level processes. supervenient: In Sperry’s sense, describes mental states that may simultaneously influence neuronal events and be influenced by them. Event-Related Potentials CT / MRI on pg 34 event related potential (ERP): an electrical signal emitted by the brain after the onset of a stimulus Positron Emission Tomography PET: an imaging technique in which a participant is injected with a radioactive substance that mingles with the blood and circulates to the brain. A scanner is then used to detect the flow of blood to the particular areas of the brain info on pg 36