in Cognitive Neuroscience

Transcription

1 Finish: History of Cognitive Psychology Then: Physiological Measures. in Cognitive Neuroscience Psychology 355: Cognitive Psychology Instructor: John Miyamoto 03/29/2018: Lecture 01-4 Note: This Powerpoint presentation may contain macros that I wrote to help me create the slides. The macros aren t needed to view the slides. You can disable or delete the macros without any change to the presentation.

2 Outline Finish: History of cognitive psychology Physiological measures in cognitive neuroscience Single cell electrical recordings What are they? Strengths and weaknesses of this method for researching brain function Event-Related Potentials (ERPs) What are they? Strengths and weaknesses of this method for researching brain function fmri brain scanning What is it? Strengths and weaknesses of this method for researching brain function Application of fmri scanning to human face perception Lecture probably ends here Psych 355, Miyamoto, Spr 18 Overview of the History of Cognitive Psychology 2

3 Overview of the History of Cognitive Psychology Precursors to cognitive psychology Aristotle, Plato epistemology, theory of ideas and their relation to human action Experimental psychology begins in 19th century Germany Done! Franciscus Donders (response time analysis, method of subtraction) Hermann von Helmholtz (perception, unconscious inference) Hermann Ebbinghaus (experimental study of memory) Wilhelm Wundt (analytic introspection, analysis of conscious experience) Behaviorist hiatus in America: roughly During the behaviorist period ( ), cognitive psychology continued to be studied in Europe. Revival of cognitive psychology in America ( ) 1970 present: Cognitive psychology plays a major role in psychology pretty much everywhere in the world Why Did Behaviorism Lose Its Dominance in American Psychology? Psych 355, Miyamoto, Spr '18 3

4 Why did behaviorism lose its hold on American psychology? ( ) Problematic results Learning without responding: Rats that are temporarily paralyzed with atropine can learn the layout of a maze from being wheeled around the maze on a stretcher. Learning without reinforcement: Rats that explore a maze with no reinforcements show learning of the maze when they are later rewarded for running the maze. Behaviorist theories could not provide insightful explanations or a productive research strategy for studying obvious important behaviors such as: Human language production and comprehension; also, language learning. Human problem solving; human decision making. Human attention and perception. It takes a theory to kill a theory! Psych 355, Miyamoto, Spr '18 The Legitimacy of Hypothetical Constructs in Psychology 4

5 Psych 355, Miyamoto, Spr '18 Experimental / Modeling / Physiological Approaches to Cognitive Psychology 5 Is It Unscientific to Postulate Unobserved Processes? Is it unscientific to postulate unobserved psychological processes in a psychological theory? Behaviorists "Yes" Cognitivists "No"

6 Cognitive Psychology Since 1960 Experimental cognitive psychology Emphasizes the behavioral approach Perception & Attention, Memory, Language, Reasoning & problem solving, Cognitive development Behavioral Approach: All dependent measures in a study are observed behavior. Computer modeling of cognitive processes Usually a mixture of the behavioral and computational approach Modeling Approach: Physiological Approach Single-cell recordings Neural imaging: PET, fmri, ERP Study effects of drugs Physiological Approach: All dependent measures in a study are measures of physiological states or physiological responses. Hybrid Approach (Cognitive Neuroscience): The study attempts to explain behavioral responses and physiological responses, and may include computational modeling of behavior. Summary of History Psych 355, Miyamoto, Spr '18 6

7 Cognitive Psychology Since 1960 Experimental cognitive psychology Emphasizes the behavioral approach Perception & Attention, Memory, Language, Reasoning & problem solving, Cognitive development Computer modeling of cognitive processes Usually a mixture of the behavioral and computational approach Physiological Approach Single-cell recordings Neural imaging: PET, fmri, ERP Study effects of drugs Summary of History Psych 355, Miyamoto, Spr '18 7

8 Summary 19 th Century European origins of cognitive research Some research during the first half of the 20 th century : Beginning of modern cognitive psychology 1960 present: Extensive behavioral research 1990 present: Cognitive neuroscience stimulated by new imaging techniques. Present: Combination of behavioral, neuroscience and computational approaches. Review of Neural Information Processing:. Psych 355,, Miyamoto, Spr '18 Start with Diagram of Nerve Cell & Info Transmission 8

9 The Parts of a Neuron (Nerve Cell) Cell body or soma main body of the neuron. Dendrites brushy projections that receive stimulation from other cells. Axon long projection that carries stimulation to other cells. Terminal buttons (a.k.a. axon terminals or synaptic terminals) End of axon where a neurochemical signal is passed to other nerve cells. Psych 355, Miyamoto, Spr '18 Enlarged Diagram of a Synapse 9

10 The Synapse Point of Contact Between Two Nerve Cells Image downloaded from Wikipedia (1/9/07): Goldstein (2014), Figure 2.5, p. 30. Nice pictures of a synapse are available at: and Psych 355, Miyamoto, Spr '18 Information Transfer at the Synapse 10

11 Information Transmission at the Synapse Neurotransmitters (chemicals) are transferred from one neuron to the next at a synapse. At any synapse, the transmission is in only one direction. One neuron is the sending neuron. The other neuron is the receiving neuron. Neurons can either excite or inhibit the neural actions of other neurons. Image downloaded from Wikipedia (1/9/07): Nice pictures of a synapse are available at: and Psych 355, Miyamoto, Spr '18 Action Potentials are All-of-None 11

12 Action Potentials: Electrochemical waves that pass down the axon of a neuron. Action potentials are all-or-nothing. The size is the same for all action potentials. The rate of action potentials matters. The resting rate is not zero. Neural Information Processing: Time of Occurrence of an Action Potential (Spike) Time Psych 355, Miyamoto, Spr '18 Summary re Neural Signals 12

13 Summary re Neural Signals Information is carried by the firing rate of a neuron, not the size of an action potential (all are of equal size). Inputs to a neuron can increase (excite) or decrease (inhibit) the firing rate of the neuron. The signal is transmitted from one neuron to the next by means of neurotransmitter chemicals that are passed from one neuron to another at the synapse. Psych 355, Miyamoto, Spr '18 Next: Strengths and Weaknesses of Different Physiological Measures 13

14 Next: Strengths and Weaknesses of Different Physiological Measures Single-cell recordings Event Related Potentials (ERPs) fmri Psych 355,, Miyamoto, Spr '18 14 Single Cell Recordings

15 The firing rate of individual neurons is measured by means of single cell recordings. Today it is possible to record simultaneously from a number of of individual cells. Single Cell Recordings Psych 355, Miyamoto, Spr '18 Strengths and Weaknesses of Single Cell Recordings 15

16 Strengths and Weaknesses of Single Cell Recording Methods Strengths Excellent spatial information the scientist has a very good idea where the recording is located in the brain. Excellent temporal information the scientist knows when the neuron fires to a high level of precision. Drawbacks Practically difficult to record from more than a small number of cells at a given time, e.g., 15 to 20 cells simultaneously. The method is very invasive. In humans, single-cell recordings are restricted to patients who have other reasons for undergoing brain surgery. Psych 355, Miyamoto, Spr '18 Event-Related Potentials (ERP s) 16

17 Event-Related Potentials (ERP s) Measures electrical potentials on the scalp while processing a stimulus. Psych 355, Miyamoto, Spr '18 Strengths and Weaknesses of ERP s 17

18 Event-Related Potentials (ERP s) Strengths and weaknesses of ERP s as research tool. Poor spatial resolution. Excellent temporal resolution. Relatively non-invasive. Sketchy understanding of the brain processes that are producing the EEG signal. The graph shows the electrical recording at one location. Similar graphs can be made for every recording location. Psych 355, Miyamoto, Spr '18 Functional Magnetic Resonance Imaging (fmri) 18

19 Thursday, 29 March, 2018: The Lecture Ended Here Psych 355,, Miyamoto, Spr '18 19