History and Introduction to Cognitive Psychology Chapter 1 1 What is Cognitive Psychology? Cognition co- + gnoscere to come to know. Knowing requires mental activity which involves acquiring, storage, transformation and use of knowledge (Matlin, 2002). Cognitive Psychology deals with how people perceive, learn, remember and think about information (Sternberg, 2003) and how do they use this information (Matlin, 2002). 2 Why study Cognitive Psychology? 1. Cognitive psychology holds a major domain in human psychology. 2. It studies the mind and how it works. 3. And it has a widespread influence on other areas of psychology. 3 1
History of Cognitive Psychology Generally speaking two approaches have been used to study the mind. 1. Historically, philosophical approaches have rendered an understanding to the workings of the mind using introspection. 2. And biology, has used observational (and empirical) methods to study the mind. 4 Mind & Reality Plato (ca. 447-327 BC) Reality does not reside in concrete objects but in abstract forms represented in our mind. Aristotle (384-322 BC) Reality lies only in the concrete world of objects accessed through the senses. 5 Comparison Rationalism Understanding of mind (or knowledge) through logical analysis and introspection (rationalism). Innateness of mind or mental faculties. Theory building in psychology today. Empiricism Observations of the external world are the only means to arrive at truth (empiricism). Acquired experiences through interaction with the environment. Experimentation in psychology today. 6 2
Seventeenth Century Rene Descartes (1596-1650) John Locke (1632-1704) Descartes agreed with Plato and emphasized reflective methods (rationalism) over observation to study mind. Locke favored Aristotle and emphasized observation as a method (empiricism) to study mental processes. 7 Immanuel Kant In eighteenth century German philosopher Kant addressed the issue of rationalism and empiricism and said that both approaches must be used to decipher truth and about reality of mind. (1724-1804) 8 Structuralism 1. First psychology lab in Leipzig, Germany (1879). 2. To analyze the structure of the mind. Through the method of introspection. 3. Elements of mind: sensation, feelings, and images. Wilhelm Wundt (1832-1920) 9 3
Functionalism 1. Mind or consciousness cannot be divided into elements. 2. Introspection cannot yield measures about the mind. 3. Mind or consciousness have adaptive value. William James (1842-1910) Self-portrait 10 Behaviorism 1. No room for mind or consciousness. 2. Overt behavior needs to be the scientific domain of psychology. 3. Behaviorism is an extreme form of associationism between environment (S) and observable behavior (R). John Watson (1878-1958) 11 Gestalt Psychology 1. Opposed behaviorism and structuralism. 2. S-R components or mental elements could not explain behavior or mind of an individual. 3. Holistic approach to understanding behavior or mind. Wolfgang Kohler (1887-1967) 12 4
Associationism 1. Studied higher mental processes, like memory and forgetting. 2. Used systematic experimental introspection. 3. Followed Aristotelian law of association. Repetition improves memory. Hermann Ebbinghaus (1850-1909) 13 Memory Studies Ebbinghaus Bartlett In the late 19 th and early 20th century we see differences in approaches to the problem of memory. Ebbinghaus promoted quantitative study of memory using nonsense material, Bartlett on the other hand used qualitative methods to study memory. 14 Is the debate over? Certainly not! Understanding mind and its reality has its adherents belong both to nurture (acquired mind) or nature (innate mind) or both domains. 15 5
Early Beginnings of Cognitive Psychology 1. Lashley s research showed that large amounts of the brain could be destroyed without affecting learning. 2. Hebb, Lashley s student proposed stimulation (learning) led to forming strong connections among neurons called cell assemblies. Stimulus Brain Cell Assembly Response 16 Birth date of Cognitive Psychology 1. Cognitive psychology was born on Sep. 11, 1956, when Neisser, Miller, and Simon read seminal papers at a symposium at MIT. 2. Neisser wrote the first book of Cognitive Psychology (1967). 3. Defined how people learn, structure, store and use knowledge. Ulric Neisser George Miller Herbert Simon 17 Computer Sciences 1. In 40s and 50s, electronic engineering and computer sciences started developing machines and programs that mimicked human learning and thinking. 2. Turing developed a test (Turing test) for a computer to think like a human. Alan Turing (1912-54 ) 18 6
1960s A number of sciences and disciplines like psychobiology, linguistics, anthropology, computer sciences and artificial intelligence started gathering data that developed the strong foundations of cognitive psychology. 19 Current Trends in Cognitive Psychology 20 Cognitive Science Cognitive science is a broad category of loosely associated disciplines that include psychology, philosophy, computer science, linguistics, anthropology, neuroscience and of course cognitive psychology is also a part of its domain. Most researchers are likely to work in an interdisciplinary fashion. 21 7
Cognitive Neuroscience Can we explain cognitive processes by studying the anatomy (structure) and physiology (function) of the brain? The field of cognitive neuroscience expanded around the 1980s when neuroscientists started using imaging techniques on people performing different cognitive functions. 22 Neuroscientific Methodology 23 History of Brain Lesions Human brain damage (gladiators) and its consequences were noted by Hippocrates who wrote that people s behavior changed after such damage. Similar observations had been made in wars victims in the 19 th century. It was not until world war II that physicians started to document disorders that were caused by damage to certain regions of the brain. 24 8
Brain Lesions Our understanding of brain function comes largely from brain lesion studies in animals. Lesion studies provide clues to the organization of the brain. Which brain region engages in what kind of cognitive function. Cognitive functions can remain elusive because of recovery of function (Lashley, 1932). 25 Brain Angiography Is an X-ray method to look at arteries of the brain. Provides information about abnormalities in the brain like strokes or tumors. Carotid artery in the brain imaginis.com 26 CT Scan Is also another X-ray method that images the brain and makes use of multiple X-ray photos taken with a moving X-ray device. Finally reconstructing a 3D picture of the brain. Resolution poor. Cannot determine structure function relationships. CT scan of the brain 27 imaginis.com 9
Magnetic Resonance Imaging (MRI) A strong magnetic pulse and moves molecules in the brain. Motion of these molecules are picked up as radio frequencies and reconstructed in 3-D images. MRI has better resolution than CT scans. No structure function relationship. MRI scan of the brain www.mgh.org 28 Positron Emission Tomography (PET) Increased radio-labeled glucose activity is scanned in the brain while subjects engage in different cognitive processes. Spatial Resolution good. Temporal resolution not good. Invasive procedure. PET scan of the brain www.chm.bris.ac.uk 29 Functional Magnetic Resonance Imaging (fmri) Detects changes in blood flow to particular areas of the brain when these areas are active. It provides both an anatomical and a functional view of the brain. Not invasive like PET scans and provides a better spatial and temporal resolution. fmri scan of the brain 30 www.sciencemuseum.org.uk 10
Event-related Potential Event-related potential measures the brain's electrical activity (potentials) as it corresponds to impinging stimuli (events). Excellent temporal resolution (faster response) compared to PET or fmri. 31 Event-related Potential Single-Cell recordings in non-human subjects provide a wealth of information on the functioning of a single or multiple neurons. For example, Hubel & Wiesel (1960) showed responses of a single neuron in the primary visual cortex detecting an edge (feature). 32 Computer Sciences 33 11
Computers and Mind Parallels between human mind and machines have been made since ancient times. Computer analogy is recent. There are number of attributes that are similar between computers and humans. www.research.att.com The first electrical digital computer 34 Artificial Intelligence (AI) 1. Machines or programs using intelligence to solve complex problems, the way humans solve problems. 2. Application will include computers doing medical diagnoses, flying jet planes, being the senses of the disabled. aimovie.warnerbros.com/ 35 Artificial Intelligence (AI) 3. AI involves making programs or devices that are efficient, flexible, and learn through experience. They may or may not mimic human consciousness. 4. Computer simulation involves designing a system that simulates human performance on a selected cognitive task. R2-D2 (Artoo-Detoo) & C-3PO (See-ThreePio) 36 www.starwars.com 12
Cognitive Sciences 37 Processing Serial Processing involves processing of information or data in a stage by stage format. Time consuming. Parallel Processing on the other hand involves processing information or data simultaneously. Much faster. 38 Parallel Distributed Processing (PDP) McClelland and Rumelhart (1986) proposed that cognitive processes must be understood in terms of networks that process information in parallel. Characteristics of PDP Model 1. Many cognitive processes are based on parallel operations. 2. Neural activity for a cognitive process is spread out in the brain and is termed as a node. 39 13
Parallel Distributed Processing (PDP) Characteristics of PDP Model 3. A node reaches a critical activation level to affect another node 4. When two nodes are activated the bond between them strengthens. 5. Multiple nodes and parallel processing aids and reconstructs information that is partial or inadequate to begin with. Node 40 Issues in Cognitive Psychology 41 1. Nature or Nurture? If we believe in nature affects our cognitive functions then we should design our experiments looking at environmental factors as the cause cognitive phenomena. On the other hand if we believe in nurture then our experiments need to look at innate/inborn processes. Today cognitive psychologists believe that both the nature and nurture interact to affect cognitive phenomena. 42 14
2. Rationalism or Empiricism? What kind of methodology should we use to study cognitive phenomena? Should we use logical reasoning to explore cognitive phenomena or should we engage in observation and experimentation to do the above? 3. Structures or Processes? Should we study the structure (contents, attributes, and products) of the mind or should we study the processes of our mind (thinking)? 43 4. General or Specific Domains? Do cognitive processes limited to singular domains or do they apply to multiple domains in our minds? Do processes/functions in a single domain similar to other domains? 44 5. Causal or Ecological Validity? Should we study cognitive processes using controlled [but artificial] experiments to make valid causal inferences or develop experiments [resembling life] that provide us with ecologically valid findings but at the cost of losing some experimental control? 45 15
6. Applied or Basic Research? Should we study cognitive processes for the sake of simply understanding them or should we study them to help people make use of them for practical considerations? 7. Biological or Behavioral Research? Should we study cognitive processes by analyzing the brain and its functions or should we study these processes by behavioral measures, reaction times, errors etc? 46 16