Nelson Cowan
USERN Advisory Board
Biography:
Born March 7, 1951, Washington, D.C. Married, 1 child, 2 stepchildren
Education:
Ph.D. 1980, University of Wisconsin, Madison (Psychology)
M.S. 1977, University of Wisconsin, Madison (Psychology)
B.S. 1973, University of Michigan, Ann Arbor (Independent Major, Neurosciences)
Doctoral Thesis: Toward an understanding of morphological segmentation in unfamiliar languages. Dissertation Abstracts International, 42, 398-B. Advisor: Philip A. Morse.
Professional Positions:
Current Position: Curators' Distinguished Professor, University of Missouri, Department of Psychological Sciences
2017 Senior Beckman Fellow, University of Illinois (summer)
2016 Taught 23rd International Summer School in Cognitive Science, Sofia, Bulgaria
2013-16 Professorial Fellow (20% senior position), University of Edinburgh, UK
2008-11 Director, Brain Imaging Center, Department of Psychological Sciences, MU
2005-07 Director, Cognition & Neuroscience Training Area, Dept. of Psychological Sciences
1995-2000: Middlebush Professor of the Social Sciences, University of Missouri (honorific title to 1 professor every 5 years on the basis of research and teaching accomplishments.)
1994- Professor, Department of Psychology, University of Missouri
2003: Visiting research scientist, Institute for Psychology, Budapest, Hungary
2000: Benjamin Meaker Visiting Professor, Institute for Advanced Studies, University of Bristol, United
Kingdom.
1999: Distinguished Visitor, University of Western Australia
1999: Visiting research scientist, University of Leipzig, Germany
1994-96: Director, Experimental Training Area, Dept. of Psychology
1991: Visiting Research Scientist (March through May), Psychology Department, University of Helsinki,
Finland (Collaboration with Risto Näätänen)
1989-94: Associate Professor, Dept. of Psychology, University of Missouri
1985-89: Assistant Professor, Psychology Department, University of Missouri
1982-85: Assistant Professor, Psychology Department, University of Massachusetts at Amherst
1981-82: Postdoctoral Fellow, Psychology Department, New York University
Sponsor: Martin D.S. Braine
Honors and Awards:
Lifetime Achievement Award, American Psychological Association, Division 3, Society for Experimental
Psychology and Cognitive Science, 2020
Doctor Honoris Causa (honorary doctorate), Université de Liège, Belgium, to be conferred 28 March, 2015.
Fellow, AAAS, 2012
Named one of “18 sensational psychology professors in Missouri” by StateStats.org, 2013
President’s Faculty Award for Sustained Excellence, University of Missouri System, 2011
Charter Fellow, Midwestern Psychological Association, 2009
Fellow, Society of Experimental Psychologists, Elected 2007
Curators’ Distinguished Professor, University of Missouri. Appointment beginning Sept., 2004.
Doctor of Philosophy honoris causa (honorary doctorate), University of Helsinki (Nov. 22, 2002; conferred June
6, 2003)
Charter Fellow, Association for Psychological Science, 1998 (formerly the American Psychological Society)
Fellow, American Psychological Association, 1999
Fellow, American Psychological Association, Division 3 (Experimental Psychology), 1998
Chancellor’s Award for Outstanding Faculty Research and Creative Activity in the Behavioral and Social
Sciences, University of Missouri (1998)
Middlebush Professor of the Social Sciences, University of Missouri (1995-)
(Awarded to 1 professor at MU every 5 years, for research and teaching quality) (above)
Golden Chalk Award, for graduate teaching and education, University of Missouri (1999)
Editor’s Award (with R. Gillam & J. Marler), American Speech, Language, and Hearing Association, 1999, for
Gillam et al. (1998)
Distinguished visiting professorships, Univ. of Bristol and Univ. of Western Australia (above)
New Investigator Research Award (1984)
Phi Kappa Phi Honor Society, University of Wisconsin Chapter
Sigma Xi, The Scientific Research Society
Sloan Scholar, University of Michigan, 1969-1973
Contributions to Science (from NIH Biosketch):
1. Identification of the core capacity limit of working memory.
History: Based on George Miller’s 1956 seminal work, it is commonly believed that people can hold in working memory about seven meaningful objects or ideas (chunks) at once. Miller, however, provided no theoretical basis for this limit.
Central findings: When people are unable to combine the presented items to form larger units or chunks, normal young adults retain in working memory only 3-4 items on average. The same thing is found with larger units when chunking is controlled; for example, people can retain 3-4 learned word pairs. The intraparietal sulcus seems to be involved in holding pointers to the brain representations of items in this core working memory.
Influence: Many neural deficits result in impaired working memory, which affects the ability to carry out high-level cognitive tasks such as math, reading comprehension, and problem-solving. Distinguishing the contributions of attention (limited to several chunks) versus mnemonic strategies should allow better management of various disorders.
Role: I was the lead investigator on studies showing the systematic nature of the capacity literature and providing the most-often-used formula to estimate capacity from array recognition tasks (Cowan, 2001, cited over 3,500 times); showing how to control chunking, which led to a relatively constant estimate of capacity even when chunking occurred (e.g., Cowan et al., 2004, 2012); and showing that a brain area previously said to reflect visual working memory capacity actually reflected working memory capacity more generally, across both verbal and nonverbal stimuli (Cowan et al., 2011).
a. Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87-185. PMID:11515286
b. Cowan, N., Chen, Z., & Rouder, J.N. (2004). Constant capacity in an immediate serial-recall task: A logical sequel to Miller (1956). Psychological Science, 15, 634-640. PMID:15327636
c. Rouder, J.N., Morey, R.D., Cowan, N., Zwilling, C.E., Morey, C.C., & Pratte, M.S. (2008). An assessment of fixed-capacity models of visual working memory. Proceedings of the National Academy of Science (PNAS), 105(16), 5975–5979. PMC2329704
d. Cowan, N., Rouder, J.N., Blume, C.L., & Saults, J.S. (2012). Models of verbal working memory capacity: What does it take to make them work? Psychological Review, 119, 480-499. PMC3618891
2. Examining the sharing of attention in working memory across modalities and materials.
History: At least since the work of Alan Baddeley and Graham Hitch (1974), it has been shown that there are modest tradeoffs between visual and verbal items in working memory, as one would expect if there is a central capacity for all stimuli supplemented by some means to hold different types of materials in storage devices with little cross-materials interference (i.e., peripheral storage). The amounts of each type of storage were, however, difficult to quantify.
Central findings: The capacity estimation techniques of Cowan (2001) and subsequent papers make it possible to obtain data indicating the capacity of central storage in chunks and to assess peripheral contributions. Results of Cowan et al. (2014), reporting about 10 experiments, suggest that several items from a set (e.g., an array of simple visual objects) are encoded into the focus of attention and then off-loaded (though remaining accessible) to allow encoding of another, different type of set (e.g., a verbal list during suppression of verbal rehearsal), with only about 1 item of interference between different sets.
Influence: Research on practical topics such as phone conversations while driving show that people are not as good at sharing attention and working memory between tasks as they think they are. Public safety, education, and cognitive processing in normal and disabled individuals depends on good information about the limits of multi-tasking.
Role: Chen and Morey were my graduate students when some of this research was pursued. I took the lead on several other articles to analyze and integrate findings and provide a theoretical synthesis.
a. Morey, C.C., & Cowan, N. (2005). When do visual and verbal memories conflict? The importance of working-memory load and retrieval. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31, 703-713. PMC2610475
b. Chen, Z., & Cowan, N. (2009). How verbal memory loads consume attention. Memory & Cognition, 37, 829-836. PMC2804027
c. Cowan, N., Li, D., Moffitt, A., Becker, T.M., Martin, E.A., Saults, J.S., & Christ, S.E. (2011). A neural region of abstract working memory. Journal of Cognitive Neuroscience, 23, 2852-2863. PMC3138911
d. Cowan, N., Saults, J.S., & Blume, C.L. (2014). Central and peripheral components of working memory storage. Journal of Experimental Psychology: General, 143, 1806-1836. PMC4172497
3. Childhood development of working memory capacity. History: Developmental psychologists have proposed many different bases of the developmental improvement in working memory. NeoPiagetians proposed that the basic number of items that can be retained increases with maturity but others have proposed that the developmental improvement in performance can be explained solely through the development of knowledge, encoding efficiency, or mnemonic strategies.
Central findings: In a series of studies beginning in 1999, we have found that working memory capacity increases during the elementary school years on direct working memory tasks (e.g., as opposed to the looking-time tasks used with infants) and that this increase can be seen even with materials for which knowledge, encoding efficiency, and mnemonic strategies are controlled across age groups.
Influence: Given that most cognitive tasks depend on working memory and its capacity is highly correlated with cognitive aptitude, understanding the basis of working memory development is important for an understanding of the potential basis of developmental disabilities that involve working memory. Role: I have taken the lead on a number of studies in my laboratory in which we have examined working memory capacity with other factors controlled.
a. Cowan, N., Elliott, E.M., Saults, J.S., Morey, C.C., Mattox, S., Hismjatullina, A., & Conway, A.R.A. (2005). On the capacity of attention: Its estimation and its role in working memory and cognitive aptitudes. Cognitive Psychology, 51, 42-100. PMC2673732
b. Cowan, N., Morey, C.C., AuBuchon, A.M., Zwilling, C.E., & Gilchrist, A.L. (2010). Seven-year-olds allocate attention like adults unless working memory is overloaded. Developmental Science, 13, 120-133. PMC2819460
c. Cowan, N., AuBuchon, A.M., Gilchrist, A.L., Ricker, T.J., & Saults, J.S. (2011). Age differences in visual working memory capacity: Not based on encoding limitations. Developmental Science, 14, 1066-1074. PMC3177168
d. Cowan, N., Ricker, T.J., Clark, K.M., Hinrichs, G.A., & Glass, B.A. (2015). Knowledge cannot explain the developmental growth of working memory capacity. Developmental Science, 18, 132-145. PMC4270959
4. Role of time in memory. History: The passage of time has been of interest since the beginning of experimental psychology because of the risk of forgetting over time, but also because of the opportunity to retrieve information or consolidate it over time. Recently, Klaus Oberauer and Steve Lewandowsky have published work suggesting that working memory does not decay over time, even in the absence of covert rehearsal or refreshing.
Central findings: Throughout my career I have carried out studies clarifying the role of time. In one series of studies beginning with Cowan (1992), we showed that the timing of verbal recall depends on the speed of searching through the list items, from which the current response must be identified. Some of our other work has showed that working memory decay does occur when material cannot be adequately consolidated (e.g., when it consists of briefly-presented unfamiliar characters). Still other work shows that during dark, silent periods uninterrupted by any interfering stimuli, many densely amnesic individuals surprisingly can consolidate new information into memory.
Influence: The work speaks to the importance of avoiding interruption of attention, in order to maximize consolidation and retrieval from both working memory and long-term memory. This information could soon be applied to allow better learning and memory in the elderly and people with cognitive challenges. Role: The work on retrieval and forgetting from working memory was carried out by my students (e.g., Timothy Ricker), research assistants, and myself. The work on avoiding interruption for consolidation in aging adults and amnesic individuals has been conducted in collaboration with Sergio Della Sala and Michaela Dewar in Edinburgh, Scotland, UK but I conceived of the first study in the series and carried it to completion (Cowan et al., 2004, below).
a. Cowan, N. (1992). Verbal memory span and the timing of spoken recall. Journal of Memory and Language, 31, 668-684.
b. Cowan, N., Saults, J.S., & Nugent, L.D. (1997). The role of absolute and relative amounts of time in forgetting within immediate memory: The case of tone pitch comparisons. Psychonomic Bulletin & Review, 4, 393-397.
c. Cowan, N., Beschin, N., & Della Sala, S. (2004). Verbal recall in amnesiacs under conditions of diminished retroactive interference. Brain, 127, 825-834. PMID:14749294
d. Ricker, T.J., & Cowan, N. (2014). Differences between presentation methods in working memory procedures: A matter of working memory consolidation. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40, 417-428. PMC4056671
5. Working memory, attention, and binding. History: For many years (e.g., Cowan, 1988, Psychological Bulletin) I have suggested that an important role of the human focus of attention is to allow the parts of an object or concept to be bound together to form a new concept (e.g., a tiger is a large, striped cat; if one feature is forgotten a young child might label as a tiger what is actually a house cat, lion, or zebra).
Central findings: In a task in which locations and printed names had to be associated, Cowan et al. (2006) found that adults and older children (but not children 8-10 years old) develop a strategy in which verbal and spatial series are separately retained and then combined as necessary (e.g., verbal Item 3 goes with visual Item 3). The younger children could not use this method and thus had to hold the associations in a more attention-intensive manner. The pattern looked that way also for adults when rehearsal was prevented. Our recent studies show that there is not only a limited number of objects that can be entered into working memory, but also a limited number of features per object; if colored shapes are presented, adults can retain about 3 objects but if both features are required, some color information is lost and/or some shape information is lost, compared to when only one feature is needed.
Influence: The work on binding is beginning to show that there are dual ways in which attention limits come into play in working memory: during the encoding of objects and again during their retention. This information is likely to be important to understand classroom learning in multimodal situations, and to understand distraction in such situations (e.g., driving).
Role: I have done this work with my students, including some advanced mathematical modeling with Kyle Hardman. The role of the intraparietal sulcus in helping to bind together information in the focus of attention has been shown in fMRI studies with my former graduate student, Dawei Li (Neuroimage, 2014), and with Steve Majerus in Belgium (see below).
a. Cowan, N., Saults, J.S., & Morey, C.C. (2006). Development of working memory for verbal-spatial associations. Journal of Memory and Language, 55, 274-289. PMC1832114
b. Cowan, N., Blume, C.L., & Saults, J.S. (2013). Attention to attributes and objects in working memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 731-747. PMC3825193
c. Majerus, S., Cowan, N., Péters, F., Van Calster, L., Phillips, C., & Schrouff, J. (2016). Cross-modal decoding of neural patterns associated with working memory: Evidence for attention-based accounts of working memory. Cerebral Cortex, 26, 166-179. PMID:25146374
d. Hardman, K., & Cowan, N. (2015). Remembering complex objects in visual working memory: Do capacity limits restrict objects or features? Journal of Experimental Psychology: Learning, Memory, and Cognition, 41, 325-347. PMC4317397
Some of the products of inter-university collaborations:
Cowan, N., Adams, E.J., Bhangal, S., Corcoran, M., Decker, R., Dockter, C.E., Eubank, A.T., Gann, C.L., Greene, N.R., Helle, A.C., Lee, N., Nguyen, A.T., Ripley, K.R., Scofield, J.E., Tapia, M.A., Threlkeld, K.L., & Watts, A.L. (2019). Foundations of arrogance: A broad survey and framework for research. Review of General Psychology, 23, 425-443.
Cowan, N., Belletier, C., Doherty, J.M., Jaroslawska, A.J., Rhodes, S., Forsberg, A., Naveh-Benjamin, M., Barrouillet, P. Camos, V., & Logie, R.H. (2020). How do scientific views change? Notes from an extended adversarial collaboration. Perspectives on Psychological Science, 15, 1011-1025.
Cowan, N., Beschin, N., & Della Sala, S. (2004). Verbal recall in amnesiacs under conditions of diminished retroactive interference. Brain, 127, 825-834.
Cowan, N., Hogan, T.P., Alt, M., Green, S., Cabbage, K.L., Brinkley, S., & Gray, S. (2017). Short-term memory in childhood dyslexia: Deficient serial order in multiple modalities. Dyslexia, 23, 209-233.
Cowan, N., & Rachev, N.R. (2018), Merging with the path not taken: Wilhelm Wundt’s work as a precursor to the embedded-processes approach to memory, attention, and consciousness. Consciousness and Cognition, 63, 228-238.
Cowan, N., Winkler, I., Teder, W., & Näätänen, R. (1993). Memory prerequisites of the mismatch negativity in the auditory event-related potential (ERP). Journal of Experimental Psychology: Learning, Memory, & Cognition, 19, 909-921.
Gillam, R., Cowan, N., & Marler, J. (1998). Information processing by school-age children with specific language impairment: Evidence from a modality effect paradigm. Journal of Speech, Language and Hearing Research, 41, 913-926.
Gossaries, O., Yu, Q., LaRocque, J.J., Starrett, M.J., Rose, N.S., Cowan, N., & Postle, B.R. (2018). Parietal-occipital interactions underlying control- and representation-related processes in working memory for nonspatial visual features. Journal of Neuroscience, 38, 4357– 4366.
Gray, S., Green, S., Alt, M., Hogan, T., Kuo, T., Brinkley, S., & Cowan, N. (2017). The structure of working memory in young school-age children and its relation to intelligence. Journal of Memory and Language, 92, 183-201.
Javitt, D.C., Strous, R., Grochowski, S., Ritter, W., & Cowan, N. (1997). Impaired precision, but normal retention, of auditory sensory (“echoic”) memory information in schizophrenia. Journal of Abnormal Psychology, 106, 315-324.
Majerus, S., Cowan, N., Péters, F., Van Calster, L., Phillips, C., & Schrouff, J. (2016). Cross-modal decoding of neural patterns associated with working memory: Evidence for attention-based accounts of working memory. Cerebral Cortex, 26, 166-179.
McGhee, J.D., Cowan, N., Beschin, N., Mosconi, C., & Della Sala, S. (2020). Wakeful rest benefits before and after encoding in anterograde amnesia. Neuropsychology, 34, 524-534.
Rhodes, S., Jaroslawska, A.J., Doherty, J.M., Belletier, C., Naveh-Benjamin, M., Cowan, N., Camos, V., Barrouillet, P., & Logie, R.H. (2019). Storage and processing in working memory: Assessing dual task performance and task prioritization across the adult lifespan. Journal of Experimental Psychology: General, 148, 1204-1227.
Winkler, I., Schröger, E., & Cowan, N. (2001). The role of large-scale memory organization in the mismatch negativity event-related brain potential. Journal of Cognitive Neuroscience, 13, 59-71.
Books:
Logie, R.H., Camos, V., & Cowan, N., editors. (in press). Working Memory: State of the Science, Oxford University Press.
Cowan, N. (2016). Working memory capacity. Psychology Press and Routledge Classic Edition. New York: Routledge. [Original edition 2005. New Foreword to the Classic Edition.]
Courage, M.L., & Cowan, N. (eds.) (2009). The development of memory in infancy and childhood. Hove, U.K.: Psychology Press.
Cowan, N. (2005). Working memory capacity. Hove, East Sussex, UK: Psychology Press.
[Psychology Press and Routledge Classic Edition with new foreword, 2016]
Cowan, N. (ed.) (1997). The development of memory in childhood. Hove, East Sussex, UK:
Psychology Press. (Paperback edition: 1997)
Cowan, N. (1995). Attention and memory: An integrated framework. Oxford Psychology Series,
No. 26. New York: Oxford University Press. (Paperback edition: 1997)
Born March 7, 1951, Washington, D.C. Married, 1 child, 2 stepchildren
Education:
Ph.D. 1980, University of Wisconsin, Madison (Psychology)
M.S. 1977, University of Wisconsin, Madison (Psychology)
B.S. 1973, University of Michigan, Ann Arbor (Independent Major, Neurosciences)
Doctoral Thesis: Toward an understanding of morphological segmentation in unfamiliar languages. Dissertation Abstracts International, 42, 398-B. Advisor: Philip A. Morse.
Professional Positions:
Current Position: Curators' Distinguished Professor, University of Missouri, Department of Psychological Sciences
2017 Senior Beckman Fellow, University of Illinois (summer)
2016 Taught 23rd International Summer School in Cognitive Science, Sofia, Bulgaria
2013-16 Professorial Fellow (20% senior position), University of Edinburgh, UK
2008-11 Director, Brain Imaging Center, Department of Psychological Sciences, MU
2005-07 Director, Cognition & Neuroscience Training Area, Dept. of Psychological Sciences
1995-2000: Middlebush Professor of the Social Sciences, University of Missouri (honorific title to 1 professor every 5 years on the basis of research and teaching accomplishments.)
1994- Professor, Department of Psychology, University of Missouri
2003: Visiting research scientist, Institute for Psychology, Budapest, Hungary
2000: Benjamin Meaker Visiting Professor, Institute for Advanced Studies, University of Bristol, United
Kingdom.
1999: Distinguished Visitor, University of Western Australia
1999: Visiting research scientist, University of Leipzig, Germany
1994-96: Director, Experimental Training Area, Dept. of Psychology
1991: Visiting Research Scientist (March through May), Psychology Department, University of Helsinki,
Finland (Collaboration with Risto Näätänen)
1989-94: Associate Professor, Dept. of Psychology, University of Missouri
1985-89: Assistant Professor, Psychology Department, University of Missouri
1982-85: Assistant Professor, Psychology Department, University of Massachusetts at Amherst
1981-82: Postdoctoral Fellow, Psychology Department, New York University
Sponsor: Martin D.S. Braine
Honors and Awards:
Lifetime Achievement Award, American Psychological Association, Division 3, Society for Experimental
Psychology and Cognitive Science, 2020
Doctor Honoris Causa (honorary doctorate), Université de Liège, Belgium, to be conferred 28 March, 2015.
Fellow, AAAS, 2012
Named one of “18 sensational psychology professors in Missouri” by StateStats.org, 2013
President’s Faculty Award for Sustained Excellence, University of Missouri System, 2011
Charter Fellow, Midwestern Psychological Association, 2009
Fellow, Society of Experimental Psychologists, Elected 2007
Curators’ Distinguished Professor, University of Missouri. Appointment beginning Sept., 2004.
Doctor of Philosophy honoris causa (honorary doctorate), University of Helsinki (Nov. 22, 2002; conferred June
6, 2003)
Charter Fellow, Association for Psychological Science, 1998 (formerly the American Psychological Society)
Fellow, American Psychological Association, 1999
Fellow, American Psychological Association, Division 3 (Experimental Psychology), 1998
Chancellor’s Award for Outstanding Faculty Research and Creative Activity in the Behavioral and Social
Sciences, University of Missouri (1998)
Middlebush Professor of the Social Sciences, University of Missouri (1995-)
(Awarded to 1 professor at MU every 5 years, for research and teaching quality) (above)
Golden Chalk Award, for graduate teaching and education, University of Missouri (1999)
Editor’s Award (with R. Gillam & J. Marler), American Speech, Language, and Hearing Association, 1999, for
Gillam et al. (1998)
Distinguished visiting professorships, Univ. of Bristol and Univ. of Western Australia (above)
New Investigator Research Award (1984)
Phi Kappa Phi Honor Society, University of Wisconsin Chapter
Sigma Xi, The Scientific Research Society
Sloan Scholar, University of Michigan, 1969-1973
Contributions to Science (from NIH Biosketch):
1. Identification of the core capacity limit of working memory.
History: Based on George Miller’s 1956 seminal work, it is commonly believed that people can hold in working memory about seven meaningful objects or ideas (chunks) at once. Miller, however, provided no theoretical basis for this limit.
Central findings: When people are unable to combine the presented items to form larger units or chunks, normal young adults retain in working memory only 3-4 items on average. The same thing is found with larger units when chunking is controlled; for example, people can retain 3-4 learned word pairs. The intraparietal sulcus seems to be involved in holding pointers to the brain representations of items in this core working memory.
Influence: Many neural deficits result in impaired working memory, which affects the ability to carry out high-level cognitive tasks such as math, reading comprehension, and problem-solving. Distinguishing the contributions of attention (limited to several chunks) versus mnemonic strategies should allow better management of various disorders.
Role: I was the lead investigator on studies showing the systematic nature of the capacity literature and providing the most-often-used formula to estimate capacity from array recognition tasks (Cowan, 2001, cited over 3,500 times); showing how to control chunking, which led to a relatively constant estimate of capacity even when chunking occurred (e.g., Cowan et al., 2004, 2012); and showing that a brain area previously said to reflect visual working memory capacity actually reflected working memory capacity more generally, across both verbal and nonverbal stimuli (Cowan et al., 2011).
a. Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87-185. PMID:11515286
b. Cowan, N., Chen, Z., & Rouder, J.N. (2004). Constant capacity in an immediate serial-recall task: A logical sequel to Miller (1956). Psychological Science, 15, 634-640. PMID:15327636
c. Rouder, J.N., Morey, R.D., Cowan, N., Zwilling, C.E., Morey, C.C., & Pratte, M.S. (2008). An assessment of fixed-capacity models of visual working memory. Proceedings of the National Academy of Science (PNAS), 105(16), 5975–5979. PMC2329704
d. Cowan, N., Rouder, J.N., Blume, C.L., & Saults, J.S. (2012). Models of verbal working memory capacity: What does it take to make them work? Psychological Review, 119, 480-499. PMC3618891
2. Examining the sharing of attention in working memory across modalities and materials.
History: At least since the work of Alan Baddeley and Graham Hitch (1974), it has been shown that there are modest tradeoffs between visual and verbal items in working memory, as one would expect if there is a central capacity for all stimuli supplemented by some means to hold different types of materials in storage devices with little cross-materials interference (i.e., peripheral storage). The amounts of each type of storage were, however, difficult to quantify.
Central findings: The capacity estimation techniques of Cowan (2001) and subsequent papers make it possible to obtain data indicating the capacity of central storage in chunks and to assess peripheral contributions. Results of Cowan et al. (2014), reporting about 10 experiments, suggest that several items from a set (e.g., an array of simple visual objects) are encoded into the focus of attention and then off-loaded (though remaining accessible) to allow encoding of another, different type of set (e.g., a verbal list during suppression of verbal rehearsal), with only about 1 item of interference between different sets.
Influence: Research on practical topics such as phone conversations while driving show that people are not as good at sharing attention and working memory between tasks as they think they are. Public safety, education, and cognitive processing in normal and disabled individuals depends on good information about the limits of multi-tasking.
Role: Chen and Morey were my graduate students when some of this research was pursued. I took the lead on several other articles to analyze and integrate findings and provide a theoretical synthesis.
a. Morey, C.C., & Cowan, N. (2005). When do visual and verbal memories conflict? The importance of working-memory load and retrieval. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31, 703-713. PMC2610475
b. Chen, Z., & Cowan, N. (2009). How verbal memory loads consume attention. Memory & Cognition, 37, 829-836. PMC2804027
c. Cowan, N., Li, D., Moffitt, A., Becker, T.M., Martin, E.A., Saults, J.S., & Christ, S.E. (2011). A neural region of abstract working memory. Journal of Cognitive Neuroscience, 23, 2852-2863. PMC3138911
d. Cowan, N., Saults, J.S., & Blume, C.L. (2014). Central and peripheral components of working memory storage. Journal of Experimental Psychology: General, 143, 1806-1836. PMC4172497
3. Childhood development of working memory capacity. History: Developmental psychologists have proposed many different bases of the developmental improvement in working memory. NeoPiagetians proposed that the basic number of items that can be retained increases with maturity but others have proposed that the developmental improvement in performance can be explained solely through the development of knowledge, encoding efficiency, or mnemonic strategies.
Central findings: In a series of studies beginning in 1999, we have found that working memory capacity increases during the elementary school years on direct working memory tasks (e.g., as opposed to the looking-time tasks used with infants) and that this increase can be seen even with materials for which knowledge, encoding efficiency, and mnemonic strategies are controlled across age groups.
Influence: Given that most cognitive tasks depend on working memory and its capacity is highly correlated with cognitive aptitude, understanding the basis of working memory development is important for an understanding of the potential basis of developmental disabilities that involve working memory. Role: I have taken the lead on a number of studies in my laboratory in which we have examined working memory capacity with other factors controlled.
a. Cowan, N., Elliott, E.M., Saults, J.S., Morey, C.C., Mattox, S., Hismjatullina, A., & Conway, A.R.A. (2005). On the capacity of attention: Its estimation and its role in working memory and cognitive aptitudes. Cognitive Psychology, 51, 42-100. PMC2673732
b. Cowan, N., Morey, C.C., AuBuchon, A.M., Zwilling, C.E., & Gilchrist, A.L. (2010). Seven-year-olds allocate attention like adults unless working memory is overloaded. Developmental Science, 13, 120-133. PMC2819460
c. Cowan, N., AuBuchon, A.M., Gilchrist, A.L., Ricker, T.J., & Saults, J.S. (2011). Age differences in visual working memory capacity: Not based on encoding limitations. Developmental Science, 14, 1066-1074. PMC3177168
d. Cowan, N., Ricker, T.J., Clark, K.M., Hinrichs, G.A., & Glass, B.A. (2015). Knowledge cannot explain the developmental growth of working memory capacity. Developmental Science, 18, 132-145. PMC4270959
4. Role of time in memory. History: The passage of time has been of interest since the beginning of experimental psychology because of the risk of forgetting over time, but also because of the opportunity to retrieve information or consolidate it over time. Recently, Klaus Oberauer and Steve Lewandowsky have published work suggesting that working memory does not decay over time, even in the absence of covert rehearsal or refreshing.
Central findings: Throughout my career I have carried out studies clarifying the role of time. In one series of studies beginning with Cowan (1992), we showed that the timing of verbal recall depends on the speed of searching through the list items, from which the current response must be identified. Some of our other work has showed that working memory decay does occur when material cannot be adequately consolidated (e.g., when it consists of briefly-presented unfamiliar characters). Still other work shows that during dark, silent periods uninterrupted by any interfering stimuli, many densely amnesic individuals surprisingly can consolidate new information into memory.
Influence: The work speaks to the importance of avoiding interruption of attention, in order to maximize consolidation and retrieval from both working memory and long-term memory. This information could soon be applied to allow better learning and memory in the elderly and people with cognitive challenges. Role: The work on retrieval and forgetting from working memory was carried out by my students (e.g., Timothy Ricker), research assistants, and myself. The work on avoiding interruption for consolidation in aging adults and amnesic individuals has been conducted in collaboration with Sergio Della Sala and Michaela Dewar in Edinburgh, Scotland, UK but I conceived of the first study in the series and carried it to completion (Cowan et al., 2004, below).
a. Cowan, N. (1992). Verbal memory span and the timing of spoken recall. Journal of Memory and Language, 31, 668-684.
b. Cowan, N., Saults, J.S., & Nugent, L.D. (1997). The role of absolute and relative amounts of time in forgetting within immediate memory: The case of tone pitch comparisons. Psychonomic Bulletin & Review, 4, 393-397.
c. Cowan, N., Beschin, N., & Della Sala, S. (2004). Verbal recall in amnesiacs under conditions of diminished retroactive interference. Brain, 127, 825-834. PMID:14749294
d. Ricker, T.J., & Cowan, N. (2014). Differences between presentation methods in working memory procedures: A matter of working memory consolidation. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40, 417-428. PMC4056671
5. Working memory, attention, and binding. History: For many years (e.g., Cowan, 1988, Psychological Bulletin) I have suggested that an important role of the human focus of attention is to allow the parts of an object or concept to be bound together to form a new concept (e.g., a tiger is a large, striped cat; if one feature is forgotten a young child might label as a tiger what is actually a house cat, lion, or zebra).
Central findings: In a task in which locations and printed names had to be associated, Cowan et al. (2006) found that adults and older children (but not children 8-10 years old) develop a strategy in which verbal and spatial series are separately retained and then combined as necessary (e.g., verbal Item 3 goes with visual Item 3). The younger children could not use this method and thus had to hold the associations in a more attention-intensive manner. The pattern looked that way also for adults when rehearsal was prevented. Our recent studies show that there is not only a limited number of objects that can be entered into working memory, but also a limited number of features per object; if colored shapes are presented, adults can retain about 3 objects but if both features are required, some color information is lost and/or some shape information is lost, compared to when only one feature is needed.
Influence: The work on binding is beginning to show that there are dual ways in which attention limits come into play in working memory: during the encoding of objects and again during their retention. This information is likely to be important to understand classroom learning in multimodal situations, and to understand distraction in such situations (e.g., driving).
Role: I have done this work with my students, including some advanced mathematical modeling with Kyle Hardman. The role of the intraparietal sulcus in helping to bind together information in the focus of attention has been shown in fMRI studies with my former graduate student, Dawei Li (Neuroimage, 2014), and with Steve Majerus in Belgium (see below).
a. Cowan, N., Saults, J.S., & Morey, C.C. (2006). Development of working memory for verbal-spatial associations. Journal of Memory and Language, 55, 274-289. PMC1832114
b. Cowan, N., Blume, C.L., & Saults, J.S. (2013). Attention to attributes and objects in working memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 731-747. PMC3825193
c. Majerus, S., Cowan, N., Péters, F., Van Calster, L., Phillips, C., & Schrouff, J. (2016). Cross-modal decoding of neural patterns associated with working memory: Evidence for attention-based accounts of working memory. Cerebral Cortex, 26, 166-179. PMID:25146374
d. Hardman, K., & Cowan, N. (2015). Remembering complex objects in visual working memory: Do capacity limits restrict objects or features? Journal of Experimental Psychology: Learning, Memory, and Cognition, 41, 325-347. PMC4317397
Some of the products of inter-university collaborations:
Cowan, N., Adams, E.J., Bhangal, S., Corcoran, M., Decker, R., Dockter, C.E., Eubank, A.T., Gann, C.L., Greene, N.R., Helle, A.C., Lee, N., Nguyen, A.T., Ripley, K.R., Scofield, J.E., Tapia, M.A., Threlkeld, K.L., & Watts, A.L. (2019). Foundations of arrogance: A broad survey and framework for research. Review of General Psychology, 23, 425-443.
Cowan, N., Belletier, C., Doherty, J.M., Jaroslawska, A.J., Rhodes, S., Forsberg, A., Naveh-Benjamin, M., Barrouillet, P. Camos, V., & Logie, R.H. (2020). How do scientific views change? Notes from an extended adversarial collaboration. Perspectives on Psychological Science, 15, 1011-1025.
Cowan, N., Beschin, N., & Della Sala, S. (2004). Verbal recall in amnesiacs under conditions of diminished retroactive interference. Brain, 127, 825-834.
Cowan, N., Hogan, T.P., Alt, M., Green, S., Cabbage, K.L., Brinkley, S., & Gray, S. (2017). Short-term memory in childhood dyslexia: Deficient serial order in multiple modalities. Dyslexia, 23, 209-233.
Cowan, N., & Rachev, N.R. (2018), Merging with the path not taken: Wilhelm Wundt’s work as a precursor to the embedded-processes approach to memory, attention, and consciousness. Consciousness and Cognition, 63, 228-238.
Cowan, N., Winkler, I., Teder, W., & Näätänen, R. (1993). Memory prerequisites of the mismatch negativity in the auditory event-related potential (ERP). Journal of Experimental Psychology: Learning, Memory, & Cognition, 19, 909-921.
Gillam, R., Cowan, N., & Marler, J. (1998). Information processing by school-age children with specific language impairment: Evidence from a modality effect paradigm. Journal of Speech, Language and Hearing Research, 41, 913-926.
Gossaries, O., Yu, Q., LaRocque, J.J., Starrett, M.J., Rose, N.S., Cowan, N., & Postle, B.R. (2018). Parietal-occipital interactions underlying control- and representation-related processes in working memory for nonspatial visual features. Journal of Neuroscience, 38, 4357– 4366.
Gray, S., Green, S., Alt, M., Hogan, T., Kuo, T., Brinkley, S., & Cowan, N. (2017). The structure of working memory in young school-age children and its relation to intelligence. Journal of Memory and Language, 92, 183-201.
Javitt, D.C., Strous, R., Grochowski, S., Ritter, W., & Cowan, N. (1997). Impaired precision, but normal retention, of auditory sensory (“echoic”) memory information in schizophrenia. Journal of Abnormal Psychology, 106, 315-324.
Majerus, S., Cowan, N., Péters, F., Van Calster, L., Phillips, C., & Schrouff, J. (2016). Cross-modal decoding of neural patterns associated with working memory: Evidence for attention-based accounts of working memory. Cerebral Cortex, 26, 166-179.
McGhee, J.D., Cowan, N., Beschin, N., Mosconi, C., & Della Sala, S. (2020). Wakeful rest benefits before and after encoding in anterograde amnesia. Neuropsychology, 34, 524-534.
Rhodes, S., Jaroslawska, A.J., Doherty, J.M., Belletier, C., Naveh-Benjamin, M., Cowan, N., Camos, V., Barrouillet, P., & Logie, R.H. (2019). Storage and processing in working memory: Assessing dual task performance and task prioritization across the adult lifespan. Journal of Experimental Psychology: General, 148, 1204-1227.
Winkler, I., Schröger, E., & Cowan, N. (2001). The role of large-scale memory organization in the mismatch negativity event-related brain potential. Journal of Cognitive Neuroscience, 13, 59-71.
Books:
Logie, R.H., Camos, V., & Cowan, N., editors. (in press). Working Memory: State of the Science, Oxford University Press.
Cowan, N. (2016). Working memory capacity. Psychology Press and Routledge Classic Edition. New York: Routledge. [Original edition 2005. New Foreword to the Classic Edition.]
Courage, M.L., & Cowan, N. (eds.) (2009). The development of memory in infancy and childhood. Hove, U.K.: Psychology Press.
Cowan, N. (2005). Working memory capacity. Hove, East Sussex, UK: Psychology Press.
[Psychology Press and Routledge Classic Edition with new foreword, 2016]
Cowan, N. (ed.) (1997). The development of memory in childhood. Hove, East Sussex, UK:
Psychology Press. (Paperback edition: 1997)
Cowan, N. (1995). Attention and memory: An integrated framework. Oxford Psychology Series,
No. 26. New York: Oxford University Press. (Paperback edition: 1997)
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