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  • Ramscar Lab 16:29 on 01.10.2016 Permalink
    Tags: , , Decision Making, ,   

    Exploratory Decision-Making as a Function of Lifelong Experience, Not Cognitive Decline 

    Our latest aging study has just been published in the Journal of Experimental Psychology: General. The paper reports work done with Nate Blanco, Kirsten Smayda and Todd Maddox at the University of Texas, Austin, Bradley Love (University College London) and Ross Otto (New York University). It helps illustrate just how important computational models are to our understanding of changes in behavior across the adult lifespan, showing why it makes no sense to talk about processing declines in the absence of models of what is being processed, and how.

    Here’s the abstract:

    Older adults perform worse than younger adults in some complex decision-making scenarios, which is commonly attributed to age-related declines in striatal and frontostriatal processing. Recently, this popular account has been challenged by work that considered how older adults’ performance may differ as a function of greater knowledge and experience, and by work showing that, in some cases, older adults outperform younger adults in complex decision-making tasks. In light of this controversy, we examined the performance of older and younger adults in an exploratory choice task that is amenable to model-based analyses and ostensibly not reliant on prior knowledge. Exploration is a critical aspect of decision-making poorly understood across the life span. Across 2 experiments, we addressed (a) how older and younger adults differ in exploratory choice and (b) to what extent observed differences reflect processing capacity declines. Model-based analyses suggested that the strategies used by the 2 groups were qualitatively different, resulting in relatively worse performance for older adults in 1 decision- making environment but equal performance in another. Little evidence was found that differences in processing capacity drove performance differences. Rather the results suggested that older adults’ performance might result from applying a strategy that may have been shaped by their wealth of real-word decision-making experience. While this strategy is likely to be effective in the real world, it is ill suited to some decision environments. These results underscore the importance of taking into account effects of experience in aging studies, even for tasks that do not obviously tap past experiences.

     
  • Ramscar Lab 00:41 on 07.12.2015 Permalink  

    CogSci Symposium: Generative and Discriminative Models in Cognitive Science 

    Brad Love and I are organizing a symposium at this year’s Cognitive Science Conference, with guest speakers Matt Jones and Tom Griffiths. Come check it out!

    One popular distinction in machine learning is between discriminative and generative models (Ng & Jordan, 2001). Given the cross fertilization between research in human and machine learning, the time is ripe to ask whether the mind is a generative or discriminative learning device. This symposium tackles this question from a variety of perspectives. The aim is to explore the explanatory value of these two basic views of learning, which cut across existing distinctions in cognitive science (e.g., connectionist vs. Bayesian approaches).

     
  • Ramscar Lab 05:57 on 05.24.2015 Permalink  

    New Series by Language Science Press 

    Together with Jim Blevins and Petar Milin, I will be co-editing a new series, Morphological Investigations, published through Language Science Press. We are inviting cross-disciplinary contributions, ranging from detailed descriptive studies through to quantitative analyses, simulations and models of learning and use. For more information, please consult the open call for submissions.

     
  • Ramscar Lab 00:02 on 06.11.2014 Permalink  

    Ageing Research Featured on BBC Radio4 

    The team’s ageing research features today on BBC Radio4’s Frontiers, a programme “exploring new ideas in science and meeting the scientists and researchers responsible for them”. The episode can be streamed here.

    Geoff Watts investigates the latest thinking about our brain power in old age.

    He meets researchers who argue that society has overly negative views of the mental abilities of the elderly – a dismal and fatalistic outlook which is not backed up by recent discoveries and theories.

    Geoff talks to Professor Lorraine Tyler who leads a large study in Cambridge (CamCAN) which is comparing cognition and brain structure and function in 700 people aged between 18 and 88 years old.

    He also meets scientists and participants involved in an unique study of cognition and ageing at the University of Edinburgh. It has traced hundreds of people who were given a nationwide intelligence test as children in 1932 and 1947. Since the year 2000, the study has been retesting their intelligence and mental agility in their 70s to 90s. The Lothian Birth Cohort study is revealing what we all might do in life to keep our minds fast and sharp well into old age.

    One new and controversial idea holds that cognitive decline is in fact a myth. A team in Germany, led by Michael Ramscar, argues that older people perform less well in intelligence and memory tests because they know so much more than younger subjects and not because their brains are deteriorating. Simply put, their larger stores of accumulated knowledge slow their performance. Their brains take longer to retrieve the answers from their richer memory stores.

     
  • Ramscar Lab 04:11 on 04.24.2014 Permalink  

    Sequence, Form and Meaning… 

    The journal Psiholohija has just published Michael’s paper exploring the ways in which morphological prefixes and suffixes promote different kinds of learning.

    In short, while prefixes tend to make the lexical items that follow them more predictable in context, suffixes tend to make the lexical items they follow cohere more, increasing the semantic similarity between them.

     
  • Ramscar Lab 17:11 on 02.25.2014 Permalink  

    “Myth of Cognitive Decline” Q&A 

    Provider Magazine has just published a Q&A with Michael on the myth of cognitive decline. Michael discusses the cultural origins of the myth, why overturning it may contribute to the social good, and the public’s reaction to this research. A brief excerpt:

    “the myth has its roots in the way people have tended to think about our minds historically—and in the way that people often still tend to think about their minds. …just as learning to think about our bodies as part of the natural world has helped people understand how to better take care of their physical health, thinking about our minds as part of the natural world can help us make sense of the changes we experience as our minds grow older. “

     
  • Ramscar Lab 09:59 on 01.21.2014 Permalink  

    New Research Blog 

    In light of the recent press coverage of our ageing work, Michael has started a new blog, to provide more detailed coverage of our research program. The inaugural post — What happens to our minds and memories in healthy ageing? — is now live.

     
  • Ramscar Lab 20:12 on 01.13.2014 Permalink
    Tags: , , , ,   

    Ageing research goes to press 

    We are pleased to announce that Topics in Cognitive Science has just released our extended article The myth of cognitive decline: Non-linear dynamics of lifelong learning, with a companion introduction to the research by Profs Wayne Gray and Thomas Hills, who ask: Does cognition deteriorate with age or is it enhanced by experience?

    Abstract for “The Myth of Cognitive Decline”

    As adults age, their performance on many psychometric tests changes systematically, a finding that is widely taken to reveal that cognitive information-processing capacities decline across adulthood. Contrary to this, we suggest that older adults’ changing performance reflects memory search demands, which escalate as experience grows. A series of simulations show how the performance patterns observed across adulthood emerge naturally in learning models as they acquire knowledge. The simulations correctly identify greater variation in the cognitive performance of older adults, and successfully predict that older adults will show greater sensitivity to fine-grained differences in the properties of test stimuli than younger adults. Our results indicate that older adults’ performance on cognitive tests reflects the predictable consequences of learning on information-processing, and not cognitive decline. We consider the implications of this for our scientific and cultural understanding of aging.

    You can check out some of the press at Language Log, The New York Times, National GeographicThe Telegraph, The Independent, Psychology Today (in Fulfillment at Any Age Statistical Life), The Daily Mail, Forbes, The Huffington Post, The National Post, The Times of India, and Gawker. Or listen to the radio segment on the BBC’s World Service. There’s also a lively comment thread over at Reddit Science.

     
  • Ramscar Lab 16:10 on 01.08.2014 Permalink
    Tags:   

    An overdue update 

    A listing of recent talks by Michael on our cognitive aging research:

    • 19th September 2013 — Colloquium: Cognitive Development Center, Central European University, Budapest.
    • 10th October 2013 — Colloquium: Department of Psychology, Warwick University.
    • 15th October 2013 — Colloquium: Department of Cognitive, Perceptual and Brain Sciences, University College London.
    • 23 October 2013 — Colloquium: Cognitive Science Institute at Osnabrück University.
    • 29 October 2013 — Colloquium: Donders Centre for Cognition, Nijmegen University.
    • 13th November, 2013 — Invited talk: Department of Psychology, Indiana University, Bloomington.
    • 15th November, 2013 — Psychonomic Society Annual Meeting, Toronto, Canada.
    • 18th November, 2013 — Invited talk: Department of Speech & Hearing, Indiana University, Bloomington.

    Coming up:

    • 16th January 2014 — Harald Baayen will present our work at the Linguistics Department Colloquium, Berkeley, CA.
    • 23rd January, 2014 — Michael will give a colloquium at the Basque Center on Cognition Brain and Language, San Sebastien.
    • 21st February, 2014 — Michael will give a colloquium for the University of Sheffield’s Psychology Department.
     
  • Ramscar Lab 20:32 on 12.13.2013 Permalink
    Tags: , , , Overregularization, ,   

    The many curious cases of mouses 

    Error and expectation in language learning: The curious absence of ‘mouses’ in adult speech has just come out in Language, and opens, enticingly enough, with a quote from the Silver Blaze:

    Gregory: “Is there any other point to which you would wish to draw my attention?”

    Holmes: “To the curious incident of the dog in the nighttime”.

    Gregory: “The dog did nothing in the nighttime”.

    Holmes: “That was the curious incident”.

    –Sir Arthur Conan Doyle

    For more puzzles on learning, morphology, and negative evidence, we turn to the abstract:

    As children learn their mother tongues, they make systematic errors. For example, English speaking children regularly say “mouses” rather than “mice”. Because children’s errors aren’t explicitly corrected, it has been argued that children could never learn to make the transition to adult language based on the evidence available to them, and thus that learning even simple aspects of grammar is logically impossible without recourse to innate, language specific constraints. Here, we examine the role children’s expectations play in language learning, and present a model of plural noun learning that generates a surprising prediction: At a given point in learning, exposure to regular plurals (e.g. rats) can decrease children’s tendency to overregularize irregular plurals (e.g. mouses). Intriguingly, the model predicts that the same exposure should have the opposite effect earlier in learning. Consistent with this, we show that testing memory for items with regular plural labels contributes to a decrease in irregular plural overregularization in six-year-olds, but an increase in four-year-olds. Our model and results suggest that children’s overregularization errors both arise and resolve themselves as a consequence of the distribution of error in the linguistic environment, and that far from presenting a logical puzzle for learning, they are inevitable consequences of it.

     
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