Ernst Strüngmann Forum


Cognitive Search

Evolution, Algorithms, and the Brain

Peter M. Todd and Trevor Robbins, Chairpersons

February 20–25, 2011

Frankfurt am Main, Germany

Program Advisory Committee

Thomas Hills (Initiator), Center for Cognitive and Decision Sciences, University of Basel, 4056 Basel, Switzerland
John McNamara, School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW, U.K.
Jeroen Raaijmakers, Programmagroep Psychonomy, University of Amsterdam, 1018 WB Amsterdam, The Netherlands
Trevor Robbins Behavioural and Clinical Neurosciences Institute, University of Cambridge, Downing Street, Cambridge, CB2 3EB, U.K.
Peter M. Todd (Initiator), Cognitive Science, Informatics and Psychology, Indiana University, Bloomington, IN 47406-7512, U.S.A.


  • To explore the conserved properties of both behavior and adaptive expectations in search behaviors in different domain-specific environments (e.g., spatial, visual, memory, social).
  • To work toward conceptual understanding of the possible neural, molecular, and adaptive origins of search behavior in human and animal cognition.
  • To aim for comparison of species and areas, in search of common principles.
  • To establish future research directions for understanding the breadth and limits of generalized cognitive search processes.
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Background and Significance of the Topic

Search is a common and crucial behavior for most organisms mediating the trade-off between exploration and exploitation of resources distributed in space or time. The literature of search behavior is largely spread over multiple disciplines and paradigms, ranging across foraging for food, visual search for targets, drug-seeking behavior in addicts, memory search in recall and recognition tasks, the search for information on the web, and the search for mates in social environments. Recent molecular and comparative biological findings support a putative common ancestral precursor for many of these search behaviors in animal foraging. Moreover, with our developing understanding of the shared control among neural correlates of response selection (prefrontal cortex and basal ganglia), exploration and memory (e.g., the hippocampus), and visual attention (e.g., the parietal cortex), so grows the increasing realization that numerous goal-directed processes central to cognition rely on the integration of search-related architectures.  This leads to the surprising conclusion that the same processes may underlie much of human behavior—when characterized as cognitive search—both in the external world and in internal memory (reviewed in Hills, 2006).

Search behavior is moving to the forefront of scientific inquiry in a number of fields as a result of several recent findings and methodological developments, including the following:

  1. The discovery of dopaminergic mechanisms across multiple species that control the search for and evaluation of resources.
  2. Characterizations from network science of large-scale mental spaces (such as lexicons) and social spaces (such as friendship networks), which provide terrains for modeling search behavior in those domains.
  3. Extension of the principles of adaptive foraging to the exploration of human decisions in information environments such as the World Wide Web.
  4. Multidisciplinary interest in the trade-off between exploring for and exploiting found resources and the development of cognitive models to characterize these behaviors and their dynamic interplay.
  5. Developments in genetic analysis and neuroimaging that have shown the importance of individual genetic differences and specific brain regions (e.g., prefrontal cortex, striatum, hippocampus, and parietal cortex) for understanding human explore/exploit decision making in a variety of environments.

Search, as a behavioral process, is so common that it is constantly being reexamined and redefined by various disciplines; however, these disciplines often act independently of one another in their scientific endeavors. The primary goals of this forum will help us approach collectively, and work to overcome, what we perceive to be this interdisciplinary blind spot in the study of human and animal cognition. Although the fields that compose cognitive science have each furthered our understanding of cognition at various levels of analysis, the combined success of these endeavors has contributed to a modular view of the mind, composed of separate processes independently evolved to solve specific problems. Little attention has been paid to how the processes may share similar algorithms, neurocognitive control systems, or arise from a common ancestry. At the same time, individual fields have found exactly these commonalities among search processes. For instance, cognitive neuroscience has explored how interactions between the striatum and prefrontal cortex modulate a diversity of goal-directed behaviors, involving similar molecular machinery, and handling problems as diverse as spatial search for a target and abstract decision making. Moreover, studies of adaptive spatial, information, and social foraging find remarkably similar theoretical descriptions of behavior across mental, spatial, and social domains.

This Ernst Strüngmann Forum offers the unique opportunity for members of various disciplines to identify the commonalities and distinctions among cognitive domains related to search, as well as to identify possible future directions for investigating common molecular and evolutionary origins of human goal-directed cognition. In doing so, this forum would enable science to construct a common intellectual ground between the varied disciplines and provide a new conceptual basis upon which future research can be based.

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Group 1: Evolution of Search, Adaptation and Phylogeny

  • What adaptive problems has search evolved to solve (e.g., food, habitat, mates, social partners, information, search objects, target memories)?
  • What are the common features of the problems (e.g., patchy vs. uniform distribution, competition, certain vs. uncertain)?
  • What are the common features of the solutions (e.g., individual vs. group foraging, exploration vs. exploitation, local vs. global, parallel vs. serial)?
  • What is the evolutionary history and fate of strategies (e.g., phylogeny, homology, exaptation)?

Group 2: Search, Goals and the Brain

  • How does the brain implement:
    • goal maintenance and switching?
    • spatial vs. nonspatial search?
    • attentional control mechanisms?
    • neuromodulation of search processes?
  • What can be learned from pathologies of goal-directed search?

Group 3: Mechanisms and Processes of Cognitive Search

  • Are there common aspects to various types of cognitive search (e.g., visual, memory, spatial)?
  • What are the components of search (e.g., exploration/sampling, evaluating, stopping rules)?
  • How is search directed and controlled (e.g., inhibition, cue selection, tip of the tongue)?

Group 4: Search Environments, Representation, and Encoding

  • How do we represent different search domains (e.g., topological representations of resources in physical, mental and social environments)?
  • Where do these representations come from; how are they formed (e.g., ontogeny, network growth)?
  • How does search in high-dimensional spaces differ from search in low-dimensional spaces?
  • What search strategies are appropriate for high-dimensional spaces? • How do we facilitate search in different environments (e.g., semantic web, social networks)
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