@article{KhaderPachurMeieretal.2011,
  author    = {Khader, Patrick H. and Pachur, Thorsten and Meier, Stefanie and Bien, Siegfried and Jost, Kerstin and Roesler, Frank},
  title     = {Memory-based decision-making with heuristics evidence for a controlled activation of memory representations},
  series = {Journal of cognitive neuroscience},
  volume    = {23},
  journal   = {Journal of cognitive neuroscience},
  number    = {11},
  publisher = {MIT Press},
  address   = {Cambridge},
  issn      = {0898-929X},
  pages     = {3540 -- 3554},
  year      = {2011},
  abstract  = {Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by activating long-term memory representations of only those attributes that are necessary for the decision. However, from behavioral studies alone, it is unclear whether using heuristics is indeed associated with limited memory search. The present study tested this assumption by monitoring the activation of specific long-term-memory representations with fMRI while participants made memory-based decisions using the "take-the-best" heuristic. For different decision trials, different numbers and types of information had to be retrieved and processed. The attributes consisted of visual information known to be represented in different parts of the posterior cortex. We found that the amount of information required for a decision was mirrored by a parametric activation of the dorsolateral PFC. Such a parametric pattern was also observed in all posterior areas, suggesting that activation was not limited to those attributes required for a decision. However, the posterior increases were systematically modulated by the relative importance of the information for making a decision. These findings suggest that memory-based decision-making is mediated by the dorsolateral PFC, which selectively controls posterior storage areas. In addition, the systematic modulations of the posterior activations indicate a selective boosting of activation of decision-relevant attributes.},
  language  = {en}
}
@article{JostKhaderDueseletal.2012,
  author    = {Jost, Kerstin and Khader, Patrick H. and D{\"u}sel, Peter and Richter, Franziska R. and Rohde, Kristina B. and Bien, Siegfried and R{\"o}sler, Frank},
  title     = {Controlling conflict from interfering long-term memory representations},
  series = {Journal of cognitive neuroscience},
  volume    = {24},
  journal   = {Journal of cognitive neuroscience},
  number    = {5},
  publisher = {MIT Press},
  address   = {Cambridge},
  issn      = {0898-929X},
  pages     = {1173 -- 1190},
  year      = {2012},
  abstract  = {Remembering is more than an activation of a memory trace. As retrieval cues are often not uniquely related to one specific memory, cognitive control should come into play to guide selective memory retrieval by focusing on relevant while ignoring irrelevant information. Here, we investigated, by means of EEG and fMRI, how the memory system deals with retrieval interference arising when retrieval cues are associated with two material types (faces and spatial positions), but only one is task-relevant. The topography of slow EEG potentials and the fMRI BOLD signal in posterior storage areas indicated that in such situations not only the relevant but also the irrelevant material becomes activated. This results in retrieval interference that triggers control processes mediated by the medial and lateral PFC, which are presumably involved in biasing target representations by boosting the task-relevant material. Moreover, memory-based conflict was found to be dissociable from response conflict that arises when the relevant and irrelevant materials imply different responses. The two types of conflict show different activations in the medial frontal cortex, supporting the claim of domain-specific prefrontal control systems.},
  language  = {en}
}