Cerebral blood flow changes in limbic regions induced by unsolvable anagram tasks. Academic Article uri icon



  • OBJECTIVE: The study addressed the question of whether unsolvable as opposed to solvable cognitive problems activate discrete neuronal systems in the human brain. METHOD: Twelve healthy humans tried to solve unsolvable anagrams. Solvable anagrams and a resting baseline after each anagram task served as control conditions in a within-subject design. Activation was measured with the equilibrium infusion method by using 15O-labeled water and positron emission tomography, with absolute quantitation of anatomically defined regional cerebral blood flow (CBF). RESULTS: Compared to rest, both anagram tasks increased activity in frontal and temporal regions. The soluble task condition increased hippocampal activation and decreased mammillary bodies activity, while unsolvable anagrams were associated with increased CBF to the mamillary bodies and amygdala and decreased hippocampal activity. CONCLUSIONS: A limbic network integrating negative emotion and cognition seems reflected in reciprocal diencephalic and limbic activation with solvable and unsolvable anagrams. Since unsolvable anagrams have been used to induce learned helplessness in humans, this finding may provide an initial step toward clarifying its neural substrate.

publication date

  • February 1, 1996



  • Cerebrovascular Circulation
  • Helplessness, Learned
  • Limbic System
  • Problem Solving


Scopus Document Identifier

  • 0030070411

PubMed ID

  • 8561200

Additional Document Info


  • 153


  • 2