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Frode Svartdal

Publications and source records attributed to Frode Svartdal.

2 recordsLinked to original sources
PubMed2004

Does color synesthesia pose a paradox for early-selection theories of attention?

P.M. is a synesthete who experiences colors when viewing alphanumeric symbols. Her search for a target differing from distractors by a synesthetic color feature takes the form of a pop-out search. Thus, it would seem that synesthesia can occur preattentively. However, discrepancies between the regression functions of response times observed in target-present trials and target-absent trials, and the fact that fast response times occur only when the target is within a few degrees of visual angle from fixation, indicate that P.M.'s synesthesia does not occur preattentively, but rather is within the focus of attention. We conclude that synesthesia is a genuine perceptual phenomenon that can have substantial influence on visual processing.

Attention↗
PubMed2003

Extinction after partial reinforcement: predicted vs. judged persistence.

The partial reinforcement extinction effect (PREE) (i.e., increased persistence following partial reward) is one of the most important generalizations from experimental studies of learning. Many theories of PREE assume that it involves cognitive and emotional mechanisms, but investigations of PREE have focused almost exclusively on behavioral measures. Four experiments with human adults investigated whether PREE is also reflected in cognitive measures. Independent groups of subjects learned an instrumental response under CRF vs. PRF contingencies, and then predicted (Experiments 1, 2, and 3) and/or judged (Experiments 3 and 4) their own persistence under extinction conditions. Predictions of persistcnce were unrelated to prior continuous or partial reinforcement contingencies (Experiments 1, 2, and 3), but subsequent judgments of persistence behavior were accurate (Experiments 3 and 4). These results indicate that increased persistence due to occasional reward is not well represented cognitively prior to its behavioral manifestation, but it is well represented after that manifestation. Possible explanations and implications of this apparent behavior cognition dissociation are discussed.

Adult↗