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Torstein Låg

Publications and source records attributed to Torstein Låg.

4 recordsLinked to original sources
PubMed2005

The visual basis of category effects in object identification: evidence from the visual hemifield paradigm.

The basis for the category specific living things advantage in object recognition (i.e., faster and more accurate identification of living compared to nonliving things) was investigated in two experiments. It was hypothesised that the global shape of living things on average provides more information about their basic level identity than the global shape of nonliving things. In two experiments subjects performed name-picture or picture-name verification tasks, in which blurred or clear images of living and nonliving things were presented in either the right or the left visual hemifield. With blurred images, recognition performance was worst for nonliving things presented to the right visual field/left hemisphere, indicating that the lack of visual detail in the stimulus combined with a left hemisphere bias toward processing high frequency visual elements proved detrimental for processing nonliving stimuli in this condition. In addition, an overall living things advantage was observed in both experiments. This advantage was considerably larger with blurred images than with clear. These results are compatible with the global shape hypothesis and converge with evidence using other paradigms.

Adult↗
PubMed2005

Category-specific effects in object identification: what is "normal"?

Previous research on category-specific effects in subjects with intact brains, have found a disadvantage for the identification of natural objects compared to artefacts. This has been taken to support the explanation that natural object deficits in brain-damaged subjects are nothing more than an exaggeration of a "normal" tendency. More recent investigations have, however, uncovered the opposite normal tendency, an advantage for natural objects (Gerlach, 2001; Laws and Neve, 1999). The present study investigated the possible causes of this discrepancy. Three experiments revealed category-specific disadvantages for natural objects in normal subjects despite using stimulus materials rigorously balanced for a) concept familiarity, b) visual complexity, c) name frequency and d) name length. Furthermore, it was found that the very same set of stimulus materials could lead to natural object advantages as well as natural object disadvantages, depending on whether trials in a matching paradigm were positive or negative. In a naming paradigm, there was no natural object disadvantage when stimulus presentation durations were short. The discrepancy present in the literature can be solved by an account emphasising perceptual strategies instead of invoking a lack of adequate experimental control in the previous studies.

Adult↗
PubMed2005

Reduced Stroop interference for opponent colors may be due to input factors: evidence from individual differences and a neural network simulation.

Sensory or input factors can influence the strength of interference in the classic Stroop color-word task. Specifically, in a single-trial computerized version of the Stroop task, when color-word pairs were incongruent, opponent color pairs (e.g., the word BLUE in yellow) showed reduced Stroop interference compared with nonopponent color pairs (e.g., BLUE in red). In addition, participants' color discrimination ability was measured by standard color vision tests (i.e., Farnsworth-Munsell 100-Hue Test and Ishihara plates). Error rates in the Farnsworth-Munsell test correlated positively with the amount of Stroop interference. Neural network simulations (variants of J. D. Cohen, K. Dunbar, & J. L. McClelland's, 1990, model) showed that only a distributed trichromatic input layer was able to simulate these findings. Thus, sensory input from the color system needs to be incorporated into current accounts of the Stroop effect.

Adult↗