Masked fear words produce increased SCRs: an anomaly for Ohman's theory of pre-attentive processing in anxiety.

A. Oehman and J. J. F. Soares (1994) demonstrated that masked presentation of phobic pictures produces increased skin conductance responses (SCRs) in phobic Ss. Oehman (1993) explained this phenomenon in terms of a hypothetical "feature detector" that identifies physical characteristics of stimuli and activates the arousal system without involving significance evaluation or consciousness. This explanation was tested by exposing 41 Ss with spider phobia (mean age 32 yrs) to spider words, general threat words, and neutral words instead of pictures. Words were presented both masked and unmasked while electrodermal activity was measured. Under unmasked conditions, SCRs were largest for spider words followed by general threat words, then neutral words. When masked, the difference between spider words and general threat words disappeared but SCRs remained significantly smaller for neutral words. The authors conclude that activation of the arousal system by masked threat cues does not necessarily depend on their perceptual characteristics.