The effects of interference on recognition of haptic pictures in blindfolded sighted participants: the modality of representation of haptic information

Haptic picture recognition was tested in 36 undergraduate students to determine whether haptic representations are visual or multi-modal. Participants explored target haptic pictures and were asked to recognize the target from three alternatives. Each participant completed eight control and eight interference trials in visual, lexical and tactile recognition modalities. For interference, participants were assigned to either an articulatory suppression (repeat "the" at a constant rate) or a visual interference (watch a visual display) condition, to prevent recoding into a verbal or visual code. The results showed that accuracy was higher at control compared to interference trials and for tactile compared to lexical recognition. Additionally, lexical and tactile recognition decreased with articulatory suppression whereas only tactile recognition decreased with visual interference. These findings suggest that haptic pictures may be represented by coordinating visual and verbal codes.