Contextual cueing: implicit memory of tactile context facilitates tactile search

Abstract

In visual search, participants detect and subsequently discriminate targets more rapidly when these are embedded in repeatedly encountered distractor arrangements, an effect termed contextual cueing (Chun & Jiang Cognitive Psychology, 36, 28-71, 1998). However, whereas previous studies had explored contextual cueing exclusively in visual search, in the present study we examined the effect in tactile search using a novel tactile search paradigm. Participants were equipped with vibrotactile stimulators attached to four fingers on each hand. A given search array consisted of four stimuli (i.e., two items presented to each hand), with the target being an odd-one-out feature singleton that differed in frequency (Exps. 1 and 2) or waveform (Exp. 3) from the distractor elements. Participants performed a localization (Exps. 1 and 2) or discrimination (Exp. 3) task, delivering their responses via foot pedals. In all three experiments, reaction times were faster when the arrangement of distractor fingers predicted the target finger. Furthermore, participants were unable to explicitly discriminate repeated from nonrepeated tactile configurations (Exps. 2 and 3). This indicates that the tactile modality can mediate the formation of configural representations and use these representations to guide tactile search.

Fig. 1

Illustration of the experimental setup. Participants placed their fingers (except the thumbs) on eight solenoids delivering tactile stimulation. The solenoids are indicated by the rings in the figure. In Experiments 1 and 2, participants indicated the location of a feature-singleton target, defined by a different frequency relative to the distractors, as being delivered to a left- or a right-hand finger by pressing the corresponding (left or, respectively, right) foot pedal. In Experiment 3, participants indicated the target identity using the appropriate foot response, regardless of the hand or finger stimulated

Fig. 2

Schematic figure displaying the distribution of items in old and new configurations across search epochs (and the recognition task, for Exps. 2 and 3). In old configurations, the target location is constant and paired with constant distractor locations; in new configurations, by contrast, only the target location is held constant across repetitions

Fig. 3

Experiment 1: a Mean response times across epochs for old and new configurations, with error bars representing within-participants standard errors of the means (Cousineau, 2005). b Mean error rates across epochs, shown separately for old and new configurations, with error bars representing standard errors of the means. ^* p < .05

Fig. 4

Experiment 2: Mean response times (a) and error rates (b). See Fig. 3 for information about the error bars. ^* p < .05

Fig. 5

Waveforms of two tactile targets. The upper panel indicates the waveform of Target 1 (T1), a 5-Hz square wave with a 30 % duty cycle delivered via 150-Hz vibrations. The lower panel shows the waveform of Target 2 (T2), a burst square wave (mean frequency of 4.17 Hz) with an average 30 % duty cycle delivered via 150-Hz vibrations. The distractors are constant vibrations of 150 Hz

Fig. 6

Experiment 3: Mean response times (a), and error rates (b). See Fig. 3 for information about the error bars. ^* p < .05, ^*** p < .001