Perceptual processing at adjacent location son a single finger: Masking and response competition

Abstract

When target patterns and nontarget patterns are presented either to the same or to adjacent locations on the distal pad of the index finger, the amount of interference in identifying targets depends on both the shape and the location ofthe nontarget (Horner, 1997), In the present study, the question of whether such interference is caused by masking (the masker in some way distorts the initial representation of the target) or by response competition (the observer mistakenly responds with the masker, rather than with the target) was investigated. A 4-to-2 paradigm was used (Craig, 1995), in which four stimuli were mapped to only two responses. Targets and nontargets were randomly selected from the set of four stimuli and presented to the same or adjacent locations on the same fingerpad. Both the distal pad and the medial pad of the index finger were tested, because innervation density varies proximodistally on the distal pad, but not on the medial pad. The results indicated that response competition was an important factor limiting perception. Furthermore, perception was affected by varying location on the distal pad, but not on the medial pad. Finally, varying location on the distal pad affected perception only when responses were based on pattern shape, not when responses were based on direction of motion. The results are discussed in ternlS of differences in innervation density between adjacent locations and possible resultant differences in the spatial filtering properties of the skin.

Tactile selective attention and body posture: Assessing the multisensory contributions of vision and proprioception

“…Such tactile interference effects do not merely reflect the consequences of sensory masking, since an attentional component to the effect has also been identified (e.g., Craig, 1974;Evans & Craig, 1991;Horner, 1997Horner, , 2000. Moreover, in accord with previous studies of distractor interference effects in other sensory modalities (such as vision or audition; see, e.g., Chan, Merrifield, & Spence, 2004;Eriksen & Eriksen, 1974; see Styles, 1997, for a review), somatosensory interference effects have been shown to decline as the spatial distance between the target and the distractor/mask is increased.…”

The impact and specificity of nerve perturbation on novel vibrotactile sensory letter learning

“…Few of those studies have considered their findings relative to the anatomically known density of innervation, or pathway of innervation relative to the different spatial locations (Gilson 1969). For simple stimulus detection, innervation density has been used to describe the results of concurrent tactile masking studies (Kekoni et al 1987(Kekoni et al , 1990Horner 2000). Innervation density of target location has also been used to describe letter acquisition study results (Craig 1984;Heller 1986).…”

Temporal masking of multidimensional tactual stimuli

“…Response competition has been widely studied as the source of errors in temporal masking ͑e.g., Evans and Craig, 1992;Craig and Evans, 1995;Horner, 2000͒. The rationale for this type of interference is based on the notion that both the target and the masker are fully processed to their respective responses, but that the subject mistakenly chooses the masker response instead of the target response at brief values of SOA.…”