Biomedical subjects

Charles Spence

Publications and source records attributed to Charles Spence.

At least 19 recordsLinked to original sources

PubMed2007

'Prior entry' for pain: attention speeds the perceptual processing of painful stimuli.

We investigated whether the perception of simultaneity for pairs of nociceptive and visual stimuli was dependent upon the focus of participants' attention to a particular sensory modality (either pain or vision). Two stimuli (one painful and the other visual) were presented randomly at different stimulus onset asynchronies (SOAs) using the method of constant stimuli. Participants made unspeeded verbal responses as to which stimulus they perceived as having been presented first, or else responded that the two stimuli were presented simultaneously. This temporal discrimination task was repeated under three different attention conditions (blocks): divided attention, attend pain, and attend vision. The results showed that under conditions of divided attention, nociceptive stimuli had to be presented before visual stimuli in order for the two to be perceived as simultaneous. A comparison of the two focused attention conditions revealed that the painful stimulus was perceived as occurring earlier in time (relative to the visual stimulus) when attention was directed toward pain than when it was directed toward vision. These results provide the first empirical demonstration that attention can modulate the temporal perception of painful stimuli.

Adult↗

PubMed2006

Crossmodal change blindness between vision and touch.

Change blindness is the name given to people's inability to detect changes introduced between two consecutively-presented scenes when they are separated by a distractor that masks the transients that are typically associated with change. Change blindness has been reported within vision, audition, and touch, but has never before been investigated when successive patterns are presented to different sensory modalities. In the study reported here, we investigated change detection performance when the two to-be-compared stimulus patterns were presented in the same sensory modality (i.e., both visual or both tactile) and when one stimulus pattern was tactile while the other was presented visually or vice versa. The two to-be-compared patterns were presented consecutively, separated by an empty interval, or else separated by a masked interval. In the latter case, the masked interval could either be tactile or visual. The first experiment investigated visual-tactile and tactile-visual change detection performance. The results showed that in the absence of masking, participants detected changes in position accurately, despite the fact that the two to-be-compared displays were presented in different sensory modalities. Furthermore, when a mask was presented between the two to-be-compared displays, crossmodal change blindness was elicited no matter whether the mask was visual or tactile. The results of two further experiments showed that performance was better overall in the unimodal (visual or tactile) conditions than in the crossmodal conditions. These results suggest that certain of the processes underlying change blindness are multisensory in nature. We discuss these findings in relation to recent claims regarding the crossmodal nature of spatial attention.

Adult↗

PubMed2006

Assessing the effect of verbal working memory load on visuo-spatial exogenous orienting.

The aim of this study was to assess whether or not loading verbal working memory (WM) affects the exogenous orienting of visuo-spatial attention. Visuo-spatial exogenous orienting was measured under low/high WM load conditions by means of an orthogonal spatial cuing paradigm. Participants had to discriminate the elevation (up versus down) of a visual target preceded by a peripheral spatially-nonpredictive visual cue presented on either the left or right. This elevation discrimination task was carried out in-between a verbal WM test, in which a sequence of six digits (to be remembered for report at the end of the trial) was presented either in numerically ascending or random order (i.e., low and high load conditions, respectively). Participants made significantly more recall errors in the high load than in the low load condition, demonstrating that the verbal WM load manipulation had been effective. However, WM load did not interact with visuo-spatial exogenous orienting (i.e., comparable cuing effects were reported in both load conditions). These results are consistent with the view that peripheral visual onsets automatically capture spatial attention, regardless any concurrent increase of verbal WM load.

Adult↗

PubMed2006

Adaptation to audiotactile asynchrony.

Previous research has revealed the existence of perceptual mechanisms that compensate for slight temporal asynchronies between auditory and visual signals. We investigated whether temporal recalibration would also occur between auditory and tactile stimuli. Participants were exposed to streams of brief auditory and tactile stimuli presented in synchrony, or else with the auditory stimulus leading by 75ms. After the exposure phase, the participants made temporal order judgments regarding pairs of auditory and tactile events occurring at varying stimulus onset asynchronies. The results showed that the minimal interval necessary to correctly resolve audiotactile temporal order was larger after exposure to the desynchronized streams than after exposure to the synchronous streams. This suggests the existence of a mechanism to compensate for audiotactile asynchronies that results in a widening of the temporal window for multisensory integration.

Acoustic Stimulation↗

PubMed2006

Comparing intramodal and crossmodal cuing in the endogenous orienting of spatial attention.

The endogenous orienting of spatial attention has been studied with both informative central cues and informative peripheral cues. Central cues studies are difficult to compare with studies that have used uninformative peripheral cues due to the differences in stimulus presentation. Moreover, informative peripheral cues attract both endogenous and exogenous attention, thus making it difficult to disentangle the contribution of each process to any behavioural results observed. In the present study, we used an informative peripheral cue (either tactile or visual) that predicted that the target would appear (in different blocks of trials) on either the same or opposite side as the cue. By using this manipulation, both expected and unexpected trials could either be exogenously cued or uncued, thus making it possible to isolate expectancy effects from cuing effects. Our aim was to compare the endogenous orienting of spatial attention to tactile (Experiment 1) and to visual targets (Experiment 2) under conditions of intramodal and crossmodal spatial cuing. The results suggested that the endogenous orienting of spatial attention should not be considered as being a purely supramodal phenomenon, given that significantly larger expectancy effects were observed in the intramodal cuing conditions than in the crossmodal cuing conditions in both experiments.

Adult↗

PubMed2006

Temporal order judgments for audiovisual targets embedded in unimodal and bimodal distractor streams.

We investigated whether the presence of unimodal or bimodal (synchronous) distractors would affect temporal order judgments (TOJs) for pairs of asynchronous audiovisual target stimuli. Participants made unspeeded TOJs regarding which of a pair of auditory and visual stimuli, presented at different stimulus onset asynchronies using the method of constant stimuli, occurred first. These asynchronous target stimuli were presented in a fixed position amongst a stream of three (auditory, visual, or audiovisual) distractors in each block of trials. The largest just noticeable differences (JNDs) were reported when the target stimuli were presented in the middle (position 3) of the distractor stream. Importantly, audiovisual distractors were shown to interfere with TOJ performance far more than unimodal (auditory or visual) distractors. The point of subjective simultaneity (PSS) was also influenced by the modality of the distractors, and by the position of the target within the distractor stream. These results confirm the existence of a specifically bimodal crowding effect, with audiovisual TOJs being impaired far more by the presence of audiovisual distractors that by unimodal auditory or visual distractors.

Acoustic Stimulation↗

PubMed2006

An investigation into the temporal dimension of the Mozart effect: evidence from the attentional blink task.

In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task.

Acoustic Stimulation↗

PubMed2006

Audiovisual synchrony perception for music, speech, and object actions.

We investigated the perception of synchrony for complex audiovisual events. In Experiment 1, a series of music (guitar and piano), speech (sentences), and object action video clips were presented at a range of stimulus onset asynchronies (SOAs) using the method of constant stimuli. Participants made unspeeded temporal order judgments (TOJs) regarding which stream (auditory or visual) appeared to have been presented first. Temporal discrimination accuracy was significantly better for the object actions than for the speech video clips, and both were significantly better than for the music video clips. In order to investigate whether or not these differences in TOJ performance were driven by differences in stimulus familiarity, we conducted a second experiment using brief speech (syllables), music (guitar), and object action video clips of fixed duration together with temporally reversed (i.e., less familiar) versions of the same stimuli. The results showed no main effect of stimulus type on temporal discrimination accuracy. Interestingly, however, reversing the video clips resulted in a significant decrement in temporal discrimination accuracy as compared to the normally presented for the music and object actions clips, but not for the speech stimuli. Overall, our results suggest that cross-modal temporal discrimination performance is better for audiovisual stimuli of lower complexity as compared to stimuli having continuously varying properties (e.g., syllables versus words and/or sentences).

Acoustic Stimulation↗

PubMed2006

Evaluating the influence of frame rate on the temporal aspects of audiovisual speech perception.

We investigated whether changing the frame rate at which speech video clips were presented (6-30 frames per second, fps) would affect audiovisual temporal perception. Participants made unspeeded temporal order judgments (TOJs) regarding which signal (auditory or visual) was presented first for video clips presented at a range of different stimulus onset asynchronies (SOAs) using the method of constant stimuli. Temporal discrimination accuracy was unaffected by changes in frame rate, while lower frame rate speech video clips required larger visual-speech leads for the point of subjective simultaneity (PSS) to be achieved than did higher frame rate video clips. The significant effect of frame rate on temporal perception demonstrated here has not been controlled for in previous studies of audiovisual synchrony perception using video stimuli and is potentially important given the rapid increase in the use of audiovisual videos in cognitive neuroscience research in recent years.

Acoustic Stimulation↗

PubMed2006

The differential effect of vibrotactile and auditory cues on visual spatial attention.

Previous research has shown that the presentation of spatially predictive auditory and vibrotactile warning signals can facilitate driver responses to driving events seen through the windscreen or rearview mirror. The present study investigated whether this facilitation reflects the priming of the appropriate response (i.e. braking vs. accelerating) or an attentional cuing effect (i.e. a perceptual benefit that facilitates subsequent behavioural responding). In the experiments reported here, participants had to discriminate the colour of a number plate (red vs. blue) following the presentation of either spatially predictive vibrotactile (experiment 1) or auditory (experiment 2) warning signals that indicated the likely location (front or back) of the visual target, while simultaneously performing a highly attention-demanding rapid serial visual presentation task. Numberplate discrimination performance was facilitated following the presentation of valid auditory cues, but not following the presentation of equally informative vibrotactile cues. The use of an orthogonal spatial cuing design enabled with us to rule out of a potential response priming account of these data. The results suggest that whilst directional congruency between a warning signal and a target event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation effects may also require the co-location of the cue and target within the same functional region of space.

Adolescent↗

PubMed2006

Olfactory-tactile compatibility effects demonstrated using a variation of the Implicit Association Test.

We investigated whether the crossmodal associations between olfaction and touch reported previously in studies involving subjective report measures could also be demonstrated using an indirect measure of crossmodal association. To this end, we used a modified version of the Implicit Association Test. The participants had to make speeded discrimination responses to a series of unimodally presented olfactory (lemon vs. animal odour) or tactile stimuli (soft vs. rough fabric) using two response keys. In compatible blocks of trials, the olfactory and tactile stimuli that were mapped onto the same response key were considered to share a stronger association (e.g., the lemon odour and the soft fabric) than those that were combined onto the same response key in the incompatible blocks of trials (e.g., the animal odour and the soft fabric). The results showed that the participants responded significantly more rapidly in the compatible response mapping blocks than in the incompatible blocks, thus confirming the existence of associations between the stimuli that were considered to be compatible. These results provide the first empirical evidence that olfactory-tactile crossmodal associations are stable enough to influence performance even when not directly relevant to a participant's task.

Adult↗

PubMed2006

Assessing the influence of schematic drawings of body parts on tactile discrimination performance using the crossmodal congruency task.

Seeing one's own body (either directly or indirectly) can influence visuotactile crossmodal interactions. Recently, it has been shown that even viewing a simple line drawing of a hand can also modulate such crossmodal interactions, as if the picture of the hand somehow corresponds to (or primes) the participants' own hand. Alternatively, however, it could be argued that the modulatory effects of viewing the picture of a hand on visuotactile interactions might simply be attributed to cognitive processes such as the semantic referral to the relevant body part or to the orientation cues provided by the hand picture instead. In the present study, we evaluated these various different interpretations of the hand picture effect. Participants made speeded discrimination responses to the location of brief vibrotactile targets presented to either the tip or base of their forefinger, while trying to ignore simultaneously-presented visual distractors presented to either side of central fixation. We compared the modulatory effect of the picture of a hand with that seen when the visual distractors were presented next to words describing the tip and base of the forefinger (Experiment 1), or were superimposed over arrows which provided another kind of directional cue (Experiment 2). Tactile discrimination performance was modulated in the hand picture condition, but not in the word or arrow conditions. These results therefore suggest that visuotactile interactions are specifically modulated by the image of the hand rather than by cognitive cues such as simply semantic referral to the relevant body sites and/or any visual orientation cues provided by the picture of a hand.

Adult↗

PubMed2006

The modulation of crossmodal integration by unimodal perceptual grouping: a visuotactile apparent motion study.

We adapted the crossmodal dynamic capture task to investigate the modulation of visuotactile crossmodal integration by unimodal visual perceptual grouping. The influence of finger posture on this interaction was also explored. Participants were required to judge the direction of a tactile apparent motion stream (moving either to the left or to the right) presented to their crossed or uncrossed index fingers. The participants were instructed to ignore a distracting visual apparent motion stream, comprised of either 2 or 6 lights presented concurrently with the tactile stimuli. More crossmodal dynamic capture of the direction of the tactile apparent motion stream by the visual apparent motion stream was observed in the 2-lights condition than in the 6-lights condition. This interaction was not modulated by finger posture. These results suggest that visual intramodal perceptual grouping constrains the crossmodal binding of visual and tactile apparent motion information, irrespective of finger posture.

Adult↗

PubMed2006

Assessing the effectiveness of "intuitive" vibrotactile warning signals in preventing front-to-rear-end collisions in a driving simulator.

This study was designed to investigate the possibility that driver responses to potential front-to-rear-end collision situations could be facilitated by implementing vibrotactile warning signals that indicate the likely direction of the potential collision. In a car following scenario in a driving simulator, participants drove along a rural road while trying to maintain a safe headway distance to the lead car using a visual distance display. Participants had to respond as quickly as possible to the sudden deceleration of the lead car which had its brake lights disabled, either with or without vibrotactile cues (presented in different experimental blocks). The results demonstrated significantly faster braking responses and larger safety margins when the vibrotactile warning signal was presented than when it was not. These findings demonstrate the effectiveness of vibrotactile cues in helping drivers to orient their spatial attention in the appropriate direction. Our results add to a growing body of empirical evidence highlighting the potential benefits of using "intuitive" vibrotactile in-car displays, in this case, to alert drivers to potential collisions and to provide time-critical directional information.

Accidents, Traffic↗

PubMed2006

Cross-modal associations between odors and colors.

In the present study, we investigated the nature of any cross-modal associations between colors and odors. In Experiment 1, we show that participants consistently match certain odors to specific colors when asked to explicitly select from among different colors the one that best matched a given odor. In Experiment 2, we investigated the robustness of these cross-modal associations using a cross-modal variant of the implicit association test (IAT). Participants made speeded discrimination responses to a random sequence of odors (strawberry vs. spearmint) and color patches (pink vs. turquoise). On the basis of the results of Experiment 1, the assignment of these targets onto the two response keys was manipulated in order to generate compatible (e.g., responding to the pink color and to the strawberry odor with the same response key) and incompatible (e.g., responding to the pink color and to the spearmint odor with the same response key) blocks of trials. The results showed that participants responded more rapidly and accurately to odor-color pairings having a stronger association than to those having a weaker (or no) association. These results suggest that odor-color associations can be both systematic and robust. The paradigm developed here provides a novel cross-modal extension of the IAT to probe the nature of color-odor associations.

Adult↗

PubMed2006

Tactile perception of the roughness of the end of a tool: what role does tool handle roughness play?

We investigated whether the perceived roughness of the end of a tool is influenced by the texture of the handle used to hold it. Participants rated the roughness of the ends (caps) of a series of tools by rubbing them along their forearm, and indicated the perceived roughness of the tool's cap by means of an anchored visual scale. The caps of the tools had one of eight different levels of roughness varying from very smooth (sample 1) to very rough (sample 8). The participants held the tool handle in one hand while rubbing the cap of the tool against their contralateral forearm. The tool handle was either smooth (similar in smoothness to sample 1) or else very rough (matched in roughness to sample 8). Overall, participants were remarkably good at ignoring the roughness of the tool's handle when discriminating the roughness of the tool's cap. Nevertheless, the roughness of the tool handle was shown to modulate roughness judgments concerning the tool cap under certain conditions: in particular, tool caps at the rougher end of the scale (6 and 7) were rated as being significantly less rough when the participants held tools with a rough handle than when they held tools with a smooth handle. Our results therefore demonstrate a small but significant effect of the roughness of the handle of a tool on the perceived roughness of its cap.

Adult↗

PubMed2006

Back-to-front: improved tactile discrimination performance in the space you cannot see.

We investigated any differences in people's ability to reconstruct the appropriate spatiotemporal ordering of multiple tactile stimuli, when presented in frontal space (a region where visual inputs tend to dominate) versus in the space behind the back (a region of space that we rarely see) in professional piano players and in non-musicians. Even though tactile temporal order judgments were much better in the musicians overall, both groups showed a much reduced crossed-hands deficit when their hands were crossed behind their backs rather than at the front. These results suggest that because of differences in the availability of visual input, the spatiotemporal representation of non-visual stimuli in front versus rear space is different.

Adult↗

PubMed2006

Direction-dependent integration of vision and proprioception in reaching under the influence of the mirror illusion.

Recent models of multisensory integration predict differential weighting of information from different sensory modalities in different spatial directions. This direction-dependent weighting account suggests a heavier weighting for vision in the azimuthal (left-right) direction and a heavier weighting for proprioception in the radial (near-far) direction. Visually induced reaching errors, as demonstrated in previous 'mirror illusion' reaching experiments, should therefore be greater under visual-proprioceptive conflict in the azimuthal direction than in the radial direction. We report two experiments designed to investigate the influence of direction-dependent weighting on the visual bias of reaching movements under the influence of a mirror-illusion. In Experiment 1, participants made reaches straight forward, and showed terminal reaching errors that were biased by vision in both directions, but this bias was significantly greater in the azimuthal as compared to the radial direction. In Experiment 2, participants made reaches from right to left, and showed a significant bias only in the azimuthal direction. These results support the direction-dependent weighting of visual and proprioceptive information, with vision relatively more dominant in the azimuthal direction, and proprioception relatively stronger in the radial direction.

Adult↗