Exploring Pure Endogenous Processing: Eliminating Spatial Cues

Introduction

In experiment the spatial component of the informative cue was removed to investigate pure endogenous processing. While previous research by Spence and Driver (1996) investigated this effect by the methods of blocking the side of valid targets or by using a central arrow, they only did so by using a cross-modal target of either visual or auditory. Furthermore, they did not explore different SOA conditions using a randomly generated SOA for each trial between 600-900ms. Hence the exploration of a purely endogenous auditory cue with an auditory target has not been performed with regard to different SOA conditions.

Although the modality of the cue is probably not important in cognitive based cueing, it is desirable to keep the modality of the cue and target as auditory to ensure no possible complications of using a visual cue with an auditory target. Also due to the conjecture of differences between exogenous and endogenous processes in the temporal distribution of the presence and size of the response time advantage at different SOA, exploration of the purely endogenous process in the auditory modality is desirable.

Get quality help now

KarrieWrites

Verified writer

Proficient in: Nervous System

5 (339)

“ KarrieWrites did such a phenomenal job on this assignment! He completed it prior to its deadline and was thorough and informative. ”

+84 relevant experts are online

Hire writer

The origins of the cuing effect

A study examined the origins of the cuing effect, whether it was induced by attentional processes or by visual interaction, the researches found that the subjects performance on peripheral cuing tasks deteriorated in the peripheral-central condition than in the outer peripheral condition, thus indicating that covert attention is allocated automatically (Takei, Takeuchi & Yokosawa, 2004).

An interesting study by Spence and Driver (1996, 1997) had a subject stare at a fixed point at the center of a screen where lights were placed on the four corners of the screen.

At the back of each light was a speaker, the task of the subject was to discriminate whether light or sound came from the upper and lower corners of the screen. They found that when a non-predictive visual cue was presented on one side an auditory target on the same location was processed faster and more accurately.

Hence, measuring endogenous processing using cuing paradigms for visual attention has the same impact on auditory attention. The results obtained for experiment  found a significant response time advantage for valid cues only at the middle SOA condition (500ms). The lack of a response time advantage for valid cues at the shorter SOA of 200ms can be expected with a purely endogenous cue, however at the longer SOA of 1100ms a response time advantage was expected to be found.

Closer inspection of the results

On closer inspection of the results it is found that the average response time advantage for the SOA of 1100ms (28ms) is higher than that recorded for the middle SOA of 500ms (25ms) which was found to have a significant response time advantage for valid cues. The addition of extra subjects may have produced a significant response time advantage for the SOA condition of 1100ms, however the same may be said for the short SOA of 200ms which also had a moderate average valid cue response time advantage (16ms).

As expected the removal of the spatial component and the replacement of the pure tone for speech, has weakened the response time advantage for the short SOA (200ms) that was found in experiment 3. Contrary to expectations the failure to find a significant response time advantage for the longer SOA (1100ms) was surprising. The said finding may be due to a number of factors, like the unavoidable cognitive processing of the words in the speech cues for as thinking organisms we have learned early on to discriminate and process words especially if it is given as an instruction.

Another reason for this observation is that negative priming may have occurred as part of the cognitive processing, since there is no spatial cuing, thus the subjects had to rely only on the speech cues. Spence and Driver (1996) found that by using purely endogenous cues (side blocking and central arrow) with an auditory target response time were significant for higher SOA (600-900ms) and since the task still involved visual cues the results may have been affected by it.

The performance of individuals

Accordingly, a study comparing the performance of individuals in tasks that used monophonic sound without verbal information, monophonic sound with verbal information, 3-D audio without verbal information and 3-D audio with verbal information found that average response time for the 3-D audio conditions was faster than for the monophonic conditions and that performance in conditions in which verbal information was present was better than conditions without verbal information (Oving & Bronkhorst, 1999).

In a similar light, Rorden and Driver (2001) in their study of spatial distribution of covert attention in auditory tasks following a spatially non-predictive peripheral auditory cues or following symbolic central cues that predicted the likely location of the target found that attention can be focused not only on one hemifield versus another but also within one hemifield in an auditory task but found no meridian effect in audition. Based on the said result, it was desirable to determine whether a combination of informative speech and spatial cues would affect the response time of subjects.