Previous research on factors that influence divided attention have focused on resource allocation, age of participants, task difficulty and familiarity, practice effects as well as brain areas that control dual task performance. The present study examined the effects of task difficulty and stimulus similarity on dual-task performance. One hundred and twenty participants, divided into four equal groups were asked to read a typewritten passage and at the same time to listen to an auditory message. The tasks for each group differed in terms of similarity and difficulty. The results showed no significant main effect of task difficulty (F(1.116) = 1.36, p>0.05) and a significant main effect of stimulus similarity (F(1.116) = 51.51, p<0.05). Performance in the conditions was dependent on stimulus similarity and information type. In terms of significant interaction effects, interference effects were observed more in the easy—dissimilar and difficult—dissimilar conditions than in the easy—similar and difficult—similar conditions. The results are discussed in the context of language processing and dual—task processing. Suggestions for future research are made.
AnnetJ. M.LeslieJ. C. (1996). Effects of visual and verbal interference on olfactory memory: The role of task complexity. British Journal of Psychology, 87(3), 447–461.
2.
ArringtonC. M.AltmanE. M.CarrT. H. (2003). Tasks of a feather flock together: Similarity effects in ask switching. Memory and Cognition, 5(5), 781–790.
3.
BaddeleyA. (1986). Working memory.Oxford: Clarendon Press.
4.
BaddeleyA. (1990). Human memory: Theory and practice.Boston, MA: Allyn and Bacon.
5.
BaddeleyA.SalaDella S. (1996). Working memory and executive control. Philosophical Transition of the Royal Society of London. Series B, 351, 1397–1404.
6.
BaddeleyA.HitchG. (2000). Development of working memory: Should the Pascual-Leone and the Baddeley and Hitch models be merged?Journal of Experimental Child Psychology, 77(6), 128–137.
7.
BarghJ. A.FergusonM. J. (2000). Beyond behaviourism: On the automaticity of higher mental processes. Psychological Bulletin, 126(6), 925–945.
8.
BeckerJ. T.MorrisR. G. (1999). Working memory(s). Brain and Cognition, 41(1), 1–8.
9.
Ben-ShakarG.ShefferL. (2001). The relationship between the ability to divide attention and standard measures of general cognitive abilities. Intelligence, 29(4), 293–307.
10.
BroadbentD. E. (1958). Perception and communication.London: Pergamon Press.
11.
ChaseW. G.EricssonK. A. (1982). Skill and working memory. In BowerG. H. (Ed.), The psychology of learning and motivation (Vol. 16) (pp. 1–58). New York: Academic Press.
12.
ChaseW. G.SimonH. A. (1973). The mind's eye in the chess. In ChaseW. G. (Ed.), Visual information processing (Vol. 12) (pp. 1–67). New York: Academic Press.
13.
CherryE. C. (1953). Some experiments on the recognition of speech with one and with two ears. Journal of Acoustic Society of America, 25(3), 975–979.
14.
CurryR. E.KleinmanD. L.HoffmanW. C. (1977). A design procedure for control/display systems. Human Factors, 19, 421–436.
15.
DanemanM.CarpenterP. A. (1980). Individual differences in working memory and reading. Journal of Verbal Learning and Verbal Behaviour, 19(17), 450–466.
16.
EricssonK. A. (1985). Memory skill. Canadian Journal of Psychology, 39(7), 188–231.
17.
EysenckM. W.KeaneM. T. (1990). Cognitive psychology: A student handbook.Hove: Laurence Erlbaum.
18.
FrackerM. L.WickensC. D. (1989). Resources, confusions and compatibility in dual-axis tracking: Displays, controls, and dynamics. Journal of Experimental Psychology: Human Perception and Performance, 2(21), 80–97.
19.
HelmanS.BerryD. C. (2003). Effects of divided attention and speeded responding on implicit and explicit retrieval o artificial grammar knowledge. Memory and Cognition, 31(5), 703–715.
20.
HirstW.KalmarD. (1987). Characterising attentional resources. Journal of Experimental Psychology: General, 116(1), 68–81.
21.
KahnemanD. (1973). Attention and effort.Englewood Cliffs: Prentice Hall.
22.
KintschW.van DijkT. A. (1978). Towards a model of text comprehension. Psychological Review, 85(13), 363–394.
23.
MakoniK. (1995). Effects of task difficulty, stimulus familiarity and practice on dual-task performance. Unpublished Dissertation, University of Zimbabwe, Harare.
24.
MatherD. S. (2003). Dyslexia and dysgraphia: More than the written language difficulties in common. Journal of Learning Disabilities, 36(4), 307–318.
25.
NavonD.MillerJ. (1987). The role of outcome conflict in dual-task interference. Journal of Experimental Psychology: Human Perception and Performance, 13, 435–448.
26.
O'SheaS.MorrisM. E.IansekR. (2002). Dual-task interference in people with Parkinson's disease: Effects of motor versus cognitive secondary tasks. Physical Therapy, 82(9), 999–898.
27.
PashlerH.JohnsonJ. C.RuthruffE. (2001). Attention and performance. Annual Review of Psychology, 7, 629–641.
28.
PetersM. (1981). Attentional asymmetries during concurrent bimanual performance. Quarterly Journal of Experimental Psychology, 33A, 95–103.
29.
PosnerM. I. (1990). The attention system in the human brain. Annual Review of Nuero-Science, 78(4), 25–42.
30.
PotterM. C.LombardiL. (1990). Regeneration in the short-term recall of sentences. Journal of Memory and Learning, 29(21), 633–654.
31.
RichardC. M.WrightR. D.EeC.PrimeS. L.ShimizuY.VavrikJ. (2002). Effect of a concurrent auditory task on visual search performance in a driving related image flicker task. Human Factors, 44(1), 108–120.
32.
RuthruffE.PashlerH. E.KlaasenA. (2001). Processing bottlenecks in dual-task performance: Structural limitation or strategic postponement. Psychonomic Bulletin Review, 8(1), 73–80.
33.
SchumacherE. L.LauberE. J.GlassJ. M.ZurbriggenE. L.GmeindlL.KierasD. E.MeyerD. E. (1999). Concurrent response-selection process in dual-task performance: Evidence for adaptive executive control of task scheduling. Journal of Experimental Psychology: Human Perception and Performance, 25(3), 791–815.
34.
SzameitatA. J.SchubertT.MullerK.von CramonD. Y. (2002). Localisation of executive functions in dual-task performance with MRI. Journal of Experimental Psychology, 15(6), 56–70.
35.
TreismanA. M. (1961). Strategies and models of selective attention. Psychological Review, 75(8), 282–299.
36.
TreismanA.DaviesA. (1973). Divided attention to eye and ear.New York: Academic Press.
37.
TverskyA. (1977). Features of similarity. Psychological Review, 84(14), 327–349.
38.
WickensC. D. (1984). Engineering psychology in human performance.Columbus, Ottawa: Merril.
39.
WickensC. D.CarswellM. C. (1995). The proximity compatibility principle: Its psychological foundation and relevance to display design. Human Factors, 37(3), 473–495.
40.
WickensC. D.HollandJ. G. (2000). Engineering psychology and human performance (3rd Ed). London: Prentice Hall.
41.
WilcoxT.KraftR. H. (1989). Lateral differences in schematic face encoding during dual-task performance with increasing levels of difficulty. Perceptual and Motor Skills, 5(1), 767–779.
