What do eye movements reveal about the role of memory in visual search?

Horowitz and Wolfe (1998, 2003) have challenged the view that serial visual search involves memory processes that keep track of already inspected locations. The present study used a search paradigm similar to Horowitz and Wolfe's (1998), comparing a standard static search condition with a dynamic condition in which display elements changed locations randomly every 111 ms. In addition to measuring search reaction times, observers' eye movements were recorded. For target-present trials, the search rates were near-identical in the two search conditions, replicating Horowitz and Wolfe's findings. However, the number of fixations and saccade amplitude were larger in the static than in the dynamic condition, whereas fixation duration and the latency of the first saccade were longer in the dynamic condition. These results indicate that an active, memory-guided search strategy was adopted in the static condition, and a passive “sit-and-wait” strategy in the dynamic condition.     

Variability, covariation, and invariance with respect to coordinate systems in motor control: reply to Smeets and Louw (2007)

In their comment on the tolerance-noise covariation (TNC) method for decomposing variability by H. Müller and D. Sternad (2003, 2004b), J. B. J. Smeets and S. Louw show that covariation (C), as defined within the TNC method, is not invariant with respect to coordinate transformations and contend that it is, therefore, meaningless. Although the observation is correct, their interpretation is misleading in the following ways: (a) They equate covariation C with the known statistical quantity covariance and noise (N) with standard deviations. The two quantities C and N are conceptually different statistical measures. (b) Dependency on the reference frame is not only a feature of C but of all 3 components. However, such dependency is ubiquitous in motor control. (c) As the frame of reference in biological systems is poorly understood, the TNC method may afford evaluation of different coordinates for control.     

Book reviews and notes

GENERAL

ISLAM AND HUMAN RIGHTS: TRADITION AND POLITICS. By Ann Elizabeth Mayer. Boulder and San Francisco: Westview Press/London: Pinter Publishers, 1991. xix + 258pp. Hb. £35.00. ISBN 0–8133–8091‐X [U.S.] ISBN 0–86187–091–3 [U.K.].

TOWARD AN ISLAMIC REFORMATION: CIVIL LIBERTIES, HUMAN RIGHTS, AND INTERNATIONAL LAW. By Abdullahi Amhed AN‐NA'IM. Foreword by John Voll. New York: Syracuse Press, 1990. xvi + 253pp. Hb. $29.95. ISBN 0–81656–2484–8.

WAS JEDER VOM ISLAM WISSEN MUSS. Edited by Lutherischen Kirchenamt Der Vereinigten Evangelischen‐Lutherischen Kirche Deutschlands and Kirchenamt der Evangelischen Kirche in Deutschland. Gutersloh: Gerd Mohn, 1990. 224pp. Pb. np. ISBN 3–579–00786–6.

WER WAR MUHAMMAD? LEBENSGESCHICHTE UND PRO‐PHETISCHER ANSPRUCH. By Adel Theodor Khoury. Freiburg im Breisgau: Herder, 1990. 125pp. Pb. DM10.90. ISBN 3–451–08719–7.

DER ISLAM: SEIN GLAUBE — SEINE LEBENSORDNUNG — SEIN ANSPRUCH. By Adel Theodor Khoury. Freiburg im Breisgau: Herder, 1988. 238pp. Pb. DM12.90. ISBN 3–451–08602–6.

MOHAMMED UND DER KORAN. By Rudi Paret. Stuttgart: Kohlhammer, 1991. 181pp. Pb. DM20.00. ISBN 3–17–011317–8.

DER ISLAM: RELIGION‐ETHIK‐POLITIK. By Peter Antes et al. Stuttgart, Berlin, Koln: Kohlhammer, 1991.151pp. Pb. DM29.80. ISBN 3–17–011737–8.

INTRODUCING ISLAM FROM WITHIN. By Mona Abul‐Fadl. Leicester: The Islamic Foundation, 1991. 135pp. Pb. n.p. ISBN 0–86037–209‐X.

MUSLIMS: THEIR RELIGIOUS BELIEFS AND PRACTICES: VOLUME 1: THE FORMATIVE PERIOD. By Andrew Rippin. London:. Routledge, 1990. 155pp. Pb. £9.99. ISBN 0–415–04519–3.

MACHT UND EINSAMKEIT GOTTES: DIALOG MIT DEM ISLAMISCHEN RADKAL‐MONOTHEISMUS. By Thomas Mooren. Religionswissenschaftliche Studien, hrsg. von A. Th. Khoury und L. Hagemann; 17. Wurzburg: Echter/Altenberge: Oros, 1991. 408pp. Pb. DM59.80. ISBN 3–429–01411–5 (Echter); ISBN 3–89375–040–1 (Oros).

DER KORAN: ARABISCH‐DEUTSCH: UBERSETZUNG UND WISSENSCHAFTLICHER KOMENTAR. By Adel Theodor Khoury. Band 1: Muhammad. Der Koran Sure 1,1–2,74. Giitersloh: Giitersloher Verlagshaus Gerd Mohn, 1990. 367pp. Hb. DM250.00 for subscribers to the whole work: DM195.00 per volume. ISBN 3–579–00336–4. Band 2: Sure 2,75–2,212. Gutersloh: Gutersloher Verlagshaus Gerd Mohn, 1991.384pp. Hb. DM250.00. ISBN 3–579–00337–2.

THE ISMAILIS: THEIR HISTORY AND DOCTRINES. By Farhad Daftary. Cambridge: Cambridge Univeristy Press, 1990. 804pp. Hb. £60.00; $79.50. ISBN 0–521–37019–1.

BELIEF AND LAW IN IMAMI SfflTSM. By Etan Kohlberg. Alder‐shot: Variorum, 1991. x + 352pp. Hb. n.p. ISBN 0–86078–292–1.

NAQSHBANDIS: HISTORICAL DEVELOPMENTS AND PRESENT SITUATION OF A MUSLIM MYSTICAL ORDER: PROCEEDINGS OF THE SEVRES ROUND TABLE 2–4 MAY 1985. Edited by Marc Gaborieau, Alexandre Popovic and Thierry Zarcone. Varia TurcicaXVII. Istanbul‐Paris: Editions ISIS, 1990.750pp. HB. n.p. ISBN 2–906053–12–0.

LE LIVRE REUNISSANT LES DEUX SAGESSES. (Kitab‐e Jami al‐Hikmatayri). By Nasir‐e. Khosraw. Translation from the Persian, introduction and notes by Isabelle de Gastines. Paris: Fayard, 1990.345pp. Pb. FF130.00. ISBN 9–782213–026138.

ISLAM AND LIBERATION THEOLOGY. By Asghar Ali Engineer. New Delhi: Sterling Publishers, 1990. 238pp. Hb. RS200.00. ISBN 81–207–1046–0.

ISLAMIC HISTORY: A FRAMEWORK FOR INQUIRY. By R. Stephen Humphreys. London: I.B. Tauris, 1991. Revised edition. 401pp. Pb. £9.95. ISBN 1–85043–360–7.

THE ELEMENTS OF SUFISM. By Shaykh Fadhlalla Haeri. Shaftesbury: Element Books Ltd., 1990. 118pp. Pb. £4.99; $7.95. ISBN 1–8523O‐O68‐X.

MELANGES — Volume 20. Edited by Institute Dominicain d'Etudes Orientales du Caire: Louvain‐Paris, Editions Peeters, 1991. 597pp. Hb. n.p. No ISBN number.

DEBATING MUSLIMS: CULTURAL DIALOGUES IN POSTMODER‐NITY AND TRADITION. By Michael M.J. Fischer and Mehdi Abedi. Wisconsin: University of Wisconsin Press, 1990. 564pp. Hb. n.p. ISBN 0–299–12430–4.

MUSLIM TRAVELLERS: PILGRIMAGE, MIGRATION AND THE RELIGIOUS IMAGINATION. Edited by Dale F. Eickelman and James Piscatori. London: Routledge, 1990. 281pp. Pb. £40.00. ISBN 0–415–05033–2.

PRINCIPLES OF ISLAMIC JURISPRUDENCE. By Mohammed Hashim Kamali. Cambridge: Islamic Texts Society, 1991. 417pp. Hb. £25.00. ISBN Hb. 0–946621–23–3; Pb. 0–946621–24–1.

RELIGION, LEARNING AND SCIENCE IN THE ‘ABBASID PERIOD. Edited by M.J.L. Young, J.D. Latham and R.B. Serjeant. Cambridge: Cambridge University Press, 1991. 587pp. Hb. £60.00; $95.00. ISBN 0–521–32763–6.

THE SOCIAL LAWS OF THE QUR'AN: By Robert Roberts. London: Curzon Press Ltd.,. 1990. First pub. 1925. 125pp. Pb. £3.75. ISBN 0–391–03661–0.

BUSINESS ACCOUNTING AND ETHICS. By TREVOR GAMBLING and Rifaat Ahmed Abdel Karim. London and New York: Mansell, 1991. 152pp. Hb. n.p. ISBN 0–7201–2074–8.

ISLAMIC FAMILY LAW. Edited by Chibli Mallat and Jane Connors. London and Norwell: Graham and Trotman Ltd, 1990. 358pp + appendix and index. Hb. n.p. ISBN 1–85333–301–8.

THE SAYINGS OF MUHAMMAD. Selected and translated from the Arabic by Neal Robinson. London: Duckworth, 1991 63pp. Pb. £499. ISBN 0–7156–2365–6.

ECONOMIE DU MONDE ARABE ET MUSULMAN. EDITIONS EMAN. Cachan: Editions EMAM, 1990. 240pp. Pb. FF230.00. ISBN 2–9503–484–2–4.

SCHLAGLICHTER UBER DAS SUFITUM: ABU NASR AS‐SARRAGS KITAB AL‐LUMA’. Eingeleitet, iibersetzt und kommentiert von Richard Gramlich. Freiburger Islamstudien, Band XIII. Stuttgart: Franz Steiner Verlag, 1990. 676pp. Pb. DM270.00. ISBN 3–515–05199–6.

THE MUSLIM MIND. By Charis Waddy. London: Grosvenor Books, 1990. 3rd Edition. 218pp. Pb. £7.50. ISBN 1–85239–008–5.

DECREE AND DESTINY: THE FREEDOM OF NO CHOICE. By ShaykhFadhlallaHaeri. Shaftesbury: Element Books in association with Sahra Publications, 1991. 147pp. Pb. £7.99. ISBN 1–85230–178–3.

REGIONAL

Africa

RELIGION AND PROPERTY IN NORTHERN NIGERIA. By Lissi Rasmussen. Copenhagen: Academic Press, 1990. 278pp. Pb. DKR228.00. ISBN 87–500–2944–4.

DER GNAWA‐KULT: TRANCESPBELE, GEISTERBESCHWORUNG UND BESESSENHEIT IN MAROKKO. By Frank Maurice Welte. Frankfurt: Peter Lang, 1990. 379pp. Pb. DM36.00. ISBN 3–631–42273–3.

SUDAN AFTER NIMIERI. Edited by Peter Woodward. London: Routledge, 1991. 223pp. Hb. £35.00. ISBN 0–415–00480–2.

MODERN ALGERIA: A HISTORY FROM 1830 TO THE PRESENT. By Charles‐Robert Ageron. London: Hurst & Co., 1991.166pp. Hb. £16.50; Pb. £9.50. ISBN Hb. 1–85065–027–6; Pb. 1–85065–106‐X.

THE BEDOUIN OF CYRENAICA: STUDIES IN PERSONAL AND CORPORATE POWER. By the late Emrys L. Peters. Edited by Jack Goody and Emanuel Marx. Cambridge: Cambridge University Press, 1990. 310pp. Hb. £32.50, $47.50. ISBN 0–521–38561‐X.

LE TROUPEAU DES SONGS. By Alain Le Pichon and Souleymane Balde. Paris: Editions de la Maison des Sciences de l'Homme, 1990. 353pp. FF240.00. ISBN 2–7351–0411–7.

Asia

RESISTANCE AND CONTROL IN PAKISTAN. By Akbar S. Ahmed. London: Routledge, 1991. 207pp. Pb. n.p. ISBN 0–415–05797–3.

PAKISTAN: SOCIAL SCIENTISTS’ PERSPECTIVE. Edited by Akbar S. Ahmed. Karachi, Oxford: OUP, 1990. 298pp. £12.95. ISBN 0–19–577388–8.

MUSLIM SEPARATISM: THE MOROS OF SOUTHERN PHILIPPINES AND THE MALAYS OF SOUTHERN THAILAND. By W.K. Che Man. Oxford: OUP, 1990. 240pp. Hb. £22.50. ISBN 0–19–588924‐X.

TURKEY AND THE MIDDLE EAST. By Philip Robins. London: Pinter Publishers, 1991. 130pp. Pb. £7.95. ISBN 0–86187–198–7.

INDIEN AM SCHEIDEWEG ZWISCHEN SAKULARISMUS UND FUNDAMENTALISMUS. By Ernst Pulsfort. Religionswissen‐schaftlich Studien, 18. Wurzburg: Echter Verlag; Altenberge: Oros Verlag, 1991. 97pp. + 14 maps and tables. Pb. DM19.80. ISBN 3–429–01412–3 (Echter); 3–89375–041‐X (Oros Verlag).

FROM ZARATHUSTRA TO KHOMEINI: POPULISM AND DISSENT IN HIAN. By Manochehr Dorraj. London: Lynne Rienner, 1990. 220pp. Hb. £29.95. ISBN 1–55587–181‐X.

Europe

ISLAM IN BRITAIN: PAST, PRESENT AND THE FUTURE. By Mohammad S. Raza. Leicester: Volcano Press Ltd., 1991. 120pp. Pb. n.p. ISBN 0–06–066837–7.

NEW CHALLENGES — OLD STRATEGIES: THEMES OF VARIATION AND CONFLICT AMONG PAKISTAN MUSLIMS IN NORWAY, by Nora Ahlberg. Helsinki: Finnish Anthropological Society, 1990. 295pp. Hb. FIM130.00. ISBN 951–95435–5–4.

THE INTEGRATION OF ISLAM AND HINDUISM IN WESTERN EUROPE. Edited by W.A.R. Shadid and P.S. van Koningsveld. The Hague: Kok Pharos, 1991, 254pp. Pb. n.p. ISBN 90–242–3078–0.

SACRILEGE VERSUS CIVILITY: MUSLIM PERSPECTIVES ON THE SA TANIC VERSES AFFAIR. Edited by M.M. Ahsan and A.R. Kidwai. Leicester: the Islamic Foundation, 1991. 383pp. Pb. £8.50. ISBN 0–86037–210–3.

ISLAM IN EUROPEAN THOUGHT. By ALBERT HOURANI. Cambridge: CUP, 1991. 199pp. Hb. £25.00; $34.50. ISBN 0–521.39213–6.

WERELDGODSDIENSTEN IN NEDERLAND. Edited by JAN SLOMP. Amersfoort/Leuven: De Horstink, 1991. 234pp. Pb. n.p. ISBN 90–6184–361–8.

VEILED HALF TRUTHS: WESTERN TRAVELLERS’ PERCEPTIONS OF MIDDLE EASTERN WOMEN. Selected and introduced by Judy Mabro. London; New York. I.B. Tauris, 1991.275pp. Hb. £19.95. ISBN 1–85043–097–7.

Middle East

NO TRUMPETS, NO DRUMS: A TWO‐STATE SETTLEMENT OF THE ISRAELI‐PALESTINIAN CONFLICT. By Sari Nusseibeh and Mark A. Heller. London: I.B. Tauris, 1991. 183pp. Hb. £12.95. ISBN 1–85043–365–8.

ISTANBUL HOUSEHOLDS: MARRIAGE, FAMILY AND FERTILITY, 1880–1940. By Alan Duben and Cem Behar. Cambridge: CUP, 1991. 276pp. Hb. £30.00, $59.50. ISBN 0–521–38375–7.

CHRISTIAN‐MUSLIM RELATIONS

INDIGENOUS CHRISTIAN COMMUNITIES IN ISLAMIC LANDS: CONVERSION AND CONTINUITY: EIGHTH TO EIGHTHEENTH CENTURIES. Edited by Michael Gervers and Ramzi Jibran Bikhazi. Toronto: Pontifical Institute of Medieval Studies, 1990. 559pp. Pb. CNS49.50. ISBN 0–88844–809–0.

PLANNING STRATEGIES FOR WORLD EVANGELIZATION. By Edward R. Dayton and David A. Fraser. Monrovia, California: MARC and Grand Rapids/Michigan: Wm. B‐ Eerdmans, 1990. First edition pub. 1980. 349pp. Pb. US$15.95. ISBN 0–8028–0422–5.

KAISER JOHANNES VI: KANTAKUZENOS UND DER ISLAM: POLTTISCHE REAUTAT UND THEOLOGISCHE POLEMIK IM PALAIOLOGENZEITLICHEN BYZANZ. By Klaus‐Peter Todt. Religjonswissenschaftliche Studien 16. Wiirzberg: Echter and Altenberge: Oros‐Verlag, 1991. lx + 705pp. Pb. DM94.80. ISBN 3–429–01370–4 (Echter); 3–89375–035–5 (Oros‐Verlag).

CHRIST IN ISLAM AND CHRISTIANITY. By Neal Robinson. London: Macmillan Press, 1991.235pp. Hb. £40.00. ISBN 0–333–52209–5.

GUIDELINES FOR DIALOGUE BETWEEN CHRISTIANS AND MUSLIMS. By Maurice Borrmans. Mahwah, New Jersey: Paulist Press, 1990 (English Translation). Originally published 1981, in French: 132pp. Pb. US$12.95. ISBN 0–8091–3181–1.

WIE TOLERANT 1ST DER ISLAM? Edited by Walter Kerber. Munich: Kindt Verlag, 1991.. 147pp. Pb. n.p. ISBN 3–925412–11–5.

GEMEINSAM VOR GOTT: RELIGIONENIM GESPRACH. Edited by R. Kirste, P. Schwarzenau and U. Tworuschska. Hamburg E.B.‐Verlag Rissen, 1991. 335pp. Pb. np. ISBN 3–923002–54–8.

‘GOTT 1ST CHRISTUS, DER SOHN DER MARIA’: EINE STUDIE ZUM CHRISTUSBILD IM KORAN. By Günter Risse. Bonn: Borengasser, 1989. 273pp. Hb. DM34.00. ISBN 3–923946–17–1.

JUDAISM, CHRISTIANITY AND ISLAM: THE CLASSICAL TEXTS AND THEIR INTERPRETATION. Edited by F.E. Peters. Vols. 1, 2 and 3. Princeton: Princeton University Press, 1990. xxv + 408; xxv + 395; xxv+408pp. Hb. £75.00. Pb. £14.95 (Vol.1); £14.95 (Vol.2); £14.95 (Vol.3). ISBN 0–691–02044–2; 0–691–02054‐X; 0–691–02055–8.

FULNESS OF LIFE (John 10:10): ENCOUNTERING ISLAM, APOSTOLIC VISION. Special issue No.2 of Petit Echo of the’ missionaries of Africa. Rome: Missionaries of Africa, 1991. 172pp. Pb. n.p. No ISBN number.

TRENDS IN MISSION: TOWARD THE 3RD MILLENNIUM. Edited by William Jenkinson and Helene O'Sullivan. Maryknoll, New York: Orbis Books, 1991. 419pp. Pb. $26.95. ISBN 0–88344–766–5.     

Searching for unknown feature targets on more than one dimension: Investigating a “dimension-weighting” account

Search for odd-one-out feature targets takes longer when the target can be present in one of several dimensions as opposed to only one dimension (Müller, Heller, & Ziegler, 1995; Treisman, 1988). Müller et al. attributed this cost to the need to discern the target dimension. They proposed adimension-weighting account, in which master map units compute, in parallel, the weighted sum of dimension-specific saliency signals. If the target dimension is known in advance, signals from that dimension are amplified. But if the target dimension is unknown, it is determined in a process that shifts weight from the nontarget to the target dimension. The weight pattern thus generated persists across trials, producing intertrial facilitation for a target (trialn+1) dimensionally identical to the preceding target (trialn). In the present study, we employed a set of new tasks in order to reexamine and extend this account. Targets were defined along two possible dimensions (color or orientation) and could take on one of two feature values (e.g., red or blue). Experiments 1 and 2 required absent/present and color/orientation discrimination of a single target, respectively. They showed that (1) both tasks involveweight shifting, though (explicitly) discerning the dimension of a target requires some process additional to simply detecting its presence; and (2) the intertrial facilitation is indeed (largely) dimension specific rather than feature specific in nature. In Experiment 3, the task was to count the number of targets in a display (either three or four), which could be either dimensionally the same (all color or all orientation) or mixed (some color and some orientation). As predicted by the dimension-weighting account, enumerating four targets all defined within the same dimension was faster than counting three such targets or mixed targets defined in two dimensions.     

Visual and semantic factors in recognition from long-term memory

In recognition tests, physical and semantic relationships between targets and distractors have been shown, in separate manipulations, to affect the latency of subject's decision. Recognition was tested for distractors which were visually similar or dissimilar to targets and which belonged to the target categories or to nontarget categories in order to examine the interaction of these dimensions. Rejection latency was longer for target category than for nontarget category distractors. Latency was also longer for visually similar than visually dissimilar distractors, but only when combined with target category probes. This interaction can be explained by the hypothesis that word recognition depends on the analysis of several dimensions of the probe stimulus, and rejection can occur before all such analyses have been completed.     

Analysis of timing variability in human movements by aligning parameter curves in time

The analysis of timing in human movements requires a reference with which timing can be quantified. In reactive movements this reference is given by the stimulus. However, many movements do not respond to such an external event. In throwing, for instance, the hand opening for release has to be timed to an acceleration of the throwing arm. A common approach to analyzing release-timing variability is to choose a landmark in the movement that is supposed to have a fixed temporal relation to the release. Such distinct landmarks, however, are not always well definable. Therefore, the present article describes an alternative approach analyzing timing variability on the basis of the alignment of different trials relative to their kinematic shape, by shifting the trials in the time domain. The basic assumption behind this approach is that single throwing movements are one instance of an acquired movement template, and thus show a considerable similarity. In contrast, the location of the temporal moment of release varies from trial to trial, generating imprecision regarding the release timing. In trials synchronized with respect to the release, this variability can be assessed by shifting the kinematic profiles of the throwing movements in time such that they superimpose as closely as possible. As a result, the corresponding time shifts for all trials represent a measure of the release time deviations across trials, and the standard deviation of these deviations represents the timing variability. Aside from timing analyses in such movements as throwing, the approach can be applied to very different tasks with timing demands—for example, to neurophysiological signals.     

Processing order in dual-task situations: The “first-come,first-served” principle and the impact of task order instructions

When two overlapping tasks are processed, they hit a bottleneck at a central processing stage that prevents simultaneous processing of the two tasks. Thus far, however, the factors determining the processing order of the tasks at the bottleneck are unknown. The present study was designed to (re)investigate whether the arrival times of the two tasks at the central bottleneck are a key determinant of the processing order (cf. Sigman & Dehaene, 2006). To this end, we implemented a visual–auditory dual task with a random stimulus order, in which we manipulated arrival time by prolonging the initial, perceptual processing stage (stimulus analysis) of the visual task and compared the effects of this manipulation with those of one impacting the central bottleneck stage of the visual task. Additionally, we implemented two instruction conditions: Participants were told to respond either in the order of stimulus presentation or in the order they preferred. The manipulation of the visual perception stage led to an increase in task response reversals (i.e., the response order was different from the order of stimulus presentation), whereas there was no such increase when the bottleneck stage was manipulated. This pattern provides conclusive evidence that the processing order at the bottleneck is (at least in part) determined by the arrival times of the tasks at that point. Reaction time differences between the two instruction conditions indicated that additional control processes are engaged in determining task processing order when the participants are expressly told to respond in the order of stimulus presentation.     

Region-based shielding of visual search from salient distractors: Target detection is impaired with same- but not different-dimension distractors

Shielding visual search against interference from salient distractors becomes more efficient over time for display regions where distractors appear more frequently, rather than only rarely Goschy, Bakos, Müller, & Zehetleitner (Frontiers in Psychology 5: 1195, 2014). We hypothesized that the locus of this learned distractor probability-cueing effect depends on the dimensional relationship of the to-be-inhibited distractor relative to the to-be-attended target. If the distractor and target are defined in different visual dimensions (e.g., a color-defined distractor and orientation-defined target, as in Goschy et al. (Frontiers in Psychology 5: 1195, 2014), distractors may be efficiently suppressed by down-weighting the feature contrast signals in the distractor-defining dimension Zehetleitner, Goschy, & Müller (Journal of Experimental Psychology: Human Perception and Performance 38: 941–957, 2012), with stronger down-weighting being applied to the frequent- than to the rare-distractor region. However, given dimensionally coupled feature contrast signal weighting (cf. Müller J, Heller & Ziegler (Perception & Psychophysics 57:1–17, 1995), this dimension-(down-)weighting strategy would not be effective when the target and the distractors are defined within the same dimension. In this case, suppression may operate differently: by inhibiting the entire frequent-distractor region on the search-guiding master saliency map. The downside of inhibition at this level is that, although it reduces distractor interference in the inhibited (frequent-distractor) region, it also impairs target processing in that region—even when no distractor is actually present in the display. This predicted qualitative difference between same- and different-dimension distractors was confirmed in the present study (with 184 participants), thus furthering our understanding of the functional architecture of search guidance, especially regarding the mechanisms involved in shielding search from the interference of distractors that consistently occur in certain display regions.