ISSN : 1226-9654
The present study examined Visual Working Memroy (VWM) storage efficiency when items with different features are displayed across different positions. In separate-memory condition of Experiment 1, either colored boxes or orientation bars were displayed respectively on either side of the visual fields as memory items whereas the items were all colored boxes or orientations bar in a control condition. Subjects were asked to remember the features of the memory items followed by a brief memory delay. After the delay, test items were displayed and subjects reported presence or absence of a change in either color or orientation across the memory and test items. The results showed that change detection performance was significantly higher in the separate memory condition than the control condition. Also, the difference became more apparent if the set size became larger. In Experiment 2, the items in separate-memory condition were replaced with colored orientation bars (i.e., conjunction items). The change in the test items could occur in either color or orientation dimension, but the side of visual fields for its occurrence was designated exclusively for each features (e.g., left for color vs. right for orientation). In the control condition (i.e., integrate-memory condition), no such constraint was present and either color or orientation change could occur randomly across the sides of visual fields. The results showed that the difference in change detection performance between separate-memory and the control conditions was greatly reduced, and no differential effect of the setsize manipulation was observed across each condition. These results support the weak-object hypothesis where items in VWM are represented flexibly either as a form of well-bound features or of independently-stored discrete features. rather than the strict models according to integrated-object or parallel-independent storage hypothesis.
Awh E, Dhaliwal H, Christensen S, Matsukura M (2001), Evidence for two components of object-based selection. Psychological Science, 12, 4, 329-334.
Cowan, N. (2001), The magical number 4 in short-term memory: A reconsideration of mental storage capacity, Behavioral and Brain Sciences, 24, 87-185.
Gajewski, D. A., & Brockmole, J. R. (2006). Feature bindings endure without attention: Evidence from an explicit recall task. Psychonomic Bulletin & Review, 13, 581-587.
Huang, L., & Pashler, H. (2012). Distinguishing Different Strategies of Across-Dimension Attentional Selection. Journal of Experimental Psychology: Human Perception and Performance, 38, 2, 453-463.
Jiang, Y., Chun, M., & Olson, I. (2004). Perceptual grouping in change detection. Perception & Psychophysics, 66, 446-453.
Jiang, Y., Olson, I., & Chun, M. (2000). Organization of visual short-term memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 683-702.
Loftus, G. R. and Masson, M. E. J. (1994). Using confidence intervals in within-subject designs, Psychonomic Bulletin & Review, 1, 476-490.
Luck, S. J. and Vogel, E. K. (1997), The capacity of visual working memory for feature and conjunctions, Nature, 390, 279-281.
Luria, R., & Vogel, E. K. (2011). Shape and color conjunction stimuli are represented as bound objects in visual working memory. Neuropsychologia, 49, 1632-1639.
Magnussen, S., Greenlee, M. W., & Thomas, J. P. (1996). Parallel processing in visual short-term memory. Journal of Experimental Psychology: Human Perception and Performance, 22, 202-212.
Miller, G. A. (1956) The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63, 81-97.
Olson, I. R., & Jiang, Y. (2002). Is visual short-term memory object based? Rejection of the “strong object” hypothesis. Perception & Psychophysics, 64, 1055-1067.
Pashler, H. (1988). Familiarity and visual change detection. Perception & Psychophysics, 44, 369- 378.
Rouder, J. N., Morey, R. D., Morey, C. C., & Cowan, N. (2011). How to measure working memory capacity in the change detection paradigm. Psychonomic Bulletin & Review, 18, 324-330.
Sperling, G. (1960). The information available in brief visual presentations. Psychological Monographs, 74, 1-29.
Wilken, P., & Ma, W. J. (2004). A detection theory account of change detection. Journal of Vision, 4, 12, 1120-1135.
Woodman, G. F., Vecera, S. P., & Luck, S. J. (2003). Perceptual organization influences visual working memory. Psychonomic Bulletin & Review, 10, 80-87.
Xu, Y. (2010), The Neural Fate of Task-Irrelevant Features in Object-Based Processing. Journal of Neuroscience. 30, 42, 14020-14028
Vogel, E. K., Woodman, G. F. & Luck, S. J. (2001), Storage of features, conjunctions and objects in visual working memory. Journal of Experimental Psychology: Human Perception and Performance, 27, 92-114