Rapid Development of Feature Binding in Visual Short-Term Memory

Abstract

The binding of object identity (color) and location in visual short-term memory (VSTM) was examined in 6.5- to 12.5-month-old infants (N= 144). Although we previously found that by age 6.5 months, infants can represent both color and location in VSTM, in the present study we observed that 6.5-month-old infants could not remember trivially simple color-location combinations across a 300-ms delay. However, 7.5-month-old infants could bind color and location as effectively as 12.5-month-old infants. Control conditions confirmed that the failure of 6.5-month-old infants was not a result of perceptual or attentional limitations. This rapid development of VSTM binding between 6.5 and 7.5 months occurs during a period of rapid increase in VSTM storage capacity and just after a period of dramatic neuroanatomical changes in parietal cortex. Thus, the ability to bind features and the ability to store multiple objects may both depend on a process that is mediated by posterior parietal cortex and is perhaps related to focused attention.

The development of visual working memory capacity during early childhood

“…The modified version of the change detection task presented here allowed younger children to complete a task that had previously been too challenging; however, the capacity estimates it yielded do not reach 3 or 4 items until between 5 and 7 years of age, much later than the 10 months suggested by Ross-Sheehy and colleagues (or possibly 7.5 months, as in Oakes et al, 2006). Thus, it seems that the difficulty with the adult change detection task is not the explanation of the conflicting findings by Ross-Sheehy and colleagues and Riggs et al (2006).…”

“…First, Oakes, Ross-Sheehy, and Luck (2006) showed that the ability to bind colors to locations in the preferential looking task coincided developmentally with the increase in capacity from 1 to 2 or more items at 7.5 months of age. As described above, Oakes et al (2009) showed that young infants did not prefer the changing stream at a set size of 3 even when all 3 items in the display changed with every blink.…”

Neural correlates of binding features within- or cross-dimensions in visual conjunction search: An fMRI study

“…Evidence in support of such a distinction comes from behavioral studies that demonstrated illusory conjunctions of color and form, but not of conjunctions within the form domain in normal observers (Cohen and Feintuch, 2002); intact binding of form features, but not color-form conjunctions in Balint's patients (Friedman-Hill et al, 1995;Humphreys, 2001;Humphreys et al, 2000); and a developmentally later onset of successful binding of color-form compared to within-form conjunctions in young children (Oakes et al, 2006). Importantly, patients with posterior parietal lesions showed deficits in conjoining color, size, and form features, but were unimpaired in search for form conjunctions in visual search (Humphreys et al, 2009).…”

Dorsal stream development in motion and structure-from-motion perception

“…Others, however, suggested that a third area, probably in the posterior, superior parietal cortex, needs to be activated that binds both motion and shape processing areas (Zeki, 2001). This (temporary) binding between shape and motion may be related to attention or spatial processing, and which may have a different developmental time course (Oakes et al, 2006;Rentschler et al, 2004;Ross-Sheehy et al, 2003). Thus, it remains unknown to what extend neural development of SFM processing depends on both the development of motion processing related areas and areas that are not directly related to shape or motion processing.…”