The effects of uniform field flicker and blurring on the global precedence effect

Lovegrove, William; Lehmkuhle, Stephen; Baro, John A.; Garzia, And Ralph

doi:10.3758/bf03333921

Cited by 13 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yetthere are a number of instances in which such manipulation provides results that are consistent with other lines ofevidence in suggesting a predominant, ifnot exclusive, role for one or other pathway (Livingstone & Hubel, 1987;Lovegrove et al, 1991;B. A. Steinman et aI., 1997).…”

Section: Discussionsupporting

confidence: 73%

Do the magnocellular and parvocellular visual pathways contribute differentially to subitizing and counting?

Simon

Peterson

Patel

et al. 1998

Perception & Psychophysics

View full text Add to dashboard Cite

We investigated the neurobiological basis of visual processes involved in object enumeration. Subitizing, the ability to rapidly and accurately enumerate four or fewer objects, is thought to depend on preattentive processing of visual stimuli, whereas counting of more numerous objects is thought to require serial shifts of attention. Weattempted to distinguish between the hypothesis that the magnocellular (M) visual pathway is the preferential route for subitizing, and the alternative hypothesis that there is no selectivity for the Mpathway or its counterpart, the parvocellular (P) visual pathway, in visual object enumeration. Green rectangles were presented on an equiluminant red background to impair M pathway processing. This slowed enumeration performance relative to a control condition in which object/background luminance differed, especially when the rectangles were relatively large and widely spaced and had constant retinal eccentricity. When low luminance contrast was used to impair processing along the P pathway, enumeration performance was slowed relative to a high-contrast control condition, especially when the rectangles were small and closely spaced. Overall, our manipulations affected enumeration performance without selectivity for subitizing or counting ranges and without altering the slope of the functions relating reaction time to numerosity. Thus, our results favor the hypothesis that visual enumeration does not depend preferentially on either the M or the P pathway.

show abstract

Section: Discussionsupporting

confidence: 73%

Do the magnocellular and parvocellular visual pathways contribute differentially to subitizing and counting?

Simon

Peterson

Patel

et al. 1998

Perception & Psychophysics

View full text Add to dashboard Cite

show abstract

“…First, several studies have shown that altering the spatial frequency content of hierarchically organised stimuli affects the global RT advantage and/or interference between global and local forms (Badcock et al, 1990;Hughes et al, 1990;Lamb & Yund, 1993;LaGasse, 1993;Lovegrove, Lehmkuhle, Baro, & Garzia, 1991). Second, a number of studies have demonstrated patterns of performance with targets defined by spatial frequency (i.e.…”

mentioning

confidence: 98%

Spatial Frequency and Interference Between Global and Local Levels of Structure

Lamb¹

1996

Visual Cognition

View full text Add to dashboard Cite

“…That inhibitory interactions between spatial-frequency channels are responsible for the global advantage has also been suggested by Lovegrove, Lehmkuhle, Baro, and Garzia (1991), who investigated the effect of uniform field flicker (UFF) on the processing of compound stimuli. UFF is known to affect response times to low but not to high spatial frequencies.…”

mentioning

confidence: 99%

The effect of spatial frequency on global precedence and hemispheric differences

Hübner

1997

Perception & Psychophysics

View full text Add to dashboard Cite

There are many conditions in which identification proceeds faster for the global form of a hierarchical pattern than for its local parts. Since the global form usually contains more lower spatial frequencies than do the local forms, it has frequently been suggested that the higher transmission rate of low spatial frequencies is responsible for the global advantage. There are also functional hemispheric differences. Whilethe right hemisphere is better at processing global information, the left hemisphere has an advantage with respect to local information. In accordance with the spatial-frequency hypothesis, it has been speculated that this difference is due to a differential capacity of the hemispheres for processing low and high spatial frequencies. Totest whether low spatial frequencies were responsible for the global advantage and/or for the observed hemispheric differences, two experiments were carried out with unfiltered and highpass-filtered compound-letter stimuli presented at the left, right, or center visual field. The first experiment, in which the target level was randomized in each trial block, revealed that low spatial frequencies were not necessary for either global advantage or for hemispheric differences. Highpass filtering merely increased the response times. In the second experiment, the target level was held constant in each block. This generally increased the speed of responding and produced interactions between filtering and global-local processing. It was concluded that both sensory and attentional or control mechanisms were responsible for global precedence and that the hemispheres differed with respect to the latter.Since the pioneering paper of Navon (1977; also see Kinchla, 1974), the time course of the processing ofhierarchical stimuli has been extensively investigated. Navon used so-called compound letters, which are global letter forms constructed from identical smaller local letters (see Figure 1). Usually, it is easy to focus one's attention on either the local or the global level. Interestingly, Navon found that the identification of the global form proceeded faster than that of the local letters. Moreover, if the information at the global and local levels was conflicting, then global information interfered with local processing, but not vice versa. 1will denote a response time advantage for the processing of global forms together with an interference asymmetry as global advantage. To account for the global advantage observed in his data, Navon formulated the global-precedence hypothesis, which states that the information is processed serially at both levels and that the global information is processed first.Meanwhile, it has been demonstrated that the global response time advantage varies over a wide range and can even become negative (e.g., .

show abstract

The effects of uniform field flicker and blurring on the global precedence effect

Cited by 13 publications

References 11 publications

Do the magnocellular and parvocellular visual pathways contribute differentially to subitizing and counting?

Do the magnocellular and parvocellular visual pathways contribute differentially to subitizing and counting?

Spatial Frequency and Interference Between Global and Local Levels of Structure

The effect of spatial frequency on global precedence and hemispheric differences

Contact Info

Product

Resources

About