Differential age effects for case and hue mixing in visual word recognition.

Abstract

The authors compare older adults' lexical-decision data with younger adults' data reported in P. Allen, A. F. Smith, et al. (2002). On the basis of their work, it was proposed that consistent-case wordswould be processed by the faster holistic (magnodominated) stream, but that mixed-case words would be processed by the slower analytic (interblob-dominated or blob-dominated) steams. Hue mixing was predicted to have no effect on consistent-case performance, but mixed-hue/mixed-case words were predicted to be recognized faster than monochrome/mixed-case words. Younger adults showed the predicted results, but older adults did not. These results suggest that holistic central processes are maintained, but that older adults exhibited an analytic decrement

A multistream model of visual word recognition

“…Although younger adults in the present four experiments consistently showed a mixed-case, mixed-hue advantage (relative to mixed-case monochrome presentation) for words, other studies have failed to observe this effect for cognitively healthy older adults (Allen et al, 2002) or for cognitively healthy older adults and older adults diagnosed with the amnestic type of mild cognitive impairment (Bush, Allen, Kaut, & Ogrocki, 2007). Allen et al (2002) and Bush et al used the same stimulus conditions as those used in Experiment 1 of this article.…”

“…Allen et al (2002) and Bush et al used the same stimulus conditions as those used in Experiment 1 of this article. The finding that older adults do not show the same huemixing effects as younger adults suggests that older adults are even more holistically biased than are younger adults (Allen et al, 2002).…”

Constructing isoluminant stimuli for word recognition research: A precautionary study

“…This provides some evidence of M pathway involvement in word recognition. The findings of Chase, Ashourzadeh, Kelly, Monfette, and Kinsey (2003), who used single word stimuli, also suggest that the M pathway provides the dominant source of information for word recognition under normal contrast conditions (see also Allen et al, 2002;Floyd & Dain, 2000;Kempner, Aggarwala, Zemon, Gordon, Hainline, & Riddell, 1996;Lehky, 2000;Ojanpää & Näsänen, 2003;Omtzigt, Hendriks, & Kolk, 2002).…”

“…The most straightforward approach is to match the onscreen luminance of the different components so they have the same physical luminance, as measured by a photometer (see, e.g., Chase et al, 2003;Knoblauch et al, 1991;Lehky, 2000;Ojanpää & Näsänen, 2003;Travis et al, 1990; see also Allen et al, 2002). Unfortunately, onscreen isoluminance does not guarantee that stimuli are isoluminant in either retinal images or postretinal neural responses (see, e.g., Bilodeau & Faubert, 1997; see also Cavanagh, MacLeod, & Anstis, 1987;Dobkins, Gunther, & Peterzell, 2000;Livingstone & Hubel, 1987;Metha & Mullen, 1996;von Berg, Ziebell, & Stiehl, 2002), and luminance differences may therefore be readily perceived by the observer.…”

“…To date, most studies using isoluminant stimuli to investigate word recognition have been based on isoluminance that was determined by equating physical onscreen luminance (Chase et al, 2003;Knoblauch et al, 1991;Ojanpää & Näsänen, 2003;Travis et al, 1990; see also Allen et al, 2002;Lehky, 2000), so these studies are exposed to concerns about the validity of this approach. Some studies have used HFP (Floyd & Dain, 2000;Legge et al, 1990;Omtzigt et al, 2002), but each of these studies used stimuli in the HFP task that differed substantially from the stimuli used to assess word recognition.…”