Letter processing and font information during reading: beyond distinctiveness, where vision meets design

Letter identification is a critical front end of the reading process. In general, conceptualizations of the identification process have emphasized arbitrary sets of distinctive features. However, a richer view of letter processing incorporates principles from the field of type design, including an emphasis on uniformities across letters within a font. The importance of uniformities is supported by a small body of research indicating that consistency of font increases letter identification efficiency. We review design concepts and the relevant literature, with the goal of stimulating further thinking about letter processing during reading

Loss of high-level perceptual knowledge of object structure in DAT

Peer reviewe

On the role of the upper part of words in lexical access : evidence with masked priming

More than 100 years ago, Huey (1908) indicated that the upper part of words was more relevant for perception than the lower part. Here we examined whether mutilated words, in their upper/lower portions (e.g., , , , ), can automatically access their word units in the mental lexicon. To that end, we conducted four masked repetition priming experiments with the lexical decision task. Results showed that mutilated primes produced a sizeable masked repetition priming effect. Furthermore, the magnitude of the masked repetition priming effect was greater when the upper part of the primes was preserved than when the lower portion was preserved –this was the case not only when the mutilated words were presented in lowercase but also when the mutilated words were presented in uppercase. Taken together, these findings suggest that the front-end of computational models of visual-word recognition should be modified to provide a more realistic account at the level of letter features.The research reported in this article has been partially supported by Grant PSI2008-04069/PSIC and CONSOLIDER-INGENIO2010 CSD2008-00048 from the Spanish Ministry of Science and Innovation and by Grant PTDC/PSI-PCO/104671/2008 from the Portuguese Foundation for Science and Technology

Holistic Processing of Words Modulated by Reading Experience

Perceptual expertise has been studied intensively with faces and object categories involving detailed individuation. A common finding is that experience in fulfilling the task demand of fine, subordinate-level discrimination between highly similar instances is associated with the development of holistic processing. This study examines whether holistic processing is also engaged by expert word recognition, which is thought to involve coarser, basic-level processing that is more part-based. We adopted a paradigm widely used for faces – the composite task, and found clear evidence of holistic processing for English words. A second experiment further showed that holistic processing for words was sensitive to the amount of experience with the language concerned (native vs. second-language readers) and with the specific stimuli (words vs. pseudowords). The adoption of a paradigm from the face perception literature to the study of expert word perception is important for further comparison between perceptual expertise with words and face-like expertise

The role of higher order image statistics in masking scene gist recognition

In the present article, we investigated whether higher order image statistics, which are known to be carried by the Fourier phase spectrum, are sufficient to affect scene gist recognition. In Experiment 1, we compared the scene gist masking strength of four masking image types that varied in their degrees of second- and higher order relationships: normal scene images, scene textures, phase-randomized scene images, and white noise. Masking effects were the largest for masking images that possessed significant higher order image statistics (scene images and scene textures) as compared with masking images that did not (phase-randomized scenes and white noise), with scene image masks yielding the largest masking effects. In a control study, we eliminated all differences in the second-order statistics of the masks, while maintaining differences in their higher order statistics by comparing masking by scene textures rather than by their phase-randomized versions, and showed that the former produced significantly stronger gist masking. Experiments 2 and 3 were designed to test whether conceptual masking could account for the differences in the strength of the scene texture and phase-randomized masks used in Experiment 1, and revealed that the recognizability of scene texture masks explained just 1% of their masking variance. Together, the results suggest that (1) masks containing the higher order statistical structure of scenes are more effective at masking scene gist processing than are masks lacking such structure, and (2) much of the disruption of scene gist recognition that one might be tempted to attribute to conceptual masking is due to spatial masking

Determining isoluminance in naive subjects using heterochromatic modulation photometry

We used HMP1 to establish isoluminance for 667-nm, R, and 550-nm, G, counterphase flickering lights in thirty-eight university males. In HMP, R and G are presented in a series of fixed luminance ratios (R/G) and modulation. M. is reduced to the flicker threshold. Plots of log 1/M vs log R/G are V-shaped. Isoluminance is determined by using a model to estimate the location of the V with respect to the log R/G axis. The model requires that M depend on the sensitivity to luminance contrast S and that S depend on the observer’s limiting Weber fraction C w , and the mean luminance L of each stimulus: S = 1q/(C w ). We initially assumed linearity (q = 1.0). Goodness of fit was highly variable but improved significantly if q was allowed to vary (0.2 ≤ q ≤ 1.0). We also examined the assumption that C w is invariant with chromaticity by holding the mean luminance constant across R/G in two experienced observers. That assumption proved true for R/G less than the isoluminance point but not for greater values of R/G.</jats:p

Deuteranomalous trichromacy in a subject revealing only an L-cone pigment gene

A 19-year-old male was shown to have a deutan defect when he was examined with the FM-100 hue test (186 errors). The subject's performance on the Nagel anomaloscope was consistent with that of a person with deuteranomalous trichromacy: His match point was broad and shifted towards the green end of the red/green scale (10-40). However, southern blot analysis of the subject's DNA by means of probes for the X-linked photopigment genes revealed an absence of the restriction fragments characteristic of M-cone pigment genes. By this analysis, the subject should have deuteranopia. The differences between the psychophysical and molecular genetic results cannot be accounted for by rod intrusion into the subject's color matches: The quantal match predicted by rod and L-cone pigments falls outside the subject's anomaloscope match range. These results suggest that there are M-cone photopigment genes that are missed by conventional molecular genetic analysis.</jats:p