PubMed Health⌕ Search

Biomedical subjects

T Sanocki

Publications and source records attributed to T Sanocki.

7 recordsLinked to original sources
PubMed1991

Intra- and interpattern relations in letter recognition.

Strings of 4 unrelated letters were backward masked at varying durations to examine 3 major issues. (a) One issue concerned relational features. Letters with abnormal relations but normal elements were created by interchanging elements between large and small normal letters. Overall accuracy was higher for letters with normal relations, consistent with the idea that relational features are important in recognition. (b) Interpattern relations were examined by mixing large and small letters within strings. Relative to pure strings, accuracy was reduced, but only for small letters and only when in mixed strings. This effect can be attributed to attentional priority for larger forms over smaller forms, which also explains global precedence with hierarchical forms. (c) Forced-choice alternatives were manipulated in Experiments 2 and 3 to test feature integration theory. Relational information was found to be processed at least as early as feature presence or absence.

Adult↗
PubMed1991

Looking for a structural network: effects of changing size and style on letter recognition.

The accuracy of identifying backward-masked strings of unrelated letters was measured to test a prediction of a structural network model in which information about the absolute size of letters in a font is factored out from other types of information and is represented by a single size parameter. In this model, variation from block to block in the font size should be handled relatively easily by changing this parameter. In contrast, variation in several aspects of the font style would require changing multiple parameters and should be more difficult. In three experiments, the font was alternated in style, size, size and style, or not at all, at the end of each block of eight trials. The accuracy was lower overall when the font was varied, but contrary to the predictions of the model, variation in size reduced the accuracy of performance as much as did variation in style and variation in size and style.

Cognition↗
PubMed1991

Effects of early common features on form perception.

Recognizing forms may involve a contingency in which later processing is modified, depending on the results of early analyses. This hypothesis can be distinguished from feature models, in which features (including early global features) accumulate over time. In four experiments, shape primes were presented briefly, followed immediately and in the same location by a similarly or differently shaped target, and then a mask. Accuracy was measured with a two-alternative forced-choice discrimination. The primes facilitated discriminations between a similarly shaped target and differently shaped foil, as would be expected. More important is that the primes also facilitated discriminations between similarly shaped targets and similarly shaped foils, even though the primes contained only features common to the alternatives and thus provided no discrimination-relevant information. The facilitation effect was constant over variations in the size of the target set, the type of mask, and the type of baseline condition. This result is consistent with the idea of early-to-late contingencies in processing but was not predicted by feature models.

Adult↗
PubMed1991

Perceptual adjustments on representations of familiar patterns: change over time and relational features.

Subjects classified individual stimuli as exact copies or as distortions of previously viewed prototype letters. Perceptual adjustments were induced by the presence of difficult (subtle) distortions within the stimulus set. In Experiment 1, subjects initially made feature-based adjustments, and, with experience, adjustments became identity-based. Decisional adjustments also occurred. A similar change over time was obtained in Experiment 2; in addition, the feature-based adjustments could not be explained by overall similarity between letters. Experiment 3 indicated that feature-based adjustments can be long lasting under appropriate circumstances. Experiment 4 indicated that the relevant features are not functionally independent parts of letters, but rather relations between neighboring parts. The results are consistent with the idea that adjustments can change between levels over time, and that the adjusted features are relational in nature.

Adult↗
PubMed1988

Font regularity constraints on the process of letter recognition.

Strings of four unrelated letters were presented for subjects to identify, followed by a patterned mask and then a forced choice test of each letter position. In Experiment 1, the type style in the regular conditions was consistent--all of the letters were of a single type font--whereas in the mixed condition, each string contained letters from two type fonts. Compared with the mixed condition, accuracy in the regular conditions was higher overall and increased at a faster rate as a function of processing time. This held across four sessions. In Experiment 2, the font in the mixed condition was varied either between or within letter strings; sizeable advantages for the regular conditions were found with both mix-methods. The results are consistent with the idea of a schemalike perceptual system that becomes tuned to the regularities of a particular font in order to process visual information efficiently.

Adult↗
PubMed1987

Visual knowledge underlying letter perception: font-specific, schematic tuning.

The representation of visual information about letters is proposed to be highly systematic, involving not only abstract information that is invariant across type faces (or fonts), but also a number of parameters whose values are determined by the current font. The system exploits regularities that are characteristic of letters and fonts by becoming tuned to the details of the font. This should result in efficient letter perception when the stimuli are regular (when all of the letters are of a consistent font), but not when the stimuli are irregular (when the letters are from a variety of fonts). The prediction of faster processing with a regular font, as compared with a mixed font, was examined in three experiments requiring the recognition of four-letter strings. Experiment 1 confirmed the prediction, and Experiment 2 replicated the effect with the number of "features" equated across conditions. Experiment 3 showed that the disadvantage for a mixture of fonts is related to how much the representational system must be adjusted to handle the different fonts.

Attention↗