Reaction time to a word in different orientations with letters rotated separately in different orientations

Six men and six women were timed as they made judgments about a word whose line of letters and individual letters were separately turned in different angular orientations. The subjects were asked to indicate by manual key-pressing responses whether the letters in the word were normal letters or reflected, mirror-image letters. Analysis showed that (1) reaction time (RT) was slower for reflected letters than for normal letters, and for subjects using the left (nondominant) hand rather than the right (dominant) hand for responding to normal letters. (2) RT generally increased in relation to the deviation of the individual letters from normal upright orientation but increased more reliably for normal than for reflected letters. (3) Although there were exceptions, RT for words composed of normal letters generally increased in relation to the deviation of the individual letters from normal upright, regardless of the orientation of the line of letters.     

Reaction time to letter name or letter case

Subjects were shown two letters from the set BDGbdg. In one condition, subjects were required to decide whether or not the letters had the same name. In the other condition, subjects decided whether or not the two letters were presented in the same case. Reaction times were always faster when the two letters on a given trial were physically identical. However, there was no difference in the speed of a name match or a case match when the two letters were not physically identical. Since subjects could have based a case match on the presence or absence of a single feature — a protruding vertical line — it was concluded that subjects are not able to selectively attend to a single visual feature in order to identify a letter. Rather, a subject analyzes several features in parallel in order to arrive at a simultaneous decision about a letter's name or case.     

Memory for disguised same- and cross-race faces: The eyes have it

According to research on the cross-race effect, through experience, observers learn which diagnostic facial features are important for recognizing same-race compared to cross-race faces. These diagnostic facial features differ across racial groups; whereas the upper facial region is more diagnostic for White faces, the lower facial region is more diagnostic for Black faces. We tested how disguises at encoding (sunglasses [upper region] or bandana [lower region]) affect White and Black observers’ recognition memory for White and Black faces. We found that disguises override the diagnosticity of race-specific regions and have similar effects on recognition of same- and cross-race faces. Relative to no disguise, recognition memory was impaired more by disguising upper (sunglasses) than lower (bandana) facial regions. This supports the hypothesis that facial features trump race-specific diagnostic regions, and the eye region provides relatively more diagnostic information than lower facial features.     

Resistance of voice onset time variability to intoxication.

Voice onset times of /d/ and /t/ were measured for 16 adult subjects (age range 21 to 26 years) under conditions of sobriety and intoxication. Subjects consumed beer to reach intoxication levels between 0.075 and 0.100% as measured using a portable breathalyzer test. Analysis indicated consistent variabilities over time for each subject and resistance of VOT variability to alcohol influence.     

Learning to label letters by sounds or names: a comparison of England and the United States

Learning about letters is an important foundation for literacy development. Should children be taught to label letters by conventional names, such as /bi/ for b, or by sounds, such as /b/? We queried parents and teachers, finding that those in the United States stress letter names with young children, whereas those in England begin with sounds. Looking at 5- to 7-year-olds in the two countries, we found that U.S. children were better at providing the names of letters than were English children. English children outperformed U.S. children on letter-sound tasks, and differences between children in the two countries declined with age. We further found that children use the first-learned set of labels to inform the learning of the second set. As a result, English and U.S. children made different types of errors in letter-name and letter-sound tasks. The children's invented spellings also differed in ways reflecting the labels they used for letters.     

Processing sets of letters for order: Evidence from reaction time experiments

In two experiments, subjects were required to impose different levels of organization on randomly ordered letters. In a between-subject design, the subject was to identify the letter in the set coming first in the alphabet or to reorganize the set into an alphabetic sequence. In a within-subject design, presentation of the letters was followed by an instruction to carry out the identification or reorganization task or to recite the letters in left-to-right order. Reaction time varied systematically with level of required organization, size of the presented set, and position and spacing of the letter set in the alphabet. The results are discussed in terms of two simple models.     

Negative priming without reaction time: Effects on identification of masked letters

Responses to an object are often slower and/or less accurate if that object is related to a recently ignored object. Thisnegative priming effect has previously been examined only in reaction time tasks. In the present experiment, target letters and flanking distractor letters were displayed for 33, 100, or 300 msec, followed by a pattern mask. Subjects attempted to identify the target letters, with no demand for speed. Identification accuracy was reduced for targets that matched distractors presented on the immediately preceding trial. However, there was no bias against reporting preceding distractors on catch trials with no presented target. Implications for theories of negative priming are discussed.     

How to Tell If a Particular Memory Is True or False

ABSTRACT— How can you tell if a particular memory belonging to you or someone else is true or false? Cognitive scientists use a variety of techniques to measure groups of memories, whereas police, lawyers, and other researchers use procedures to determine whether an individual can be believed or not. We discuss evidence from behavioral and neuroimaging studies and research on lying that have attempted to distinguish true from false memories.     

Reaction time to tones in tonal backgrounds and a comparison of reaction time to signal onset and offset

In order to learn more about the processing of auditory information, simple reaction time (RT) measurements were made when subjects were asked to respond to tones presented against a tonal background. In the first experiment, a counterintuitive result was obtained: with two widely separated frequencies, 1,900 and 4,000 Hz, the presence of the background facilitated RT. In a second experiment, using two frequencies which were closer together (3,500 and 4,000 Hz), slowing of RT in the presence of the background was observed, as would be expected from the literature on auditory masking. A third experiment suggested that the information carried by signal offset is not an important factor in the facilitation observed with widely separated tones. In this experiment an unexpected result was found: subjects receiving offsets in their right ears responded significantly more slowly than did subjects receiving offsets in their left ears.     

Training to use voice onset time as a cue to talker identification induces a left-ear/right-hemisphere processing advantage

We examined the effect of perceptual training on a well-established hemispheric asymmetry in speech processing. Eighteen listeners were trained to use a within-category difference in voice onset time (VOT) to cue talker identity. Successful learners (n=8) showed faster response times for stimuli presented only to the left ear than for those presented only to the right. The development of a left-ear/right-hemisphere advantage for processing a prototypically phonetic cue supports a model of speech perception in which lateralization is driven by functional demands (talker identification vs. phonetic categorization) rather than by acoustic stimulus properties alone.     

Reaction time methodology and the aphasic patient: a reply to Hagoort (1988)

P. Hagoort (1988, Brain and Language, 36, 335-348) suggests that the results of an experiment conducted with aphasic patients reported by W. Milberg, S. E. Blumstein, and B. Dworetzky (1987, Brain and Language, 31, 138-150) are "difficult to interpret in terms of a selective access model for normal processing because of a confound caused by the use of repeated lexical decision targets." We argue that the use of repeated lexical decision targets and other methodological compromises are necessary for using the lexical decision reaction time paradigm with aphasic patients. Furthermore, the minor differences between our data and those presented by Hagoort do not undermine our claims concerning semantic processing in different subgroups of aphasics, nor our comparisons of these patients to normal subjects.     

Memory and time of day

Subjects performed a memory task on two occasions, one in the morning and the other in the afternoon. The task comprised two components, one involved immediate recall of sequences of nine digits, the other involved the repeated item technique devised by Hebb (1961), in which one nine-digit sequence is surreptitiously repeated, each repetition being separated by two non-repeated sequences. Performance on the immediate memory task was better in the morning than the afternoon. The repeated item was recalled more accurately than non-repeated items, but this effect was not influenced by time of day. An explanation in terms of the relationship between arousal and memory reported by Kleinsmith and Kaplan (1963) is suggested.