Visual persistence as measured by reaction time

Latency of reaction to onset of a visual display was subtracted from latency of reaction to offset. Persistence was defined as difference between the two latency values. Persistence was inversely related to stimulus duration and was comparable for monoptic presentation and for presentation of the first half of the stimulus duration to one eye and the second half to the other. A power function described the relation between persistence and stimulus duration. The possible effects of central intermittency on this type of reaction time measure are discussed.     

Comparative studies of comprehension: An investigation of Chinese,Norwegian, and English

Memory & Cognition - The present paper compared the processing of complex embedded sentences in Chinese, Norwegian, and English to determine if the underlying mental operations are similar in...     

Aphasia, dyslexia and the phonological coding of written words

A possible account of the reading difficulty of certain aphasic-dyslexic patients includes the notion that they are impaired in translating the written word into a phonological code via grapheme-phoneme conversion rules. This notion was tested in two experiments, both utilizing orthographically regular non-words (like dake) as stimuli. The first experiment provides an analysis of two patients' (largely successful) attempts to repeat non-words, and their (almost totally unsuccessful) attempts to read them. Second, in a lexical decision task (is this written letter-string a word or not?), the finding that normals are slowed by non-words homophonic with real words (like flore) was replicated using a modified technique. This effect, attributable to phonological coding, was not shown by the patients. At the same time, their ability to discriminate between words and non-words was essentially intact. Consideration was given to mechanisms which might underlie such patients' correct and erroneous readings of words and non-words.     

The relation between comprehending and remembering some complex sentences

This research concerns the distinction between processes in sentence comprehension and those in sentence memory. Comprehension was monitored by timing subjects while they decided whether a sentence was true or false of their knowledge of the world. The memory process was tapped by examining subjects' incidental memory for the sentences they had previously verified. The verification latencies indicated that at the time of comprehension, sentences likeIt is true that a fire isn't cold were often recoded into an equivalent affirmative form, namely,It is true that a fire is hot. However, negative sentences likeIt isn't true that a fire is cold were not recoded during comprehension. Recoding in recall occurred only for those types of sentences that were recoded at the time of comprehension.     

Eye fixations and cognitive processes

This paper presents a theoretical account of the sequence and duration of eye fixation during a number of simple cognitive tasks, such as mental rotation, sentence verification, and quantitative comparison. In each case, the eye fixation behavior is linked to a processing model for the task by assuming that the eye fixates the referent of the symbol being operated on.     

Agraphia selective for written spelling : An experimental case study

A 56-year-old right-handed man suffered left posterior parieto-temporal ischemia leading to mild aphasia, Gerstmann syndrome, and a novel variant of agraphia. This variant compromised his spelling by writing and manual sorting of letters more than his oral spelling. The dissociation was experimentally documented. It principally involved the intrusion of extraneous letters, independent of input modality. It did not generalized to numbers or an arbitrary code. Postoperatively the disability disappeared. It was concluded that the programs which translate letter choice into visual terms for purposes of written (as distinct from oral) spelling either originate or are transmitted in a distinct cerebral location. This location, which may be the left posterior parasagittal parietal area, can be selectively impaired by a focal lesion.     

Semantic cueing in recognition and recall

This study is concerned with the recognition and recall of semantically ambiguous words (homographs) presented in a semantic context. Changing the semantic context lowered test scores relative to test conditions both without context and with the same semantic context. This effect was found to obtain in both recognition and recall. The results are discussed in terms of the role of retrieval in recognition and recall.     

Methylphenidate increases selectivity of visual scanning in children referred for hyperactivity

Visual scanning patterns were investigated in 32 children referred for symptoms of hyperactivity in a doubleblind crossover comparison of methylphenidate and placebo treatments. Total errors, response latency, and visual fixations were recorded as the child scanned computer-generated visual matching-to-sample problems. Results indicated that the number of fixations on the standard stimulus in the matching task was significantly larger in the methylphenidate state. Drug treatment also resulted in a significant increase in the number of systematic comparisons between the standard and the variants in the task. However, the increased selectivity of attention to the standard stimulus was not accompanied by a reduction of total errors. It was suggested that the stimulant drug may increase attentional selectivity even when such a shift fails to produce improvement in task performance.This research is based in part upon a master's thesis completed by the first author in the department of Psychology, University of Guelph. The authors are indebted to Dean H. Owen for providing the random polygons used in the experiment. The research was supported by grants from the Ontario Mental Health Foundation and the Medical Research Council of Canada to James M. Swanson.     

Cerebral lateralization, preferred cognitive mode, and reading ability in normal children

In a sample of 105 children (aged 6 to 12), a stylistic preference for a verbal approach to problem-solving correlated positively with reading ability (independently of age) and degree of right-ear advantage in the report of dichotic stop consonant-vowel syllables (but not with verbal intelligence or hand preference). Verbal strategic preference may: (1) foster the acquisition of reading skill, and (2) bias attention toward input from the right by generating differential left-hemisphere activation.     

Correlates of the Temporal Consistency of rsonality Patterns in Childhood

ABSTRACT The temporal consistency of children's personality patterns as measured by the California Child Q-set was investigated in a sample of 151 German children between ages 4 and 6 years, and in a sample of 87 Dutch children between ages 10 and 12 years. Children's personality patterns showed a high interindividual variance of consistency. Correlational analyses revealed that children's ego resiliency predicted the longitudinal consistency of their Q-sort patterns irrespective of variations in age, culture, and type of judge. Itemwise extreme group comparisons of very consistent and very inconsistent children with a middle group showed that consistent children were characterized by culturally desirable traits, and inconsistent children by undesirable traits. The items typical for consistent children changed with age in agreement with the change in major developmental tasks. Discussion focuses on the processes that mediate the positive relations between the temporal consistency of personality, ego resiliency, and the age-appropriateness of personality.