Diminished gaze fixation is one of the core features of autism and has been proposed to be associated with abnormalities in the neural circuitry of affect. We tested this hypothesis in two separate studies using eye tracking while measuring functional brain activity during facial discrimination tasks in individuals with autism and in typically developing individuals. Activation in the fusiform gyrus and amygdala was strongly and positively correlated with the time spent fixating the eyes in the autistic group in both studies, suggesting that diminished gaze fixation may account for the fusiform hypoactivation to faces commonly reported in autism. In addition, variation in eye fixation within autistic individuals was strongly and positively associated with amygdala activation across both studies, suggesting a heightened emotional response associated with gaze fixation in autism.Autism is a pervasive developmental disorder associated with a unique profile of social and emotional behavior. The core symptomatology of autism highlights these deficits and includes diminished gaze fixation, lack of social or emotional reciprocity, and failure to develop age-appropriate peer relationships 1,2 . Recent studies have focused on attention to faces and face processing abilities in children with autism, because of the crucial importance of faces as a medium of social communication among humans [3][4][5][6][7][8] . These studies demonstrate that inattention to faces is an early developmental sign of autism that is apparent as early as 1 year of age 9,10 . In addition, many children with autism are delayed in early, face-related social milestones, such as looking to another person's face to reference that person's

SummaryAmid ongoing public speculation about the reasons for sex differences in careers in science and mathematics, we present a consensus statement that is based on the best available scientific evidence. Sex differences in science and math achievement and ability are smaller for the midrange of the abilities distribution than they are for those with the highest levels of achievement and ability. Males are more variable on most measures of quantitative and visuospatial ability, which necessarily results in more males at both high-and low-ability extremes; the reasons why males are often more variable remain elusive. Successful careers in math and science require many types of cognitive abilities. Females tend to excel in verbal abilities, with large differences between females and males found when assessments include writing samples. High-level achievement in science and math requires the ability to communicate effectively and comprehend abstract ideas, so the female advantage in writing should be helpful in all academic domains. Males outperform females on most measures of visuospatial abilities, which have been implicated as contributing to sex differences on standardized exams in mathematics and science. An evolutionary account of sex differences in mathematics and science supports the conclusion that, although sex differences in math and science performance have not directly evolved, they could be indirectly related to differences in interests and specific brain and cognitive systems. We review the brain basis for sex differences in science and mathematics, describe consistent effects, and identify numerous possible correlates. Experience alters brain structures and functioning, so causal statements about brain differences and success in math and science are circular. A wide range of sociocultural forces contribute to sex differences in mathematics and science achievement and abilityincluding the effects of family, neighborhood, peer, and school influences; training and experience; and cultural practices. We conclude that early experience, biological factors, educational policy, and cultural context affect the number of women and men who pursue advanced study in science and math and that these effects add and interact in complex ways. There

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For adults, skill at comprehending written language correlates highly with skill at comprehending spoken language. Does this general comprehension skill extend beyond language-based modalities? And if it does, what cognitive processes and mechanisms differentiate individuals who are more versus less proficient in general comprehension skill? In our first experiment, we found that skill in comprehending written and auditory stories correlates highly with skill in comprehending nonverbal, picture stories. This finding supports the hypothesis that general comprehension skill extends beyond language. We also found support for the hypotheses that poorer access to recently comprehended information marks less proficient general comprehension skill (Experiment 2) because less skilled comprehenders develop too many mental substructures during comprehension (Experiment 3), perhaps because they inefficiently suppress irrelevant information (Experiment 4). Thus, the cognitive processes and mechanisms involved in capturing and representing the structure of comprehensible information provide one source of individual differences in general comprehension skill.Individuals differ in many ways, including comprehension skill. Laboratory research documents these differences. However, the lion's share of this research investigates comprehension of only one modality-namely, the printed word-and individuals who differ at only one stage of skill development-namely, beginning readers. Therefore, it is not too surprising that the processes suggested to underlie differences in comprehension skill are often specific to reading (see excellent reviews by Carr, 1981;Perfetti, 1985).

We investigated whether the cognitive mechanism of suppression underlies differences in adult comprehension skill. Less skilled comprehenders reject less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meaning of spade), the incorrect forms of homophones (e.g., patients vs. patience), the highly typical but absent members of scenes (e.g., a tractor in a farm scene), and words superimposed on pictures or pictures surrounding words. However, less skilled comprehenders are not less cognizant of what is contextually appropriate; in fact, they benefit from a biasing context just as much (and perhaps more) as more skilled comprehenders do. Thus, less skilled comprehenders do not have difficulty enhancing contextually appropriate information. Instead, we suggest that less skilled comprehenders suffer from a less efficient suppression mechanism, which we conclude is an important component of general comprehension skill. Many of the processes and mechanisms that are involved in language comprehension are general cognitive processes and mechanisms. We have described a few of those processes and mechanisms using a very simple framework as a guide; we call it the structure building framework (Gernsbacher, 1990). According to the structure building framework, comprehension entails building coherent mental representations or "structures." Several component processes are involved. First, comprehenders lay foundations for their mental structures. Next, comprehenders develop their mental structures. They map incoming information onto their developing structures when that incoming information coheres or relates to the previous information. However, if the incoming information is less related, comprehenders use another process: They shift and develop a new substructure. The building blocks of mental structures are memory nodes. Memory nodes represent previously stored memory traces. Their representation might be either in the traditional sense of an individual node representing an individual trace or in the distributed sense of a group of nodes representing an individual trace. Memory nodes are activated by incoming stimuli. Once activated, the information they represent can be used by cognitive processes.

Numerous word recognition studies conducted over the past 2 decades are examined. These studies manipulated lexical familiarity by presenting words of high versus low printed frequency and most reported an interaction between printed frequency and one of several second variables, namely, orthographic regularity, semantic concreteness, or polysemy. However, the direction of these interactions was inconsistent from study to study. Six new experiments clarify these discordant results. The first two demonstrate that words of the same low printed frequency are not always equally familiar to subjects. Instead, subjects' ratings of "experiential familiarity" suggest that many of the low-printed-frequency words used in prior studies varied along this dimension. Four lexical decision experiments reexamine the prior findings by orthogonally manipulating lexical familiarity, as assessed by experiential familiarity ratings, with bigram frequency, semantic concreteness, and number of meanings. The results suggest that of these variables, only experiential familiarity reliably affects word recognition latencies. This in turn suggests that previous inconsistent findings are due to confounding experiential familiarity with a second variable.Twenty years of research on word recognition has repeatedly shown that the familiarity of a word greatly affects both the speed and the accuracy of its recognition. More familiar words can be recognized faster and more accurately than less familiar words. Traditionally, lexical familiarity has been operationalized as the frequency with which a word occurs in printed English text. Experimenters typically construct their stimulus sets by consulting one of three widely used indices: Thorndike and Lorge's (1944) Teacher's Word Book of 30,000 Words, Kučera and Francis's (1967) Computational Analysis of Present-Day American English, or Carroll, Davies, and Richman's (1971) American Heritage Word Frequency Book. Within these corpora, one would find that the English word amount occurs relatively frequently (with an average frequency score of 110 occurrences per million words of text), whereas the Copyright 1984 by the American Psychological Association, Inc.Requests for reprints should be sent to Morton Ann Gernsbacher, who is now at the Department of Psychology, University of Oregon, Eugene, Oregon 97403-1227. 1 Experiential familiarity ratings were collected on all (126) of the low-printed-frequency homographic and non-homographic words presented in the Rubenstein et al. (1970) and Rubenstein et al. (1971b) and Forster and Bednall (1976) studies, with the same procedures described in the Method section of Experiment 2. The results of the analyses performed on these ratings mirrored the results found in the original lexical decision task (for the Forster & Bednall, 1976, study) and the results presented by Clark (1973) The Effect of Printed FrequencyHowes and Solomon (1951) reported that printed frequency could account for approximately half of the variance found in tachistoscopic thre...

Two mechanisms, suppression and enhancement, are proposed to improve referential access. Enhancement improves the accessibility of previously mentioned concepts by increasing or boosting their activation; suppression improves concepts' accessibility by decreasing or dampening the activation of other concepts. Presumably, these mechanisms are triggered by the informational content of anaphors. Six experiments investigated this proposal by manipulating whether an anaphoric reference was made with a very explicit, repeated name anaphor or a less explicit pronoun. Subjects read sentences that introduced two participants in their first clauses, for example, "Ann predicted that Pam would lose the track race," and the sentences referred to one of the two participants in their second clauses, "but Pam/she came in first very easily." While subjects read each sentence, the activation level of the two participants was measured by a probe verification task. The first two experiments demonstrated that explicit, repeated name anaphors immediately trigger the enhancement of their own antecedents and immediately trigger the suppression of other (nonantecedent) participants. The third experiment demonstrated that less explicit, pronoun anaphors also trigger the suppression of other nonantecedents, but they do so less quickly--even when, as in the fourth experiment, the semantic information to identify their antecedents occurs prior to the pronouns (e.g., "Ann predicted that Pam would lose the track race. But after winning the race, she..."). The fifth experiment demonstrated that more explicit pronouns--pronouns that match the gender of only one participant-trigger suppression more powerfully. A final experiment demonstrated that it is not only rementioned participants who improve their referential access by triggering the suppression of other participants; newly introduced participants do so too (e.g., "Ann predicted that Pam would lose the track race, but Kim..."). Thus, both suppression and enhancement improve referential access, and the contribution of these two mechanisms is a function of explicitness. The role of these two mechanisms in mediating other referential access phenomena is also discussed.

Autistics are presumed to be characterized by cognitive impairment, and their cognitive strengths (e.g., in Block Design performance) are frequently interpreted as low-level by-products of highlevel deficits, not as direct manifestations of intelligence. Recent attempts to identify the neuroanatomical and neurofunctional signature of autism have been positioned on this universal, but untested, assumption. We therefore assessed a broad sample of 38 autistic children on the preeminent test of fluid intelligence, Raven's Progressive Matrices. Their scores were, on average, 30 percentile points, and in some cases more than 70 percentile points, higher than their scores on the Wechsler scales of intelligence. Typically developing control children showed no such discrepancy, and a similar contrast was observed when a sample of autistic adults was compared with a sample of nonautistic adults. We conclude that intelligence has been underestimated in autistics.