Asperger Syndrome: Tests of Right Hemisphere Functioning and Interhemispheric Communication

The primary aim of this investigation was to assess to what extent Rourke's (1989, 1995) nonverbal learning disabilities syndrome (NLD) model resembles the pattern of assets and deficits seen in people with Asperger syndrome (AS). NLD can be characterized by a cluster of deficits primarily affecting nonverbal aspects of functioning, in the presence of proficiency in single word reading and a superior verbal memory. The neurological underpinnings of this syndrome may be dysfunction of white matter affecting right hemisphere functioning and interhemispheric communication. To explore this hypothesis, eight participants with AS (ages 10 to 41 years) were assessed in the following areas: the pragmatics of language and communication, verbal and visual memory, visual-spatial abilities, and bimanual motor skills. Results confirmed the close similarity in the neuropsychologic profiles of NLD and AS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44619/1/10803_2004_Article_374850.pd

Re-evaluating age-of-acquisition effects: Are they simply cumulative-frequency effects?

Abstract The time it takes to read or produce a word is in¯uenced by the word's age of acquisition (AoA) and its frequency (e.g. Quarterly Journal of Experimental Psychology 12 (1973) 85). Lewis (Cognition 71 (1999) B23) suggested that a parsimonious explanation would be that it is the total number of times a word has been encountered that predicts reaction times. Such a cumulative-frequency hypothesis, however, has always been rejected because the statistical effects of AoA and frequency are additive. Here, it is demonstrated mathematically that the cumulative-frequency hypothesis actually predicts such results when applied to curvilinear learning. Further, the data from four in¯uential studies (two of which claim support for independent effects of AoA and frequency) are re-analyzed to reveal that, in fact, they are consistent with a cumulative-frequency hypothesis. The conclusion drawn is that there is no evidence with which to refute the most parsimonious of explanations, i.e. cumulative frequency can account for both frequency and AoA effects.

Exploring a neural-network account of age-of-acquisition effects using repetition priming of faces

The question of whether age-of-acquisition(AoA), frequency, and repetition priming effects occur at a common stage or at different stages of processing is addressed. Two single-stage accounts (i.e., cumulative frequency and a neural-network simulation) are considered in regard to their predictions concerning the interactions between AoA and frequencywith aging and priming effects.A repetition-priming face-classification task was conducted on both older and younger participants to test these predictions. Consistent with the predictions of the neural-network simulation, AoA had an effect on reaction times that could not be explained by cumulative frequency alone. Also, as predicted by the simulation, the size of the priming effect was determined by the cumulative frequency of the item. It is discussed how this evidence is supportive of the notion that AoA, frequency, and priming all have effects at a common and single stage during face processing

Satiation in name and face recognition

Massive repetition of a word can lead to a loss of meaning (i.e., semantic satiation). Satiation is a general property of neurons and so it would be expected that semantic satiation would be found for stimuli other than words. Three experiments examined the occurrence of satiation for the repetition of names, the visualization of faces, and the repetition of faces. Reaction times to a decision based on a repeated name or face were longer following 30 repetitions than following 3 repetitions, indicating that satiation had occurred. Mere visualization over the same time interval, however, did not elicit satiation effects

Repeated repetition priming in face recognition

Prior exposure to an item can facilitate subsequent recognition of that item. This effect, known as repetition priming, has been found for the recognition of many stimuli including faces (Bruce & Young, 1986). Three experiments are reported, which investigated whether repetition priming is limited to the first repetition or whether subsequent repetitions continually act to increase the speed of face processing. Experiment 1 demonstrated that repetition can reduce categorization time for faces after the first exposure, and this effect is independent of practice effects. Experiment 2 demonstrated that the relationship between reaction time and number of repetitions fits a negative power function. Experiment 3 investigated how delay affects this power function. Delay was found to decrease the negative gradient of the power curve. The effects of priming and delay are discussed in terms of the predictions made by Burton's (1994) interactive activation and competition with learning (IACL) model of face recognition and accounts of automaticity

The effects of massive repetition on speeded recognition of faces

Models of face processing suggest that recognizing a person should prime recognition of a consecutive, but different, image of the same person. This prediction is tested in four experiments using large blocks of different views of the same person. The experiments demonstrate that reaction times decreased according to a negative power function as the number of repetitions increased. After sufficient repetitions, however, the reaction times lengthened. The presentation of a different familiar person between blocks of repetitions caused the reaction time for the target to increase to a level equivalent to that with no repetitions. Experiments 2 and 3 investigated the effect of different intervening stimuli (unfamiliar faces and objects). Such stimuli reduced the effect of mass repetition—but the reduction using a familiar face was greater than that with either unfamiliar faces or objects. Experiment 4 confirmed that the effects of massive repetition occur for a face familiarity task as well as for face identification tasks. The results are discussed in termsof the predictions of Burton's (1994) IACL model

Satiation in name and face recognition

Massive repetition of a word can lead to a loss of meaning (i.e., semantic satiation). Satiation is a general property of neurons and so it would be expected that semantic satiation would be found for stimuli other than words. Three experiments examined the occurrence of satiation for the repetition of names, the visualization of faces, and the repetition of faces. Reaction times to a decision based on a repeated name or face were longer following 30 repetitions than following 3 repetitions, indicating that satiation had occurred. Mere visualization over the same time interval, however, did not elicit satiation effects

Mistaken first impressions: A response [Letter]

In this journal, Cummins et al reported an experiment that examined clinicians' predictions of causes of death from subjects' pre-morbid photographs. They found that clinicians performed at chance. The validity of two of their other conclusions are challenged. First, that clinicians routinely form impressions of how a person will die from their appearance. Second, that certain health professionals use common judgements to form these impressions. These claims are found to be based upon non-falsifiable hypothesis and inappropriate statistics; hence, an experiment employing pictures of feet (or any arbitrary personal detail) would have led the authors to the same conclusions