The effects of affective picture stimuli on blink modulation in adults and children

Two experiments examined blink modulation during viewing of pleasant, neutral and unpleasant picture stimuli in non-selected adults (N = 21) and children (N = 60) and children with anxiety disorders (N = 12). Blink reflexes were elicited by a white noise probe of 105 dB at lead stimulus intervals of 60, 240, 3500, and 5000 ms and during intertrial intervals. Blink modulation during unpleasant pictures was significantly different from blink modulation during neutral pictures at the 60 ms lead interval in children whereas adults showed no significant differences. Picture content had no differential effect on the extent of blink modulation for adults or children at the 240 ms lead interval. At the long lead intervals, blink modulation during unpleasant and pleasant pictures was significantly larger than during neutral pictures in adults. Picture valence did not differentially affect the extent of blink modulation at long lead intervals in children. Comparing the extent of blink modulation in anxious and non-selected children, blinks were significantly modulated during unpleasant pictures at the 60 ms lead interval for both groups. However, the extent of blink modulation was larger overall at this very short lead interval in anxious children. Children did not differ at other lead intervals. (C) 2004 Elsevier B.V. All rights reserved.

Top-down influences on lexical selection during spoken word production: A 4T fMRI investigation of refractory effects in picture naming

Spoken word production is assumed to involve stages of processing in which activation spreads through layers of units comprising lexical-conceptual knowledge and their corresponding phonological word forms. Using high-field (4T) functional magnetic resonance imagine (fMRI), we assessed whether the relationship between these stages is strictly serial or involves cascaded-interactive processing, and whether central (decision/control) processing mechanisms are involved in lexical selection. Participants performed the competitor priming paradigm in which distractor words, named from a definition and semantically related to a subsequently presented target picture, slow picture-naming latency compared to that with unrelated words. The paradigm intersperses two trials between the definition and the picture to be named, temporally separating activation in the word perception and production networks. Priming semantic competitors of target picture names significantly increased activation in the left posterior temporal cortex, and to a lesser extent the left middle temporal cortex, consistent with the predictions of cascaded-interactive models of lexical access. In addition, extensive activation was detected in the anterior cingulate and pars orbitalis of the inferior frontal gyrus. The findings indicate that lexical selection during competitor priming is biased by top-down mechanisms to reverse associations between primed distractor words and target pictures to select words that meet the current goal of speech.

A comparison of picture description abilities in individuals with vascular subcortical lesions and Huntington's Disease

The lexical-semantic and syntactic abilities of a group of individuals with chronic nonthalamic subcortical (NS) lesions following stroke (n = 6) were investigated using the Western Aphasia Battery (WAB) picture description task [Kertesz, A. (1982). The Western aphasia battery. New York: Grune and Stratton] and compared with those of a group of subjects with Huntington's Disease (HD) (n = 6) and a nonneurologically impaired control group (n = 6) matched for age, sex, and educational level. The performance of the NS and HD subjects did not differ significantly from the well controls on measures of lexical-semantic abilities. NS and HD subjects provided as much information about the target picture as control subjects, but produced fewer action information units. Analysis of syntactic abilities revealed that the HD subjects produced significantly more grammatical errors than both the NS and control subjects and that the NS group performed in a similar manner to control subjects. These findings are considered in terms of current theories of subcortical language function Learning outcomes: As a result of this activity, the reader will obtain information about the debate surrounding the role of subcortical language mechanisms and be provided with new information on the comparative picture description abilities of individuals with known vascular and degenerative subcortical pathologies and healthy control participants. (c) 2005 Elsevier Inc. All rights reserved.

Get the picture? The effects of iconicity on toddlers' reenactment from picture books

What do toddlers learn from everyday picture-book reading interactions? To date, there has been scant research exploring this question. In this study, the authors adapted a standard imitation procedure to examine 18- to 30-month-olds' ability to learn how to reenact a novel action sequence from a picture book. The results provide evidence that toddlers can imitate specific target actions on novel real-world objects on the basis of a picture-book interaction. Children's imitative performance after the reading interaction varied both as a function of age and the level of iconicity of the pictures in the book. These findings are discussed in terms of children's emerging symbolic capacity and the flexibility of the cognitive representation.