During sentence comprehension, older adults are less likely than younger adults to predict features of likely upcoming words. A pair of experiments assessed whether such differences would extend to tasks with reduced working memory demands and time pressures. In Experiment 1, event-related brain potentials were measured as younger and older adults read short phrases cuing antonyms or category exemplars, followed three seconds later by targets that were either congruent or incongruent and, for congruent category exemplars, of higher or lower typicality. When processing the less expected low typicality targets, younger – but not older – adults elicited a prefrontal positivity (500–900 ms) that has been linked to processing consequences of having predictions disconfirmed. Thus, age-related changes in prediction during comprehension generalize across task circumstances. Analyses of individual differences revealed that older adults with higher category fluency were more likely to show the young-like pattern. Experiment 2 showed that these age-related differences were not due to simple slowing of language production mechanisms, as older adults generated overt responses to the cues as quickly as – and more accurately than – younger adults. However, older adults who were relatively faster to produce category exemplars in Experiment 2 were more likely to have shown predictive processing patterns in Experiment 1. Taken together, the results link prediction during language comprehension to language production mechanisms and suggest that although older adults can produce speeded language output on demand, they are less likely to automatically recruit these mechanisms during comprehension unless top-down circuitry is particularly strong.

E v e r y d a y e x p e r i e n c e s u g g e s t s t h a t h i g h l y e m o t i o n a l e v e n t s a r e o f t e n t h e m o r facts t h a t c a n be a s s e s s e d verbally). We i n v e s t i g a t e d t h e d e c l a r a t i v e m e m o r y o f t w o r a r e p a t i e n t s w i t h selective b i l a t e r a l a m y g d a l a d a m a g e . B o t h subjects s h o w e d i m p a i r m e n t s i n long-tetan d e c l a r a t i v e m e m o r y f o r e m o t i o n a l l y a r o u s i n g m a t e r i a l . T h e d a t a s u p p o r t t h e h y p o t h e s i s t h a t t h eh u m a n a m y g d a l a n o r m a l l y e n h a n c e s a c q u i s i t i o n o f d e c l a r a t i v e k n o w l e d g e r e g a r d i n g e m o t i o n a l l y a r o u s i n g stimuli.

Although the basal ganglia have been shown to be critical for the expression of emotion in prosody and facial expressions, it is unclear whether they are also critical for recognition of emotions. Selective pathology of parts of the basal ganglia is a hallmark of individuals with Parkinson's disease, and such patients have been examined in several studies of emotion. We examined 18 patients with Parkinson's disease (11 men, 7 women) and 13 age-, education-, gender ratio-, and IQ-matched normal controls on their ability to recognize emotions signaled by facial expressions. Parkinson's patients performed entirely normally on a quantitative task of recognizing emotional facial expressions. The findings do not support the notion that the sectors of basal ganglia that are dysfunctional in Parkinson's disease are essential for recognizing emotion in facial expressions.

Protein tyrosine phosphorylation is a major signal transduction pathway involved in cellular metabolism, growth, and differentiation. Recent data indicate that tyrosine phosphorylation also plays a role in neuronal plasticity. We are using conditioned taste aversion, a fast and robust associative learning paradigm subserved among other brain areas by the insular cortex, to investigate molecular correlates of learning and memory in the rat cortex. In conditioned taste aversion, rats learn to associate a novel taste (e.g., saccharin) with delayed poisoning (e.g., by LiCl injection). Here we report that after conditioned taste aversion training, there is a rapid and marked increase in tyrosine phosphorylation of a set of proteins in the insular cortex but not in other brain areas. A major protein so modulated, of 180 kDa, is abundant in a membrane fraction and remains modulated for more than an hour after training. Exposure of the rats to the novel taste alone results in only a small modulation of the aforementioned proteins whereas administration of the malaise-inducing agent per se has no effect. To the best of our knowledge, this is the first demonstration of modulation of protein tyrosine phosphorylation in the brain after a behavioral experience.Protein tyrosine phosphorylation is a major signal transduction pathway involved in cellular metabolism, growth, and differentiation (1). Recently, it became apparent that tyrosine phosphorylation also plays a key function in neuronal activity and plasticity. Activation of receptor tyrosine kinases by growth and neurotrophic factors is required for development, remodeling, and possibly also maintenance of neural tissue. Prominent among this class of molecules are members of the trk family that respond to a variety of neurotrophic factors including nerve growth factor, brain-derived neurotrophic factor, and neurotrophin 3 (2-4). Protein tyrosine kinases appear also to be involved in mediating the effect of neural cell adhesion molecules on neuronal membrane-associated cytoskeleton (5) and in modulating neurotransmitter receptors (6, 7). In addition, activation of nonreceptor protein tyrosine kinases may play a role in encoding intracellular neuronal responses to specific ligands, probably in the context of cross-talk between signal transduction cascades (8-10).The function of protein tyrosine phosphorylation in longterm structural modification of neurons is especially pertinent to the study of behavioral plasticity, since consolidation of long-term memory is postulated to involve modulation of gene expression, culminating in altered synaptic morphology and physiology (11,12). Indeed, inhibitors of protein tyrosine kinase were reported to block long-term potentiation in hippocampal CAl region in the guinea pig (9) and knockout of the fyn gene, encoding a nonreceptor tyrosine kinase, was found to impair long-term potentiation, spatial learning, and hippocampal morphology in transgenic mice (13).Analysis of the modulation of protein tyrosine phosphorylation in brai...

This study was designed to assess the development of spatial attentional orienting during the school-age years. To that end, we used a cost-benefit attentional cueing task with short (100 ms) and long (800 ms) cue-to-target intervals to examine attentional processing independent of motor skills and perceptual processing in 200 7-17-year-olds and 40 adults. We found that orienting attention, disengaging attention and visual processing in an unattended location, were all progressively more accurate and faster with increasing age. Our data thus suggest that the efficiency of attentional orienting improves in an age-related manner throughout the school-age years.