Sources of sentence constraint on lexical ambiguity resolution

Results from a series of naming experiments demonstrated that major lexical categories of simple sentences can provide sources of constraint on the interpretation of ambiguous words (homonyms). Manipulation of verb (Experiment 1) or subject noun (Experiment 2) specificity produced contexts that were empirically rated as being strongly biased or ambiguous. Priming was demonstrated for target words related to both senses of a homonym following ambiguous sentences, but only contextually appropriate target words were primed following strongly biased dominant or subordinate sentences. Experiment 3 showed an increase in the magnitude of priming when multiple constraints on activation converged. Experiments 4 and 5 eliminated combinatorial intralexical priming as an alternative explanation. Instead, it was demonstrated that each constraint was influential only insofar as it contributed to the overall semantic representation of the sentence. When the multiple sources of constraint were retained but the sentence-level representation was changed (Experiment 4) or eliminated (Experiment 5), the results of Experiments 1, 2, and 3 and were not replicated. Experiment 6 examined the issue of homonym exposure duration by using an 80-msec stimulus onset asynchrony. The results replicated the previous experiments. The overall evidence indicates that a sentence context can be made strongly and immediately constraining by the inclusion of specific fillers for salient lexical categories. The results are discussed within a constraint-based, context-sensitive model of lexical ambiguity resolution.     

Factor-defined abilities in patients with unilateral brain lesions.

Administered a battery of 4 tests adapted from the structure of intellect model of differential abilities to 72 adults with right and left cerebral lesions and normals. Findings show that both brain-damaged groups exhibited slower response times than normals and that there was a relation between locus of the lesion and performance. However, results do not sufficiently demonstrate the advantage of factor-defined ability tests over tests of global intelligence and question the validity of these factor-defined tests in that they do not distinguish behaviors that are factorially distinct in normal populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of stimulus emotionality and sentence generation on memory for words in adults with unilateral brain damage.

Does sentence generation and/or stimulus emotionality enhance verbal memory in patients with neurological impairment? This question was addressed by testing 40 patients with unilateral stroke (20 with left-brain and 20 with right-brain damage) and 20 healthy control participants for recall and recognition of 48 target words. During encoding, emotional and nonemotional words were either presented in sentences (read condition) or used to form sentences (generate condition). Both word emotionality and generative processing improved memory performance in all groups. The authors suggest that a similar influence (i.e., cognitive activation) underlies both of these memory-enhancing effects, although the putative origins of the 2 effects are quite different. Neuropsychological underpinnings and clinical implications of these phenomena are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disorders of visuo-spatial attention in patients with unilateral brain damage

Visuo-spatial inattention (VSI) was examined in 390 patients with ischemic insult to the right or left cerebral hemispheres. VSI was revealed in 44 out of 80 patients with right parietal lobe damage and in 30 out of 70 subjects with right occipital lobe injury. Only one patient out of 100 with left hemisphere injury has shown the signs of VSI. These data confirm the suggestion that the right parietal and occipital regions are crucial for visuo-spatial attention, whereas the left hemisphere is of minor import.     

Ideation in patients with unilateral or bilateral midline brain lesions.

Hypothesized that persons with left vs. right unilateral brain lesions differ in complicated ideational processes in 50 Ss with well localized lesions. On a multiple-discriminant analysis, 7 selected Rorschach variables differentiated the left, right, and midline-bilateral groups at the .0001 level. Interpretation of Discriminant I, ideation, yields a modus operandi of left-hemisphere Ss which is limited and constricted; of right-hemisphere Ss which is expansive and uncritically innovative. Discriminant II, uniqueness of pathology, indicates that left and right groups differ significantly and are significantly divergent, with the midline group undistinguished on this dimension. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prosodic influences on the resolution of temporary ambiguity during on-line sentence processing

We present three experiments designed to investigate the role of prosody during sentence processing. The first investigated the question of whether an utterance's prosodic contour influences its comprehension on-line. We spliced the beginning and end portions of direct object and embedded clause sentences and observed the consequent effects on comprehension using a dual-task procedure to measure processing load. Our second experiment sought to determine whether the constituent structure of these sentences could be reliably predicted using prosodic information. We found that the duration and F0 contour associated with the main-clause verb and the following NP reliably distinguished between the direct object and embedded clause constructions. In the final experiment, we manipulated the duration of the main-clause verb and found that subjects used this information to guide their initial parse during on-line sentence comprehension. The need for a model of sentence processing that addresses the use of prosodic information is discussed.     

Intellectual stability in children with unilateral brain lesions

Developmental differences in behavior and self-perception were examined in a group of 44 preschool and school-age children referred for evaluation of sexual abuse and 41 comparison children with no history of sexual abuse, matched on age and gender, and from a similar socioeconomic background. Children suspected of having been sexually abused were rated by their parents as having more internalizing and externalizing problems than comparison children. When children rated their self-competence and social acceptance, there were no group differences between children based on their abuse status; however, there was significant within-group variation among the children suspected of having been sexually abused. Preschool children had elevated scores of perceived competence and social acceptance, and school-age children had depressed scores. There were no age differences among the children in the comparison group. The results suggest that among children suspected of abuse, not only does their self-perception vary by their developmental level, but preschool children may respond with elevated perceptions of themselves. Focusing on individual differences in children's response to suspicions of sexual abuse enables us to identify risk and protective factors that contribute to the psychological outcomes of child sexual abuse.     

Long-term changes of ionotropic glutamate and GABA receptors after unilateral permanent focal cerebral ischemia in the mouse brain

The mechanisms by which chemotherapeutic agents kill neoplastic cells have been controversial. Recently, however, accumulated evidence has suggested that these agents exert their cytotoxic effects mainly by inducing apoptosis in tumor cells. This article reviews the findings of recent studies on the mechanisms by which chemotherapeutic agents induce apoptosis and their implications in cancer chemotherapy.     

The interpretation of opinion statements as a function of message ambiguity and recipient attitude.

The purpose of this study was to replicate an earlier one by the author (Manis, 1960) to determine the validity that the interpretation of ambiguous statements permits of greater interpretation in the light of personal opinions than nonambiguous statements. College Ss having 3 opinions towards fraternity (positive, negative, neutral) were presented with statements regarding fraternities. Half the Ss were presented with nonambiguous statements, half with the same statements with every other word omitted (ambiguous). In general, the results supported the hypothesis. From Psyc Abstracts 36:04:4GD76M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consistency of intermanual discrepancies in normal and unilateral brain lesion patients.

Examined the distribution of intermanual discrepancies on 3 motor tests (grooved pegboard, finger tapping, and dynamometer) among 331 normal controls, 63 patients with right brain damage (RBD), and 40 patients with left brain damage (LBD). All Ss were right-handed. Considerable variability in the intermanual discrepancies was observed in all 3 samples. About 25% of the normal sample obtained scores more than 1 standard deviation from the control mean on a single measure. RBD tended to accentuate the pattern of intermanual discrepancies observed with controls, while LBD moved the discrepancy in the opposite direction. Results confirm the difficulties related to clinical judgments of deficits in preferred-hand motor performance and suggest the need to examine patterns of performance across several motor tests. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Narrative discourse in children with early focal brain injury

Children with early brain damage, unlike adult stroke victims, often go on to develop nearly normal language. However, the route and extent of their linguistic development are still unclear, as is the relationship between lesion site and patterns of delay and recovery. Here we address these questions by examining narratives from children with early brain damage. Thirty children (ages 3:7-10:10) with pre- or perinatal unilateral focal brain damage and their matched controls participated in a storytelling task. Analyses focused on linguistic proficiency and narrative competence. Overall, children with brain damage scored significantly lower than their age-matched controls on both linguistic (morphological and syntactic) indices and those targeting broader narrative qualities. Rather than indicating that children with brain damage fully catch up, these data suggest that deficits in linguistic abilities reassert themselves as children face new linguistic challenges. Interestingly, after age 5, site of lesion does not appear to be a significant factor and the delays we have witnessed do not map onto the lesion profiles observed in adults with analogous brain injuries.     

Semantic ambiguity resolution in positive schizotypy: A right hemisphere interpretation.

Positive schizotypal traits have been associated with right hemisphere activation. Previous research has indicated that the left and right hemispheres differ in their processing of semantic ambiguity; specifically, given sufficient time, the left hemisphere primes dominant meanings and inhibits subordinate meanings, and the right hemisphere primes both dominant and subordinate meanings. The authors examined whether individuals who differed in positive schizotypy demonstrated different patterns of priming on a semantic ambiguity task, reflective of differences in hemispheric activation. Individuals low in schizotypy demonstrated the expected pattern of priming the dominant meaning while inhibiting the subordinate meaning. Individuals high in schizotypy demonstrated similar priming of the dominant meaning but no inhibition of the subordinate meaning. The role of this failure of inhibition in the generation of schizotypal thought is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The decoding of emotional concepts in patients with focal cerebral lesions

The effects of focal brain lesions on the decoding of emotional concepts in facial expressions were investigated. Facial emotions are hierarchically organized patterns comprising (1) structural surface features, (2) discrete (primary) emotional categories and (3) secondary dimensions, such as valence and arousal. Categorical decoding was measured using (1) selection of category labels and selection of the named emotion category; (2) matching one facial expression with two choice expressions. Dimensional decoding was assessed by matching one face with two different expressions with regard to valence or arousal. 70 patients with well documented cerebral lesions and 15 matched hospital controls participated in the study. 27 had left brain damage (LBD; 10 frontal, 10 temporal, 7 parietal); 37 had right brain damage (RBD; 15 frontal, 11 temporal, 11 parietal). Six additional patients had lesions involving both frontal lobes. Right temporal and parietal lesioned patients were markedly impaired in the decoding of primary emotions. The same patients also showed a reduced arousal decoding. In contrast to several patients with frontal and left hemisphere lesions, emotional conceptualization and face discrimination was not independent in these groups. No group differences were observed in valence decoding. However, right frontal lesions appeared to interfere with the discrimination of negative valence. Moreover, a distraction by structural features was noted in RBD when facial identities were varied across stimulus and response pictures in matching tasks with differing conceptual load. Our results suggest that focal brain lesions differentially affect the comprehension of emotional meaning in faces depending on the level of conceptual load and interference of structural surface features.     

Anxiety and the interpretation of ambiguity: A text comprehension study.

A. T. Beck's influential cognitive account of anxiety has led to the prediction that individuals vulnerable to anxiety should favor threatening interpretations of ambiguity (e.g., Beck and D. A. Clark, 1988; Beck et al, 1986). The current study introduces a novel adaptation of the RSVP technique, previously used in text comprehension research, to evaluate this hypothesis. Results suggest that a group of 24 high trait anxious students did indeed selectively impose threatening interpretations on unconstrained ambiguous sentences. In contrast, a matched group of 24 low trait anxious students appeared to selectively impose non-threatening interpretations on such ambiguous sentences. These findings are fully consistent with the predicted anxiety-linked interpretative bias. Specific testable hypotheses are developed concerning the types of interpretative idiosyncrasies that plausibly may contribute to pathological anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular size of IgG in patients with focal glomerulosclerosis

Nineteen patients with focal glomerulosclerosis and with anomalously high clearance of IgG into the urine have been investigated by G.200 column chromatography. The findings are compared with normal sera, with 14 patients with minimal change disease and with 12 patients with proliferative glomerulonephritis. No significant reduction in the molecular size of IgG was found as compared with normal sera and the other diseases in 18 of the patients. In patients with minimal change disease and focal glomerulosclerosis an increased proportion of the IgG eluted in the void volume     

The effects of focal brain damage on pragmatic expression.

Five Broca's and 5 Wernicke's aphasic males (ages 37–73 yrs) described 9 triplets of pictures in each of which 1 element varied and the others remained constant. Dependent variables included probability of lexicalization vs ellipsis, pronominalization, definite and indefinite article use, pragmatic word order variations in dative structure, and use of connectors. Both groups showed pragmatic sensitivity in at least 2 of these areas suggesting that the topic-focus function per se is not impaired in these aphasias. Broca's aphasics were pragmatically sensitive in lexicalization and dative structure; Wernicke's aphasics were pragmatically sensitive in lexicalization and article use. The contribution of specific grammatical and lexical impairments to the expression of a common pragmatic motive is discussed. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task demands and sentence comprehension in patients with dementia of the Alzheimer's type

Patients with dementia of the Alzheimer's type (DAT) and matched normal controls were given three tests of syntactic comprehension in which nonlinguistic visual and memory task demands were varied. In all tasks, subjects were presented spoken semantically reversible sentences with a variety of syntactic structures and required to match the sentence to a picture. In the first experiment, subjects matched the spoken sentence to one of two pictures that appeared either before or immediately following the presentation of the sentence. The target picture depicted the spoken sentence correctly and the foil depicted the reversed thematic roles to those in the sentence (i.e., it was a syntactic foil). The second experiment employed a sentence video-verification task in which subjects were required to determine if the spoken sentence matched a videotaped depiction of the action in the sentence or a syntactic foil. In the third experiment, in different conditions, subjects were required to determine whether the spoken sentence matched a single picture or to choose the picture that matched the sentence from an array of two or three pictures. In this experiment, both lexical and syntactic foils were used. In all tasks, DAT patients were affected by the number of propositions in the presented sentence, but not by the syntactic complexity of the sentence. Control subjects also were unaffected by the syntactic complexity of the sentence; the number-of-proposition effect was present in some experiments in the control population. Comparison of performance across the one-, two-, and three-picture versions of the task showed that the magnitude of the effect of number of propositions increased as the number of pictures in the array increased. In addition, analysis of the data from each of the tasks separately showed that the effect of number of propositions only occurred when subjects were attempting to match the target to a syntactic foil (one-picture version) or to choose between the target and a syntactic foil (two- and three-picture versions). The results support the view that patients with DAT do not have disturbances affecting syntactic processing. In addition, they suggest that the effect of number of propositions arises at a stage of analysis that is partially separate from assigning sentence meaning, such as in holding a representation of the sentence in memory until the pictures can be analyzed and encoded and/or in comparing the results of the picture analysis with a stored representation of the sentence meaning.