An on-line assessment of causal reasoning during comprehension

Fletcher and Bloom (1988) have argued that as readers read narratives, clause by clause, they repeatedly focus their attention on the last preceding clause that contains antecedents but no consequences in the text. This strategy allows them to discover a causal path linking the text's opening to its final outcome while minimizing the number of times long-term memory must be searched for missing antecedents or consequences. In order to test this hypothesis, we examined the reading times of 25 subjects for each clause of eight simple narrative texts. The results show that: (1) causal links between clauses that co-occur in short-term memory (as predicted by the strategy) increase the time required to read the second clause; (2) potential causal links between clauses that never co-occur in short-term memory (again as predicted by the strategy) have no effect on reading time; and (3) reinstatement searches are initiated at the end of sentences that are causally unrelated to the contents of short-term memory or that contain clauses that satisfy goals no longer in short-term memory. These results support the claim that subjects engage in a form of causal reasoning when they read simple narrative texts.     

Predicate-argument structure as a link between linguistic and nonlinguistic representations

We present a study wherein a severe Broca's aphasic patient was trained to learn symbols representing both pure transitive and dative predicates--predicates differing in argument structure--in a visually based artificial language (c-ViC). We found a decrease in performance when two symbols, rather than one, were used to depict these "verbs." However, this decrease in performance was more pronounced for symbols representing pure transitive verbs--those that allow only one argument structure--than for symbols representing dative verbs--those that allow two different argument structures. Also, dative "verbs" yielded better performance when they were inserted in more complex, three-argument "sentences" than when they were inserted in two-argument "sentences." The opposite pattern was found for pure transitives. These results are discussed in terms of our claim that argument structure serves as a point of connection between linguistic information and non-linguistic visual information and in terms of the possibility that argument structure entries are shaped by the form in which visual information is parsed.     

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.The work reported in this paper was supported in part by NTH grant DC00494.     

On the structure of motor recognition memory

Two experiments determined the influence of the range and number of auditory sensory consequences, associated with a rapid timing task, on the development of motor recognition. Experiment 1 observed no beneficial effect upon subsequent movement-transfer performance from experience with the criterion-movement-time sound compared to experience with either a narrow or a wide range of sounds that bracketed the criterion sound (not including the criterion); 60 sound trials prior to transfer did not produce better transfer than did six sounds. The second experiment examined transfer outside of the range of previous listening experience by having subjects transfer to one of two possible criterion movement times after having received either constant, or one of two types of variable, listening experience. Transfer performance was influenced by the amount of variability in listening experience. These results were seen as support for a schematic representation for motor recognition memory (Schmidt, 1975)     

Help Seeking: Effects of Visibility of Task Performance and Seeking Help

This study manipulated independently whether help seeking and task performance were public or private, since in public settings persons may lose esteem by seeking help or by demonstrating unsuccessful performance. Subjects were given false feedback that they were doing poorly on a task involving judging levels of neuroticism in others, and were given all opportunity to seek help by consulting a set of guidelines. The main result was an interaction with help seeking most likely when task performance was public and help seeking was private.     

Linguistic negation in autistic and normal children

Young, severely maladaptive autistic children with some speech competence were compared to normally developing 3-year-old children of lower and middle class and 5-year-olds of lower class on negation tasks. All subjects were shown 12 sets of cards depicting negative contrasts designed to elicit semantic categories of nonexistence, denial, and rejection and were tested for production, imitation, and comprehension. Syntactic and semantic analysis revealed that autistic children were superior imitators and poor producers but showed skills in comprehension comparable to a 4-year-old's level of functioning. While retarded in some functions, the experimental group produced syntactic structures that were more rigid, suggesting the significantly greater use of imitation as a major strategy in linguistic coding.This work was done at the NYU-Bellevue Medical Center with partial support by NIMH Grant No. MH 07331 to R. K.     

Letter familiarity does not aid feature extraction

Summary Familiarity effects in visual letter processing were examined by means of a mutilation detection task. The uppercase E was used as the non-mutilated letter. One or two horizontal bars of the E were delected, to produce an upright or inverted F or L. These four mutilations of the E were assigned to the same response. In Experiment 1, brief exposure of the stimuli was followed by a backward mask. Experiment 2 was identical to Experiment 1, except that the display duration of the stimulus was increased and the backward mask was omitted. In Experiment 3, the overall luminance of the stimuli (luminance per point times length of the constituent line segments) was held constant. In Experiment 4, the upright and inverted non-E letter occurred in different blocks to encourage a normal (upright) letter processing strategy in the upright letter blocks. Accuracy (Experiment 1) and mean correct response times (all experiments) were not different for the upright and inverted F or for the upright and inverted L. These findings and converging results from other studies indicate that the higher familiarity of the upright letters did not aid feature extraction.