Cognitive task effects on hemispheric blood flow in humans: Evidence for individual differences in hemispheric activation

Evidence from two indirect measures of hemispheric activity, EEG α and conjugate lateral eye movements, has pointed to the existence of individual differences in hemispheric activation. Results from a more direct indicator of hemispheric activity, regional cerebral blood flow as measured by the ¹³³Xe inhalation method, show that such individual differences can be detected in the distribution of blood in the two hemispheres and that the amount of increase in blood flow in the right relative to the left hemisphere is correlated with performance on a spatial task. These results corroborate and extend the findings from the EEG and eye movement studies and suggest that the dimension of individual differences in hemispheric activation may exert significant influence on cognitive performance and on problem-solving strategies.     

Ending social encouters

Certain classes of verbal behavior—content summary statements (S_c); affective summary statements (S_a); continuity (C), justification (J), and well-wishing (W) statements; and statements of positive affect (P)—were hypothesized to be constituents of interpersonal endings. These statements are shown to increase during the terminal phase of a social encounter as a function of whether the conversation is between friends or strangers and whether it is structured or unstructured. A hypothesis concerning the sequence in which these five classes of statements will occur during the ending of an interaction, namely, [S_c] → [J] → [_Sa^P] → [C] → [W], is tested and confirmed.     

A constraint on comparisons: Equally detailed alternatives

Children's errors in collective comparison tasks are atributed to the comparison of the wrong classes. It is specifically hypothesized that alternative classes are erroneously formed subject to the constrain that the same kinds of properties are criterial for each alternative. This hypothesis, called the equally detailed alternatives hypothesis, is tested in three experiments with hierarchically organized stimuli and requests to compare a superordinate class and a nonincluded subclass, for example, dogs and yellow cats. In all three experiments 4-year-old children's comparisons were found to be in accord with the hypothesis. In the first experiment both perceptual and linguistic factors determine which classes are compared. In the second experiment, as predicted, erroneous subclass comparisons were more common when all subclasses were distinguished by the same kinds of properties. In the third experiment, the children were asked to partition the stimulus objects into the classes to be compared. The vast majority of partitions were erroneous and in accord with the hypothesis. Potential benefits of the constrain are considered.     

Preschoolers' counting: principles before skill

Three- to 5-year-old children participated in one of 4 counting experiments. On the assumption that performance demands can mask the young child's implicit knowledge of the counting principles, 3 separate experiments assessed a child's ability to detect errors in a puppet's application of the one-one, stable-order and cardinal count principles. In a fourth experiment children counted in different conditions designed to vary performance demands. Since children in the errror-detection experiments did not have to do the counting, we predicted excellent performance even on set sizes beyond the range a young child counts accurately. That they did well on these experiments supports the view that errors in counting—at least for set sizes up to 20—reflect performance demands and not the absence of implicit knowledge of the counting principles. In the final experiment, where children did the counting themselves, set size did affect their success. So did some variations in conditions, the most difficult of which was the one where children had to count 3-dimensional objects which were under a plexiglass cover. We expected that this condition would interfere with the child's tendency to point and touch objects in order to keep separate items which have been counted from those which have not been counted.     

Incentive shift in the rat following training to resist punishment

An incentive shift paradigm was used to test for the similarity of fear and frustration. In Experiment 1, rats trained to resist electric shock punishment showed neither a negative contrast effect nor any performance decrement when reward was shifted from 10 to one pellet. Experiment 2 replicated the basic findings of Experiment 1, but also showed that punishment training did not influence the magnitude of performance shift for animals receiving increases in reward magnitude. Finally, Experiment 3 additionally found that rats sensitized to punishment showed an increase in negative contrast effect. These results support the hypothesized functional similarity between conditioned fear and conditioned frustration with learned persistence or sensitivity to one generalizing to the other as suggested by Amsel's (1972) theory of persistence.     

Conditioned enhancement of human's liking for flavor by pairing with sweetness

This paper reports a procedure, like classical conditioning, that produces enhancement of liking for flavors by humans. The procedure is “pairing” of a relatively neutral flavor with sugar (a hedonically positive taste). Specifically, subjects drank 24 small samples of flavor A sweetened and 24 small samples of flavor B unsweetened. They were then tested for their liking for flavors A and B, both sweetened and unsweetened. In three different studies, varying in a number of aspects of stimulus presentations and context, a relative enhancement in liking for flavor A appeared both on the day of exposure and 1 week later. An absolute enhancement in liking of flavor B (a “mere exposure” effect) also occurred in two of the three experiments.     

Feedback during exposure to inescapable shocks and subsequent shock-escape performance

In two experiments, we assessed the ability of a feedback stimulus during helplessness training to reduce the performance deficits common to inescapable shock. In each experiment, four groups of rats were exposed to either escapable shock (E), inescapable shock with a feedback stimulus following shock termination (Y-FS), inescapable shock with no feedback stimulus (Y-NFS), or no shock (N). The feedback stimulus eliminated the interference effects of inescapable shock when tested with an FR-3 lever press escape task (Experiment 1) or on an FR-1 task with a 3-s delay between the response and shock termination (Experiment 2). These results suggest that stress-induced biochemical changes may mediate the interference effects seen in inescapably shocked rats.     

Sensitivity to grammatical structure in so-called agrammatic aphasics

Comprehension failures in agrammatic aphasics, as well as their difficulties in sentence construction, have been attributed to an underlying deficit involving the retrieval of syntactic structure. In this study we show that four agrammatic patients display a remarkable sensitivity to structural information, as indicated by their performance on a grammaticality judgment task. These results indicate significant sparing of syntactic knowledge in agrammatism, and suggest that the sentence comprehension disturbances in these patients do not reflect loss of the capacity to recover syntactic structure. In particular, accounts of the comprehension deficit in agrammatism that implicate a failure to exploit information carried by the closed class (function word) vocabulary are called seriously into question. Alternative explanations of the comprehension problem in agrammatism are explored.     

Developmental trends in free classification: Evidence for a new conceptualization of perceptual development

Two studies are reported to explore the hypothesis that young children perceive integrally some stimuli that older children perceive separably. In both, kinder-garteners, second graders, and fifth graders (approximately 5, 8, and 11 years old) are required to classify sets of stimuli that vary in size and brightness. Triads are used in Experiment 1 and tetrads are used in Experiment 2. Also, in Experiment 2, second classifications, judgments of which classification is “best,” and verbal justifications for classifications are obtained. The general finding is that the kinder-garten data systematically implicate integrality of size and brightness while the fifth-grade data systematically implicate separability of size and brightness. The second-grade data are more ambiguous. Issues related to refining the developmental hypothesis and to extending its supportive data base are considered in a final discussion.     

Looking where you listen: visual cues and auditory attention

In the non-laboratory environment, we are generally able to see the source of the sounds to which we are attending. In a preliminary examination of how and to what degree we might use this visual information, subjects shadowed one of two female voices when able to see the persons speaking (Experiment I) or when able to see, and thus precisely localize, the auditory loudspeakers (Experiment II). Selective performance was improved by being able to see the lip movements of the people whose voices were heard, and by being able to localize visually the sources of the voices.     

An analysis of writing in a case of deep dyslexia

In tests of her ability to produce written and spoken language, this deep dyslexic patient produced semantic, visual, and derivational errors, including functor substitutions, and exhibited part-of-speech and abstractness effects in oral reading, oral and written naming, and writing to dictation, but not in repetition of single words and copying from memory. This patient therefore provides confirmation of the hypothesis presented in Nolan and Caramazza (1982) that the defining symptoms of deep dyslexia will be observed in responses to any task which requires lexical mediation. The patient's written responses in all tasks but direct copying were characterized by spelling errors which included transpositions, omissions, substitutions, and additions of letters. A model of writing is proposed which explains these errors in terms of a disruption of a phoneme-grapheme conversion process which normally functions to prevent decay of information from a Graphemic Buffer.     

Commentary on social class differences in sociodramatic play in historical context: A reply to McLoyd

Historical origins of the research on the cultural correlates of imaginative behavior by the Israeli psychologists Feitelson, Smilansky, and Eifermann are presented. It is argued that despite McLoyd's searching analysis of the deficiencies in studies which attempt to relate level of imaginative play to social class, those earlier cross-cultural studies, together with some 50 years of prior research on social class and play in general, provide a context which gives support to those studies despite their particular methodological deficiencies.     

What the classical aphasia categories can't do for us, and why

A good deal of activity in contemporary aphasia research goes under the label "neurolinguistics." What characterizes this enterprise is, among other things, its goal of identifying neurally realized computational subsystems that support language processing. In this essay the thesis is put forward that this goal will not be served by the continued exploitation of the classical (Wernicke-Lichtheim) taxonomic categories. These categories, it is argued, cannot by virtue of their "polytypic" structure support the relevant neurolinguistic generalizations.     

Evaluating the stage learning hypothesis

A procedure for evaluating the Genevan stage learning hypothesis is illustrated by analyzing Inhelder, Sinclair, and Bovet's (Learning and the development of cognition. Cambridge: Harvard University Press 1974) guided learning experiments. The method is a chi-square-based model fitting strategy which enables comparisons to be made among different models. The method eschews critical measurement problems and is easily implemented. There appears little evidence for the Genevan position, although failure to report critical data and sample size considerations makes definitive evaluation of the Genevan position difficult. Suggestions for future research are proposed.     

Sources of error in the psychoeducational diagnosis of children

A detailed exploration of the role of diagnostic practices is presented, with special attention given to such practices in school psychology. Basic principles related to diagnostic typology and concepts of reliability and validity are reviewed in the context of recent diagnostic decision-making research. Finally, the intrusion and eventual reduction of particular errors of consistency and inconsistency and psychodiagnosis are examined with a view toward improvements in future training and practice.     

Cortical involvement in the semantic processing of coarticulated speech cues

Auditory evoked responses (AER) were recorded from scalp locations over the left and right temporal regions in response to CVC words and nonsense syllables. Various components of the AER were found to vary systematically with changes in stimulus meaning. One such component reflected subcortical involvement in semantic processing. Other components reflected changes in voicing and place of articulation as well as hemisphere differences.