Recognition memory of retrieved sequences of words

The subject was asked to retrieve words belonging to a given category, natural or artificially created. After n words were retrieved, a recognition task was given either immediately after or after a delay (4 hours, 7, 14, or 28 days). Several probe words were presented and the subject had to decide whether each had been retrieved or not. The length of retrieval sequence, n, was systematically varied. Results of three experiments showed that, in general, mean decision time was almost independent of n. Namely, recognition regarding self-generated lists of words seems to be due to a different information processing than recognition regarding lists of words presented by the experimenter to memorize. Implications of the findings for retrieval from long term memory were discussed.     

Distortions in memory for maps

Evidence is presented for systematic errors in memory for real and artificial maps, local environments, and visual forms. These errors are attributed to two heuristics that are derived from principles of perceptual organization. Maps of countries or localities are conceived of as figures in backgrounds. Remembering the absolute location of figures is difficult, and is facilitated by remembering locations relative to other figures and/or relative to the natural directions of the figure. In alignment, figures are lined up relative to one another, a phenomenon related to perceptual grouping by proximity. In rotation, the natural axes induced by a figure converge with frame axes (north-south, east-west, or horizontal, vertical), a phenomenon related to perceptual organization by common fate. Heuristic-induced errors occur in a variety of tasks, and even when subjects are explicitly forewarned. These heuristics may be invoked in forming representations as well as in inference, and function analogously to syntax in locating smaller elements in larger units.     

Skin temperature biofeedback in children and adults

Skin temperature biofeedback performance was studied in 38 children, ages 6 to 10, and 38 of their parents, across two sessions of audio biofeedback segments in which the participants alternately attempted hand-warming and hand-cooling. Skin temperature from each hand was monitored throughout, but only one hand at a time was in the feedback loop. The major finding was that children were superior to adults in controlling skin temperature in the presence of biofeedback (p < .001). Adults showed no skin temperature control. For children, temperature changes were greater for the hand in the feedback loop as compared to the contralateral hand (p < .001). Children were equally successful in increasing and decreasing skin temperature. The results are consistent with earlier studies and suggest that children have considerable potential for neuropsychological self-regulation.     

Asymmetries for the categorization of kanji nouns, adjectives, and verbs presented to the left and right

Kanji is one form of written Japanese in which the symbolic/analytic characteristics of language are dissociated from systematic phonetic characteristics; as such, it makes possible a more careful test of which aspect of language is responsible for the frequently observed superior left-hemisphere performance. In this study, subjects were asked to categorize tachistoscopically presented kanji as nouns, adjectives, or verbs. The previously reported (Hatta 1977, Neuropsychologia, 15, 685–688) left-visual-field advantage for kanji was found only in the case of nouns. Adjectives and verbs were processed more rapidly and correctly in the right visual field.     

Hierarchical structure in perceptual representation

A theoretical framework for perceptual representation is presented which proposes that information is coded in hierarchical networks of nonverbal propositions. The hierarchical structure of the representations implies selective organization: Some subsets of a figure will be encoded as integral, structural units of that figure, while others will not. A context-sensitive metric for the “goodness” of a part within a figure is developed, corresponding to the probability that the subset will be encoded as a structural unit. Converging evidence supporting this position is presented from four different tasks using simple, straight-line figures. The tasks studied are (a) dividing figures into “natural” parts, (b) rating the “goodness” of parts within figures, (c) timed verification of parts within figures, and (d) timed mental synthesis of spatially separated parts into unitary figures. The results are discussed in terms of the proposed theory of representation, the processes that operate on those representations, and the general implications of the data for perceptual theories.     

Stochastic transitivity and the unidimensional control of choice

A concurrent-chains paradigm was used to test three models of preference for schedules of reinforcement. Each model assumes choice to be a monotonic function of values on a single dimension (“simple scalability”). For choices involving variable-interval and fixed-interval schedules, this dimension is assumed to be an harmonic average of the interreinforcement intervals; for choices involving fixedinterval and fixed-ratio schedules, the dimension is the time to reinforcement irrespective of response rate; for choices involving different combinations of rate and duration of reinforcement, the dimension is the rate of “reinforcement-time”, or the product of the two parameters. Each model implies a strong form of transitivity (“functional equivalence”), which held for half the subjects (that half exclusively sensitive to the reinforcement variable specified by the model). An alternative unidimensional model which implies a weaker form of transitivity (“weak binary utility model”) was consistent with the preferences of all subjects. This model states that a single factor controls the direction of preferences but not necessarily the exact choice probability, as simple scalability assumes.     

Interruption of phonological coding in conduction aphasia

A case study of conduction aphasia, investigating single word repetition, phonological coding, and short-term memory, is reported. Evidence from intact adults suggests that repetition can occur through either a lexical route or a direct auditory-articulatory link. For this conduction aphasic, E.A., the direct link was impaired, although the lexical route could be used to produce accurate single word repetition. Several experiments demonstrated a significant impairment in the generation and maintenance of an abstract phonological code. The consequences of a disruption of phonological coding on speech perception and on verbal short-term memory are discussed.     

Agrammatism in a case-inflected language: Comprehension of agent-object relations

Yugoslav agrammatic aphasics and normal control subjects were tested for comprehension of agent-object relations in a series of simple Serbo-Croatian sentences consisting of two nouns (N) and a transitive action verb (V). The availability of nominative and accusative case inflections and a semantic contrast was systematically varied across sentences. Sentences were also varied with respect to the two sequences NVN and VNN. An analysis of subjects' agent-object assignments yielded the following results: While Broca's aphasics did show some sensitivity to case inflections, their ability to process such cues was greatly impaired relative to normal subjects, for whom morphological cues were almost completely deterministic. To a lesser degree, Broca's aphasics were impaired in their ability to employ a strategy of “choose the first noun as agent” when case inflections and semantic contrasts were not available. While Broca's aphasics showed no impairment in their ability to exploit semantic contrasts for agent-object assignment, there was no absolute compensatory increase in the degree to which they relied on semantic cues. Differences in word sequence had no effect on agent-object assignment in Broca's aphasics. Finally, Broca's aphasics frequently responded unsystematically when cues to agent-object relations occurred in isolation or in competition with one another, but when there was a convergence of cues their performance approached that of normal subjects. This result was interpreted in terms of an accessing hypothesis.