The development of memory structure as reflected by semantic-priming effects

This study was designed to investigate the development of knowledge about categorical and associative relationships as reflected by the presence or absence of semantic priming effects. Kindergarteners and second-graders were shown pairs of pictures, one picture at a time, and asked to name each picture as rapidly and accurately as possible. Picture pairs were of four types which reflected the factorial combination of associative relatedness (high and low) with categorial relatedness (high and low). An analysis of naming times revealed a significant main effect of associative relatedness, i.e., second pictures or “target” pictures in high-associative pairs were named faster than those in low-associative pairs. This reduction in naming latency, or priming effect, was independent of developmental level. However, the effects of category relatedness varied with developmental level, i.e., target pictures in high-categorical pairs were named significantly faster than those in low pairs by second-graders, but not by kindergarteners. These findings are discussed in terms of previous estimates of children's semantic competence.     

Re-evaluation of monte carlo studies in nonmetric multidimensional scaling

Critical examination is made of the recent controversy over the value of Monte Carlo techniques in nonmetric multidimensional scaling procedures. The case is presented that the major relevance of Monte Carlo studies is not for the local minima problem but for the meaningfulness of the obtained solutions.     

Word age-of-acquisition and lexical decision making

This paper reports two experiments concerning the effects of word age-of-acquisition and other word attributes on speed of lexical decision. Analyses of group average data indicated that word length, frequency and familiarity were the major determinants of decision speed. Previous reports of age-of-acquisition effects on lexical decision are attributed to failures to control for word familiarity.     

Monaural recall and the right-ear advantage

Lists of eight nonsense syllables were monaurally presented to right-handed men and women for free recall, half to each ear on each trial. Results showed a right-ear advantage (REA) in the recall of recency items, but not primacy items and for males only. Among males only that subgroup without familial sinistrality demonstrated the REA. Results offer support for the following: (A) the language mechanisms involved in short-term “echoic” memory are particularly well-lateralized; (B) mechanisms underlying monaural REAs may be similar to those responsible for the asymmetries found in other paradigms; (C) processing demands and strategies inherent to the monaural technique may account in part for its limited reliability in yielding REA and for the present absence of REA among females.     

Attributed influence: The importance of observing change

The presence of a target's unexpected change in behavior following an influence attempt was hypothesized to be a critical variable for attributing influence to a particular agent. Observers read a brief story in which an agent's intervention was followed by the target's compliance, noncompliance, or countercompliance to the request. The results indicated that influence was attributed to the agent in the conditions demonstrating change, i.e., compliance and countercompliance, regardless of the direction of that change. Additional findings indicated that influence attributed to an agent decreased if the target delayed final compliance with the intervention.     

Temporal discrimination and a free-operant psychophysical procedure.

Pigeons were presented a series of keylight time periods (separated by blackouts) during which two response keys were lit, one by blue light and the other either by orange or green. Blue-key responses changed the color on the other key. Orange-key responses sometimes produced food during the first half of a time period; green-key responses sometimes produced food during the second half. In three experiments, the probability of a green-key response increased as a function of elapsed time. Experiment 1 compared performance when the duration of the keylight periods was varied across a wide range. Discrimination of performance was similar across the range of durations. Experiment 2 varied both relative reinforcement rate and the local reinforcement rate for orange-key and green-key responses. These manipulations produced changes in response bias but not discrimination sensitivity. Experiment 3 varied the local temporal placement of reinforcers within time periods and demonstrated that choice behavior was affected by differential reinforcement at different points during the time periods. The results were consistent with previous research on duration discrimination that used psychophysical trials procedures.     

Long-delay taste aversion learning in an unpoisoned rat: Exposure to a poisoned rat as the unconditioned stimulus

M. J. Lavin, B. Freise, and S. Coombes (Behavioral and Neural Biology, 1980, 28, 15–33) have shown that if two rats consume a flavored solution and one is poisoned, the unpoisoned partner will also exhibit a flavor aversion during a later preference test. Experiments 1 and 2 showed that a sufficient condition for obtaining this aversion is that the poisoned partner be present with the unpoisoned rat after it has consumed the flavored solution. It is not necessary that the poisoned partner be present when the flavored solution is consumed or indeed have had any exposure to the flavored solution. Experiment 3 showed that the unpoisoned partner can exhibit a flavor aversion when there is a temporal gap of as long as 6 hr between consumption of the flavored solution and exposure to the poisoned rat.     

Language lateralization in English-French bilinguals

Forty English-French bilinguals divided into equal numbers of nonfluent and fluent subjects took part in a dichotic listening test involving both intralingual and interlingual conditions. No difference in lateralization was found between primary and secondary language in either condition. In the intralingual condition, however, fluent bilinguals showed a significantly lower right ear advantage than did their nonfluent counterparts. In the interlingual condition, French-dominant subjects were found to be more ambilateral than English-dominant subjects, while both groups tended to respond preferentially to French words. These results suggest that growing bilingual proficiency does increase left ear/right hemisphere participation, but in intralingual situations only. Moreover, when both languages are contrasted, French appears to be more salient than English.     

Confirmation of linear system theory prediction: Rate of change of Herrnstein's kappa as a function of response-force requirement

Four human subjects worked on all combinations of five variable-interval schedules and five reinforcer magnitudes (¢/reinforcer) in each of two phases of the experiment. In one phase the force requirement on the operandum was low (1 or 11 N) and in the other it was high (25 or 146 N). Estimates of Herrnstein's κ were obtained at each reinforcer magnitude. The results were: (1) response rate was more sensitive to changes in reinforcement rate at the high than at the low force requirement, (2) κ increased from the beginning to the end of the magnitude range for all subjects at both force requirements, (3) the reciprocal of κ was a linear function of the reciprocal of reinforcer magnitude for seven of the eight data sets, and (4) the rate of change of κ was greater at the high than at the low force requirement by an order of magnitude or more. The second and third findings confirm predictions made by linear system theory, and replicate the results of an earlier experiment (McDowell & Wood, 1984). The fourth finding confirms a further prediction of the theory and supports the theory's interpretation of conflicting data on the constancy of Herrnstein's κ.     

Pure timing in temporal differentiation

Temporal control appears to depend on whether the critical durations are those of stimuli or those of responses. Stimulus timing (temporal discrimination) supports Weber's law, whereas response timing (temporal differentiation) indicates decreasing relative sensitivity with longer time intervals. The two types of procedure also yield different conclusions in scaling experiments designed to study the functional midpoint of two or more durations (temporal bisection procedures). In addition, the fractional-exponent power relation between emitted and required duration usually found with animals in differentiation experiments conflicts with deductions from formal analyses. The experiment reported here derived from considering differentiation arrangements as schedules of reinforcement. When analyzed from this perspective, the procedures are tandem schedules involving a required pause followed by a response, and it is the pause alone that involves temporal control. A choice procedure separated timing from responding, and enabled observations of pause timing in isolation. Pure temporal control in differentiation consisted of linear overestimation of the standard duration, and Weber's law described sensitivity. These results indicate that the two problems, the fractional-exponent power relations and the apparently different nature of sensitivity in differentiation and discrimination, disappear when temporal control is observed alone in differentiation.