Single-letter recognition as a function of exposure duration

The time course of visual letter recognition was investigated in a single-stimulus identification experiment. On each trial, a randomly chosen stimulus letter was presented at 1 of 12 equiprobable positions that were equally spaced around the circumference of an imaginary circle centered on fixation. Exposure duration was varied from 10 to 200 ms, and the letter was followed by a pattern mask. The subject's task was to report the identity of the stimulus letter but refrain from guessing. For the briefest exposures, correct reports never occurred. For longer exposures, the function relating the probability p of recognizing the letter to the duration t of the stimulus exposure was well approximated by an exponential distribution function: p(t) = 1 − exp[−v·(t−t ₀)], where v is the rate of processing and t ₀ is the minimum effective exposure duration. The generality of this finding may be limited to cases in which stimuli are highly discriminable and response criteria are conservative. Extensions to Poisson counter or random walk models are considered for cases in which stimuli are confusable. Received: 1 July 1997 / Accepted: 2 July 1998     

On the theory of biased bisection operations and their inverses

A theory of fundamental measurement involving multiple operations is presented. The operations are bisection, and two inverses of the bisection operation called right and left displacement, analogous to “displacement” of an interval “up” or “down” a scale. Following Pfanzagl, “biased” operations are permitted, and linear, reflexive representations are presented for the biased operations. Results are obtained on the constructability of unbiased scaling operations, and several methods of constructing standard sequences of equally spaced stimuli using biased operations, are described. A striking property of biased linear representation models is derived, showing that if bias is present, indefinite iterations of one or the other of the two displacement operations will converge to asymptote. Preliminary data support this surprising convergence property.     

The muskrat (Ondatra zibethicus) as a laboratory animal

Methods for the capture, maintenance, taming, and behavioral testing of wild-born muskrats(Ondatra zibethicus) are described. The muskrat is simple and inexpensive to maintain in the laboratory and seems suitable for behavioral research.     

Marital conflict,parenting, and toddler conduct problems

The present research examined relationships involving marital conflict, parenting, and toddler conduct problems. Sixty mother-toddler dyads (30 boys and 30 girls) participated as subjects. Mothers completed measures of general marital satisfaction, overt marital conflict, and toddler conduct problems. Maternal parenting and toddler deviance were assessed during a laboratory observation. Marital conflict was positively correlated with observations of toddler deviance and maternal reports of conduct problems. Marital conflict also correlated positively with the frequency of maternal disapproval statements directed toward sons' misbehaviors and was correlated negatively with the ratio of disapproval statements to daughters' misbehaviors. The present results indicate that marital conflict is associated with toddler conduct problems. The results also suggest the importance of examining parenting practices and child characteristics that may mediate the relationship between marital conflict and child behavior problems.This research was supported, in part by a Sigma XI grant to the second author.     

Time course of priming for associate and inference words in a discourse context

The construction of word meanings in a discourse context was conceptualized as a process of sense activation, sense selection, and sense elaboration. In three experiments, subjects read texts presented by a rapid serial visual procedure and performed a lexical decision on visually presented targets that followed ambiguous prime words. When the target was a word, it was either an associate of the prime word, a probable inference suggested by the discourse, or an unrelated word. For associates, lexical decisions that related to either the appropriate or the inappropriate sense of the ambiguous word were generally facilitated at short (200-400 msec) prime-target stimulus onset asynchronies (SOAs). At longer SOAs, responses were faster to appropriate than to inappropriate associates. For the thematic inferences, there was no difference between these (appropriate) inferences and (inappropriate) control words at short SOAs. At long SOAs (1,000 and 1,500 msec), however, inference words were facilitated. The results are interpreted as consistent with a model of lexical processing in which sense activation functions independently of context. Discourse context effects, whether on sense selection (suppression of inappropriate associates) or on sense elaboration (creation of inferences), are seen as postlexical.     

Attitudes toward the division of child-rearing responsibility

Though the theoretical and clinical ramifications of attribution of primary responsibility to mothers for child rearing have been discussed extensively, there is little empirical data in this area. In the present study a sample of parents rated several child-rearing behaviors in terms of ideal maternal and paternal responsibility. Mothers were attributed primary responsibility for the largest proportion of behaviors, fathers for the smallest, and an intermediate number of items were rated as parentally shared. In addition, item analysis indicated a relationship between the directionality of responsibility attribution and traditional sex-role stereotypes. Implications for patterns of intrafamilial blame and clinical intervention are discussed.     

Factor analysis of the McCarthy scales of children's abilities on preschool children

The McCarthy Scales of Children's Abilities (MSCA) was administered to 200 children, 100 males and 100 females, with a mean chronological age of 3–9. The results were subjected to factor analysis to determine the validity of MSCA alignment into six distinct indexes, or factors, and to determine if there were sex differences in factors produced by the MSCA. A general (“g”) factor was derived for both females and males. Specific factors (Abstract Verbal Reasoning and Remote Verbal Memory) were derived for the female sample. Two specific factors (Sequential Memory and Nonverbal Cognition) were derived for the male sample. Only the “g” factors derived for male, female, and total samples corresponded to the General Cognitive Index (GCI) used in the MSCA. The results suggested that clinical interpretation of the MSCA should be made cautiously for both normal and exceptional children until further exploration of the construct validity and sex differences in the MSCA can be conducted.     

Becoming the Harvard man: person-environment fit, personality development, and academic success

The continuity and change of the needs and evaluations of the college environment and person-environment fit (PE fit) with the college environment were studied in a 4-year longitudinal study of students (N = 191). Perceptions of the environment changed more dramatically than corresponding self-perceived needs. PE fit demonstrated moderate levels of consistency over the 4-year span, but no significant increases in mean levels were found over time. Antecedents to PE fit in the college environment included both intelligence and openness to experience. Outcomes associated with PE fit included changes in personality traits linked to openness to experience and higher academic achievement. The implications of the findings for personality development and the relationship of PE fit to successful outcomes are discussed.