Continuity of father-rated temperament from infancy to middle childhood

Continuity of father-rated temperament in Finnish children (n = 115) aged from 6 months (the IBQ) to 5.5 years (the CBQ) was explored within the theoretical framework developed by Rothbart. Father-rated activity level, smiling and laughter and distress to limitations showed significant differential homotypic and heterotypic continuity, while soothability, duration of orienting and fear showed significant differential heterotypic continuity. On the level of latent superconstructs, father-rated positive and negative infant affectivity accounted for 5.1, 22.7 and 10.0% of the variance in childhood extraversion, effortful control and negative affectivity, respectively. Inter-parental comparisons (n = 109 family units) revealed that father-rated continuity was similar to mother-rated continuity. These findings give empirical credence to Rothbart's theory and to father-rated temperamental continuity from infancy onwards.     

Transactional development of parent personality and child temperament

Stability and change in parental extraversion and neuroticism were studied in transaction with their views of their child's temperament from the age of six months to the age of five‐and‐a‐half years in 109 mother–father–child triads (parent–daughter: n = 61, parent–son: n = 48). While parental traits showed high stability, infants' higher positive affectivity predicted an increase in parental extraversion over 5 years, and infant's higher activity predicted a decrease in parental neuroticism. Parent‐rated temperament showed expected heterotypic continuity. Initially higher parental extraversion predicted an increase in the child's effortful control, and higher parental neuroticism predicted an increase in the child's negative affectivity. The results indicate that parental personality and child temperament develop in transaction promoting change in each other. Copyright © 2008 John Wiley & Sons, Ltd.     

The K-factor: Individual differences in life history strategy

Until recently, variations in life history strategy were studied exclusively at the species level. Although this domain of study has been extended to examine systematic differences in life history strategy among various human ethnic groupings, more recent evolutionary theories of human development and related behavioral genetic work imply substantial within-group individual variation in life history strategy. We constructed a latent variable model identifying a single common factor, denoted as K, which underlies a variety of otherwise disparate life history parameters. This “K-Factor” loaded 0.36 on childhood attachment to the biological father, −0.36 on childhood attachment to any non-biological father figure, 0.38 on adult romantic partner attachment, −0.51 on mating effort, −0.58 on Machiavellianism, and −0.41 on risk propensity. The bivariate correlations of the K-factor with higher-order personality factors were statistically significant, −0.24 with “Big Neuroticism” and −0.67 with “Big Psychoticism”, and approached significance, correlating 0.12, with “Big Extraversion”. The K-factor appears to be an underappreciated individual difference variable of major importance to human development.     

A longitudinal study of temperament continuity through IBQ,TBAQ and CBQ

The aim of this work was to study the continuity of temperament in a Spanish sample (n = 60), covering the developmental stages of infancy, toddlerhood and childhood. Temperamental dimensions showed, with few exceptions, as much homotypic as heterotypic continuity as was to be expected. At the level of latent superconstructs continuity, we found that Anger and Fear followed different developmental paths and showed continuity over all the periods evaluated. Positive Affect/Regulation superconstruct showed continuity from infancy to toddlerhood. From toddlerhood, Positive Affect/Regulation showed continuity with the superconstruct of Effortful Control but not with the superconstruct of Surgency/Extraversion. At an ipsative level, we found two groups of subjects, labeled ‘nonexpressive/controlled’ and ‘noncontrolled/expressive’. Generally, these results confirm the stability of temperament in the periods analyzed and underline the importance of toddlerhood as a transitional period in the maturity of self-regulatory capabilities shown in childhood.     

Inhibitory control and emotion regulation in preschool children

This research investigated the relation between individual differences in inhibitory control and emotion regulation. Preschool children (N = 53) ages 4–6 (M = 5; 0) were assessed on brief batteries of inhibitory control of prepotent responses and emotion regulation. Individual differences in inhibitory control were significantly correlated with children's ability to regulate their emotions. This relation held up even after controlling for age and verbal ability, and persisted for both Emotion Understanding and “online” control of emotional expressions that were negative (Disappointing Gift) or positive (Secret Keeping). Parent report of children's self-control and emotion regulation corroborated the behavioral results. These findings suggest that executive control of attention, action, and emotion are skills that develop in concert in the preschool period. However, there was also evidence of a quadratic relation in which emotion regulation was optimal at intermediate levels of inhibition, highlighting the interplay of both cognitive control and temperament in socio-emotional functioning.     

Temperamental consequences of infant difficultness

Two central issues pertaining to the construct of infant temperamental “difficultness” were investigated in this longitudinal project. First, the cross-time convergent validity of two parent-report measures of temperament was examined. Second, the temperamental consequences of difficultness during infancy were studied by prospectively following children from infancy to adolescence. Additionally, using MANOVA and structural equation modeling, gender comparisons were conducted to determine whether or not the construct of difficultness was similar for males and females. Analyses were based on parent reports (Ns=96−110) of infant difficultness on the Infant Characteristics Questionnaire (ICQ) when children were 18 months of age. The nine temperament dimensions of the New York Longitudinal Study model were also assessed by parent report inventories when children were 2, 3, 3.5, 5, 8, 10, and 12 years old. Results showed no pervasive evidence of gender differences in infant difficultness. Convergent validity between the ICQ and subsequent temperament measures was evidenced by significant cross-time canonical correlations reaching to moderate magnitude and significant bivariate correlations between infant difficultness and specific temperament dimensions. Temperamental difficultness during infancy predicted subsequent adverse temperamental qualities such as unadaptability and negative mood at every age from 2 through 12 years.     

Maternal ratings of infant regulatory competence from 6 to 12 months: influence of perceived stress, birth-weight, and intervention: a randomized controlled trial

Mothers’ reports of preterm and term infants’ temperament from 6 to 12 months of age were studied, with intervention and stress as predictors. Preterm infants with a birth weight <2000 g were randomized to an intervention (71) or a control (69) group. A control group of healthy term infants (74) was also established. The intervention was a modified version of the “Mother–Infant Transaction Program”, aimed at sensitizing caregivers to the infants’ individual characteristics. Temperament was measured with the Infant Behavior Questionnaire, and stress with the Parenting Stress Index. There were no group differences in temperament at 6 or 12 months or in change during the same period. There was a strong association between stress and negative reactivity in the preterm control group at 12 months. In the preterm intervention group, there were strong negative correlations between stress and regulatory competence at 6 months. The intervention seemed to change the relationship between stress and temperament. The strength of this association indicates that the intervention sensitized mothers to the temperamental regulatory competence of their preterm infants.     

Cognitive and projective measures of differentiation and their relationship to empathy

The present investigation compared cognitive and projective methods of assessing “differentiation,” Witkin's Embedded Figures Test (EFT) and Blatt's Concept of the Object Scale (COS), and reexamined expectations concerning the relationship between level of differentiation and capacity for empathy. Whether lesser or greater differentiation would promote empathy was of specific interest. Two forms of empathy were investigated, an “affective” form assessed by the Mehrabian Empathy Scale and a “cognitive” form assessed by the Hogan Empathy Scale. Expected sex differences in differentiation and empathy were also investigated. Results demonstrated consonance between COS and EFT measures of differentiation within the male sample only (p < .05). Individuals classified by EFT as relatively less differentiated (“field dependent”) produced more part object responses (p < .02) and those classified as more differentiated (“field independent”) showed a trend toward more whole object responses (p < .10) on the COS. Associations between measures of differentiation and empathy reached significance or showed trends in the male group only. Men with relatively lesser differentiation on the EFT (“field dependent”) showed greater “affective empathy” (p < .10) and men with greater differentiation on the COS showed greater “cognitive” empathy (p < .05). Women demonstrated higher levels of “affective” empathy than men (p < .001).     

Motivationally neutral stimulation of the nucleus basalis induces specific behavioral memory

The cholinergic system has been implicated in learning and memory. The nucleus basalis (NB) provides acetylcholine (ACh) to the cerebral cortex. Pairing a tone with NB stimulation (NBstm) to alter cortical state induces both associative specific tuning plasticity in the primary auditory cortex (A1) and associative specific auditory behavioral memory. NB-induced memory has major features of natural memory that is induced by pairing a tone with motivational reinforcers, e.g., food or shock, suggesting that the cholinergic system may be a “final common pathway” whose activation promotes memory storage. Alternatively, NB stimulation might itself be motivationally significant, either rewarding or punishing. To investigate these alternatives, adult male rats (n = 7) first formed a specific NB-induced memory (CS = 8.0 kHz, 2.0 s paired with NBstm, ISI = 1.8 s, 200 trials), validated by post-training (24 h) frequency generalization gradients (1–15 kHz) of respiration interruption that were specific to the CS frequency. Thereafter, they received the same level of NBstm that had induced memory, while confined to one quadrant of an arena, and later tested for place-preference, i.e., avoidance or seeking of the quadrant of NBstm. This NBstm group exhibited neither preference for nor against the stimulated quadrant, compared to sham-operated subjects (n = 7). The findings indicate that specific associative memory can be induced by direct activation of the NB without detectable motivational effects of NB stimulation. These results are concordant with a memory-promoting role for the nucleus basalis that places it “downstream” of motivational systems, which activate it to initiate the storage of the current state of its cholinergic targets.     

Locus of control and the perception of freedom in an agent of reinforcement

Internals and externals observed a staged videotape presentation that portrayed a “teacher” and a “learner” engaging in a 20-item anagrams task. For externals, any variability (10, 50, and 90% schedule) in the reinforcing behavior of the “teacher” (agent of reinforcement) resulted in significantly greater perceived freedom than when no variability (0 and 100% schedule) occurred in behavior. For internals, perceived freedom was a negative linear function of the amount of reinforcement administered. Internals indicated that they could influence the behavior of the “teacher” in all reinforcement conditions, whereas externals indicated that they could influence only the “teachers” in the variable reinforcement conditions. It was concluded that greater freedom is attributed to a person whose behavior is perceived as congruent with the person's inner disposition.     

Maternal depressive symptoms and child temperament: Longitudinal associations with executive functioning

The present study investigated the contributions of maternal depressive symptoms and child temperament to youths' executive functioning (EF) across an 18-year longitudinal study. The primary hypothesis proposed that the association between youths' exposure to early maternal depressive symptoms (ages 3 & 5) and their EF (age 18) would be moderated by temperament in middle childhood (ages 8 & 10). Temperament was a significant moderator of the association between early maternal depressive symptoms and youth EF. Positive child temperament (high effortful control, EC, and low negative affectivity, NA) was associated with higher EF when maternal depressive symptoms during early childhood were low. In contrast, elevated maternal depressive symptoms overrode any associations between child temperament and later EF. Parallel analyses examining the interaction between child temperament and maternal depressive symptoms during middle childhood (controlling for earlier maternal depressive symptoms) revealed a different pattern of results. Clinical implications for prevention/intervention work on EF are discussed.     

Intervention and sleeper effects: A reply to Clarke and Clarke

The evolution of the concept of “sleeper effects” is traced from the work of C. I. Hovland, A. A. Lumsdaine, and F. D. Sheffield, Experiments on Mass Communication. Princeton, N.J.: Princeton Univ. Press, 1949, to the present time. The concept originally referred to the delayed emergence of attitude change in persuasibility research. It has also been used in developmental investigations, with attendant theoretical problems that have not been fully addressed. These problems are examined, with the recommendation that the social psychologist's sleeper effect should be modified to meet developmental needs and renamed “delayed treatment effects”. Such effects are highly relevant to recent findings from studies of early childhood intervention programs.     

Time stamp in conditioned place avoidance can be set to different circadian phases

We have reported that the expression of conditioned place avoidance (CPA) in the golden hamster is regulated in a circadian pattern such that the preference is exhibited strongly at the circadian time of prior training but not at other circadian times [Cain, S. W., Chou, T., & Ralph, M. R. (2004a). Circadian modulation of performance on an aversion-based place learning task in hamsters. Behavioural Brain Research, 150(1–2), 201–205]. In that study, animals that were trained at a specific circadian time to discriminate between a “safe” context and one paired with foot shock, showed strong avoidance of the paired context at 24 and 48 h following the last training session, and showed no avoidance at 32 and 40 h following training. In the present study, we hypothesized that this “time stamp” effect is settable to any circadian phase. This was tested by training animals at one of two times of day (ZT13 or ZT4) and testing whether a time stamp would be observed, with avoidance occurring only when training and testing times match. Results confirmed our hypothesis, suggesting that the time stamp in the performance of learned tasks can be set to any circadian phase. Such an ability may allow animals in nature to predict the recurrence of 24 h events, regardless of the time of day the event was encountered.     

Early manifestations of childhood depression: influences of infant temperament and parental depressive symptoms

In this longitudinal study, 83 parents of infants between 3 and 12 months completed questionnaires assessing demographic information, infant temperament, and maternal depression. When these children were at least 18 months of age, parents completed follow‐up questionnaires assessing toddler temperament and depression‐like symptoms. We were primarily interested in the contributions of infant temperament and maternal depression to toddler depressive problems, and the analytic strategy involved controlling for toddler temperament in order to isolate the influence of infancy characteristics. The findings indicated that lower levels of infant regulatory capacity and greater severity of maternal depression were predictive of toddler depression‐like symptoms. Moderator effects of infant temperament were also examined, with the negative affectivity * maternal depression interaction emerging as significant. Follow‐up analyses indicated that the risk for early manifestations of depression was attenuated for children with lower negative affectivity in infancy and parents who reported lower levels of their own depressive symptoms; conversely, children exhibiting higher infant negative emotionality had higher levels of depression‐like symptoms as toddlers, regardless of their parents' level of depression. The present findings further suggest that parental depressive symptoms need not be ‘clinically significant’ to predict toddler affective problems. Copyright © 2008 John Wiley & Sons, Ltd.     

Voice onset time production and perception in apraxic subjects

This study explored the relationship between the perception and production of voice onset time (VOT) in apraxic subjects. Spectrograms of the words, “bees” and “peas” spoken by apraxic subjects were acoustically analyzed to obtain a measure of VOT. The subjects also identified the initial cognate (“b” or “p”) from synthetically generated speech spanning a voiced to voiceless time continuum. The results suggest that apraxic subjects have production as well as perceptual errors in the voicing feature but no significant relationship was found between the two measures.     

The self and dreams during a period of transition

The content of dreams and changes to the self were investigated in students moving to University. In study 1, 20 participants completed dream diaries and memory tasks before and after they had left home and moved to university, and generated self images, “I am…” statements (e.g. I am an undergraduate), reflective of their current self. Changes in “I ams” were observed, indicating a newly-formed ‘university’ self. These self, images and related autobiographical knowledge were found to be incorporated into recent dreams but not into dreams from other periods. Study 2 replicated these findings in a different sample (N = 55). We suggest that these data reflect a period of self-consolidation in which new experiences and self images are incorporated into autobiographical memory knowledge structures representing personal goals during sleep.     

Memory for emotionally provocative words in alexithymia: A role for stimulus relevance

Alexithymia is associated with emotion processing deficits, particularly for negative emotional information. However, also common are a high prevalence of somatic symptoms and the perception of somatic sensations as distressing. Although little research has yet been conducted on memory in alexithymia, we hypothesized a paradoxical effect of alexithymia on memory. Specifically, recall of negative emotional words was expected to be reduced in alexithymia, while memory for illness words was expected to be enhanced in alexithymia.Eighty-five high or low alexithymia participants viewed and rated arousing illness-related (“pain”), emotionally positive (“thrill”), negative (“hatred”), and neutral words (“horse”). Recall was assessed 45 min later.High alexithymia participants recalled significantly fewer negative emotion words but also more illness-related words than low alexithymia participants. The results suggest that personal relevance can shape cognitive processing of stimuli, even to enhance retention of a subclass of stimuli whose retention is generally impaired in alexithymia.     

Taxometric analysis supports a dimensional latent structure for schizotypy

The existence of a discrete class of people vulnerable to schizophrenia spectrum disorders is the most replicated finding of taxometric research. Evidence for such a “taxon” has been obtained with diverse measures of schizotypy in clinical, high-risk, and normal samples. However, recent demonstrations that skewed indicators of a latent dimension can yield a spuriously taxonic pattern of results may call some of these findings into question. Normal adults (N = 1073) completed measures of positive (perceptual aberration, magical ideation) and negative (physical and social anhedonia) components of schizotypy. Taxometric curves resembled those obtained previously, but when a simulation procedure took skew into account, dimensional models of schizotypy received stronger support than taxonic models for most schizotypy components, with findings for magical thinking inconclusive. A re-evaluation of previous taxonic conclusions regarding the latent structure of schizotypy is indicated.     

Nicotinic modulation of tone-evoked responses in auditory cortex reflects the strength of prior auditory learning

Nicotinic acetylcholine receptors (nAChRs) contribute to sensory-cognitive function, as demonstrated by evidence that nAChR activation enhances, and nAChR blockade impairs, neural processing of sensory stimuli and sensory-cognitive behavior. To better understand the relationship between nAChR function and behavior, here we compare the strength of nAChR-mediated physiology in individual animals to their prior auditory behavioral performance. Adult rats were trained on an auditory-cued, active avoidance task over 4 days and classified as “good,” “intermediate” or “poor” performers based on their initial rate of learning and eventual level of performance. Animals were then anesthetized, and tone-evoked local field potentials (LFPs) recorded in layer 4 of auditory cortex (ACx) before and after a test dose of nicotine (0.7 mg/kg, s.c.) or saline. In “good” performers, nicotine enhanced LFP amplitude and decreased response threshold to characteristic frequency (CF) stimuli, yet had opposite effects (decreased amplitude, increased threshold) on responses to spectrally distant stimuli; i.e., cortical receptive fields became more selective for CF stimuli. In contrast, nicotine had little effect on LFP amplitude in “intermediate” or “poor” performing animals. Nicotine did, however, reduce LFP onset latency in all three groups, indicating that all received an effective dose of the drug. Our findings suggest that nicotinic regulation of cortical receptive fields may be a distinguishing feature of the best-performing animals, and may facilitate sensory-related learning by enhancing receptive field selectivity.     

A decidable multi-modal logic of context

We give a logic for formulas φ−ψ, with the informal reading “ψ is true in the context described by φ”. These are interpreted as binary modalities, by quantification over an enumerable set of unary modalities c−ψ, meaning “ψ is true in context c”. The logic allows arbitrary nesting of contexts.A corresponding axiomatic presentation is given, and proven to be decidable, sound, and complete.Previously, quantificational logic of context restricted the nesting of contexts, and was only known to be decidable in very special cases.