Semantic processing without conscious identification: evidence from event-related potentials

Three event-related potential (ERP) experiments examined whether semantic content can be accessed from visually presented words that cannot be consciously identified. Category labels were shown to participants, followed by masked, briefly exposed words that were either exemplars of the category or not exemplars. The task was to verify the category, by guessing if necessary, and to identify the word, naming it if possible. Exposure durations were selected to allow identification in approximately half the trials. For identified words, there was a marked difference in the ERP response between in-category and out-of-category words because of an N400 component. For unidentified words, there was a similar although smaller difference. Conscious identification was defined using a variety of approaches: verbal report, 6-alternative forced choice, and binary categorization (in the context of the regression method; A. G. Greenwald, M. R. Klinger, & E. S. Schuh, 1995). By any definition, ERPs for unidentified words showed evidence of semantic processing. In addition, there were differences in the neuronal populations recruited to process above-threshold versus below-threshold words, suggesting qualitative differences.     

The memorability of names and the divergent effects of prior experience

Pre-experimental familiarity can have paradoxical effects on episodic memory. Knowledge of the stimulus domain usually enhances memory, but word frequency—a presumed correlate of prior experience—is negatively related to recognition accuracy. The present study examined episodic recognition of names and its relation to two measures of pre-experimental knowledge, name frequency, and fame. Frequency was operationalised as the number of hits in a national telephone directory, and fame as hits on national mass media websites. Recognition accuracy was increased by fame, but diminished by frequency. Four experiments confirmed the findings, using yes/no recognition, ROC curves, and remember-know paradigms. Hit rates were consistently more strongly influenced by fame than by frequency, whereas the reverse was true for false alarm rates. These dissociations suggest that two different forms of semantic memory, specific and nonspecific knowledge, interact with episodic memory in separate ways.     

The proposed interaction between working memory and inhibition

Two experiments investigated the determinants of performance on a go/no-go task by studying the interplay of two executive function components, working memory (WM) and inhibition. Systematically varied task demands on WM and inhibition were used in the analysis of performance together with individual capacity measures of both functions, thereby investigating an interactive view of WM and inhibition. Further analyses were conducted with individual differences in general fluid intelligence (gF), in an attempt to study the role of higher order cognition in handling task demands. The results are new in presenting empirical evidence for interactive effects of the task demand variables in concert with individual WM capacity as well as with gF, suggesting that executive processes common to WM and gF are involved in inhibitory performance, whereas gF appears to reflect a broader function in controlling behaviour in relation to task goals, whether it involves active responding or not.     

Hyperactivity,shyness, and sex: Development and socio‐emotional functioning

Based on formulations about the possible consequences for adaptation of gender non‐normative behaviour, we investigated predictive and concurrent relations of hyperactivity and shyness to various aspects of adaptation focusing on possible effects of sex. At ages 5–6, parents and preschool teachers rated hyperactivity and shyness for 151 children (50% boys). At age 9, we obtained teacher ratings of hyperactivity, internalizing and externalizing problems, self‐ratings of trait anxiety, and peer nominations of shyness, social preference, and aggression. Several effects of sex were found. Hyperactivity ratings were more strongly related across time and raters for boys than for girls. In the predictive analyses, boys' hyperactivity was more strongly related to aggression than was girls' hyperactivity, and in concurrent analyses, girls' hyperactivity was more strongly associated with low social preference than was boys' hyperactivity. There was a protective effect of shyness with regard to aggression that applied only to boys, that is, at high hyperactivity levels, boys with high shyness levels were less aggressive than boys with low shyness levels. There were also main effects of hyperactivity and shyness. In predictive and concurrent analyses, hyperactivity was associated with low social preference, high levels of externalizing problems and with aggression, whereas shyness was associated with high levels of internalizing problems. Finally, there was an interactive effect of hyperactivity and shyness. In the concurrent analyses, an exacerbating effect was demonstrated insofar as high shyness was associated with low social preference at high, but not at low levels of hyperactivity. The different developmental risks of hyperactivity and shyness were discussed.