A developmental study of semantic elaboration and interpretation in recognition memory

Can personal task choice shield against fear and anger prime effects on effort? A study on cardiac response

This experiment tested whether personal task choice can shield against implicit affective influences on sympathetically mediated cardiovascular response, reflecting effort. Participants were N = 121 healthy university students who completed a moderately difficult memory task with integrated briefly flashed and masked fear vs. anger primes. Half of the participants believed they could choose between an attention and a memory task, while the other half was automatically assigned to the task. Replicating previous research, we expected an influence of the affect primes on effort when the task was externally assigned. By contrast, when participants were given a task choice, we predicted strong action shielding and thus a weak implicit affect effect on resource mobilization. As expected, participants in the assigned task condition showed stronger cardiac pre-ejection period reactivity when exposed to fear primes than when processing anger primes. Importantly, this affect prime effect disappeared when participants could ostensibly choose the task. These findings add to other recent evidence for action shielding by personal task choice and importantly extend this effect to implicit affective influences on cardiac reactivity during task performance.

Insights from child development on the relationship between episodic and semantic memory

The present study was motivated by a recent controversy in the neuropsychological literature on semantic dementia as to whether episodic encoding requires semantic processing or whether it can proceed solely based on perceptual processing. We addressed this issue by examining the effect of age-related limitations in semantic competency on episodic memory in 4-6-year-old children (n=67). We administered three different forced-choice recognition memory tests for pictures previously encountered in a single study episode. The tests varied in the degree to which access to semantically encoded information was required at retrieval. Semantic competency predicted recognition performance regardless of whether access to semantic information was required. A direct relation between picture naming at encoding and subsequent recognition was also found for all tests. Our findings emphasize the importance of semantic encoding processes even in retrieval situations that purportedly do not require access to semantic information. They also highlight the importance of testing neuropsychological models of memory in different populations, healthy and brain damaged, at both ends of the developmental continuum.

What colour is the car? Implicit memory for colour information in children

Three experiments were conducted to examine age-related differences in colour memory. In Experiment 1, preschool age and elementary school age children were given a conceptual test of implicit colour memory (a colour-choice task). They were presented with the names or achromatic versions of previously studied coloured line drawings and asked to select an appropriate colour. Significant priming could be demonstrated: The children chose the previously seen colours more often than was expected by chance. Equivalent priming was found for both versions (pictorial and verbal) suggesting that colour priming may be conceptually mediated. Moreover, colour priming proved to be age invariant. Experiment 2 replicated and extended this finding by using a wider age group (preschool, elementary school, and young adults) and by giving a perceptual implicit task (picture identification) in addition to a verbal colour-choice task. Colour did not affect priming in the perceptual task. Whereas priming showed no developmental change, age-related improvements were observed on an explicit colour memory task that differed only in the test instructions from the implicit colour-choice task (Experiments 2 and 3). Taken together, the results suggest that implicit colour memory may be mediated by conceptual processes that are age invariant.

Effects of color on children's naming of pictures

Two experiments assessed possible effects of memory for the typical colors of objects on children's naming of pictures. Children, 5 to 10 yr. old (N = 54 per experiment), named pictures of familiar objects in uncolored, typically colored (red for apple), and atypically colored (blue for apple) versions. Presentation of the three types of pictures was mixed in Exp. 1 and blocked in Exp. 2. With mixed presentation, reaction times for naming were unaffected by typical colors but slowed by atypical colors. With blocked presentation, naming was speeded by typical colors, but only for younger children, and was unaffected by atypical colors. Implications are discussed for understanding the processes by which objects are identified and named and the development of knowledge regarding the color of objects.

The colour cognition of children

It is well known that young children have great difficulty in stating the appropriate colour name when presented with a colour stimulus, even though they may be effective at matching one colour stimulus with another and possess a good vocabulary of colour terms. The present studies demonstrate a further, but distinct, impairment in dealing with coloured stimuli. Three- to four-year-old children were given the task of distinguishing an appropriately coloured option from one with an inappropriate colour. Despite displaying a preference for the appropriate colour over the inappropriate one, children found the task very difficult. In contrast, they succeeded on the task more frequently when the alternatives were presented verbally, rather than in terms of two pictures. We discuss the results within a theoretical framework which distinguishes the access to object-colour knowledge from colour naming. The model makes divisions within the mental templates required for object matching. In particular, colour detail is functionally separated from shape detail and appears to be represented in more than one code.

Event-related potential investigations of cognitive development and aging

Comparison of the results of the studies of cognitive development and normal aging suggests a large degree of commonality in both behavioral and ERP effects across a wide age range. Whether measured in young children, adolescents, young, middle-aged or elderly adults, the size of the ERP repetition effect did not differ among the various age groups. This was true whether memory was tested directly during continuous recognition or indirectly during variants of semantic categorization tasks. Similarly, in the studies of adult aging, the degree of RT facilitation during the semantic task did not differ with age and, in both the studies of cognitive development and aging, the degree of RT prolongation during the explicit tasks did not appear to differ as a function of age. Moreover, in the studies of adult aging, the effects of three versus two exposures of a word assessed in the PM session (TABLE 1), modulated RT similarly in all three age groups. These data argue for continuity of information processing across a very wide age range during both direct and indirect memory tasks, when retention is assessed during the recognition (for explicit testing) and repetition (for implicit testing) phases of the task. Since ERP and RT modulation do not appear to differ with age during the retrieval phases of these experiments, how can the performance differential seen in young children and older adults be explained? Some evidence comes from the ERP data recorded during the study phases of our explicit tasks. During continuous recognition, both young children and elderly adults did not show the typical subsequent "memory effect." In the case of the children, the subsequently unrecognized ERP was larger than the subsequently recognized ERP, whereas for the older adults, there was no difference between these two ERPs. Moreover, during these same tasks, the young children did show the "crossover" (new greater than old) pattern for slow wave activity, whereas the older adults did not. Since these ERP findings were obtained during the acquisition phase (i.e., to new items that had to be encoded for subsequent retrieval), the data argue for encoding difficulties as one means of explaining the performance differences seen at the two ends of the age spectrum. However, since the older adults displayed a different new/old pattern for slow wave activity, the two age groups may differ qualitatively in the strategies employed to encode items for subsequent retrieval.(ABSTRACT TRUNCATED AT 400 WORDS)