A cognitive-psychological perspective on Gillespie's "Lights and lattices": some relations among perception, imagery, and thought

George Gillespie's valuable observations on light and lattice imageries are played in the context of current research and theory on cognitive imagery (Kosslyn, Pylyshyn), ordinary and lucid dreaming, representational geometric imagery in scientific thought, the author's previous writings on altered states of consciousness, and Gibson's views on perception and imagery. Gillespie's reports show categories of imagery deconstruction and abstraction that link these areas and suggest an integrative model of the varieties of symbolic imagery.     

Individual differences in secondary task performance

The purpose of this research was to use secondary task performance as a predictor of performance on a difficult primary task. Reaction time (RT) to secondary probes that occurred during the rehearsal period of an easy memory task were used to measure spare capacity associated with the memory task. This measure was then correlated with performance on a harder version of the same memory task. Experiments 1-4 involved a paired associate memory task. Probe RT was sensitive to the difficulty of the paired associate task, and analysis of individual differences showed that probe RT during the easy version of the task was correlated with performance on a harder version of the task. Experiment 4 also utilized a spatial memory task. Probe RT was less sensitive to the demands of the spatial memory task, and in that case, the "easy-to-hard" prediction was not successful.     

On memory for metaphor

Three experiments investigated how metaphors are represented in memory and the effects on memory of variables known to affect metaphor comprehension. Ten theoretically relevant dimensions were examined. In Experiments 1 and 2, free recall across a variety of orienting tasks was consistently and positively predicted by the rated imageability of metaphoric topics (sentence subjects) and the rated number of interpretations for each metaphor. The number of interpretations effect was reversed in the cued recall task of Experiment 3, as metaphors with fewer interpretations were remembered better. These and other results supported previous suggestions that memory for metaphor involves wholistic representations akin to metaphoric grounds. They also revealed consistent differences in the roles of several variables in comprehension and memory for metaphor.     

The role of attention in eye-movement awareness

People are unable to accurately report on their own eye movements most of the time. Can this be explained as a lack of attention to the objects we fixate? Here, we elicited eye-movement errors using the classic oculomotor capture paradigm, in which people tend to look at sudden onsets even when they are irrelevant. In the first experiment, participants were able to report their own errors on about a quarter of the trials on which they occurred. The aim of the second experiment was to assess what differentiates errors that are detected from those that are not. Specifically, we estimated the relative influence of two possible factors: how long the onset distractor was fixated (dwell time), and a measure of how much attention was allocated to the onset distractor. Longer dwell times were associated with awareness of the error, but the measure of attention was not. The effect of the distractor identity on target discrimination reaction time was similar whether or not the participant was aware they had fixated the distractor. The results suggest that both attentional and oculomotor capture can occur in the absence of awareness, and have important implications for our understanding of the relationship between attention, eye movements, and awareness.     

Effects of diurnal variation and caffeine consumption on Test of Variables of Attention (TOVA) performance in healthy young adults

The Test of Variables of Attention (TOVA) is a continuous performance test (CPT) that assesses attention, impulsivity, and processing speed. CPTs are used in the assessment of attention-deficit/hyperactivity disorder (ADHD) in children, but more young adults are being assessed for ADHD as well. The TOVA norms are based on a standardization sample that was tested early in the day, and any TOVA administered after 1:00 p.m. will be flagged as potentially invalid. Whereas the testing time recommendations make sense for pediatric samples, it is unclear whether they are appropriate for young adults in college, who typically show significant phase delay in their diurnal rhythms. In addition, many college students consume large amounts of caffeine, and it is unclear how caffeine consumption affects TOVA performance. The current study examined the impact of time of day, self-reported diurnal preference, and caffeine consumption on TOVA performance in a double-blind, placebo-controlled experiment with healthy college students. There was evidence of diurnal variation on average response time and impulsivity but not on overall ADHD score, with participants tested in the afternoon responding faster but making more commission errors than did participants tested in the morning. Caffeine consumption led to significantly faster response times, but only for participants who typically consumed relatively little caffeine. We conclude that the TOVA can be administered to young adults outside the recommended time constraints without compromising the validity of test score interpretation but that the caffeine consumption of participants should be closely monitored.     

Distinctiveness effects in children's long-term retention

In 3 experiments, kindergarten and second-grade children's retention was examined in the context of 2 distinctiveness manipulations, namely, the von Restorff and bizarre imagery paradigms. Specifically, children learned lists of pictures (Experiments 1a and 1b) or interactive images (Experiment 2) and were asked to recall them 3 weeks later. In Experiments 1a and 1b, distinctiveness was manipulated perceptually (changing colors) and conceptually (changing categories or switching to a numeral), whereas in Experiment 2, distinctiveness concerned the interaction (common or bizarre) between the referents. The results showed that (a) older children retained more information than younger children, (b) younger but not older children failed to benefit from numerically distinct information, and (c) distinctiveness in other domains facilitated children's retention. These results highlight the importance of distinctive information in children's retention.