In this article, we investigated the role of color in the recognition and naming of everyday objects. In the first experiment we found that color pictures were named faster than black-and-white and that shape information did not facilitate color naming. Experiment 2 was carried out to determine at which stage of object processing the color facilitation occurred. We found that color had no effect on object recognition but did facilitate object naming, even when color was redundant for discrimination. This did not apply to naming abstract shapes. Experiment 3 replicated the findings of Experiment 2 using different objects and colors. The results showed that color could facilitate but not inhibit object naming and did not affect object recognition.

Amnesic patients with mesial temporal lobe pathology often produce normal priming effects despite severely impaired memory. This is generally interpreted to mean that whereas limbic structures are involved in conscious memory, other structures, comprising a separate memory system, mediate priming effects. Priming and recognition memory measures were correlated with MRI measures of damage to specific brain structures in a sample of 30 subjects. The results provide evidence that both priming and recognition memory may be adversely affected by mesial temporal lobe damage. Furthermore, the results suggest that striatal damage is associated with lexical or perceptual deficits and larger measured priming effects. Thus, co-existing striatal and limbic damage may lead to normal priming performance in some memory-impaired patients. In these instances, normal priming performance may not be mediated by a separate (implicit) memory processing system in the brain.In human memory research, a distinction has been drawn between explicit memory tasks, that is, those tasks requiring conscious recall or recognition of previous experience, and implicit memory tasks, that is, those tasks in which performance is altered as a function of previous experience but which do not require conscious recall of that experience (Graf & Schacter, 1985). Currently, the distinction between explicit and implicit memory is also used to label separate memory systems or separate processes believed to mediate performance on explicit and implicit memory tasks

Conflicting findings with respect to the effects of experimental manipulations on priming have been reported in previous studies. It is argued that, in many priming tasks, large amounts of task-relevant information are available from various sources, and that, therefore, the information available from a specific study episode will have only a small impact on overall performance level. Under such circumstances, high levels of baseline performance and small priming effects will be observed. The experiments reported here investigated the hypothesis that a high baseline performance in informationprocessing tasks that are used to measure priming may constrain priming effects. In a series of wordnaming experiments, perceptual difficulty and, therefore, baseline performance was manipulated. Under easy conditions, priming effects were relatively small and were not affected by word frequency, spaced repetition, or delay.Under more difficult conditions, priming effects were larger, and significant effects of all of the above-mentioned experimental manipulations were observed. Under conditions that produced the largest priming effects, a significantrelationship between printingand explicit-memory performance could be observed. Inthe last experiment, it was shown that the characteristics of the retrieval task can substantially affect the magnitude of priming. It is argued that priming effects should be considered to reflect interactions between memory traces and the information-processing components of the priming task.Experimental manipulations that significantly affect explicit-memory performance on tasks such as recall or recognition often have little or no significant effect on priming measures that are obtained in tasks such as tachistoscopic identification, lexical decision, and word-stem completion. These variables include massed repetition of studied items, divided versus focused attention, and levels ofprocessing ofthe study items

Repetition priming was measured in two different tasks within a single experiment--one in which subjects named briefly (tachistoscopically) presented words, and one requiring naming of visually fragmented/degraded words. Thirteen amnesic patients, 12 patients with Alzheimer's disease (AD), and 15 normal control subjects were tested under 4 experimental conditions involving the factorial combination of two variables: delay of test (10 minutes and 24 hours), and number of prior occurrences of the primed items (1 and 4). The two tasks produced very different patterns of priming effects, despite the fact that common study phases were employed. In one task the priming effect showed no decay and virtually no effect of the number of prior occurrences of the primed items, whereas both these variables affected priming in the other task. The AD patients evidenced impaired priming in both tasks. However, in the degraded-word-naming task the deficit was only apparent under some experimental conditions. The amnesics produced priming effects that in absolute terms were similar to those produced by control subjects. However, when group differences in overall performance level were taken into account in the tachistoscopic task, these patients also showed clear evidence of impaired priming. It is argued that the complex pattern of priming effects obtained is best explained by the characteristics of the retrieval cues provided in the tasks, and, generally, that such characteristics may determine whether or not experimental variables will affect measured priming.

Two experiments are reported that extend the findings of Ostergaard and Davidoff (1985) on the role of colour in object processing. Two types of categorial judgements were investigated from pictorial stimuli: size judgement and living/non-living classifications. The effect of real size on size judgements (Paivio, 1975) was replicated. It was found that colour did not affect either of the categorial judgements, but the facilitation occurring in object naming tasks was confirmed. It is argued that semantic judgements can precede name retrieval, that physical colour input does not enter the semantic system, and that the representation of object colour information in the semantic system may be largely verbal.