Predicting individual false alarm rates and signal detection theory: A role for remembering

The relationships between hit, remember, and false alarm rates were examined across individual subjects in three remember-know experiments in order to determine whether signal detection theory would be consistent with the observed data. The experimental data differed from signal detection predictions in two critical ways. First, remember reports were unrelated, or slightly negatively related, to the commission of false alarms. Second, both response types (remembers and false alarms) were uniquely related to hit rates, which demonstrated that the hit rate cannot be viewed as the result of a single underlying strength process. These results are consistent with the dual-process signal detection model of Yonelinas (1994), in which performance is determined by two independent processes--retrieval of categorical context information (remembering) and discriminations based on continuous item strength. Remember and false alarm rates selectively tap these processes, whereas the hit rate is jointly determined. Monte Carlo simulations in which the dual-process model was used successfully reproduced the pattern in the experimental data, whereas simulations in which a signal detection model, with separate "old" and "remember" criteria, was used, did not. The results demonstrate the utility of examining individual differences in response types when one is evaluating memory models.     

Colour matching of isoluminant samples and backgrounds: a dimming effect

Sequential asymmetrical colour matching of forty Munsell samples simulated under illuminant C and one of eight test illuminants was carried out. The subjects matched the appearance of each sample under illuminant C with its appearance under the test illuminant. Samples and background (N7) were presented for 1 s under the test illuminant and were isoluminant with each other. Subjects adjusted hue, chroma, and value under illuminant C. The experiments distinguished two groups of subjects; some observers needed to reduce the luminance of the sample to make a match while others did not. This 'dimming' occurred when the matches were close to cardinal axes, especially the tritanopic confusion line. A model of luminance and cone-opponent mechanisms contributing to brightness can account for the dimming effect. Details of analysis in cone-opponent space (L - M, L + M - S, L + M) are presented in the companion paper (Stanikunas et al, 2005 Perception 34 this issue).     

Emotional intensity of idiographic sad memories in depression predicts symptom levels 1 year later

When cued with generic happy and sad words, depressed individuals have been found to articulate contextually impoverished memories of autobiographical events. Although this pattern predicts a worse symptomatic course of disorder in some depressed samples, longitudinal findings with the cue-word paradigm are inconsistent. To address the etiological significance of autobiographical memories outside the cue-word paradigm, the authors used an idiographic interview in which depressed participants generated memories of their happiest and saddest lifetime events. Each memory was coded for detail and emotional intensity. At a 1-year follow-up, participants' levels of depressive symptoms were reassessed. Lower emotional intensity of saddest memories predicted higher levels of depressive symptoms at follow-up. Several implications for understanding sadness and emotional disclosure in depression are discussed.     

The development of color categories in two languages: a longitudinal study

This study unites investigations into the linguistic relativity of color categories with research on children's category acquisition. Naming, comprehension, and memory for colors were tracked in 2 populations over a 3-year period. Children from a seminomadic equatorial African culture, whose language contains 5 color terms, were compared with a group of English children. Despite differences in visual environment, language, and education, they showed similar patterns of term acquisition. Both groups acquired color vocabulary slowly and with great individual variation. Those knowing no color terms made recognition errors based on perceptual distance, and the influence of naming on memory increased with age. An initial perceptually driven color continuum appears to be progressively organized into sets appropriate to each culture and language.     

Sensory discrimination and intelligence: testing Spearman's other hypothesis

At the centenary of Spearman's seminal 1904 article, his general intelligence hypothesis remains one of the most influential in psychology. Less well known is the article's other hypothesis that there is "a correspondence between what may provisionally be called 'General Discrimination' and 'General Intelligence' which works out with great approximation to one or absoluteness" (Spearman, 1904, p. 284). Studies that do not find high correlations between psychometric intelligence and single sensory discrimination tests do not falsify this hypothesis. This study is the first directly to address Spearman's general intelligence-general sensory discrimination hypothesis. It attempts to replicate his findings with a similar sample of schoolchildren. In a well-fitting structural equation model of the data, general intelligence and general discrimination correlated .92. In a reanalysis of data published byActon and Schroeder (2001), general intelligence and general sensory ability correlated .68 in men and women. One hundred years after its conception, Spearman's other hypothesis achieves some confirmation. The association between general intelligence and general sensory ability remains to be replicated and explained.     

Prepared movements are elicited early by startle

A startle stimulus has been shown to elicit a ballistic response in a reaction time (RT) task at very short latencies without involvement of the cerebral cortex (J. Valls-Sole, J. C. Rothwell, F. Gooulard, G. Cossu, & E. Munoz, 1999). The present authors examined the nature of the startle response. A simple RT task was used in which 8 participants performed arm extension movements to 3 target distances (20 degrees, 40 degrees, and 60 degrees ) in a blocked design. An unpredictable startling acoustic stimulus (124 dB) replaced the imperative stimulus in certain trials. The authors verified the presence of a startle response independent from the prepared response by observing electromyographic (EMG) activity in sternocleidomastoid and orbicularis oculi muscles. Findings indicated that when the participant was startled, the intended voluntary response was produced at significantly shorter response latencies. Furthermore, the kinematic variables of the observed response during startle trials for all 3 target distances were mostly unchanged. The EMG characteristics of the responses were not modified, indicating that the response produced was indeed the prepared and intended response.     

Size of the neocerebellar vermis is associated with cognition in healthy elderly men

Cerebellar volumes show small positive correlations with cognitive ability in young adults, but no studies have examined this relationship in older adults. Furthermore, no studies have examined relationships between sizes of subareas of the cerebellum and cognitive ability. We hypothesized that size of the two areas of the neocerebellar vermis would correlate with a battery of eight cognitive tests in 50 men aged 65-70. Size of the neocerebellar areas of the vermis correlated positively with several cognitive tests (r's=.29-.37, p<.05), whilst sizes of other parts of the vermis did not correlate with any cognitive tests. Total cerebellar volumes correlated significantly with a test of nonverbal reasoning (r=.030, p=.42). These findings suggest a specific association of neocerebellar vermis size with variations in cognitive ability in older adults.     

The paradox of promoting creativity in the Asian classroom: an empirical investigation

To shed light on the paradox of promoting creativity in the Asian classroom, the authors conducted 3 studies. The 1st study found that novice teachers classified student behaviors as desirable but uncreative (DBU) versus creative but undesirable (CBU). The 2nd study found that conservative-autocratic teachers were more likely to encourage DBU behaviors in class, whereas liberal-democratic teachers were more likely to encourage CBU behaviors in class. The 3rd study found that cultural individualism-collectivism had a positive impact on liberal-democratic teaching attitude but a negative impact on conservative-autocratic teaching attitude. In turn, liberal-democratic teaching attitude had a positive impact on the tendency to promote CBU behaviors, whereas conservative-autocratic teaching attitude had a positive impact on the tendency to promote DBU behaviors.     

Online versus offline processing of visual feedback in the production of component submovements

The present authors tested the assumptions in R. S. Woodworth's (1899) 2-component model regarding the specific roles of vision in the production of both the initial impulse and the error-correction phases of movement. Participants (N = 40) practiced a rapid aiming task (1,500 trials), with either no visual feedback, vision of only the 1st 50% of the movement, vision of only the 1st 75% of the movement, or vision of the entire movement. Consistent with previous research, the availability of vision over the 1st half of the movement had no effect on aiming accuracy during acquisition. In contrast, when visual feedback was available over the 1st 75% of the movement and the entire movement, initial impulse endpoints were less variable and the efficiency of the error-correction phase was improved. Analysis of spatial variability at various stages in the movement revealed that participants processed visual feedback offline to improve programming of the initial impulse and processed it online in regulating the deceleration of the initial impulse.     

The role of video in facilitating perception and action of a novel coordination movement

Two groups (n = 10 in each) practiced a novel, bimanual coordination pattern that was demonstrated on video. One of the groups received augmented video feedback of their own responses after each trial following a demonstration. The video-feedback group showed better performance in acquisition and retention than the no-feedback group. On error-detection tests, the video-feedback group was better able to distinguish between correct and incorrect movement patterns. The authors concluded that video feedback helps to make relative phase information salient by aiding the discrimination process. Prepractice ability on a scanning task revealed that individuals who persevered with in-phase-type movements, even though the task demands dictated otherwise, had the most difficulty determining and subsequently performing the required movement. Video feedback helped them to compensate for those difficulties.