Fractal fluctuations in gaze speed visual search

Visual search involves a subtle coordination of visual memory and lower-order perceptual mechanisms. Specifically, the fluctuations in gaze may provide support for visual search above and beyond what may be attributed to memory. Prior research indicates that gaze during search exhibits fractal fluctuations, which allow for a wide sampling of the field of view. Fractal fluctuations constitute a case of fast diffusion that may provide an advantage in exploration. We present reanalyses of eye-tracking data collected by Stephen and Mirman (Cognition, 115, 154-165, 2010) for single-feature and conjunction search tasks. Fluctuations in gaze during these search tasks were indeed fractal. Furthermore, the degree of fractality predicted decreases in reaction time on a trial-by-trial basis. We propose that fractality may play a key role in explaining the efficacy of perceptual exploration.     

Long-term repetition priming in spoken and written word production: evidence for a contribution of phonology to handwriting

Although it is relatively well established that access to orthographic codes in production tasks is possible via an autonomous link between meaning and spelling (e.g., Rapp, Benzing, & Caramazza, 1997), the relative contribution of phonology to orthographic access remains unclear. Two experiments demonstrated persistent repetition priming in spoken and written single-word responses, respectively. Two further experiments showed priming from spoken to written responses and vice versa, which is interpreted as reflecting a role of phonology in constraining orthographic access. A final experiment showed priming from spoken onto written responses even when participants engaged in articulatory suppression during writing. Overall, the results support the view that access to orthography codes is accomplished via both the autonomous link between meaning and spelling and an indirect route via phonology.     

Personality and American state differences in obesity prevalence

The study was conducted to determine whether state obesity-prevalence rates can be predicted by state differences in residents' levels on the Big Five personality variables (O. P. John & S. Srivastava, 1999). State obesity prevalence was the mean percentage of the state population from 2000 to 2005 with a body mass index > or = 30.0 as assessed by the Behavioral Risk Factor Surveillance System (Centers for Disease Control and Prevention, 2010), which currently interviews more than 350,000 adults annually. State neuroticism, extraversion, agreeableness, conscientiousness, and openness z scores, based on the responses of 619,397 residents to an Internet survey from 1999 to 2005, were taken from P. J. Rentfrow, S. D. Gosling, and J. Potter (2008). Alaska, Hawaii, and North Dakota had scores outside -3 and +3 standard deviations on at least 1 variable and were excluded as outliers. For the 47 remaining states, state obesity prevalence was significantly correlated with neuroticism (.35), agreeableness (.38), openness (-.44), socioeconomic status (-.74), white percentage (-.34), and urbanization (-.43). Multiple regression analysis showed that socioeconomic status could account for 54.0% of the criterion variance and that agreeableness, neuroticism, and openness together could account for another 17.1%.     

Reduced sensitivity to visual looming inflates the risk posed by speeding vehicles when children try to cross the road

Almost all locomotor animals respond to visual looming or to discrete changes in optical size. The need to detect and process looming remains critically important for humans in everyday life. Road traffic statistics confirm that children up to 15 years old are overrepresented in pedestrian casualties. We demonstrate that, for a given pedestrian crossing time, vehicles traveling faster loom less than slower vehicles, which creates a dangerous illusion in which faster vehicles may be perceived as not approaching. Our results from perceptual tests of looming thresholds show strong developmental trends in sensitivity, such that children may not be able to detect vehicles approaching at speeds in excess of 20 mph. This creates a risk of injudicious road crossing in urban settings when traffic speeds are higher than 20 mph. The risk is exacerbated because vehicles moving faster than this speed are more likely to result in pedestrian fatalities.     

Effects of Orthography on Speech Production in Chinese

The potential role of orthographic representations on spoken word production was investigated with speakers of Chinese, a non-alphabetic and orthographically non-transparent language. Using the response generation procedure, we obtained the well-known facilitation from word-initial phonological overlap, but this effect was unaffected by whether or not responses shared the initial character. In a study which manipulated the visual similarity of the word-initial character, a significant inhibitory effect of orthography was found. However, this effect disappeared when prompt stimuli were presented auditorily, suggesting that the orthographic effect might be attributable to the memorization stage of the response generation task, rather than reflecting processes genuine to speaking. By contrast, a reliable orthographic effect was found in an oral reading task, suggesting that orthography plays a role only when it is relevant to the word production task. Furthermore, the present findings show that the orthographic effect is tied to the correspondence between orthography and phonology of a language when orthography is relevant to the task used.     

Testing QuickEst: No evidence for the Quick-Estimation heuristic

The Quick-Estimation heuristic (QuickEst) was introduced by Hertwig, Hoffrage, and Martignon (1999 Hertwig , R. , Hoffrage , U. , & Martignon , L. (1999) . Quick estimation: Letting the environment do the work . In G. Gigerenzer , P. M. Todd , & the ABC Research Group (Eds.) , Simple heuristics that make us smart (pp. 209 – 234) . New York : Oxford University Press . [Google Scholar]) as a fast and frugal method to generate numerical estimates. The heuristic posits that estimate-relevant knowledge is organised and searched according to ordered reference classes that are based on binary cue values. Two experiments tested two main predictions derived from QuickEst with respect to the memory search and estimation behaviour of human participants. The results provided no evidence that QuickEst is used in numerical estimation processes. As alternative explanation of our findings, we discuss a cyclic sampling mechanism that retrieves information from memory according to their associative strength.     

Conservatism,Openness, and Creativity: Patents Granted to Residents of American States

This study was conducted to determine the relation of creative production to conservatism and openness to experience with American states as the units of analysis. Patents per state population from 2001 to 2005 served as the criterion. Conservatism was gauged by a composite based on (a) state-aggregated conservative self-placement among over 141,000 respondents to 122 national telephone surveys between 1976 and 1988 and (b) state percentage voting for Bush in 2004. State openness scores were based on state-aggregated survey responses of over 600,000 residents to a common Big Five personality questionnaire. For 46 states (excluding Alaska, Hawaii, Nevada, and Idaho because of lack of suitable data), patents per state population was negatively related to conservatism (r = ? .65) and positively related to openness (r = .50). These associations persisted when state socioeconomic status (SES), estimates of IQ, and degree of urbanization were statistically considered. Multiple regression analysis showed that conservatism and openness together accounted for 46.5% of the criterion variance without controls and 22.7% with SES controlled. Variance in state creative production accounted for by conservatism and openness indicated that the 2 predictors had both overlapping and separate components but that conservatism was the predominant of the 2 dispositional variables.     

A Multitrait-Multimethod Analysis of the MCMI-II Clinical Syndrome Scales

Multitrait-multimethod procedures and factor analyses were utilized to assess convergent/discriminant validity of the revised version of the Millon Clinical Multiaxial Inventory (MCMI-II) clinical syndrome scales and effects of item overlap on scale performance. Except for the Delusional Disorder Scale (PP), convergent validity was supported, but poor discriminant validity was found for the Alcohol Dependence (B) scale, Drug Dependence (T) scale, and Scale PP. Item overlap did not influence performance for many scales. In fact, results indicate that some scales, such as Bipolar: Manic (N), may perform better in overlapping form, whereas others, such as Somatoform (H) and Scales B and T, are most affected by item overlap. Factor structure was generally stable, regardless of whether overlapping or nonoverlapping scales were utilized. However, substance abuse/ dependence emerged as an independent factor when common item artifact was removed. Findings are discussed in terms of their implications for clinical practice and further research.