Individual and group advice taking in judgmental forecasting: Is group forecasting superior to individual forecasting?

We examined how individuals and groups behave in making judgmental forecasts when they are given external forecast advice. We compare individual and group advice-taking behavior under different conditions: (a) when advice quality is fixed, (b) when advice quality is randomly varied, and (c) when there is feedback on advice quality or not. Participants in Study 1 received fixed advice of either reasonable or unreasonable quality while making their decisions. Participants in Study 2 randomly received both reasonable and unreasonable advice. We found in both studies that groups feel more confident than individuals. This greater confidence decreased the groups' reliance on advice. We also found that groups are better than individuals at discerning the quality of advice. In the group treatment, the group's reliance on advice increased according to the degree of disagreement with the initial decisions of the group members. In Study 3, participants randomly received both reasonable and unreasonable advice, and in addition, they received feedback on actual realizations that enabled them to learn about the quality of advice. In the presence of feedback on random advice quality, groups are no longer less receptive to advice than individuals; with feedback, both individuals and groups discount advice more than they do without feedback. Nevertheless, groups are still better than individuals at discerning the quality of advice. We conclude that group forecasting is better than individual forecasting across various conditions that we investigate except when advice quality is known to be consistently reliable.     

Intransigent vowel-consonant position in Korean dysgraphia: evidence of spatial-constructive representation

Dysgraphia due to a focal brain lesion can be characterized by substitution, transposition, deletion and/or addition errors of graphemes or strokes. However, those linguistic errors can be language-specific because the writing system of a given language may influence error patterns. We investigated a Korean stroke patient, a 57-year-old English teacher with dysgraphia both in Korean Han-geul [see text] and in English alphabet writings. The results of an experimental testing revealed transposition errors between a consonant and a vowel only in English but not in Korean writings. This austerity of vowel-consonant position may be attributed to a unique Korean writing system of a spatially well-formed syllabic configuration or block with consonant(s) and a vowel. In light of a neuropsychological model of writing, which depicts a multi-level spelling and writing process, we suggest a spatial-constructional component of internal orthographic representations in Korean writing. This Korean graphemic configuration feature may be resistant to a focal, left cerebral damage, and thus, we also discuss our results in terms of cerebral lateralization of the writing processes.     

Use of eye movement to measure smokers' attentional bias to smoking-related cues.

Smokers have attentional biases towards smoking-related cues, and such cues elicit cravings. Smokers also feel anxious during nicotine deprivation, and anxiety may exacerbate attentional biases toward aversive cues. We examined the attentional bias of smokers (n = 14) and a control group of nonsmokers (n = 16) towards smoking-related and aversive cues. Using an eye-tracking device, we measured eye movement when smoking-related, aversive, and control cues were presented simultaneously. We analyzed the number of initial fixations, and gaze duration, to identify the attentional bias. Smokers initially fixed their gaze on aversive cues, and maintained their gaze longer on smoking-related cues, in comparison to the control group. These results suggest that smokers show biased attentional orientation to smoking-related and aversive cues.     

Suppression of brain activity related to a car-following task with an auditory task: An fMRI study

Driving a car in daily life involves multiple tasks. One important task for safe driving is car-following, the interference of which causes rear-end collisions: the most common type of car accident. Recent reports have described that car-following is hindered even by hands-free mobile telephones. We conducted functional MRI with 18 normal volunteers to investigate brain activity changes that occur during a car-following task with a concurrent auditory task. Participants performed three tasks: a driving task, an auditory task, and a dual task in an fMRI run. During the driving task, participants use a joystick to control their vehicle speed in a driving simulator to maintain a constant distance from a leading car, which moves at varying speed. Language trials and tone discrimination trials are presented during the auditory task. Car-following performance was worse during the dual task than during the single-driving task, showing positive correlation with brain activity in the bilateral lateral occipital complex and the right inferior parietal lobule. In the medial prefrontal cortex and left superior occipital gyrus, the brain activity of the dual task condition was less than that in the single-driving task condition. These results suggest that the decline of brain activity in these regions may induce car-following performance deterioration.