PRIMING FROM THE ATTENTIONAL BLINK:

Abstract —When people must detect several targets in a very rapid stream of successive visual events at the same location, detection of an initial target induces misses for subsequent targets within a brief period. This attentional blink may serve to prevent interruption of ongoing target processing by temporarily suppressing vision for subsequent stimuli. We examined the level at which the internal blink operates, specifically, whether it prevents early visual processing or prevents quite substantial processing from reaching awareness. Our data support the latter view. We observed priming from missed letter targets, benefiting detection of a subsequent target with the same identity but a different case. In a second study, we observed semantic priming from word targets that were missed during the blink. These results demonstrate that attentional gating within the blink operates only after substantial stimulus processing has already taken place. The results are discussed in terms of two forms of visual representation, namely, types and tokens.     

The onset of stuttering following drug overdose

Recently, some attention has been focused on acquired stuttering, disfluencies that begin in adulthood. The nature of acquired stuttering differs in several respects from developmental stuttering. A case of acquired stuttering following drug overdose is presented and contrasted with previously reported cases. The case is noteworthy in that, while many characteristics of acquired stuttering are evidenced, several symptoms associated with developmental stuttering are also observed. The findings are discussed in terms of a possible link between developmental and acquired forms of stuttering.     

Related attributes in the choice of comparison others: It's there,but it isn't all there is

Subjects within a group of nine were supposedly given different amounts of practice prior to taking a test on which performance was either related or unrelated to practice. After taking the test, each subject was given his score, his rank order in the group, and the amount of practice presumably done by each of the other group members. The subject was then given a choice of which performance score he would like to know; a second choice was also given. On both first and second choices, subjects in the related condition were more likely to choose to see the scores of others with the same amount of practice. Related condition subjects were more interested in their comparison choices and thought they had done better on the task than unrelated subjects. In addition to this confirmation of the related attributes hypothesis, there was a significant tendency toward comparison on the basis of similarity of performance per se and a significant tendency toward upward comparison.     

The effect of methyl parathion on susceptibility of bobwhite quail (Colinus virginianus) to domestic cat predation

Bobwhite quail (Colinus virginianus) that received either 0, 2, 4, or 8 mg/kg methyl parathion (O,O-dimethyl o-p-nitrophenyl phosphorothioate) treatment were investigated as to their susceptibility to predation by a cat (Felis domesticus) predator. Four hours after receiving methyl parathion (MP), physical activity levels were monitored in quail and included the number of seconds spent still, walking, running, or flying before and after a cat was introduced into an experimental arena. The cholinesterase (ChE) activity for each quail on experiment was determined. Quail that were captured exhibited significantly greater inhibition of brain ChE activity and spent significantly more time being still than noncaptured birds. Birds receiving MP at 8 mg/kg spent more seconds being still than those in other treatment groups and had ChE activity reduced to 42.8% of normal activity. There was a tendency for quail at increasing treatment levels to be more susceptible to capture by the cat predator. The neurological and behavioral effects of methyl parathion may have important ecological ramifications.     

Crossmodal links between vision and touch in covert endogenous spatial attention

The authors report a series of 6 experiments investigating crossmodal links between vision and touch in covert endogenous spatial attention. When participants were informed that visual and tactile targets were more likely on 1 side than the other, speeded discrimination responses (continuous vs. pulsed, Experiments 1 and 2; or up vs. down, Experiment 3) for targets in both modalities were significantly faster on the expected side, even though target modality was entirely unpredictable. When participants expected a target on a particular side in just one modality, corresponding shifts of covert attention also took place in the other modality, as evidenced by faster elevation judgments on that side (Experiment 4). Larger attentional effects were found when directing visual and tactile attention to the same position rather than to different positions (Experiment 5). A final study with crossed hands revealed that these visuotactile links in spatial attention apply to common positions in external space.     

Spatial constraints on visual-tactile cross-modal distractor congruency effects

Across three experiments, participants made speeded elevation discrimination responses to vibrotactile targets presented to the thumb (held in a lower position) or the index finger (upper position) of either hand, while simultaneously trying to ignore visual distractors presented independently from either the same or a different elevation. Performance on the vibrotactile elevation discrimination task was slower and less accurate when the visual distractor was incongruent with the elevation of the vibrotactile target (e.g., a lower light during the presentation of an upper vibrotactile target to the index finger) than when they were congruent, showing that people cannot completely ignore vision when selectively attending to vibrotactile information. We investigated the attentional, temporal, and spatial modulation of these cross-modal congruency effects by manipulating the direction of endogenous tactile spatial attention, the stimulus onset asynchrony between target and distractor, and the spatial separation between the vibrotactile target, any visual distractors, and the participant’s two hands within and across hemifields. Our results provide new insights into the spatiotemporal modulation of crossmodal congruency effects and highlight the utility of this paradigm for investigating the contributions of visual, tactile, and proprioceptive inputs to the multisensory representation of peripersonal space.     

Configuration-specific attentional modulation of flanker- -target lateral interactions

Elements of a contour are often easier to detect when they possess collinearity, with their local orientations matching the global orientation of the contour. We recently reported attentional modulation of such lateral interactions between a central near-threshold target Gabor patch and flanking high-contrast patches (Freeman et al, 2001 Nature Neuroscience 4 1032-1036). Here, we examined whether such attentional effects reflect specific modulation of mechanisms sensitive to collinear configurations, or instead more general modulation of sensitivity to either the global or local orientation-components of the stimulus. Thresholds for detecting a central Gabor target were measured, while observers also judged the Vernier alignment between one pair of flankers and ignored a second flanker pair (when present). Target contrast-thresholds were facilitated only when attending collinear flankers. There was no facilitation when attending flankers that shared only local orientation with the target, or flankers that fell on a global axis aligned with target orientation but having orthogonal local orientation. Ignored collinear flankers had no effect on target thresholds. These results demonstrate strong and specific attentional modulation of contour-integration mechanisms in early vision sensitive to collinear configurations.     

Effects of a carbohydrate-restricted diet on affective responses to acute exercise among physically active participants

Currently, the carbohydrate-restricted diet is very popular. Atkins' book, Dr. Atkins' Diet Revolution, has sold millions in its more than 25 years of existence. His book promotes the carbohydrate-restricted diet, which focuses on the consumption of proteins and fats as primary calorie and energy sources, while severely restricting carbohydrates. However, when carbohydrates are restricted from the diet, the body's primary energy source is reduced considerably. Therefore, the purpose of this study was to compare the psychological responses to exercise of individuals when on a carbohydrate restrictive diet and when on a noncarbohydrate restrictive diet. For this study, 17 participants practiced a noncarbohydrate-restricted diet for three weeks and the carbohydrate-restricted diet for three weeks, while maintaining previous exercise habits. After each exercise session, the participants completed the Physical Activity Affect Scale, which measures Positive Affect, Negative Affect, Tranquility, and Fatigue. Simple one-way analyses of variance indicated significant treatment differences (ps<.05) relative to Negative Affect, Positive Affect, and Fatigue. The results of the study indicate as predicted, that, when a person restricts carbohydrates from the diet, he will experience more fatigue, more negative affect, and less positive affect in response to exercise than those individuals who are not restricting carbohydrates.