Effects of Complexity on Visuo-spatial Working Memory

Author version made available in accordance with the publisher's policy.Four experiments are reported in which the effect of complexity on short-term retention of visuo-spatial material was explored. The determinants of complexity can be separated into a quantitative factor, which sets an upper bound on complexity, and a structural factor, which reduces complexity. Variants of the Corsi blocks task were administered across the various experiments. Quantitative complexity was manipulated through the number of blocks on the board. Structural complexity was induced through the positioning of the blocks. Visuo-spatial span was found to be susceptible to both measures of complexity. Performance was inversely related to the number of blocks. Recall was also better when the blocks were positioned in a matrix than in a random fashion. Moreover, the effect of complexity was shown to be moderated by an interaction between structure and amount of information presented. These results demonstrate that complexity is an important characteristic of visuo-spatial working memory. This phenomenon may be used to further explore the properties of the visuo-spatial sketch pad, and advance its theoretical development

Complexity effects in visuo-spatial working memory: Implications for the role of long-term memory

Author version made available in accordance with the publisher's policy.Several studies have shown that the capacity of visuo-spatial working memory is limited by complexity. Using a variant of the Corsi blocks task, this paper investigated the effect of complexity of the to-be-remembered path on visuo-spatial memory span. Redundancy was determined by three Gestalt principles: symmetry, repetition and continuation. Experiment 1 revealed an effect of path complexity. The subsequent experiments explored whether the superiority for recall of structured over complex paths can be attributed solely to the operation of visuo-spatial working memory, or whether it also reflects the use of long-term knowledge. Experiment 2 demonstrated that the effect of complexity remained, even when the mechanisms for visuo-spatial coding were removed by a secondary visuo-spatial task. In Experiments 3 and 4 subjects were trained in the recall of complex paths. This led to the creation of long-term memory representations for these paths, as shown by an improvement in their span, and a concomitant lack of transfer to new paths. Finally, Experiment 5 showed that one prior repetition of a complex path was sufficient to produce specific and long-term learning effects. These results point to the involvement of long-term memory processes in the temporary retention of visuo-spatial material for which representations exist in long-term memory. They also suggest that the effect of complexity may provide a tractable technique for investigating the mechanisms underlying the limits of visuo-spatial short-term storage

Approach bias for food cues in obese individuals

This study aimed to investigate the existence of an approach bias for food cues in obese individuals. A community sample of 56 obese women and 56 normal weight controls completed an approach–avoidance variant of the implicit association task. The obese participants were faster to respond to trials that paired food words with approach words, and trials that paired non-food words with avoid words, than the converse pairings, thus, demonstrating an approach bias for food. This bias was evident for both high caloric and low caloric food words, and was not attributable to a state of deprivation or feelings of hunger. By contrast, the normal weight controls did not show any such bias. The results are consistent with recent neurocognitive perspectives of obesity. At a practical level, approach biases for food may present a potential target for modifying (excessive) food intake

Hand-held dynamic visual noise reduces naturally occurring food cravings and craving-related consumption

Author version made available in accordance with the publisher's policy for non-mandated open access submission. Under Elsevier's copyright, non-mandated authors are permitted to make work available in an institutional repository.This study demonstrated the applicability of the well-established laboratory task, dynamic visual noise, as a technique for reducing naturally occurring food cravings and subsequent food intake. Dynamic visual noise was delivered on a hand-held computer device. Its effects were assessed within the context of a diary study. Over a 4-week period, 48 undergraduate women recorded their food cravings and consumption. Following a 2-week baseline, half the participants watched the dynamic visual noise display whenever they experienced a food craving. Compared to a control group, these participants reported less intense cravings. They were also less likely to eat following a craving and consequently consumed fewer total calories following craving. These findings hold promise for curbing unwanted food cravings and craving-driven consumption in real-world settings

Olfactory stimulation curbs food cravings

Author version made available in accordance with the publisher's policy for non-mandated open access submission. Under Elsevier's copyright, non-mandated authors are permitted to make work available in an institutional repository.Based on the logic of mutual competition between cravings and odours for limited-capacity resources, this study investigated whether a simple olfactory task, involving a brief odour exposure, could reduce food cravings. In support, Experiment 1 showed that smelling a neutral unfamiliar odorant reduced cravings for highly desired food items, relative to a comparison auditory task and a no-task control condition. Experiment 2 replicated these findings specifically for chocolate cravings, which can be particularly problematic. Thus olfactory stimulation offers potential scope for curbing unwanted food cravings. Keywords: craving; food; odour; craving reductio

A Cognitive Experimental Approach to Understanding and Reducing Food Cravings

Author version made available in accordance with the publisher's policy.Food cravings are a common everyday experience. Yet, they can pose significant health risks for some people. Following initial investigations into the phenomenology, antecedents and consequences of food cravings, recent scientific interest has turned to the underpinnings of the actual craving experience itself. In this article, we outline a conceptual framework for studying food cravings that is grounded in cognitive experimental psychology, along with our corresponding program of research. In particular, we present converging evidence from a number of seemingly disparate lines of research into the cognitive processes that underlie food cravings with a view to developing a craving-reduction technique

Is cake more appealing in the afternoon? Time of day is associated with control over automatic positive responses to unhealthy food

Despite researchers considering time of day an important variable in studies on implicit food evaluations and food intake, time of day effects on implicit food evaluations have yet to be tested. Positive implicit evaluations of unhealthy food stimuli measured with an implicit association test (IAT) predict behaviour toward those stimuli, and are assumed to reflect automatic reactions outside of conscious awareness and control. However, recent research has revealed controlled processing to have an influence on IAT performance. The current study tested time of day effects on implicit evaluations of unhealthy food measured with an IAT, and specifically on automatic and controlled processes underlying IAT performance. A sample of 304 undergraduate women aged 17–25 years completed a single-category IAT at varying times of the day. Results revealed that participation later in the day was associated with a more positive implicit evaluation of unhealthy food. This was mediated by a decrease in the ability to inhibit positive food reactions (i.e., controlled processing), rather than an increase in automatic positive reactions. The findings draw attention to the importance of considering time of day in studies measuring aspects of implicit cognition using tasks such as the IAT.No Full Tex

Too Depleted to Try? Testing the Process Model of Ego Depletion in the Context of Unhealthy Snack Consumption

Background: The process model proposes that the ego depletion effect is due to (a) an increase in motivation toward indulgence, and (b) a decrease in motivation to control behaviour following an initial act of self-control. In contrast, the reflective-impulsive model predicts that ego depletion results in behaviour that is more consistent with desires, and less consistent with motivations, rather than influencing the strength of desires and motivations. The current study sought to test these alternative accounts of the relationships between ego depletion, motivation, desire, and self-control. Methods: One hundred and fifty-six undergraduate women were randomised to complete a depleting e-crossing task or a non-depleting task, followed by a lab-based measure of snack intake, and self-report measures of motivation and desire strength. Results and Conclusions: In partial support of the process model, ego depletion was related to higher intake, but only indirectly via the influence of lowered motivation. Motivation was more strongly predictive of intake for those in the non-depletion condition, providing partial support for the reflective-impulsive model. Ego depletion did not affect desire, nor did depletion moderate the effect of desire on intake, indicating that desire may be an appropriate target for reducing unhealthy behaviour across situations where self-control resources vary

External eating mediates the relationship between impulsivity and unhealthy food intake

Recent evidence from the eating domain shows a link between impulsivity and unhealthy food intake. However, the mechanism underlying this relationship remains unclear. One possibility is an external eating style, which has been linked to both impulsivity and food intake. The current study investigated the potential mediating role of external eating in the relationship between impulsivity and food intake. Participants were 146 undergraduate women who completed measures of impulsivity and external eating, and took part in a laboratory taste test as a behavioural index of unhealthy snack food intake. It was found that attentional and motor impulsivity interacted in predicting sweet food intake, but only motor impulsivity predicted both external eating and sweet food intake. Furthermore, the relationship between motor impulsivity and food intake was mediated by external eating. These findings support the development of interventions aimed at targeting specific aspects of impulsivity in order to reduce unhealthy eating behaviour.This research was supported under the Australian Research Council's Discovery Project funding scheme (project number DP130103092)