Biomedical subjects

Eva Kemps

Publications and source records attributed to Eva Kemps.

14 recordsLinked to original sources

PubMed2006

Reduction of vividness and associated craving in personalized food imagery.

This study aimed to extend recent experimental work on the efficacy of visuo-spatial working memory-based techniques for reducing food cravings by adopting a more naturalistic methodology. Fifty undergraduate women formed images of their favorite foods while performing a visuo-spatial task across six successive trials. Vividness and craving intensity were rated for each food image. Concurrent visuo-spatial processing reduced the vividness of, and craving reactivity to, personally relevant food images. Forehead tracking, a novel self-administered task, proved to be as effective in reducing vividness and craving ratings as the established visuo-spatial working memory laboratory tasks of eye movements, dynamic visual noise, and spatial tapping, and thus presents a simple, accessible technique potentially applicable in the home environment. All four tasks maintained their reducing effect over multiple trials. Individual differences in imaging ability and habitual food craving did not impact upon their effectiveness, indicating that visuo-spatial tasks can be successfully used to reduce food cravings across a range of people.

Adaptation, Psychological↗

PubMed2006

Comparison of adult age differences in verbal and visuo-spatial memory: the importance of 'pure', parallel and validated measures.

The study compared age-related decrements in verbal and visuo-spatial memory across a broad elderly adult age range. Twenty-four young (18-25 years), 24 young-old (65-74 years), 24 middle-old (75-84 years) and 24 old-old (85-93 years) adults completed parallel recall and recognition measures of verbal and visuo-spatial memory from the Doors and People Test (Baddeley, Emslie & Nimmo-Smith, 1994). These constituted 'pure' and validated indices of either verbal or visuo-spatial memory. Verbal and visuo-spatial memory declined similarly with age, with a steeper decline in recall than recognition. Unlike recognition memory, recall performance also showed a heightened decline after the age of 85. Age-associated memory loss in both modalities was largely due to working memory and executive function. Processing speed and sensory functioning (vision, hearing) made minor contributions to memory performance and age differences in it. Together, these findings demonstrate common, rather than differential, age-related effects on verbal and visuo-spatial memory. They also emphasize the importance of using 'pure', parallel and validated measures of verbal and visuo-spatial memory in memory ageing research.

Adolescent↗

PubMed2005

Effects of hunger and visuo-spatial interference on imagery-induced food cravings.

The present study investigated the effects of hunger and visuo-spatial interference on imagery-induced food cravings. Forty-two women were randomly assigned to a hungry (no food for prior 4h) or not hungry condition. Participants were asked to form and maintain images of desired foods while looking at a blank computer screen (control condition) or performing a task designed to load the visuo-spatial sketchpad of working memory (dynamic visual noise). They then rated the vividness of their images and their craving intensity. Although hungry participants reported stronger food cravings, dynamic visual noise made images less vivid and cravings less intense, irrespective of participant hunger status. Thus concurrent visuo-spatial processing may offer a useful technique for treating problematic food cravings that are predominantly psychological in origin, as well as those that are hunger-driven.

Adolescent↗

PubMed2005

Relationship between dieting to lose weight and the functioning of the central executive.

The study investigated the impact of weight-loss dieting on the four identified functions of the central executive of working memory: dual-task performance, random generation, task switching and activation of long-term memory. Participants were 32 female current dieters and 32 female non-dieters who completed four well-established cognitive tasks designed to tap each specific function. Participants also completed tasks designed to load on the phonological loop and visuo-spatial sketch pad working memory systems, as well as self-report measures of depressed affect and preoccupying cognitions. Dieters performed more poorly than non-dieters on all central executive measures except random generation. These dieting-related differences were most evident on moderately complex trials, and were partially mediated by preoccupying thoughts about food, weight and body shape, but not by BMI or depressed affect. It was concluded that weight-loss dieting has a relatively global impact on central executive functioning and thus has wide-ranging cognitive consequences.

Adult↗

PubMed2005

Chocolate cravings are susceptible to visuo-spatial interference.

The study investigated the specificity of visuo-spatial working memory-based techniques as a means to reduce chocolate cravings. Twenty-four self-identified chocolate cravers and 24 non-cravers formed and maintained images of chocolate-containing foods elicited by pictures, while performing a visuo-spatial task (loading the visuo-spatial sketch pad) or an auditory task (loading the phonological loop). Vividness and craving intensity were rated for each image. Concurrent visuo-spatial processing was found to render chocolate images significantly less vivid and cravings less intense compared to concurrent verbal processing, for both cravers and non-cravers. Chocolate cravers did, however, report higher levels of chocolate craving and intake than non-cravers. It was concluded that visuo-spatial tasks provide an effective craving reduction mechanism for the management of chocolate cravings. Such techniques may be particularly useful in populations for whom eating problems are triggered by chocolate craving.

Adolescent↗

PubMed2005

Visuo-spatial processing in Parkinson's disease: evidence for diminished visuo-spatial sketch pad and central executive resources.

A dual-task study compared the visuo-spatial sketch pad and central executive components of working memory as potential cognitive mechanisms of visuo-spatial dysfunction in Parkinson's disease. Mildly to moderately affected Parkinsonian patients (n = 15) and controls (n = 15) performed the Corsi blocks task concurrently with tasks designed to load on the visuo-spatial sketch pad (spatial tapping) or the central executive (random interval repetition). Patients performed more poorly in both concurrent task conditions, implicating a reduction in both visuo-spatial sketch pad and central executive resources. The impact of the concurrent tasks varied with disease severity, with the central executive deficit prominent at disease onset, but the visuo-spatial sketch pad deficit becoming apparent only in the moderate stages of the illness.

Aged↗

PubMed2005

Effects of saccharides on brain function and cognitive performance.

This review outlines a role for saccharides in the brain and offers predictions about how saccharides might influence cognitive performance. Animal studies provide a biological mechanism by which saccharides affect brain function and, in turn, cognition. Furthermore, recent intervention studies suggest that saccharides may have an effect on the cognitive performance of humans. Because the effects of saccharide supplementation on cognitive performance are likely to be subtle, future investigations will face various methodological challenges, not the least of which is the need for sensitive outcome measures.

Animals↗

PubMed2005

Working memory performance and preoccupying thoughts in female dieters: evidence for a selective central executive impairment.

OBJECTIVE: The study aimed to extend previous research into the impaired cognitive performance of spontaneous dieters by employing the Double Span Memory Task to investigate the relationship between weight-loss dieting and performance simultaneously on the three subsystems of working memory. METHOD: A sample of 33 dieting and 33 non-dieting women were presented with increasingly longer sequences of common objects, displayed successively in different, randomly chosen locations of a 4 x 4 grid. Participants were then asked to name the objects (phonological loop), point to the locations (visuospatial sketch pad), or both (central executive). Participants also completed self-report measures of preoccupying cognitions, dietary restraint, depressed affect, and verbal intelligence. RESULTS: Current dieters performed more poorly than non-dieters on combined recall, but not on the single recall of objects or locations. They also scored more highly on self-rated preoccupying cognitions. CONCLUSION: Dieting to lose weight selectively impairs central executive functioning, rather than the storage capacity of the two slave systems. This dieting-related central executive deficit is at best partly attributable to the preoccupying thoughts about food, weight, and body shape accompanying dieting.

Adolescent↗

PubMed2005

The nature of imagery processes underlying food cravings.

OBJECTIVE: The study used a working memory approach to examine the nature of the imagery processes underlying food cravings. DESIGN AND METHOD: A sample of 60 dieters and 60 non-dieters were asked to imagine either a food induction or a holiday induction scenario. Participants then performed 18 trials of either a visual imagery task (loading the visuo-spatial sketch pad) or auditory imagery task (loading the phonological loop). Food craving was measured before and after the induction scenario, and then after every 6 trials of the imagery task. RESULTS: Craving intensity increased following instructions to imagine the food (but not holiday) induction scenario, especially for dieters. As predicted, the visual imagery task was superior to the auditory imagery task in reducing the level of food craving. DISCUSSION: The results confirmed the imaginal basis of food cravings. Specifically, they demonstrated that the imagery processes involved in food cravings are predominantly visual in nature. Hence concurrent tasks that load the visuospatial sketch pad of working memory can be used to reduce food cravings. The findings have potential application in the treatment of craving episodes in clinical populations.

Acoustic Stimulation↗

PubMed2005

Response selection involves executive control: evidence from the selective interference paradigm.

In the present study, we investigated whether response selection involves executive control, using the selective interference paradigm within Baddeley's (1986) working memory framework. The interference from response selection was estimated by comparing the patterns of dual-task interference of simple and choice RT tasks with those of a number of established working memory tasks. In Experiment 1, we compared impairment of forward and backward verbal serial recall from the RT tasks and articulatory suppression. Experiment 2 measured the adverse effects of the RT tasks and matrix tapping on forward and backward visuospatial serial recall. Finally, in Experiment 3, we examined the impairment from the RT tasks with two measures of executive control--namely, letter and category fluency. Altogether, the three experiments demonstrated that response selection interferes with executive control and that the interference is not produced at the level of working memory's slave systems, which supports the assumption of executive involvement in response selection.

Choice Behavior↗

PubMed2004

Reduction of food cravings through concurrent visuospatial processing.

OBJECTIVE: Two experiments adopted a working memory approach to evaluate the effectiveness of visuospatial tasks as a technique for reducing food cravings. METHOD: Dieting and non-dieting women were asked to form images of both food-related and nonfood items, induced by either pictures (Experiment 1) or verbal cues (Experiment 2). They were required to concurrently perform one of three tasks that load on the visuospatial sketch pad of working memory: saccadic eye movements, dynamic visual noise, or spatial tapping. RESULTS: In support of the working memory model of limited visuospatial capacity, concurrent visuospatial activity reduced the vividness of food-related images which, in turn, reduced the intensity of the associated craving. The same pattern of results was observed across dieters and non-dieters and for all stimulus types. DISCUSSION: Visuospatial tasks may provide a useful technique for the treatment of food craving episodes in both nonclinical and clinical populations.

Adolescent↗

PubMed2004

Working memory components of the Corsi blocks task.

A computerized version of the Corsi blocks task (Milner, 1971) was assessed for standard forward-recall order (Experiments 1 and 3) and for reversed-recall order (Experiments 2 and 3) either in a single-task or in a dual-task design combined with articulatory suppression, matrix-tapping, random-interval generation or fixed-interval generation as concurrent tasks during the encoding stage. Concurrent performance of the matrix-tapping task impaired memory performance for short as well as for longer block sequences. The random-interval generation task, which loads executive processes, impaired memory performance mainly at intermediate- and longer-sequence lengths, while fixed-interval generation, which is presumed to put no load on executive processing, did not show any effect. Articulatory suppression did not impair memory performance on forward-recall order, but it impaired memory for longer sequences in the backward-recall condition in Experiment 2, but not in Experiment 3. The results are discussed within the context of the working-memory model of Baddeley and Hitch (1974).

Adult↗

PubMed2003

The effect of self-initiated weight-loss dieting on working memory: the role of preoccupying cognitions.

This study investigated the effects of weight loss dieting on the components of working memory and the extent to which these effects were mediated by preoccupying cognitions concerning food, diet and body shape. A dual task paradigm was used in which dieters (n=20) and non-dieters (n=20) completed mental arithmetic problems concurrently with suppression tasks designed to engage the central executive, phonological loop, and visuo-spatial sketchpad components of working memory. In addition, tasks reflecting the articulatory control process and phonological store sub-components of the phonological loop were also completed. Results showed that dieters performed more poorly on measures of the central executive and the phonological loop compared with non-dieters. Dieters reported higher levels of preoccupying cognitions which mediated the relationship between dieting status and functioning of the central executive and phonological loop, and the phonological store in particular.

Adult↗

PubMed2002

Insensitivity of visual short-term memory to irrelevant visual information.

Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment I replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.

Adolescent↗