Stephen P. Badham

Vision-related symptoms as a clinical feature of chronic fatigue syndrome/myalgic encephalomyelitis? Evidence from the DePaul Symptom Questionnaire

Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is a debilitating disorder, affecting at least 250 000 people in the UK. Marked by debilitating fatigue, its aetiology is poorly understood and diagnosis controversial. A number of symptoms overlap with other illnesses with the result that CFS/ME is commonly misdiagnosed. It is important therefore that significant clinical features are investigated. People diagnosed with CFS/ME consistently report that they experience vision-related symptoms associated with their illness1–⇓3 and some of these reports are being verified experimentally.4 Although vision-related symptoms may represent a significant clinical feature of CFS/ME that could be useful in its diagnosis, they have yet to be included in clinical guidelines. A recently developed, standardised measure designed to assess core CFS/ME symptoms, The DePaul Symptom Questionnaire (DSQ),5 includes four vision-related items: eye pain, …

What you know can influence what you are going to know (especially for older adults)

Stimuli related to an individual’s knowledge/experience are often more memorable than abstract stimuli, particularly for older adults. This has been found when material that is congruent with knowledge is contrasted with material that is incongruent with knowledge, but there is little research on a possible graded effect of congruency. The present study manipulated the degree of congruency of study material with participants’ knowledge. Young and older participants associated two famous names to nonfamous faces, where the similarity between the nonfamous faces and the real famous individuals varied. These associations were incrementally easier to remember as the name–face combinations became more congruent with prior knowledge, demonstrating a graded congruency effect, as opposed to an effect based simply on the presence or absence of associations to prior knowledge. Older adults tended to show greater susceptibility to the effect than young adults, with a significant age difference for extreme stimuli, in line with previous literature showing that schematic support in memory tasks particularly benefits older adults.

When does prior knowledge disproportionately benefit older adults’ memory?

ABSTRACT Material consistent with knowledge/experience is generally more memorable than material inconsistent with knowledge/experience – an effect that can be more extreme in older adults. Four experiments investigated knowledge effects on memory with young and older adults. Memory for familiar and unfamiliar proverbs (Experiment 1) and for common and uncommon scenes (Experiment 2) showed similar knowledge effects across age groups. Memory for person-consistent and person-neutral actions (Experiment 3) showed a greater benefit of prior knowledge in older adults. For cued recall of related and unrelated word pairs (Experiment 4), older adults benefited more from prior knowledge only when it provided uniquely useful additional information beyond the episodic association itself. The current data and literature suggest that prior knowledge has the age-dissociable mnemonic properties of (1) improving memory for the episodes themselves (age invariant), and (2) providing conceptual information about the tasks/stimuli extrinsically to the actual episodic memory (particularly aiding older adults).

Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome

BackgroundPeople who suffer from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report that their eye movements are sluggish and that they have difficulties tracking moving objects. However, descriptions of these visual problems are based solely on patients’ self-reports of their subjective visual experiences, and there is a distinct lack of empirical evidence to objectively verify their claims. This paper presents the first experimental research to objectively examine eye movements in those suffering from ME/CFS.MethodsPatients were assessed for ME/CFS symptoms and were compared to age, gender, and education matched controls for their ability to generate saccades and smooth pursuit eye movements.ResultsPatients and controls exhibited similar error rates and saccade latencies (response times) on prosaccade and antisaccade tasks. Patients showed relatively intact ability to accurately fixate the target (prosaccades), but were impaired when required to focus accurately in a specific position opposite the target (antisaccades). Patients were most markedly impaired when required to direct their gaze as closely as possible to a smoothly moving target (smooth pursuit).ConclusionsIt is hypothesised that the effects of ME/CFS can be overcome briefly for completion of saccades, but that continuous pursuit activity (accurately tracking a moving object), even for a short time period, highlights dysfunctional eye movement behaviour in ME/CFS patients. Future smooth pursuit research may elucidate and improve diagnosis of ME/CFS.

Replicating distinctive facial features in lineups : Identification performance in young versus older adults

Criminal suspects with distinctive facial features, such as tattoos or bruising, may stand out in a police lineup. To prevent suspects from being unfairly identified on the basis of their distinctive feature, the police often manipulate lineup images to ensure that all of the members appear similar. Recent research shows that replicating a distinctive feature across lineup members enhances eyewitness identification performance, relative to removing that feature on the target. In line with this finding, the present study demonstrated that with young adults (n = 60; mean age = 20), replication resulted in more target identifications than did removal in target-present lineups and that replication did not impair performance, relative to removal, in target-absent lineups. Older adults (n = 90; mean age = 74) performed significantly worse than young adults, identifying fewer targets and more foils; moreover, older adults showed a minimal benefit from replication over removal. This pattern is consistent with the associative deficit hypothesis of aging, such that older adults form weaker links between faces and their distinctive features. Although replication did not produce much benefit over removal for older adults, it was not detrimental to their performance. Therefore, the results suggest that replication may not be as beneficial to older adults as it is to young adults and demonstrate a new practical implication of age-related associative deficits in memory.

Age-related associative deficits are absent with nonwords.

Words and nonwords were used as stimuli to assess item and associative recognition memory performance in young and older adults. Participants were presented with pairs of items and then tested on both item memory (old/new items) and associative memory (intact/recombined pairs). For words, older participants performed worse than young participants on item and associative tests but to a greater extent on the latter. In contrast, for nonwords, older participants performed equally worse than young participants on item and associative tests. This is the first study to demonstrate that a manipulation of stimulus novelty can alter age-related associative deficits.

Antimnemonic effects of schemas in young and older adults

Schema-consistent material that is aligned with an individual’s knowledge and experience is typically more memorable than abstract material. This effect is often more extreme in older adults and schema use can alleviate age deficits in memory. In three experiments, young and older adults completed memory tasks where the availability of schematic information was manipulated. Specifying nonobvious relations between to-be-remembered word pairs paradoxically hindered memory (Experiment 1). Highlighting relations within mixed lists of related and unrelated word pairs had no effect on memory for those pairs (Experiment 2). This occurred even though related word pairs were recalled better than unrelated word pairs, particularly for older adults. Revealing a schematic context in a memory task with abstract image segments also hindered memory performance, particularly for older adults (Experiment 3). The data show that processing schematic information can come with costs that offset mnemonic benefits associated with schema-consistent stimuli.

Patterns of abnormal visual attention in myalgic encephalomyelitis.

Purpose To experimentally assess visual attention difficulties commonly reported by those with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Methods Twenty-nine ME/CFS patients and 29 controls took part in the study. Performance was assessed using the Useful Field of View (UFOV), a spatial cueing task and visual search. Results Patients and controls performed similarly on the processing speed subtest of the UFOV. However, patients exhibited marginally worse performance compared with controls on the divided attention subtest and significantly worse performance on the selective attention subtest. In the spatial cueing task, they were slower than controls to respond to the presence of the target, particularly when cues were invalid. They were also impaired, relative to controls, on visual search tasks. Conclusions We have provided experimental evidence for ME/CFS-related difficulties in directing visual attention. These findings support the subjective reports of those with ME/CFS and could represent a potential means to improve diagnosis.

Age-related associative deficits and the isolation effect

ABSTRACT If all but one of the items in a list are similar (e.g., all black except one red), memory for the different item is enhanced (the isolation effect). Older adults generally show similar or smaller isolation effects compared to young adults, which has been attributed to age-related deficits in associative memory whereby older adults are less able to associate an isolated stimulus to its isolating feature. Experiment 1 examined the isolation effect for isolation based on spatial position, modality and color; in Experiment 2, the criterion for isolation was the associative relation between stimuli. The results consistently showed no differences between young and older participants in the magnitude of the isolation effect. Whilst age deficits in associative memory may act to reduce the isolation effect in older adults, age deficits in self-initiated processing and inhibitory functionality may counteract this reduction by enhancing the isolation effect in older adults.

Effects of time of day on age-related associative deficits

Time of day is known to influence cognition differently across age groups, with young adults performing better later than earlier in the day and older adults showing the opposite pattern. Thus age-related deficits can be smaller when testing occurs in the morning compared with the afternoon/evening, particularly for tasks requiring executive/controlled/inhibitory processes. Stronger influences of time of day were therefore predicted on associative than on item recognition memory based on their differential requirements for demanding recollective (rather than familiarity) processes. In 2 experiments, participants were presented with unrelated word pairs and then tested on both item recognition (old/new item?) and associative recognition (intact/recombined pair?). In Experiment 1, young adults were tested either in the morning or in the evening; recognition memory was better when time of testing matched participants’ morningness-eveningness preferences, and more so for associative than for item memory. In Experiment 2, young and older adults (evening and morning types, respectively) were tested both in the morning and in the evening; again, recognition memory was better at participants’ preferred times of day, especially for associative memory. Consequently, age-related associative deficits varied considerably—indeed more than fourfold—from a nonsignificant 8% for testing in the morning to a substantial 35% for testing in the evening, suggesting that it is important to consider time of day effects in future studies of the associative deficit hypothesis.