Music causes deterioration of source memory: Evidence from normal ageing

Previous research has shown that music exposure can impair a wide variety of cognitive and behavioural performance. We investigated whether this is the case for source memory. Forty-one younger adults and 35 healthy elderly were required to retain the location in which pictures of coloured objects were displayed. On a subsequent recognition test they were required to decide whether the objects were displayed in the same location as before or not. Encoding took place (a) in silence, (b) while listening to street noise, or (c) while listening to Vivaldi's “Four Seasons”. Recognition always took place during silence. A significant reduction in source memory was observed following music exposure, a reduction that was more pronounced for older adults than for younger adults. This pattern was significantly correlated with performance on an executive binding task. The exposure to music appeared to interfere with binding in working memory, worsening source recall.

Similarity between remembering the past and imagining the future in Alzheimer's disease: Implication of episodic memory

Recent studies suggest that common cognitive processes and neuroanatomical substrates underlie the ability to remember the past and imagine the future. We studied these cognitive processes in patients with Alzheimer's Disease (AD). We asked 27 participants with AD and 30 older controls, matched by age, sex, and educational level, to generate past and future autobiographical events. Autobiographical generation was analyzed with respect to theme, general autobiographical performance, contextual performance, self-defining memories, and autonoetic reliving/re-experiencing. Unlike older controls, most AD participants evoked similar themes when generating past and future events (n=23/30 participants). These participants also showed similar autobiographical and contextual performance, similar amount of self-defining memories, and similar autonoetic states when generating past and future events. Further, significant correlations were detected between hippocampal-dependent memory decline in AD participants and their ability to relive past and future events. These outcomes suggest striking similarities between remembering the past and imagining the future in AD. Due to their memory decline, imagining the future in AD patients is likely to draw heavily from the little amount of available information from past episodes, resulting in striking similarities between remembering the past and imagining the future. Finally, and unlike AD participants, older controls mentally "try out" alternative approaches to upcoming situations without replicating the same schemes of past events.

Autobiographical recall triggers visual exploration

Autobiographical recall is thought to rely on the ability to generate a visual image of the remembered event. Neuropsychological studies suggest a relationship between deterioration in visual mental imagery and autobiographical distortions, while neuroimaging data similarly implicate visual brain areas in autobiographical recall. However, neither whether autobiographical retrieval is associated with visual exploration, or not. Our paper aimed to provide such evidence one way or the other. Using an eye tracking system, we recorded eye movements of 40 participants during autobiographical recall and during a control condition in which participants had to count aloud. In both conditions, the participants had to look at a blank screen while their gaze location was recorded by the eye-tracker. Autobiographical recall triggered a lower number of fixations and reduced their duration. In contrast, the number, duration, and amplitude of saccades increased compared to the control condition. Our data suggest that autobiographical recall is characterized by visual processing.

Cognitive insight in schizophrenia patients and their biological parents: a pilot study

BACKGROUND

Clinical insight in schizophrenia patients is partly associated with familial environment but has been poorly studied to date. We aimed to explore (1) the relationship between parents' cognitive insight and their offspring's; (2) the relationship between parents' cognitive insight and their clinical insight into the disease of their offspring; and (3) the clinical and cognitive determinants of cognitive insight in parents.

METHODS

Cognitive insight was assessed in 37 patient-biological parent pairs/dyads with the Beck Cognitive Insight Scale (BCIS). Other measures included the Scale to assess Unawareness of Mental Disorder and cognitive assessments.

RESULTS

We found no significant association between parents' cognitive insight and their offspring's. Conversely, a positive association between parents' cognitive insight and parents' insight into their offspring's symptoms was found. Better awareness of their offspring's specific symptoms was associated with lower levels of overconfidence in one's beliefs and with BCIS total score. BCIS Self-Certainty and BCIS total score were associated with better executive functioning and verbal comprehension.

CONCLUSIONS

Better insight into their offspring's symptoms is associated with cognitive insight in biological parents of schizophrenia patients. Our results support the integration of cognitive intervention targeting parents' cognitive flexibility in family psychoeducational programs and provide an important first step towards developing a more refined understanding of the factors involved in insight into symptoms of illness in parents of schizophrenia patients.

Episodic memory decline in Huntington's disease, a binding deficit?

BACKGROUND

Huntington's disease (HD) is characterized by episodic memory deterioration.

OBJECTIVE

Our paper investigates the cognitive mechanisms that might underlie this decline. To this aim, we tested two executive hypotheses, the binding and the inhibition hypotheses.

METHODS

Fifteen HD patients (Mean Cytosine-Adenine-Guanine repeats = 44.93, SD = 2.82), and eighteen controls matched for age, gender and education were assessed with a neuropsychological battery tapping episodic memory and several executive functions, including binding and inhibition.

RESULTS

Episodic decline in patients with HD was only related to binding performance.

CONCLUSIONS

Our study shows that HD patients suffer from a perturbation of the associative or integrative mechanisms responsible for the combination of different memory features into complex episodic representations. Damage to frontal-hippocampal circuitry in HD is likely to be responsible for this impairment.

Context memory in Alzheimer's disease

Background

Alzheimer's disease (AD) is a neurodegenerative disease characterized by a gradual loss of memory. Specifically, context aspects of memory are impaired in AD. Our review sheds light on the neurocognitive mechanisms of this memory component that forms the core of episodic memory function.

Summary

Context recall, an element of episodic memory, refers to remembering the context in which an event has occurred, such as from whom or to whom information has been transmitted.

Key Messages

Our review raises crucial questions. For example, (1) which context element is more prone to being forgotten in the disease? (2) How do AD patients fail to bind context features together? (3) May distinctiveness heuristic or decisions based on metacognitive expectations improve context retrieval in these patients? (4) How does cueing at retrieval enhance reinstating of encoding context in AD? By addressing these questions, our work contributes to the understanding of the memory deficits in AD.

Destination memory in mild Alzheimer's Disease

In order to assess their destination memory, sixteen patients with probable mild Alzheimer Disease (AD), sixteen older adults and 16 young adults were asked to tell facts to pictures. On a subsequent task, they were asked to remember whether they had previously told that fact to that face or not. AD patients showed poorer destination recall than the older adults, and the older adults showed poorer destination recall than the young adults. Our results suggest that destination memory is highly impaired in AD.

Source monitoring in Alzheimer's disease

Source monitoring is the process of making judgments about the origin of memories. There are three categories of source monitoring: reality monitoring (discrimination between self- versus other-generated sources), external monitoring (discrimination between several external sources), and internal monitoring (discrimination between two types of self-generated sources). We investigated whether Alzheimer's Disease (AD) patients, when compared with young and older adults, are impaired at the same level on the three source monitoring categories. We designed three tasks, one for each source monitoring category. In the first task, aimed at reality monitoring, participants had to remember whether objects were previously placed in a bag by themselves or by the experimenter. In the second task, assessing external monitoring, participants had to remember whether the experimenter had previously placed objects in the bag with a black or white gloved hand. In the third task, measuring internal monitoring, participants had to remember whether they had previously placed or imagined themselves placing objects in the bag. Participants showed worse performances in the external and internal monitoring tasks, when compared with reality monitoring. The external monitoring deficit was even more pronounced in AD patients. Regression analyses showed that variation in the external monitoring performances was reliably predicted by inhibition. Our results emphasize the role of inhibitory processes in AD patients' source monitoring decline. The close relation between source and inhibitory decline in AD is interpreted in terms of a common neural base for both concepts.

What do we know about the relationship between source monitoring deficits and executive dysfunction?

In clinical neuropsychology, source monitoring deficits have been classically attributed to executive dysfunction. Nevertheless, in this review we identified only 16 papers that provided statistical data about the relationships between source monitoring and executive processes. Surprisingly, they reported either a total, partial or non-existent relationship between source monitoring and executive tasks. In order to understand and explain these contradictions, we classified the source and executive tasks of the 16 papers according to two well-accepted definitions. Source tasks were classified using the Source Monitoring Framework (Johnson, Hashtroudi, & Lindsay, 1993 ) which specifies reality and external and internal source monitoring. Executive tasks were classified according to the model of Miyake Friedman, Emerson, Witzki, and Howerter (2000) which specifies complex, shifting, updating and inhibition tasks. We found that evaluation of reality and internal source monitoring was limited. Regarding executive functions, there was no assessment of updating and only a limited assessment of shifting and inhibition. Therefore, the relationship between source monitoring and executive functions remains an open question. Our findings point to the need for the simultaneous assessment of source monitoring and executive functions as defined by multidimensional theoretical frameworks. Such investigations would help in understanding the relationship between specific source monitoring deficits and specific executive decline in clinical populations.