Generalization and False Memory in an Acquired Equivalence Paradigm: The Influence of Physical Resemblance Across Related Episodes

The ability to make inferences about related experiences is an important function of memory that allows individuals to build generalizable knowledge. In some cases, however, making inferences may lead to false memories when individuals misremember inferred information as having been observed. One factor that is known to increase the prevalence of false memories is the physical resemblance between new and old information. The extent to which physical resemblance has parallel effects on generalization and memory for the source of inferred associations is not known. To investigate the parallels between memory generalization and false memories, we conducted three experiments using an acquired equivalence paradigm and manipulated physical resemblance between items that made up related experiences. The three experiments showed increased generalization for higher levels of resemblance. Recognition and source memory judgments revealed that high rates of generalization were not always accompanied by high rates of false memories. Thus, physical resemblance across episodes may promote generalization with or without a trade-off in terms of impeding memory specificity.

Maintained Visual-, Auditory-, and Multisensory-Guided Associative Learning Functions in Children With Obsessive–Compulsive Disorder

Sensory-guided acquired equivalence learning, a specific kind of non-verbal associative learning, is associated with the frontal cortex–basal ganglia loops and hippocampi, which seem to be involved in the pathogenesis of obsessive–compulsive disorder (OCD). In this study, we asked whether visual-, auditory-, and multisensory-guided associative acquired equivalence learning is affected in children with OCD. The first part of the applied learning paradigm investigated association building between two different sensory stimuli (where feedback was given about the correctness of the choices), a task that critically depends upon the basal ganglia. During the test phases, which primarily depended upon the hippocampi, the earlier learned and hitherto not shown but predictable associations were asked about without feedback. This study involved 31 children diagnosed with OCD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) criteria and 31 matched healthy control participants. The children suffering from OCD had the same performance as the control children in all phases of the applied visual-, auditory-, and multisensory-guided associative learning paradigms. Thus, both the acquisition and test phases were not negatively affected by OCD. The reaction times did not differ between the two groups, and the applied medication had no effect on the performances of the OCD patients. Our results support the findings that the structural changes of basal ganglia and hippocampi detected in adult OCD patients are not as pronounced in children, which could be the explanation of the maintained associative equivalence learning functions in children suffering from OCD.

Visually guided associative learning in pediatric and adult migraine without aura

Introduction The Rutgers Acquired Equivalence Test is a visually guided equivalence learning paradigm that involves rule acquisition and generalization. Earlier we found impaired performance in this paradigm among adult migraine patients without aura. The aim of the study was to investigate if similar impairments can be found already in the pediatric form of the disease and to compare the performance of the pediatric study population with that of an adult study population. We hypothesized that the deficits observed in adults would be observable already in the pediatric population. Methods Twenty-seven children and adolescents newly diagnosed with migraine without aura and 27 age- and sex-matched healthy controls were tested with the Rutgers Acquired Equivalence Test. Their performance data were compared to each other and those of an earlier adult study population involving 22 patients and 22 age- and sex-matched healthy controls. Four parameters characterizing performance in the two main phases of the paradigm were calculated for each of the four groups. Performance parameters were compared with Mann-Whitney U test. Results In contrast to the decreased performance of the adult patients in the Rutgers Acquired Equivalence Test, no significant difference was found between pediatric patients and controls in any phase of the paradigm. Conclusion Children living with migraine without aura do not exhibit the same cognitive deficits in the Rutgers Acquired Equivalence Test as their adult counterparts. It can be hypothesized that the deficit of equivalence learning is not an inherent feature of the migrainous cognitive profile, rather the result of the interference of the disease with normal development.

Generalization and source memory in acquired equivalence

Memory allows us to remember specific events but also combine information across events to infer new information. New inferences are thought to stem from integrating memories of related events during encoding but can be also generated on-demand, based on separate memories of individual events. Integrative encoding has been argued as dominant in the acquired equivalence paradigm, where people have a tendency to assume that when two faces share one preference, they also share another. A downside may be a loss of source memory, where inferred preferences are mistaken for observed ones. Here, we tested the predictions of integrative encoding across five data sets collected using small variations of the acquired equivalence paradigm. Results showed a statistically reliable but numerically small tendency to generalize preferences across faces, with stronger evidence for on-demand inferences at retrieval rather than spontaneous integration during encoding. Newly included explicit source memory test showed that participants differentiated learned from inferred preferences to a high degree, irrespective of whether they generalized preferences across faces. Overall, the results indicate that representations of individual events and retrieval-based processes may play a larger role in acquired equivalence than previously thought, informing current theories of generalization and knowledge representation.

Acquired equivalence and related memory processes in migraine without aura

Introduction Interictal deficits of elementary visuo-cognitive functions are well documented in patients with migraine and are mostly explained in terms of neocortical hyperexcitability. It has been suggested that the basal ganglia and the hippocampi might also be affected in migraine. If so, a deterioration of learning and memory processes related to these structures is expected. Methods A visual learning paradigm thought to be capable of dissociating learning/memory processes mediated by the basal ganglia from processes mediated by the hippocampus (the Rutgers Acquired Equivalence Test) was applied to a group of patients with migraine without aura and to age- and sex-matched controls. Results Patients with migraine showed a significantly poorer performance in both main phases of the test and the deficit in the phase considered to be dependent on the hippocampi was especially marked. Conclusions These results can be interpreted as behavioural support for findings that have suggested the involvement of the basal ganglia and the hippocampi in migraine, but further research is needed to clarify these findings.