Visual short-term memory binding deficits in familial Alzheimer’s disease

Abstract

Short-term memory binding is a memory function that underpins the temporary retention of complex objects (e.g. shapes with colours). In the verbal domain, this function has been found to be impaired in sporadic Alzheimer's disease. Whether short-term memory binding is also impaired in familial Alzheimer's disease, whether this impairment extends to the visual domain and whether it could be detected earlier than other cognitive deficits are issues yet to be investigated. Twenty two patients with familial Alzheimer's disease caused by the E280A single presenilin-1 mutation, thirty carriers of the mutation who did not meet Alzheimer's disease criteria (asymptomatic carriers) and 30 healthy relatives (non-carrier healthy controls) were assessed with a visual short-term memory task and a neuropsychological battery. The short-term memory task assessed the recognition of shapes, colours or shape-colour bindings presented in two consecutive arrays (i.e. study and test). Changes, which always occurred in the test array, consisted of new features replacing studied features (single feature conditions) or of features swapping across items (the binding condition). The neuropsychological battery comprised tests of associative and non-associative memory, attention, language, visuospatial and executive functions. Patients with Alzheimer's disease and asymptomatic carriers performed significantly worse than healthy controls in the feature binding condition only. Group comparisons between asymptomatic carriers and healthy controls on standard neuropsychological tasks revealed no significant differences. Classification and area under the curve analyses confirmed that the binding task combines more sensitivity and specificity for patients with Alzheimer's disease and most notably for asymptomatic carriers of the mutation than other traditional neuropsychological measures. This suggests that visual short-term memory binding deficits may be a preclinical marker for familial Alzheimer's disease.

Deficits in object-in-place but not relative recency performance in the APPswe/PS1dE9 mouse model of Alzheimer’s disease: Implications for object recognition

“…There are other findings from the human literature that are also consistent with this suggestion. Several authors have reported selective deficits in AD patients on tasks which require the association of different aspects of a stimulus -termed memory binding [62,65,66,67], and one particular study by Parra et al [67] described results that closely mirrored our findings. Participants were presented with two visual stimuli with various colours 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 21 (C) and shapes (S).…”

Visual short-term memory binding deficits in Alzheimer's disease: a reply to Parra's commentary.

“…According to Parra, a good diagnostic task for AD should rely on measures that are not influenced by age, such as the "conjunctive" binding task he and his colleagues have developed (Parra et al, 2010a;Parra, Abrahams, Logie & Della Sala 2010b). In our opinion, the best task should have the highest predictive power when comparing individuals who will develop AD to age-matched controls who do not share the same risk factors.…”

Item familiarity and controlled associative retrieval in Alzheimer's disease: An fMRI study

“…They found that both item and associative recall were impaired in MCI patients, but that associative recall was 5 more impaired and more sensitive to MCI than item recall. Interestingly, it appeared that AD patients' difficulties with associations are not specific to long-term memory but are also robustly demonstrated in short-term memory (Della Sala et al, 2012;Parra et al, 2009Parra et al, , 2010aParra et al, , 2010bvan Geldorp et al, 2012).…”