Error can arise due to increased variability in memory for orientation of the probed item, captured by model parameter κ, where higher κ corresponds to lower variability in memory for the orientation (Fig. 2A).
This 'sensory working memory' [6] has recently been investigated in a series of functional magnetic resonance imaging (fMRI) studies, probing delay period activity in memory tasks for orientation [7] and color [8] using multi-voxel pattern analysis (MVPA [9]).
Devised by Shah and Miyake (1996) this task combines mental rotation with short-term memory for the orientation of a sequence of arrows.
Four parameters (see Figure 5a) were extracted for each participant: κ (kappa), a concentration parameter encapsulating Gaussian variability in memory for target orientations, and parameters representing the probability of reporting the target orientation, a non-target orientation and a random orientation.
A probability on each trial of misreporting one of the other, nontarget orientations in the sequence, A probability of responding with a random orientation, not related to any of the items in the sequence, Gaussian variability in memory for the target orientation.
This model, building on an earlier proposal by Zhang and Luck (2008), attributes errors in the continuous-report task to three sources: A probability on each trial of misreporting one of the other, nontarget orientations in the sequence, A probability of responding with a random orientation, not related to any of the items in the sequence, Gaussian variability in memory for the target orientation.
Rating behaviors differed between subgroups for memory, orientation and independence.
Results of comparisons between subgroups on rating as the least or most valuable domain showed significant differences (P < .05) for memory, orientation and independence.
Successful performance also requires memory for correct combination of orientation and colour.
Scored on a 30-point scale, the MMSE screens for difficulties in episodic memory, orientation, working memory, naming, language, and image copying.
Wurtman believes that is because ADAS-cog is a more general assessment that tests for orientation and movement/spatial memory as well as cognition.
