We can imagine looking at ourselves (observer perspective) or through our own eyes (field perspective). Cognitive and clinical theories suggest that compared to field perspective, observer perspective imagery reduces emotional intensity, for example, of trauma memories. Tests of causality are lacking and less is known about perspective and positive emotion. Using contrasting experimental manipulations, participants imagined 100 positive descriptions from either (1) a field perspective or (2) an observer perspective, or (3) thought about their verbal meaning. Affect was more positive after field than observer imagery and verbal conditions, with mood deterioration within the latter two. Findings are the first to demonstrate causality of imagery perspective on emotion. Further, the results demonstrate that imagining positive events from one's own perspective is critical to improving positive affect. Treatment implications include promoting field imagery to facilitate a more rose-tinted view of positive events.

Relativistic causality has dramatic consequences on the measurability of nonlocal variables and poses the fundamental question of whether it is physically meaningful to speak about the value of nonlocal variables at a particular time. Recent work has shown that by weakening the role of the measurement in preparing eigenstates of the variable it is in fact possible to measure all nonlocal observables instantaneously by exploiting entanglement. However, for these measurement schemes to succeed with certainty an infinite amount of entanglement must be distributed initially and all this entanglement is necessarily consumed. In this work we sharpen the characterisation of instantaneous nonlocal measurements by explicitly devising schemes in which only a finite amount of the initially distributed entanglement is ever utilised. This enables us to determine an upper bound to the average consumption for the most general cases of nonlocal measurements. This includes the tasks of state verification, where the measurement verifies if the system is in a given state, and verification measurements of a general set of eigenstates of an observable. Despite its finiteness the growth of entanglement consumption is found to display an extremely unfavourable exponential of an exponential scaling with either the number of qubits needed to contain the Schmidt rank of the target state or total number of qubits in the system for an operator measurement. This scaling is seen to be a consequence of the combination of the generic exponential scaling of unitary decompositions combined with the highly recursive structure of our scheme required to overcome the no-signalling constraint of relativistic causality.PACS numbers: 03.65.Yz, 05.60.Gg ‡ This situation is in contrast to the usual nonlocality without entanglement scenario where the constraint is on quantum resources and unlimited classical communication is assumed [13].

Phenomenologically speaking, we perceive the present, recall the past, and anticipate the future. We offer an account of the temporal content of the perceptual present that distinguishes it from the recalled past and the anticipated future. We distinguish two views: the Token-Reflexive Account and the Minimal Account. We offer reasons to reject the Token-Reflexive Account, and defend the Minimal Account, according to which the temporal content of the perceptual present is exhausted by its direct reference to the interval of time over which it occurs.

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