Søren Kyllingsbæk

Visual short-term memory (VSTM) has traditionally been thought to have a very limited capacity of around 3–4 objects. However, recently several researchers have argued that VSTM may be limited in the amount of information retained rather than by a specific number of objects. Here we present a study of the effect of long-term practice on VSTM capacity. We investigated four age groups ranging from pre-school children to adults and measured the change in VSTM capacity for letters and pictures. We found a clear increase in VSTM capacity for letters with age but not for pictures. Our results indicate that VSTM capacity is dependent on the level of expertise for specific types of stimuli.

In a masked priming experimental paradigm, we studied a possible subliminal perception effect on a semantic selection task. To gauge the degree to which subjects solved the SST consciously, they subsequently reported their level of confidence of having made a correct response. This was done on each trial, and the subjects used individually constructed category rating scales to do so, in order to achieve a more sensitive measurement of which trials were influenced by conscious processes. During the construction of these individual rating scales, subjects verbally reported their experiences after each trial. The present study failed to find evidence of performance above chance level when subjects themselves reported to be at chance level. In fact, performance closely covaried with subjects' confidence ratings. About half of the subjects reported they would sometimes experience a 'feeling of knowing' the correct response to the SST, despite being unaware of the specific identity of the prime. From this, we observe the methodological point that in order to demonstrate subliminal perception in a masked priming paradigm with a semantic selection task it is not enough to demonstrate a lack of conscious visual perception of the prime, since a vague, yet conscious, FOK experience can be used by subjects to solve the task.

In this paper, we propose a new mathematical model of retrieval of intentions from long-term memory. We model retrieval as a stochastic race between a plurality of potentially relevant intentions stored in long-term memory. Psychological theories are dominated by two opposing conceptions of the role of memory in temporally extended agency – as when a person has to remember to make a phone call in the afternoon because, in the morning, she promised she would do so. According to the Working Memory conception, remembering to make the phone call is explained in terms of the construction and maintenance of intentions in working-memory. According to the Long-Term Memory conception, we should explain the episode in terms of an ability to store intentions in long-term memory. The two conceptions predict different processing profiles. The aim of this paper is to present a new mathematical model of the type of memory mechanism that could realise the long-term memory representations of intentions necessary for the Long-Term Memory conception. We present and illustrate the formal model and propose a new type of experimental paradigm that could allow us to test which of the two conceptions provides the best explanation of the role of memory in temporally extended agency.

When a person decides to do something in the future, she forms an intention and her intention persists. Philosophers have thought about the rational requirement that an agent’s intention persists until its execution. But philosophers have neglected to think about the causal memory mechanisms that could enable this kind of persistence and its role in rational long-term agency. Our aim of this paper is to fill this gap by arguing that memory for intention is a specific kind of memory. We do this by evaluating and rejecting standard declarative accounts of memory for intention and arguing for the plausibility of an alternative model of memory for intention. We argue for the alternative by spelling out a number of computational principles that could enable retaining and retrieving intentions from long-term memory. These principles could explain a number of core features of intentions.