The role of action effects in motor sequence planning and execution: exploring the influence of temporal and spatial effect anticipation

Actions we perform every day generate perceivable outcomes with both spatial and temporal features. According to the ideomotor principle, we plan our actions by anticipating the outcomes, but this principle does not directly address how sequential movements are influenced by different outcomes. We examined how sequential action planning is influenced by the anticipation of temporal and spatial features of action outcomes. We further explored the influence of action sequence switching. Participants performed cued sequences of button presses that generated visual effects which were either spatially compatible or incompatible with the sequences, and the spatial effects appeared after a short or long delay. The sequence cues switched or repeated across trials, and the predictability of action sequence switches was varied across groups. The results showed a delay-anticipation effect for sequential action, whereby a shorter anticipated delay between action sequences and their outcomes speeded initiation and execution of the cued action sequences. Delay anticipation was increased by predictable action switching, but it was not strongly modified by the spatial compatibility of the action outcomes. The results extend previous demonstrations of delay anticipation to the context of sequential action. The temporal delay between actions and their outcomes appears to be retrieved for sequential planning and influences both the initiation and the execution of actions.

The Anticipation Effect of the Earnings Test Reform on Younger Cohorts

The Social Security earnings test reform in 2000 eliminated the earnings test for all individuals between the normal retirement age (NRA) and age sixty-nine. The earnings test has long been accused of imposing a disincentive on the labor supply among older workers. In this article, we argue that the policy change may also have affected the labor supply among people who were just below the NRA around 2000. We utilize approaches embedded with a difference-in-differences design to estimate the anticipation effect on the labor supply of the slightly younger group (aged sixty-two to sixty-four) using an even younger cohort as the control group. Our preferred estimates indicate that the cohort aged sixty-two to sixty-four had worked 5.4 percent more weeks per year and 5.1 percent more hours per week after the earnings test reform in 2000.

HEARINGS AND MISHEARINGS: DECRYPTING THE SPOKEN WORD

We propose a model of the speech perception of individual words in the presence of mishearings. This phenomenological approach is based on concepts used in linguistics, and provides a formalism that is universal across languages. We put forward an efficient two-parameter form for the word length distribution, and introduce a simple representation of mishearings, which we use in our subsequent modeling of word recognition. In a context-free scenario, word recognition often occurs via anticipation when, part-way into a word, we can correctly guess its full form. We give a quantitative estimate of this anticipation threshold when no mishearings occur, in terms of model parameters. As might be expected, the whole anticipation effect disappears when there are sufficiently many mishearings. Our global approach to the problem of speech perception is in the spirit of an optimization problem. We show for instance that speech perception is easy when the word length is less than a threshold, to be identified with a static transition, and hard otherwise. We extend this to the dynamics of word recognition, proposing an intuitive approach highlighting the distinction between individual, isolated mishearings and clusters of contiguous mishearings. At least in some parameter range, a dynamical transition is manifest well before the static transition is reached, as is the case for many other examples of complex systems.

Development of Predictive Responses in Theory of Mind Brain Regions

When we watch movies, we consider the characters’ mental states in order to understand and predict the narrative. Recent work in fMRI uses movie-viewing paradigms to measure functional responses in brain regions recruited for such mental state reasoning (the Theory of Mind (“ToM”) network). Here, two groups of young children (n=30 3-4yo, n=26 6-7yo) viewed a short animated movie twice while undergoing fMRI. As children get older, ToM brain regions were recruited earlier in time during the second presentation of the movie. This “narrative anticipation” effect is specific: there was no such effect in a control network of brain regions that responds just as robustly to the movie (the “Pain Matrix”). These results complement prior studies in adults that suggest that ToM brain regions play a role not just in inferring, but in actively predicting, other people's thoughts and feelings, and provide novel evidence that as children get older, their ToM brain regions increasingly make such predictions. This is a post-peer-review, pre-copyedit version of an article published in Developmental Science. The final authenticated version is available online at: https://doi.org/10.1111/desc.12863 .